0000950170-21-003937 | 10-Q | XBRL Viewer

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2021	Nov. 03, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	MCRB
Entity Registrant Name	Seres Therapeutics, Inc.
Entity Central Index Key	0001609809
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-37465
Entity Tax Identification Number	27-4326290
Entity Address, Address Line One	200 Sidney Street - 4th Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	945-9626
Entity Common Stock Shares Outstanding		91,847,137
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001
Security Exchange Name	NASDAQ

Condensed Consolidated Balance Sheets - USD ($)
$ in Thousands

Sep. 30, 2021

Dec. 31, 2020

Current assets:

Cash and cash equivalents

$ 227,460

$ 116,049

Short term investments

119,927

137,567

Prepaid expenses and other current assets

10,174

5,774

Accounts receivable

1,250

9,387

Total current assets

358,811

268,777

Property and equipment, net

17,355

13,897

Operating lease assets

11,588

9,041

Restricted investments

2,150

1,400

Long term investments

5,788

49,825

Other non-current assets

601

Total assets

396,293

342,940

Current liabilities:

Accounts payable

8,623

4,018

Accrued expenses and other current liabilities

^[1]

48,900

14,226

Operating lease liabilities

6,099

5,115

Short term portion of note payable, net of discount

9,345

454

Deferred revenue - related party

21,624

22,602

Total current liabilities

94,591

46,415

Long term portion of note payable, net of discount

16,117

24,639

Operating lease liabilities, net of current portion

12,231

10,561

Deferred revenue, net of current portion - related party

89,413

85,572

Other long-term liabilities

^[2]

8,203

1,003

Total liabilities

220,555

168,190

Commitments and contingencies (Note 11)

Stockholders' equity:

Preferred stock, $0.001 par value; 10,000,000 shares authorized at September 30, 2021 and December 31, 2020; no shares issued and outstanding at September 30, 2021 and December 31, 2020

Common stock, $0.001 par value; 200,000,000 shares authorized at September 30, 2021 and December 31, 2020; 91,841,974 and 91,459,239 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively

Additional paid-in capital

739,988

723,482

Accumulated other comprehensive income (loss)

(47)

Accumulated deficit

(564,353)

(548,776)

Total stockholders’ equity

175,738

174,750

Total liabilities and stockholders’ equity

$ 396,293

$ 342,940

[1]	Includes related party amounts of $26,734 and $0 at September 30, 2021 and December 31, 2020, respectively (see Note 10)
[2]	Includes related party amounts of $7,075 and $0 at September 30, 2021 and December 31, 2020, respectively (see Note 10)

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Related party amounts included in accrued expenses and other current liabilities	$ 26,734	$ 0
Related party amounts included in other long-term liabilities	$ 7,075	$ 0
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	91,841,974	91,459,239
Common stock, shares outstanding	91,841,974	91,459,239

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Collaboration revenue - related party	$ 126,725	$ 80	$ 136,636	$ 10,728
Type of Revenue [Extensible List]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Grant revenue	$ 0	$ 1,337	$ 1,070	$ 2,907
Collaboration revenue	0	0	0	2,016
Total revenue	126,725	1,417	137,706	15,651
Operating expenses:
Research and development expenses	39,882	23,861	105,139	65,703
General and administrative expenses	19,563	7,551	48,755	20,180
Collaboration (profit) loss sharing - related party	(1,127)		(1,127)
Total operating expenses	58,318	31,412	152,767	85,883
Income (Loss) from operations	68,407	(29,995)	(15,061)	(70,232)
Other (expense) income:
Interest income	590	100	2,385	333
Interest expense	(744)	(730)	(2,172)	(2,165)
Other (expense) income	(35)	345	(729)	1,189
Total other (expense) income, net	(189)	(285)	(516)	(643)
Net income (loss)	$ 68,218	$ (30,280)	$ (15,577)	$ (70,875)
Net income (loss) per share attributable to common stockholders, basic	$ 0.74	$ (0.36)	$ (0.17)	$ (0.93)
Net income (loss) per share attributable to common stockholders, diluted	$ 0.72	$ (0.36)	$ (0.17)	$ (0.93)
Weighted average common shares outstanding, basic	91,757,614	83,531,617	91,649,035	75,914,361
Weighted average common shares outstanding, diluted	94,953,117	83,531,617	91,649,035	75,914,361
Net income (loss)	$ 68,218	$ (30,280)	$ (15,577)	$ (70,875)
Other comprehensive income (loss):
Unrealized gain (loss) on investments, net of tax of $0	(1)	1	58	2
Total other comprehensive income (loss)	(1)	1	58	2
Comprehensive income (loss)	$ 68,217	$ (30,279)	$ (15,519)	$ (70,873)

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gain (loss) on investment, tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Statement of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2019	$ (48,324)	$ 70	$ 411,255	$ (459,649)
Beginning balance, shares at Dec. 31, 2019		70,143,252
Issuance of common stock from at the market equity offering, value	4,178	$ 1	4,177
Issuance of common stock from at the market equity offering, shares		1,230,531
Issuance of common stock upon exercise of stock options, value	60	$ 1	59
Issuance of common stock upon exercise of stock options, shares		110,967
Issuance of common stock upon vesting of RSUs, net of tax withholdings, value	120		120
Issuance of common stock upon vesting of RSUs, net of tax withholdings, shares		110,000
Issuance of common stock under ESPP, value	249		249
Issuance of common stock under ESPP, shares		76,317
Stock-based compensation expense	1,959		1,959
Unrealized gain (loss) on investments	(10)				$ (10)
Net income (loss)	(19,881)			(19,881)
Ending balance at Mar. 31, 2020	(61,649)	$ 72	417,819	(479,530)	(10)
Ending balance, shares at Mar. 31, 2020		71,671,067
Beginning balance at Dec. 31, 2019	(48,324)	$ 70	411,255	(459,649)
Beginning balance, shares at Dec. 31, 2019		70,143,252
Unrealized gain (loss) on investments	11				11
Ending balance at Jun. 30, 2020	(65,575)	$ 75	434,593	(500,244)	1
Ending balance, shares at Jun. 30, 2020		75,131,834
Beginning balance at Dec. 31, 2019	(48,324)	$ 70	411,255	(459,649)
Beginning balance, shares at Dec. 31, 2019		70,143,252
Net income (loss)	(70,875)
Ending balance at Sep. 30, 2020	188,052	$ 91	718,483	(530,524)	2
Ending balance, shares at Sep. 30, 2020		91,214,536
Beginning balance at Mar. 31, 2020	(61,649)	$ 72	417,819	(479,530)	(10)
Beginning balance, shares at Mar. 31, 2020		71,671,067
Issuance of common stock from at the market equity offering, value	14,848	$ 3	14,845
Issuance of common stock from at the market equity offering, shares		3,430,453
Issuance of common stock upon exercise of stock options, value	15		15
Issuance of common stock upon exercise of stock options, shares		30,314
Stock-based compensation expense	1,914		1,914
Net income (loss)	(20,714)			(20,714)
Ending balance at Jun. 30, 2020	(65,575)	$ 75	434,593	(500,244)	1
Ending balance, shares at Jun. 30, 2020		75,131,834
Issuance of common stock from public offering, net of commissions, underwriting discounts and offering costs, value	243,748	$ 12	243,736
Issuance of common stock from public offering, net of commissions, underwriting discounts and offering costs, shares		12,075,000
Issuance of common stock from Securities Purchase Agreement, net of offering costs - related party, value	19,900	$ 1	19,899
Issuance of common stock from Securities Purchase Agreement, net of offering costs - related party, shares		959,002
Issuance of common stock from at the market equity offering, value	5,746	$ 1	5,745
Issuance of common stock from at the market equity offering, shares		1,126,697
Issuance of common stock upon exercise of stock options, value	12,050	$ 2	12,048
Issuance of common stock upon exercise of stock options, shares		1,828,027
Issuance of common stock upon vesting of RSUs, net of tax withholdings, shares		15,000
Issuance of common stock under ESPP, value	213		213
Issuance of common stock under ESPP, shares		78,976
Stock-based compensation expense	2,249		2,249
Unrealized gain (loss) on investments	1				1
Net income (loss)	(30,280)			(30,280)
Ending balance at Sep. 30, 2020	188,052	$ 91	718,483	(530,524)	2
Ending balance, shares at Sep. 30, 2020		91,214,536
Beginning balance at Dec. 31, 2020	$ 174,750	$ 91	723,482	(548,776)	(47)
Beginning balance, shares at Dec. 31, 2020	91,459,239	91,459,239
Issuance of common stock upon exercise of stock options, value	$ 372	$ 1	371
Issuance of common stock upon exercise of stock options, shares		104,184
Issuance of common stock upon vesting of RSUs, net of tax withholdings, shares		650
Issuance of common stock under ESPP, value	392		392
Issuance of common stock under ESPP, shares		24,191
Stock-based compensation expense	3,624		3,624
Unrealized gain (loss) on investments	32				32
Net income (loss)	(35,465)			(35,465)
Ending balance at Mar. 31, 2021	143,705	$ 92	727,869	(584,241)	(15)
Ending balance, shares at Mar. 31, 2021		91,588,264
Beginning balance at Dec. 31, 2020	$ 174,750	$ 91	723,482	(548,776)	(47)
Beginning balance, shares at Dec. 31, 2020	91,459,239	91,459,239
Issuance of common stock upon exercise of stock options, shares	281,668
Net income (loss)	$ (15,577)
Ending balance at Sep. 30, 2021	$ 175,738	$ 92	739,988	(564,353)	11
Ending balance, shares at Sep. 30, 2021	91,841,974	91,841,974
Beginning balance at Mar. 31, 2021	$ 143,705	$ 92	727,869	(584,241)	(15)
Beginning balance, shares at Mar. 31, 2021		91,588,264
Issuance of common stock upon exercise of stock options, value	586		586
Issuance of common stock upon exercise of stock options, shares		125,546
Stock-based compensation expense	5,078		5,078
Unrealized gain (loss) on investments	27				27
Net income (loss)	(48,330)			(48,330)
Ending balance at Jun. 30, 2021	101,066	$ 92	733,533	(632,571)	12
Ending balance, shares at Jun. 30, 2021		91,713,810
Issuance of common stock upon exercise of stock options, value	174		174
Issuance of common stock upon exercise of stock options, shares		51,938
Issuance of common stock under ESPP, value	435		435
Issuance of common stock under ESPP, shares		76,226
Stock-based compensation expense	5,846		5,846
Unrealized gain (loss) on investments	(1)				(1)
Net income (loss)	68,218			68,218
Ending balance at Sep. 30, 2021	$ 175,738	$ 92	$ 739,988	$ (564,353)	$ 11
Ending balance, shares at Sep. 30, 2021	91,841,974	91,841,974

Condensed Consolidated Statements of Cash Flows - USD ($)
$ in Thousands

9 Months Ended

Sep. 30, 2021

Sep. 30, 2020

Cash flows from operating activities:

Net loss

$ (15,577)

$ (70,875)

Adjustments to reconcile net loss to net cash used in operating activities:

Stock-based compensation expense

14,548

6,122

Depreciation and amortization expense

4,395

5,069

Non-cash operating lease cost

2,292

1,693

Accretion of discount on investments

2,097

(105)

Non-cash interest expense

368

329

Collaboration (profit) loss sharing - related party

(1,127)

Changes in operating assets and liabilities:

Prepaid expenses and other current and long-term assets

(5,001)

(3,054)

Accounts receivable

8,137

(1,608)

Deferred revenue - related party

2,863

(11,917)

Accounts payable

4,781

1,032

Operating lease liabilities

(2,185)

(3,288)

Accrued expenses and other current and long-term liabilities

^[1]

42,960

919

Net cash provided by (used in) operating activities

58,551

(75,683)

Cash flows from investing activities:

Purchases of property and equipment

(7,988)

(365)

Purchases of investments

(66,342)

(125,995)

Sales and maturities of investments

125,982

42,804

Purchase of restricted investments

(750)

Net cash provided by (used in) investing activities

50,902

(83,556)

Cash flows from financing activities:

Proceeds from public offering of common stock, net of commissions, underwriting discounts and offering costs

244,020

Proceeds from Securities Purchase Agreement, net of issuance costs - related party

20,000

Proceeds from exercise of stock options

1,131

12,065

Proceeds from issuance of common stock and restricted common stock

120

Proceeds from at the market equity offering, net of commissions

24,772

Issuance of common stock under ESPP

827

462

Net cash provided by financing activities

1,958

301,439

Net increase in cash and cash equivalents

111,411

142,200

Cash, cash equivalents and restricted cash at beginning of period

116,049

65,126

Cash, cash equivalents and restricted cash at end of period

227,460

207,326

Supplemental disclosure of cash flow information:

Cash paid for interest

1,836

1,843

Supplemental disclosure of non-cash investing and financing activities:

Issuance costs from public offering included in accounts payable and accrued expenses

272

Securities Purchase Agreement issuance costs included in accounts payable and accrued expenses - related party

100

Proceeds from exercise of stock options in prepaid expenses and other current assets

$ 61

Lease liability arising from obtaining right-of-use assets

4,839

Property and equipment purchases included in accounts payable and accrued expenses

$ 316

[1]	Includes related party amounts of $33,809 and $0 at September 30, 2021 and December 31, 2020, respectively (see Note 10)

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Statement Of Cash Flows [Abstract]
Accrued expenses and other current and long-term liabilities, related party amounts	$ 33,809	$ 0

Nature of the Business and Basis of Presentation

9 Months Ended

Sep. 30, 2021

Accounting Policies [Abstract]

Nature of the Business and Basis of Presentation

1. Nature of the Business and Basis of Presentation

Seres Therapeutics, Inc. (the “Company”) was incorporated under the laws of the State of Delaware in October 2010 under the name Newco LS21, Inc. In October 2011, the Company changed its name to Seres Health, Inc., and in May 2015, the Company changed its name to Seres Therapeutics, Inc. The Company is a microbiome therapeutics company developing a novel class of live biotherapeutic drugs, which are consortia of microbes designed to treat disease by modulating the microbiome to treat or reduce disease by repairing the function of the microbiome to a non-disease state. The Company’s lead product candidate, SER-109, is designed to reduce further recurrence of Clostridioides difficile infection (“CDI”), a debilitating infection of the colon, in patients who have received antibiotic therapy for recurrent CDI by treating the disruption of the colonic microbiome. In August 2020, the Company announced that SER-109 had achieved its primary endpoint of superiority to placebo in reducing CDI recurrence at week 8 in its Phase 3 ECOSPOR III clinical trial in patients with recurrent CDI. SER-109 was observed to be well tolerated, with no treatment-related serious adverse events observed in the active arm and an adverse event profile comparable to placebo. If approved by the U.S. Food and Drug Administration (“FDA”), we believe SER-109 will be a first-in-field oral microbiome drug. SER-287 and SER-301 are being developed by the Company to treat ulcerative colitis (“UC”). In addition, using its microbiome therapeutics platform, the Company is also developing product candidates to treat diseases where the microbiome is implicated, including SER-155, a consortium of cultivated bacteria, therapeutic candidate designed to reduce morbidity and mortality due to gastrointestinal infections, bacteremia and graft versus host disease (“GvHD”) in immunocompromised patients, including in patients receiving allogeneic hematopoietic stem cell transplantation (“allo-HSCT”) and solid organ transplants. The Company continues to evaluate microbiome pharmacokinetic and pharmacodynamic data from across its clinical and pre-clinical portfolios using its reverse translation microbiome therapeutics capabilities to conduct research on various indications, including pathogen infection and antibiotic resistant bacteria, inflammatory and immune diseases, cancer, and metabolic diseases.

The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. Product candidates currently under development will require significant additional research and development efforts, including extensive pre-clinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance-reporting capabilities.

The Company’s product candidates are in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, or maintained, that any product candidate developed will obtain necessary government regulatory approval, or that any approved product will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees and consultants.

Under Accounting Standards Update (“ASU”) 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40) (“ASC 205-40”), the Company has the responsibility to evaluate whether conditions and/or events raise substantial doubt about its ability to meet its future financial obligations as they become due within one year after the date that the financial statements are issued. As required by ASC 205-40, this evaluation shall initially not take into consideration the potential mitigating effects of plans that have not been fully implemented as of the date the financial statements are issued.

As of September 30, 2021, the Company had an accumulated deficit of $564,353 and cash, cash equivalents and short and long-term investments of $353,175. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future. As of November 10, 2021, the issuance date of the condensed consolidated financial statements for the nine months ended September 30, 2021, the Company expects that its cash, cash equivalents and short and long-term investments will be sufficient to fund its operating expenses, debt service obligations and capital expenditure requirements for at least the next 12 months. The future viability of the Company beyond that point is dependent on its ability to raise additional capital to finance its operations.

The Company is eligible to receive contingent milestone payments under its license and collaboration agreements with Société des Produits Nestlé S.A., successor in interest to Nestec Ltd., and NHSc Pharma Partners (collectively, “Nestlé”) if certain development, regulatory approval or sales target milestones are achieved. NHSc Pharma Partners is affiliated with Société des Produits Nestlé S.A. and Nestlé Health Science US Holdings, Inc. (“Nestlé Health Science”), both of which are significant stockholders of the Company. The milestone payments are uncertain and there is no assurance that the Company will receive any of them. Until such time, if ever, as the Company can generate substantial product revenue, the Company will finance its cash needs through a combination of public or private equity offerings, debt financings, governmental funding, collaborations, strategic partnerships, or marketing, distribution or licensing arrangements with third parties. The Company may not be able to obtain funding on acceptable terms, or at all. If the Company is unable to raise additional funds as and when needed, it would have a negative impact on the Company’s financial condition, which may require the Company to delay, reduce or eliminate certain research and development activities and reduce or eliminate discretionary operating expenses, which could constrain the Company’s ability to pursue its business strategies.

Unaudited Interim Financial Information

The accompanying unaudited condensed consolidated financial statements as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2020, which was filed with the SEC on March 2, 2021 (the “Annual Report”).

The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the audited consolidated financial statements. The condensed consolidated balance sheet at December 31, 2020 was derived from audited annual financial statements, but does not contain all of the footnote disclosures from the annual financial statements. In the opinion of management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments which are necessary for a fair statement of the Company’s financial position, results of operations, and cash flows for the periods presented. Such adjustments are of a normal and recurring nature. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The significant accounting policies and estimates used in preparation of the condensed consolidated financial statements are described in the Company’s audited financial statements as of and for the year ended December 31, 2020, and the notes thereto, which are included in the Annual Report. There have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2021, with the exception of collaborative arrangements.

Collaborative Arrangements

The Company analyzes its collaboration arrangements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“Topic 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of Topic 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of Topic 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to Topic 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election. For those elements of the arrangement that are accounted for pursuant to Topic 606, the Company presents the arrangement as collaboration revenue – related party in the condensed consolidated statements of operations and comprehensive income (loss).

For collaboration arrangements that are within the scope of Topic 808, the Company evaluates the income statement classification for presentation of amounts due from or owed to other participants associated with multiple activities in a collaboration arrangement based on the nature of each separate activity. Amounts due from or owed to other participants that are the result of a collaborative relationship instead of a customer relationship are recorded as collaboration (profit) loss sharing in the condensed consolidated statements of operations and comprehensive income (loss).

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. In the condensed consolidated financial statements, the Company uses estimates and assumptions related to revenue recognition and the accrual of research and development expenses. Estimates are periodically reviewed in light of changes in circumstances, facts and experience.

The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including revenue, operating expenses, clinical trials and employee-related amounts, will depend on future developments that are highly uncertain, including new information that may emerge concerning COVID-19 and the actions taken to contain it or treat its impact and the economic impact on local, regional, national and international markets. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods. Actual results could differ from the Company’s estimates.

Net Income (Loss) per Share

Basic net income (loss) per share is computed using the weighted average number of common shares outstanding during the period. Diluted net income (loss) per share is computed using the sum of the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options and unvested restricted stock.

The restricted stock units granted by the Company entitle the holder of such awards to ordinary cash dividends paid to substantially all holders of the Company’s common stock, as if such shares were outstanding common shares at the time of the dividend. The dividends are paid in cash or shares of common stock when the applicable restricted stock unit vests. However, the unvested restricted stock units are not entitled to share in the residual net assets (deficit) of the Company. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Recently Issued Accounting Standards

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (‘‘ASU 2016-13’’), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. These changes may result in earlier recognition of credit losses. In November 2018, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses, which narrowed the scope and changed the effective date for non-public entities for ASU 2016-13. The FASB subsequently issued supplemental guidance within ASU No. 2019-05, Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief (‘‘ASU 2019-05’’). ASU 2019-05 provides an option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis. For public entities that are Securities and Exchange Commission filers, excluding entities eligible to be smaller reporting companies, ASU 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. For all other entities, ASU 2016-13 is effective for annual periods beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted. This standard will be effective for the Company on January 1, 2023. The Company is currently evaluating the potential impact that this standard may have on its condensed consolidated financial statements and related disclosures.

Fair Value Measurements

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The following tables present the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis (in thousands):


	Fair Value Measurements as of September 30, 2021 Using:
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	26,648	$	—	$	—	$	26,648
Commercial paper		—		9,911		—		9,911
Investments:
Commercial paper		—		13,347		—		13,347
Corporate bonds		—		46,748		—		46,748
Certificate of deposits		—		2,272				2,272
Government securities		—		63,348		—		63,348
	$	26,648	$	135,626	$	—	$	162,274


	Fair Value Measurements as of December 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	35,480	$	—	$	—	$	35,480
Commercial paper		—		10,313		—		10,313
Corporate bonds		—		2,014		—		2,014
Investments:
Commercial paper	$	—	$	12,343	$	—	$	12,343
Corporate bonds		—		68,289		—		68,289
Certificate of deposits		—		2,272		—		2,272
Government securities		—		104,488		—		104,488
	$	35,480	$	199,719	$	—	$	235,199

Money market funds were valued by the Company based on quoted market prices, which represent a Level 1 measurement within the fair value hierarchy. Commercial paper, corporate bonds, certificate of deposits and government securities were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 2 measurement within the fair value hierarchy. There were no transfers between Level 1 or Level 2 during the three and nine months ended September 30, 2021 and 2020.

As of September 30, 2021 and December 31, 2020, the Company held restricted investments of $2,150 and $1,400, respectively, which represent certificates of deposit that are classified as Level 2 in the fair value hierarchy.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Investments

9 Months Ended

Sep. 30, 2021

Investments Debt And Equity Securities [Abstract]

Investments

4. Investments

Investments by security type consisted of the following at September 30, 2021 and December 31, 2020 (in thousands):


	September 30, 2021
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper		13,347	$	—	$	—		$	13,347
Corporate bonds		46,742		12		(6	)		46,748
Certificate of deposit		2,272		—		—			2,272
Government securities		63,343		7		(2	)		63,348
	$	125,704	$	19	$	(8	)	$	125,715


	December 31, 2020
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper	$	12,343	$	—	$	—		$	12,343
Corporate bonds		68,333		8		(52	)		68,289
Certificate of deposits		2,272		-		-			2,272
Government securities		104,491		6		(9	)		104,488
	$	187,439	$	14	$	(61	)	$	187,392

Investments with original maturities of less than 90 days are included in cash and cash equivalents on the condensed consolidated balance sheets and are not included in the table above. Investments with maturities of less than 12 months are considered current and those investments with maturities greater than 12 months are considered non-current assets.

Excluded from the tables above are restricted investments of $2,150 and $1,400 as the cost approximates current fair value as of September 30, 2021 and December 31, 2020, respectively.

The amortized cost and fair value of investments in commercial paper, corporate bonds, certificate of deposits and government securities by contractual maturity, as of September 30, 2021 and December 31, 2020 were as follows (in thousands):


	Available-for-Sale as of September 30, 2021				Available-for-Sale as of December 31, 2020
	Cost		Fair Value		Cost		Fair Value
Due in 1-year or less	$	119,915	$	119,927	$	137,588	$	137,567
Due after 1-year through 5-years		5,789		5,788		49,851		49,825
	$	125,704	$	125,715	$	187,439	$	187,392

Property and Equipment, Net

9 Months Ended

Sep. 30, 2021

Property Plant And Equipment [Abstract]

Property and Equipment, Net

5. Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):


	September 30, 2021			December 31, 2020
Laboratory equipment	$	18,261		$	15,985
Computer equipment		3,139			2,874
Furniture and office equipment		1,096			1,033
Leasehold improvements		32,555			27,977
Construction in progress		1,020			348
		56,071			48,217
Less: Accumulated depreciation and amortization		(38,716	)		(34,320	)
	$	17,355		$	13,897

Depreciation and amortization expense was $1,493, $4,395, $1,576 and $5,069 for the three and nine months ended September 30, 2021 and 2020, respectively.

Accrued Expenses and Other Current Liabilities

9 Months Ended

Sep. 30, 2021

Payables And Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2021		December 31, 2020
Development and clinical manufacturing costs	$	13,530	$	6,339
Payroll and payroll-related costs		7,006		6,734
Liability related to 2021 License Agreement (Note 10)		26,734		-
Facility and other		1,630		1,153
	$	48,900	$	14,226

Note Payable

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Note Payable

7. Note Payable

On October 29, 2019 (the “Closing Date”), the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Hercules Capital, Inc. (“Hercules”) pursuant to which a term loan in an aggregate principal amount of up to $50,000 (the “Term Loan Facility”) was available to the Company in three tranches, subject to certain terms and conditions. The first tranche of $25,000 was advanced to the Company on the Closing Date. The Company did not meet the milestone requirements for the second tranche under the Term Loan Facility, and as such, the additional amount up to $12,500 is not available for the Company to borrow. The Company elected not to borrow the third tranche of $12,500, which was available upon Hercules’ approval until June 30, 2021.

Advances under the Term Loan Facility will bear interest at a rate equal to the greater of either (i) the Prime Rate (as reported in The Wall Street Journal) plus 4.40%, and (ii) 9.65%. The Company will make interest only payments through December 1, 2021. Following the interest only period, the Company will repay the principal balance and interest of the advances in equal monthly installments through November 1, 2023.

The Company may prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge (the “Prepayment Premium”) equal to: (a) 3.0% of amounts so prepaid, if such prepayment occurs during the first year following the Closing Date; (b) 2.0% of the amount so prepaid, if such prepayment occurs during the second year following the Closing Date, and (c) 1.0% of the amount so prepaid, if such prepayment occurs after the second year following the Closing Date.

Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company will pay (in addition to any Prepayment Premium) an end of term charge of 4.85% of the aggregate funded amount under the Term Loan Facility. With respect to the first tranche, an end of term charge of $1,213 will be payable upon any prepayment or repayment. To the extent that the Company is provided additional advances under the Term Loan Facility, the 4.85% end of term charge will be applied to any such additional amounts.

The Term Loan Facility is secured by substantially all of the Company’s assets, other than the Company’s intellectual property. The Company has agreed to not pledge or secure its intellectual property to others.

Upon issuance, the first tranche was recorded as a liability with an initial carrying value of $24,575, net of debt issuance costs. The initial carrying value will be accreted to the repayment amount, which includes the outstanding principal plus the end of term charge, through interest expense using the effective interest rate method over the term of the debt. The effective interest rate is 11.47%. As of September 30, 2021, the carrying value of the debt is $25,462, of which $9,345 is classified as a current liability and $16,117 is classified as a long-term liability on the condensed consolidated balance sheet. As of December 31, 2020, the carrying value of the debt was $25,093, of which $454 was classified as a current liability and $24,639 was classified as a long-term liability on the condensed consolidated balance sheet.

As of September 30, 2021 the future principal payments due under the arrangement, excluding interest and the end of term charge, are as follows (in thousands):


Year Ending December 31,	Principal
2021 (remaining 3 months)	$	949
2022		11,970
2023		12,081
Total	$	25,000

During the three and nine months ended September 30, 2021 and 2020, the Company recognized $744, $2,172, $730 and $2,165, respectively, of interest expense related to the Loan Agreement, which is reflected in interest expense on the condensed consolidated statement of operations and comprehensive income (loss).

Common Stock and Stock-Based Awards

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Common Stock and Stock-Based Awards

8. Common Stock and Stock-Based Awards

On May 21, 2021, the Company entered into a Sales Agreement (the “Sales Agreement”) with Cowen and Company, LLC (“Cowen”) to sell shares of the Company’s common stock, with aggregate gross sales proceeds of up to $150,000, from time to time, through an “at the market” equity offering program under which Cowen acts as sales agent. As of September 30, 2021, the Company had not sold any shares of common stock under the Sales Agreement.

Stock Options

The following table summarizes the Company’s stock option activity since December 31, 2020:


	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
						(in years)
Outstanding as of December 31, 2020		10,037,130		$	9.54		7.87	$	156,627
Granted		2,825,431			22.27
Exercised		(281,668	)		3.89
Forfeited		(1,677,450	)		12.11
Outstanding as of September 30, 2021		10,903,443		$	11.28		7.54	$	19,879,702
Options exercisable as of September 30, 2021		5,197,692		$	8.34		6.24	$	10,950,342

The weighted average grant-date fair value of stock options granted during the three and nine months ended September 30, 2021 and 2020 was $10.08, $17.89, $18.12 and $3.03 per share, respectively.

During the three months ended March 31, 2019, the Company granted performance-based stock options to employees for the purchase of an aggregate of 1.1 million shares of common stock with a grant date fair value of $4.58 per share. These stock options are exercisable only upon achievement of specified performance targets. During the three months ended March 31, 2021, the Company modified the determination date to achieve the specified performance targets for 50% of the performance-based stock options. The determination date to achieve the specified performance targets was not modified for the remaining 50% of the performance-based stock options and these options expired on April 1, 2021. As of September 30, 2021, none of the options were exercisable because none of the specified performance targets had been achieved. Because achievement of the specified performance targets was not deemed probable as of September 30, 2021, the Company did not record any expense for these performance-based stock options.

Additionally, during the three months ended March 31, 2021, the Company granted performance-based stock options to employees for the purchase of an aggregate 440 thousand shares of common stock with a grant date fair value of $14.93 per share. These stock options are exercisable only upon achievement of specified performance targets. As of September 30, 2021, none of these options were exercisable because none of the specified performance targets had been achieved. Because achievement of the specified performance targets was not deemed probable as of September 30, 2021, the Company did not record any expense for these stock options in the three and nine months ended September 30, 2021.

Restricted Stock Units

The Company has granted restricted stock units ("RSUs") with time-based vesting conditions. The table below summarizes the Company’s restricted stock unit activity since December 31, 2020:


	Number of Shares			Weighted Average Grant Date Fair Value
Unvested restricted stock units as of December 31, 2020		6,500		$	25.36
Granted		565,798		$	21.17
Vested		(650	)	$	25.36
Forfeited		(13,452	)	$	24.88
Unvested restricted stock units as of September 30, 2021		558,196		$	21.12

The Company has granted RSUs with service-based vesting conditions. RSUs represent the right to receive shares of common stock upon meeting specified vesting requirements. Unvested shares of restricted common stock may not be sold or transferred by the holder. These restrictions lapse according to the service-based vesting conditions of each award. During the nine months ended September 30, 2021, the Company granted 565,798 RSUs. RSU’s generally vest over four years, with 25% vesting after one year, and the remaining 75% vesting quarterly over the next 3 years, subject to continued service to the Company through the applicable vesting date.

Stock-based Compensation Expense

The Company recorded stock-based compensation expense in the following expense categories of its condensed consolidated statements of operations and comprehensive income (loss) (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Research and development expenses	$	2,718	$	1,368	$	7,564	$	3,358
General and administrative expenses		3,128		881		6,984		2,764
	$	5,846	$	2,249	$	14,548	$	6,122

Net Income (Loss) per Share

9 Months Ended

Sep. 30, 2021

Earnings Per Share [Abstract]

Net Income (Loss) per Share

9. Net Income (Loss) per Share

Basic and diluted net income (loss) per share attributable to common stockholders was calculated as follows:


	Three Months Ended September 30,					Nine Months Ended September 30,
	2021		2020			2021			2020
Basic Earnings Per Share:
Numerator:
Net income (loss)	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)
Income (loss) attributable to common stockholders - basic	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)

Denominator:
Weighted-average shares outstanding		91,757,614		83,531,617			91,649,035			75,914,361
Net income (loss) per share applicable to common stockholders - basic	$	0.74	$	(0.36	)	$	(0.17	)	$	(0.93	)

Diluted Earnings Per Share:
Numerator:
Net income (loss)	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)
Income (loss) attributable to common stockholders - diluted	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)

Denominator:
Weighted-average shares outstanding		91,757,614		83,531,617			91,649,035			75,914,361

Dilutive impact from:
Stock options to purchase common stock		3,186,762		—			—			—
Unvested restricted stock units		8,741		—			—			—
Weighted-average shares outstanding - diluted		94,953,117		83,531,617			91,649,035			75,914,361
Net income (loss) per share applicable to common stockholders - diluted	$	0.72	$	(0.36	)	$	(0.17	)	$	(0.93	)

Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share:
Stock options to purchase common stock		7,716,681		9,802,633			10,903,443			9,802,633
Unvested restricted stock units		549,455		—			558,196			—

The effect of dilutive securities was calculated using the treasury stock method.

The anti-dilutive potential common stock equivalents for the three months ended September 30, 2021 were excluded from the computation of diluted net income per share attributable to common stockholders because those stock options to purchase common stock and restricted stock units had an anti-dilutive impact due to the assumed proceeds per share using the treasury stock method being greater than the average fair value of the Company’s common shares for those periods.

The anti-dilutive potential common stock equivalents for the nine months ended September 30, 2021 and the three and nine months ended September 30, 2020 were excluded from the computation of diluted net loss per share attributable to common

stockholders because those stock options to purchase common stock and restricted stock units had an anti-dilutive impact as the Company reported a net loss attributable to common stockholders for those periods.

Collaboration Revenue

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Collaboration Revenue

10. Collaboration Revenue

License Agreement with NHSc Pharma Partners (Nestlé)

Summary of Agreement

In July 2021, the Company entered into a license agreement (the “2021 License Agreement”) with Nestlé. Under the terms of the Agreement, the Company granted Nestlé a co-exclusive, sublicensable (under certain circumstances) license to develop, commercialize and conduct medical affairs activities for (i) therapeutic products based on the Company's microbiome technology (including the Company's SER-109 product candidate) that are developed by the Company or on the Company's behalf for the treatment of CDI and recurrent CDI, as well as any other indications pursued for the products upon mutual agreement of the parties (the “2021 Field”) in the United States and Canada (the “2021 Licensed Territory”), and (ii) the Company's SER-109 product candidate and any improvements and modifications thereto developed pursuant to the terms of the 2021 License Agreement (the "2021 Collaboration Products") for any indications in the 2021 Licensed Territory. The Company is responsible for completing development of SER-109 in the 2021 Field in the United States until first regulatory approval for SER-109 is obtained.

Nestlé has the sole right to commercialize SER-109 in the 2021 Licensed Territory in accordance with a commercialization plan. Both parties will perform medical affairs activities in the 2021 Licensed Territory in accordance with a medical affairs plan. The Company will be responsible for the manufacturing and supply for commercialization under a supply agreement that will be entered into between the parties. Both parties will perform pre-launch activities of SER-109 prior to the first commercial sale in the United States. The Company is responsible for funding the pre-launch activities until first commercial sale of SER-109 in the 2021 Licensed Territory and in accordance with a pre-launch plan, up to a specified cap. Following first commercial sale of SER-109, the Company will be entitled to an amount equal to 50% of the commercial profits.

In connection with the 2021 License Agreement, the Company received an upfront payment of $175,000. The Company is eligible to receive additional payments of up to $360,000 if certain regulatory and sales milestones are achieved. The potential future milestone payments include up to $135,000 for the achievement of specified regulatory milestones and up to $225,000 for the achievement of specified net sales milestones.

The 2021 License Agreement continues in effect until all development and commercialization activities for all 2021 Collaboration Products in the 2021 Licensed Territory have permanently ceased. The 2021 License Agreement may be terminated by either party upon sixty days’ written notice for the other party’s material breach that remains uncured during such sixty-day period, or immediately upon written notice for the other party’s insolvency. Nestlé may also terminate the 2021 License Agreement at-will (i) with twelve months’ prior written notice, effective only on or after the third anniversary of first commercial sale of the first 2021 Collaboration Product in the 2021 Licensed Territory, (ii) if first commercial sale of the first 2021 Collaboration Product in the 2021 Licensed Territory has not occurred by the fifth anniversary of the effective date of the 2021 License Agreement, with one hundred eighty days’ prior written notice, which must be provided during a specified period set forth in the 2021 License Agreement, or (iii) if regulatory approval for SER-109 is not granted after submission by the Company of a filing seeking first regulatory approval as set forth in the development and regulatory activity plan, and the parties fail to agree on further development of SER-109 in accordance with the terms of the 2021 License Agreement, with one hundred eighty days’ prior written notice, which must be provided within a specified period set forth in the 2021 License Agreement. The Company may also terminate the 2021 License Agreement immediately upon written notice if Nestlé challenges any licensed patent in the 2021 Licensed Territory. Upon termination of the 2021 License Agreement, all licenses granted to Nestlé by the Company will terminate. If the Company commits a material breach of the 2021 License Agreement, Nestlé may elect not to terminate the 2021 License Agreement but instead apply specified adjustments to the payment terms and other terms and conditions of the 2021 License Agreement.

Accounting Analysis

The 2021 License Agreement represents a separate contract between Nestlé and the Company. The 2021 License Agreement is within the scope of Accounting Standard Update 2018-18, Collaborative Arrangements (Topic 808), and has elements that are within the scope of Topic 606 and Topic 808.

The Company identified the following promises in the 2021 License Agreement that were evaluated under the scope of Topic 606: (i) delivery of a co-exclusive license for SER-109 to develop, commercialize and conduct medical affairs in the United States and Canada; (ii) services to be performed in accordance with the development and regulatory activity plan to obtain regulatory approval of SER-109 in the United States. The Company also evaluated whether certain options outlined within the 2021 License Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options convey a material right to Nestlé and therefore are not considered separate performance obligations within the 2021 License Agreement.

The Company assessed the above promises and determined that the co-exclusive license for SER-109 and the services to obtain regulatory approval of SER-109 in the United States are reflective of a vendor-customer relationship and therefore represent

performance obligations within the scope of Topic 606. The co-exclusive license for SER-109 in the United States and Canada is considered functional intellectual property and distinct from other promises under the contract as Nestlé can benefit from the license on its own or together with other readily available resources. The services performed by the Company to obtain regulatory approval of SER-109 are not complex or specialized, could be performed by another qualified third party, are not expected to significantly modify or customize the license given that SER-109 is late-stage intellectual property that has completed clinical development and the services are expected to be performed over a short period of time. Therefore, the license and the services each represents a separate performance obligation within a contract with a customer under the scope of Topic 606 at contract inception.

The Company considers the collaborative pre-launch activities and commercialization activities to be separate units of account within the scope of Topic 808 and are not deliverables under Topic 606. The Company and Nestlé are both active participants in the pre-launch activities and commercialization activities and are exposed to significant risks and rewards that are dependent on the commercial success of the activities in the arrangement.

The up-front payment of $175,000 compensated the Company for: (i) the co-exclusive license for SER-109 to develop, commercialize and conduct medical affairs in the United States and Canada, (ii) services performed in accordance with the development and regulatory activity plan to obtain regulatory approval of SER-109 in the United States and (iii) pre-launch activities performed by Nestlé and the Company until the first commercial sale of SER-109 in the United States. The commercialization activities, which include the commercial manufacturing, participation on joint steering committees and medical affairs work, that occur after regulatory approval of SER-109 in the United States, are part of the 50/50 sharing of commercial profits. Therefore, the up-front payment of $175,000 does not compensate the Company for these activities.

The Company allocated the $175,000 between the Topic 606 unit of account and the Topic 808 unit of account by determining the standalone selling price (SSP) of each good or service. The selling price of each good or service was determined based on the Company’s SSP with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company determined the transaction price under Topic 606 to be $139,500 and the Topic 808 amount to be $35,500 at the inception of the 2021 License Agreement.

The Company determined that any variable consideration related to regulatory milestones is deemed to be fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company determined that it could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The Company also determined that sales milestones relate solely to the license of intellectual property and are therefore excluded from the transaction price under the sales- or usage-based royalty exception of Topic 606. Revenue related to these sales milestones will only be recognized when the associated sales occur, and relevant thresholds are met.

The Topic 606 transaction price of $139,500 has been allocated to the co-exclusive license for SER-109 and the services performed in accordance with the development and regulatory activity plan to obtain regulatory approval of SER-109 in the United States based on the Company’s SSP. The Company recognizes revenue for the license performance obligation at a point in time, that is upon transfer of the license to Nestlé. As control of the license was transferred in July 2021, the Company recognized $131,343 of collaboration revenue - related party during the three and nine months ended September 30, 2021 under the 2021 License Agreement. The amount allocated to the services performance obligation was not material.

The amount allocated to the Topic 808 unit of accounting relates to the pre-launch activities performed prior to the first commercial sale of SER-109 and was determined to be $35,500 based on standalone selling price.

The Company recorded the $35,500 in total liabilities on its condensed consolidated balance sheet at the inception of the arrangement. On a quarterly basis, the Company and Nestlé will provide financial information about the pre-launch activities performed by both parties. The Company will reduce the $35,500 liability as the pre-launch activities are performed and it makes payments to Nestlé for the pre-launch costs Nestlé incurs. As of September 30, 2021, there is $26,734 included in accrued expenses and other current liabilities and $7,075 included in other long-term liabilities.

The cost associated with pre-launch activities performed by the Company will be recorded within total operating expenses in the Company’s condensed consolidated statements of operations and comprehensive income (loss). In the three and nine months ended September 30, 2021, the Company recognized $1,117 in research and development expenses and $1,701 in general and administrative expenses associated with pre-launch activities performed.

As the Company and Nestlé are both active participants in the pre-launch activities, the sharing of 50% of the pre-launch costs will be recognized in collaboration (profit) loss sharing - related party in the Company’s condensed consolidated statements of operations and comprehensive income (loss). The Company recorded $1,127 of income in the collaboration (profit) loss sharing line for the three and nine months ended September 30, 2021.

Collaboration and License Agreement with Société des Produits Nestlé S.A. (Nestlé)

Summary of Agreement

In January 2016, the Company entered into a collaboration and license agreement with Nestlé (the “2016 License Agreement”) for the development and commercialization of certain product candidates for the treatment and management of CDI and inflammatory bowel disease ("IBD"), including UC and Crohn’s disease. The 2016 License Agreement supports the development of the Company’s portfolio of products for CDI and IBD in markets outside of the United States and Canada (the “2016 Licensed Territory”).

Under the 2016 License Agreement, the Company granted to Nestlé an exclusive, royalty-bearing license to develop and commercialize, in the 2016 Licensed Territory, certain products based on its microbiome technology that are being developed for the treatment of CDI and IBD, including SER-109, SER-262, SER-287 and SER-301 (collectively, the “2016 Collaboration Products”). The 2016 License Agreement sets forth the Company’s and Nestlé’s respective obligations for development, commercialization, regulatory and manufacturing and supply activities for the 2016 Collaboration Products with respect to the licensed fields and the 2016 Licensed Territory.

Under the 2016 License Agreement, Nestlé agreed to pay the Company an upfront cash payment of $120,000, which the Company received in February 2016. The Company is eligible to receive up to $285,000 in development milestone payments, $375,000 in regulatory payments and up to an aggregate of $1,125,000 for the achievement of certain commercial milestones related to the sales of the 2016 Collaboration Products. Nestlé also agreed to pay the Company tiered royalties, at percentages ranging from the high single digits to high teens, of net sales of 2016 Collaboration Products in the 2016 Licensed Territory.

Under the 2016 License Agreement, the Company is entitled to receive a $20,000 milestone payment from Nestlé following initiation of a SER-287 Phase 2 study and a $20,000 milestone payment from Nestlé following the initiation of a SER-287 Phase 3 study. In November 2018, the Company entered into a letter agreement with Nestlé which modified the 2016 License Agreement to address the current clinical plans for SER-287. Pursuant to the letter agreement, the Company and Nestlé agreed that following initiation of the SER-287 Phase 2b study, the Company would be entitled to receive $40,000 in milestone payments from Nestlé, which represent the milestone payments due to the Company for the initiation of a SER-287 Phase 2 study and a Phase 3 study. The SER-287 Phase 2b study was initiated and the $40,000 of milestone payments were received in December 2018. The letter agreement also provides scenarios under which Nestlé’s reimbursement to the Company for certain Phase 3 development costs would be reduced or delayed depending on the outcomes of the SER-287 Phase 2b study.

The 2016 License Agreement continues in effect until terminated by either party on the following bases: (i) Nestlé may terminate the 2016 License Agreement in the event of serious safety issues related to any of the 2016 Collaboration Products; (ii) the Company may terminate the 2016 License Agreement if Nestlé challenges the validity or enforceability of any of the Company’s licensed patents; and (iii) either party may terminate the 2016 License Agreement in the event of the other party’s uncured material breach or insolvency. Upon termination of the 2016 License Agreement, all licenses granted to Nestlé by the Company will terminate, and all rights in and to the 2016 Collaboration Products in the 2016 Licensed Territory will revert to the Company. If the Company commits a material breach of the 2016 License Agreement, Nestlé may elect not to terminate the 2016 License Agreement but instead apply specified adjustments to its payment obligations and other terms and conditions of the 2016 License Agreement.

Accounting Analysis

The Company assessed the 2016 License Agreement in accordance with ASC 606—Revenue From Contracts with Customers (“ASC 606”) and concluded that Nestlé is a customer. The Company identified the following promises under the contract: (i) a license to develop and commercialize the 2016 Collaboration Products in the 2016 Licensed Territory, (ii) obligation to perform research and development services, (iii) participation on a joint steering committee, and (iv) manufacturing services to provide clinical supply to complete future clinical trials. In addition, the Company identified a contingent obligation to perform manufacturing services to provide commercial supply if commercialization occurs, which is contingent upon regulatory approval. This contingent obligation is not a performance obligation at inception and has been excluded from the initial allocation as it represents a separate buying decision at market rates, rather than a material right in the contract. The Company assessed the promised goods and services to determine if they are distinct. Based on this assessment, the Company determined that Nestlé cannot benefit from the promised goods and services separately from the others as they are highly interrelated and therefore not distinct. Accordingly, the promised goods and services represent one combined performance obligation and the entire transaction price will be allocated to that single combined performance obligation.

At contract inception, the Company determined that the $120,000 non-refundable upfront amount constituted the entirety of the consideration to be included in the transaction price as the development, regulatory, and commercial milestones were fully constrained. During the year ended December 31, 2016, the Company received $10,000 from Nestlé in connection with the initiation of the Phase 1b study for SER-262 in CDI. During the year ended December 31, 2017, the Company received $20,000 from Nestlé in connection with the initiation of the Phase 3 study for SER-109. During the year ended December 31, 2018, the Company received $40,000 from Nestlé in connection with the initiation of the Phase 2b study for SER-287. During the year ended December 31, 2020, the Company received $10,000 from Nestlé in connection with the initiation of the Phase 1b SER-301 study. As of September 30,

2021, the aggregate amount of the transaction price allocated to the performance obligation of the 2016 License Agreement was approximately $200,000.

During the three and nine months ended September 30, 2021 and 2020, using the cost-to-cost method, which best depicts the transfer of control to the customer, the Company recognized ($5,883), $4,028, $80 and $10,728 of collaboration revenue – related party, respectively. During the three months ended September 30, 2021, the Company increased its estimate of the future costs that would be incurred from on-going research and development services to complete its performance obligation under the License Agreement that is recognized over time using an input method. The increase in the Company’s estimate of the future costs was based on information received in the quarter regarding clinical trial design and resulted in a reduction in collaboration revenue – related party for the three months ended September 30, 2021 of $5,883.

As of September 30, 2021 and December 31, 2020, there was $104,146 and $108,174, respectively, of deferred revenue related to the unsatisfied portion of the performance obligation under the 2016 License Agreement. As of September 30, 2021, the deferred revenue is classified as current or non-current in the condensed consolidated balance sheets based on the Company’s estimate of revenue that will be recognized within the next 12 months, which is determined by the cost-to-cost method which measures the extent of progress towards completion based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the performance obligation. All costs associated with the 2016 License Agreement are recorded in research and development expense in the condensed consolidated statements of operations and comprehensive income (loss).

AstraZeneca Research Collaboration and Option Agreement

Summary of the Agreement

In March 2019, the Company entered into a Research Collaboration and Option Agreement (the “Research Agreement”) with MedImmune, LLC, a wholly owned subsidiary of AstraZeneca Inc. (“AstraZeneca”), to advance the mechanistic understanding of the microbiome in augmenting the efficacy of cancer immunotherapy. Under the Research Agreement, the Company and AstraZeneca conducted certain research and development activities as set forth on a research plan focused on the role of the microbiome in certain cancers and cancer immunotherapies, including the research program for SER-401, in combination with AstraZeneca compounds targeting various cancers.

Pursuant to the Research Agreement, the Company agreed not to conduct research or development on any microbiome products specifically designed by the Company during the term of the Research Agreement for the treatment of cancer (“Microbiome Oncology Products”), with or on behalf of any third party without the prior approval of the joint steering committee for the Research Agreement for at least three years after the effective date (the “Exclusivity Period”). Additionally, AstraZeneca paid the Company a total of $20,000 in three equal installments, the first of which the Company received in April 2019, the second of which the Company received in December 2019, and the third of which the Company received in January 2021. Such payments were payable even if the Research Agreement was terminated in accordance with its terms, unless the Research Agreement is terminated by AstraZeneca for the Company’s uncured material breach. Additionally, AstraZeneca would bear its costs of conducting activities under the research plan and would reimburse the Company for all activities performed under the research plan based on actual full-time employee (“FTE”) time and certain third-party costs incurred by the Company in connection therewith.

Under the Research Agreement, the Company granted to AstraZeneca an exclusive option to negotiate a worldwide, sublicensable exclusive license under relevant intellectual property rights controlled by the Company to exploit Microbiome Oncology Products for the treatment of cancer. Additionally, the Company granted to AstraZeneca an additional exclusive option to obtain a worldwide, sublicensable, license under certain intellectual property rights arising out of the Research Agreement or coming into the control of the Company during the term of the Research Agreement, to exploit AstraZeneca’s oncology and other assets which are the subject of the research plan. AstraZeneca may exercise each option at any point prior to 90 days after the end of the Exclusivity Period (the “Option Exercise Period”) by delivering an option exercise notice to the Company. If AstraZeneca exercised an option during the Option Exercise Period, the parties would enter into exclusive, good faith negotiations for a period of six months (the “Negotiation Period”) regarding the terms of the definitive license agreement contemplated by such option. If no definitive agreement was reached during the Negotiation Period, subject to certain other terms and conditions applicable for a one (1) year period, the Company was free to license, further develop or otherwise exploit its assets that were the subject of the option without further obligation to AstraZeneca.

The term of the Research Agreement continued in effect until the Research Agreement was terminated by the parties in accordance with its terms by mutual written agreement. Either party may terminate the Research Agreement for the other party’s uncured material breach or bankruptcy or insolvency-related events. AstraZeneca may terminate the Research Agreement for convenience. In December 2020, the Company received written notice from AstraZeneca that AstraZeneca elected to terminate the Research Agreement by and in accordance with its terms. The termination of the Research Agreement was effective on April 2, 2021, which was 120 days from the date of the termination notice.

Accounting Analysis

The Company assessed the Research Agreement in accordance with ASC 606 and concluded that AstraZeneca is a customer. The Company identified the following promises under the contract: (i) a research license, (ii) an obligation to perform research and development services, and (iii) participating on a joint steering committee. The Company assessed the promised goods and services to determine if they are distinct. Based on this assessment, the Company determined that AstraZeneca cannot benefit from the promised goods and services separately from the others as they are highly interrelated and therefore not distinct. Accordingly, the promised goods and services represent one combined performance obligation and the entire transaction price will be allocated to that single combined performance obligation.

Each exclusive option granted to AstraZeneca provides AstraZeneca with the right to negotiate a license agreement in the future at fair value. Therefore, the Company concluded that each option does not constitute a performance obligation at inception and has been excluded from the initial allocation since each option represents a separate buying decision at market rates, rather than a material right in the contract.

At contract inception, the Company determined that the transaction price is comprised of: (i) the $20,000 fee, which represents fixed consideration, and (ii) the estimated reimbursement of research and development costs incurred, which represents variable consideration. The Company included the estimated reimbursement of research and development costs, approximately $13,900, in the transaction price at the inception of the arrangement because the Company is required to perform research and development services and the contract requires AstraZeneca to reimburse the Company for costs incurred. Also, since the related revenue would be recognized only as the costs are incurred, and the contract precludes the joint steering committee from changing the research plan without mutual agreement, the Company determined it is not probable that a significant reversal of cumulative revenue would occur.

The Company determined that revenue under the Research Agreement should be recognized over time as AstraZeneca simultaneously receives the benefit from the Company as the Company performs under the single performance obligation over time. The Company will recognize revenue for the single performance obligation using a cost-to-cost input method as the Company has concluded it best depicts the research and joint steering committee participation services performed prior to AstraZeneca’s ability to negotiate a license. Under this method, the transaction price is recognized over the contract’s entire performance period, using costs incurred relative to total estimated costs to determine the extent of progress towards completion.

In December 2020, the Company received written notice that AstraZeneca elected to terminate the Research Agreement. As a result of AstraZeneca’s decision to terminate the Research Agreement, the Company’s performance obligations under the Research Agreement ended as of December 31, 2020. The final transaction price of $23,377 is comprised of the $20,000 fixed consideration and $3,376 for the reimbursed research and development costs. The Company removed all costs associated with its remaining performance from the cost-to-cost model in the fourth quarter of 2020. This resulted in the Company recognizing the remaining deferred revenue of $15,145 to collaboration revenue in the year ended December 31, 2020.

For the three and nine months ended September 30, 2020, the Company recognized collaboration revenue of $0 and $2,016, respectively, under the Research Agreement. No collaboration revenue was recognized for three and nine months ended September 30, 2021, as the Company's performance obligations under the Research Agreement ended December 31, 2020.

Contract Balances from Contracts with Customers

The following table presents changes in the Company’s contract liabilities during the nine months ended September 30, 2021 and 2020 (in thousands):


	Balance as of December 31, 2020		Additions		Deductions			Balance as of September 30, 2021
Nine Months Ended September 30, 2021
Contract liabilities:
Deferred revenue - related party	$	108,174		8,157		(5,294	)	$	111,037


	Balance as of December 31, 2019		Additions		Deductions			Balance as of September 30, 2020
Nine Months Ended September 30, 2020
Contract liabilities:
Deferred revenue - related party	$	110,071		—		(10,728	)	$	99,343
Deferred revenue	$	9,668		827		(2,016	)	$	8,479

During the three and nine months ended September 30, 2021 and 2020 the Company recognized the following revenues as a result of changes in the contract liability balances in the respective periods (in thousands):


	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021		2020
Revenue recognized in the period from:
Amounts included in the contract liability at the beginning of the period	$	(4,618	)	$	-	$	4,028	$	11,837

When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded. Revenue is recognized from the contract liability over time using the cost-to-cost method.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130550-203045

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

+ Details

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

11. Commitments and Contingencies

Indemnification Agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of September 30, 2021 or December 31, 2020.

Legal Contingencies

The Company accrues a liability for legal contingencies when it believes that it is both probable that a liability has been incurred and that the Company can reasonably estimate the amount of the loss. The Company reviews these accruals and adjusts them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and the views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Company’s accrued liabilities would be recorded in the period in which such determination is made.

In addition, in accordance with the relevant authoritative guidance, for any matters in which the likelihood of material loss is at least reasonably possible, the Company will provide disclosure of the possible loss or range of loss. If a reasonable estimate cannot be made, however, the Company will provide disclosure to that effect. The Company expenses legal costs as they are incurred.

The Company did not accrue any liabilities related to legal contingencies in its condensed consolidated financial statements as of September 30, 2021 or December 31, 2020.

Income Taxes

9 Months Ended

Sep. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

12. Income Taxes

The Company did not provide for any income taxes in its condensed consolidated statement of operations and comprehensive income (loss) for the three and nine month periods ended September 30, 2021 or 2020. While the Company has net income for the three months ended September 30, 2021, the Company is projecting book and tax losses for the twelve months ended December 31, 2021, for which it is more likely than not that the Company will not realize a benefit for as the Company has recorded a full valuation allowance against its deferred tax assets. Therefore, the Company has not recorded any income taxes for the three and nine months ended September 30, 2021 and 2020.

The Company has evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets. Management has considered the Company’s history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and has concluded that it is more likely than not that the Company will not realize the benefits of the deferred tax assets. Accordingly, a full valuation allowance has been established against the deferred tax assets as of September 30, 2021 and December 31, 2020. Management reevaluates the positive and negative evidence at each reporting period.

As of September 30, 2021 and December 31, 2020, the Company had no accrued interest or tax penalties recorded. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. The Company is currently under examination by the Internal Revenue Service ("IRS") for the period ended December 31, 2018 related to its R&D tax credits. The Company's tax years are still open under statute from 2011 to present. All years may be examined to the extent the tax credit or net operating loss carryforwards are used in future periods.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Related Party Transactions

9 Months Ended

Sep. 30, 2021

Related Party Transactions

13. Related Party Transactions

As described in Note 10, in July 2021, the Company entered into the 2021 License Agreement with NHSc Pharma Partners (together with Société des Produits Nestlé S.A., “Nestlé”). NHSc Pharma Partners is an affiliate of two of the Company's significant stockholders, Société des Produits Nestlé S.A. and Nestlé Health Science U.S. Holdings, Inc. During the three and nine months ended September 30, 2021, the Company recognized $132,608 of related party revenue associated with the 2021 License Agreement. As of the three and nine months ended September 30, 2021 there was $6,891 of deferred revenue related to the 2021 License Agreement, which is classified as current or non-current in the condensed consolidated balance sheets. As of September 30, 2021 there was $26,734 included in accrued expenses and other liabilities and $7,075 included in other long term liabilities related to the 2021 License Agreement. The Company has made no payments to Nestlé during the three and nine months ended September 30, 2021. There is no amount due from Nestlé as of September 30, 2021.

As described in Note 10, in January 2016, the Company entered into the 2016 License Agreement with Société des Produits Nestlé S.A. (successor in interest to Nestec, Ltd.) for the development and commercialization of certain product candidates in development for the treatment and management of CDI and IBD, including UC and Crohn’s disease. Société des Produits Nestlé S.A. and its affiliate Nestlé Health Science U.S. Holdings, Inc. are two of the Company's significant stockholders. During the three and nine months ended September 30, 2021 and 2020, the Company recognized ($5,883), $4,028, $80 and $10,728 of related party revenue associated with the 2016 License Agreement, respectively. As of September 30, 2021 and December 31, 2020 there was $104,146 and $108,174 of deferred revenue related to the 2016 License Agreement, which is classified as current or non-current in the condensed consolidated balance sheets. The Company has made no payments to Nestlé during the three and nine months ended September 30, 2021 and 2020. There is no amount due from Nestlé as of September 30, 2021.

In August 2020, the Company entered into the Securities Purchase Agreement with Nestlé for the sale of 959,002 shares of its common stock at a purchase price of $20.855 per share (the “concurrent placement”). The Company received aggregate net proceeds from the concurrent placement of approximately $19,900 after deducting offering expenses payable by the Company.

In July 2019, the Company entered into a sublease agreement with Flagship Pioneering, one of the Company’s significant stockholders, to sublease a portion of its office and laboratory space in Cambridge, Massachusetts. The term of the sublease agreement commenced in July 2019 and ends on the last day of the 24th calendar month following commencement. In the second quarter of 2021, the sublease agreement was extended to November 2021. Under this agreement, the Company recorded other income of $437, $1,361, $458 and $1,357 during the three and nine months ended September 30, 2021 and 2020 respectively. The Company received cash payments of $437, $1,361, $458 and $1,357 during the three and nine months ended September 30, 2021 and 2020, respectively.

Subsequent Events

9 Months Ended

Sep. 30, 2021

Subsequent Events [Abstract]

Subsequent Events

14. Subsequent Events

Bacthera Long Term Manufacturing Agreement

On November 8, 2021, the Company entered into a Long Term Manufacturing Agreement (together with its exhibits, the “Bacthera Agreement”) with BacThera AG (“Bacthera”), a joint venture between Chr. Hansen and a Lonza Group affiliate. The Bacthera Agreement governs the general terms under which Bacthera, or one of its affiliates, will (i) construct a dedicated full-scale production suite for the Company at Bacthera’s Microbiome Center of Excellence in Visp, Switzerland, which is currently under construction; and (ii) provide manufacturing services to the Company for its SER-109 product and, if agreed by the parties, SER-287 product.

Under the terms of the Bacthera Agreement, the Company has agreed to pay Bacthera a total of at least 240,000 CHF (or approximately $262,000) for the initial term of the agreement, inclusive of the construction fees and annual operating fees (commencing with the completion of construction). The annual operating fee includes the cost of a baseline annual batch production volume. The Company has also agreed to pay certain other ancillary fees and a per-batch fee in excess of the baseline batches. These fees are subject to adjustment during construction for certain items outside of Bacthera’s control and annually against an agreed index. The Company will supply the active pharmaceutical ingredients to Bacthera to enable it to perform the services and pay for certain other raw materials and manufacturing components, which will be acquired by Bacthera.

The Bacthera Agreement has an initial term that continues until the tenth anniversary of the earlier of (a) successful completion of construction and demonstration of Bacthera’s readiness for commercial production or (b) the commencement of manufacturing.

The initial term is subject to renewals, which could extend the term to 16 years, and additional three-year terms thereafter. Each party has the ability to terminate the Bacthera Agreement upon the occurrence of certain customary conditions. The Company may also terminate the Bacthera Agreement for convenience after a defined period. In the event of a termination, the Company has certain financial obligations that would apply, and Bacthera has agreed to grant a license to Bacthera-developed manufacturing know how, if any, and provide technical assistance to the Company, so that the Company could transfer the manufacturing operations to itself or a third party. The Bacthera Agreement also contains representations, warranties and indemnity obligations as well as limitations of liability that are customary for agreements of this type.

Letter Agreement with David S. Ege, Ph.D.

On November 4, 2021, the Company entered into a letter agreement with David Ege, Ph.D. pursuant to which the Company agreed to pay Dr. Ege a special, one-time cash bonus in a lump sum amount of $131, less applicable withholdings (the “Special Bonus”). The Special Bonus will be paid by December 4, 2021, subject to Dr. Ege’s continued employment on the date of payment. Furthermore, if his employment is terminated by the Company for “Cause” or by his resignation without “Good Reason” (as such capitalized terms are defined in the employment agreement that he has entered into with the Company), in either case, within two years following the payment of the Special Bonus, Dr. Ege is required to repay the net amount of the Special Bonus to the Company within ten days following termination.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2021
Accounting Policies [Abstract]
Collaborative Arrangements	Collaborative Arrangements The Company analyzes its collaboration arrangements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“Topic 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of Topic 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of Topic 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to Topic 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election. For those elements of the arrangement that are accounted for pursuant to Topic 606, the Company presents the arrangement as collaboration revenue – related party in the condensed consolidated statements of operations and comprehensive income (loss). For collaboration arrangements that are within the scope of Topic 808, the Company evaluates the income statement classification for presentation of amounts due from or owed to other participants associated with multiple activities in a collaboration arrangement based on the nature of each separate activity. Amounts due from or owed to other participants that are the result of a collaborative relationship instead of a customer relationship are recorded as collaboration (profit) loss sharing in the condensed consolidated statements of operations and comprehensive income (loss).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. In the condensed consolidated financial statements, the Company uses estimates and assumptions related to revenue recognition and the accrual of research and development expenses. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including revenue, operating expenses, clinical trials and employee-related amounts, will depend on future developments that are highly uncertain, including new information that may emerge concerning COVID-19 and the actions taken to contain it or treat its impact and the economic impact on local, regional, national and international markets. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods. Actual results could differ from the Company’s estimates.
Net Income (Loss) per Share	Net Income (Loss) per Share Basic net income (loss) per share is computed using the weighted average number of common shares outstanding during the period. Diluted net income (loss) per share is computed using the sum of the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options and unvested restricted stock. The restricted stock units granted by the Company entitle the holder of such awards to ordinary cash dividends paid to substantially all holders of the Company’s common stock, as if such shares were outstanding common shares at the time of the dividend. The dividends are paid in cash or shares of common stock when the applicable restricted stock unit vests. However, the unvested restricted stock units are not entitled to share in the residual net assets (deficit) of the Company. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (‘‘ASU 2016-13’’), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. These changes may result in earlier recognition of credit losses. In November 2018, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses, which narrowed the scope and changed the effective date for non-public entities for ASU 2016-13. The FASB subsequently issued supplemental guidance within ASU No. 2019-05, Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief (‘‘ASU 2019-05’’). ASU 2019-05 provides an option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis. For public entities that are Securities and Exchange Commission filers, excluding entities eligible to be smaller reporting companies, ASU 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. For all other entities, ASU 2016-13 is effective for annual periods beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted. This standard will be effective for the Company on January 1, 2023. The Company is currently evaluating the potential impact that this standard may have on its condensed consolidated financial statements and related disclosures.

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Summary of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables present the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis (in thousands):


	Fair Value Measurements as of September 30, 2021 Using:
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	26,648	$	—	$	—	$	26,648
Commercial paper		—		9,911		—		9,911
Investments:
Commercial paper		—		13,347		—		13,347
Corporate bonds		—		46,748		—		46,748
Certificate of deposits		—		2,272				2,272
Government securities		—		63,348		—		63,348
	$	26,648	$	135,626	$	—	$	162,274


	Fair Value Measurements as of December 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	35,480	$	—	$	—	$	35,480
Commercial paper		—		10,313		—		10,313
Corporate bonds		—		2,014		—		2,014
Investments:
Commercial paper	$	—	$	12,343	$	—	$	12,343
Corporate bonds		—		68,289		—		68,289
Certificate of deposits		—		2,272		—		2,272
Government securities		—		104,488		—		104,488
	$	35,480	$	199,719	$	—	$	235,199

Investments (Tables)

9 Months Ended

Sep. 30, 2021

Investments Debt And Equity Securities [Abstract]

Schedule of Investments by Security Type

Investments by security type consisted of the following at September 30, 2021 and December 31, 2020 (in thousands):


	September 30, 2021
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper		13,347	$	—	$	—		$	13,347
Corporate bonds		46,742		12		(6	)		46,748
Certificate of deposit		2,272		—		—			2,272
Government securities		63,343		7		(2	)		63,348
	$	125,704	$	19	$	(8	)	$	125,715


	December 31, 2020
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper	$	12,343	$	—	$	—		$	12,343
Corporate bonds		68,333		8		(52	)		68,289
Certificate of deposits		2,272		-		-			2,272
Government securities		104,491		6		(9	)		104,488
	$	187,439	$	14	$	(61	)	$	187,392

Schedule of Amortized Cost and Fair Value of Investments by Contractual Maturity


	Available-for-Sale as of September 30, 2021				Available-for-Sale as of December 31, 2020
	Cost		Fair Value		Cost		Fair Value
Due in 1-year or less	$	119,915	$	119,927	$	137,588	$	137,567
Due after 1-year through 5-years		5,789		5,788		49,851		49,825
	$	125,704	$	125,715	$	187,439	$	187,392

Property and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2021

Property Plant And Equipment [Abstract]

Schedule of Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):


	September 30, 2021			December 31, 2020
Laboratory equipment	$	18,261		$	15,985
Computer equipment		3,139			2,874
Furniture and office equipment		1,096			1,033
Leasehold improvements		32,555			27,977
Construction in progress		1,020			348
		56,071			48,217
Less: Accumulated depreciation and amortization		(38,716	)		(34,320	)
	$	17,355		$	13,897

Accrued Expenses and Other Current Liabilities (Tables)

9 Months Ended

Sep. 30, 2021

Payables And Accruals [Abstract]

Summary of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2021		December 31, 2020
Development and clinical manufacturing costs	$	13,530	$	6,339
Payroll and payroll-related costs		7,006		6,734
Liability related to 2021 License Agreement (Note 10)		26,734		-
Facility and other		1,630		1,153
	$	48,900	$	14,226

Note Payable (Tables)

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Summary of Future Principal Payments Due Under Arrangement, Excluding Interest and End of Term Charge

As of September 30, 2021 the future principal payments due under the arrangement, excluding interest and the end of term charge, are as follows (in thousands):


Year Ending December 31,	Principal
2021 (remaining 3 months)	$	949
2022		11,970
2023		12,081
Total	$	25,000

Common Stock and Stock-Based Awards (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity since December 31, 2020:


	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
						(in years)
Outstanding as of December 31, 2020		10,037,130		$	9.54		7.87	$	156,627
Granted		2,825,431			22.27
Exercised		(281,668	)		3.89
Forfeited		(1,677,450	)		12.11
Outstanding as of September 30, 2021		10,903,443		$	11.28		7.54	$	19,879,702
Options exercisable as of September 30, 2021		5,197,692		$	8.34		6.24	$	10,950,342

Summary of Restricted Stock Unit Activity

The Company has granted restricted stock units ("RSUs") with time-based vesting conditions. The table below summarizes the Company’s restricted stock unit activity since December 31, 2020:


	Number of Shares			Weighted Average Grant Date Fair Value
Unvested restricted stock units as of December 31, 2020		6,500		$	25.36
Granted		565,798		$	21.17
Vested		(650	)	$	25.36
Forfeited		(13,452	)	$	24.88
Unvested restricted stock units as of September 30, 2021		558,196		$	21.12

Summary of Stock Based Compensation Expense

The Company recorded stock-based compensation expense in the following expense categories of its condensed consolidated statements of operations and comprehensive income (loss) (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Research and development expenses	$	2,718	$	1,368	$	7,564	$	3,358
General and administrative expenses		3,128		881		6,984		2,764
	$	5,846	$	2,249	$	14,548	$	6,122

Net Income (Loss) per Share (Tables)

9 Months Ended

Sep. 30, 2021

Earnings Per Share [Abstract]

Basic and Diluted Net Income (Loss) per Share Attributable to Common Stockholders

Basic and diluted net income (loss) per share attributable to common stockholders was calculated as follows:


	Three Months Ended September 30,					Nine Months Ended September 30,
	2021		2020			2021			2020
Basic Earnings Per Share:
Numerator:
Net income (loss)	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)
Income (loss) attributable to common stockholders - basic	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)

Denominator:
Weighted-average shares outstanding		91,757,614		83,531,617			91,649,035			75,914,361
Net income (loss) per share applicable to common stockholders - basic	$	0.74	$	(0.36	)	$	(0.17	)	$	(0.93	)

Diluted Earnings Per Share:
Numerator:
Net income (loss)	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)
Income (loss) attributable to common stockholders - diluted	$	68,218	$	(30,280	)	$	(15,577	)	$	(70,875	)

Denominator:
Weighted-average shares outstanding		91,757,614		83,531,617			91,649,035			75,914,361

Dilutive impact from:
Stock options to purchase common stock		3,186,762		—			—			—
Unvested restricted stock units		8,741		—			—			—
Weighted-average shares outstanding - diluted		94,953,117		83,531,617			91,649,035			75,914,361
Net income (loss) per share applicable to common stockholders - diluted	$	0.72	$	(0.36	)	$	(0.17	)	$	(0.93	)

Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share:
Stock options to purchase common stock		7,716,681		9,802,633			10,903,443			9,802,633
Unvested restricted stock units		549,455		—			558,196			—

Collaboration Revenue (Tables)

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Changes in Contract Liabilities

The following table presents changes in the Company’s contract liabilities during the nine months ended September 30, 2021 and 2020 (in thousands):


	Balance as of December 31, 2020		Additions		Deductions			Balance as of September 30, 2021
Nine Months Ended September 30, 2021
Contract liabilities:
Deferred revenue - related party	$	108,174		8,157		(5,294	)	$	111,037


	Balance as of December 31, 2019		Additions		Deductions			Balance as of September 30, 2020
Nine Months Ended September 30, 2020
Contract liabilities:
Deferred revenue - related party	$	110,071		—		(10,728	)	$	99,343
Deferred revenue	$	9,668		827		(2,016	)	$	8,479


	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021		2020
Revenue recognized in the period from:
Amounts included in the contract liability at the beginning of the period	$	(4,618	)	$	-	$	4,028	$	11,837

Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Entity incorporated month and year	2010-10
Entity incorporation, state or country code	DE
Accumulated deficit	$ 564,353	$ 548,776
Cash, cash equivalents and short and long-term investments	$ 353,175

Fair Value Measurements - Summary of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Investments:
Investments	$ 125,715	$ 187,392
Fair Value, Measurements, Recurring [Member]
Investments:
Investments	162,274	235,199
Fair Value, Measurements, Recurring [Member] \| Money Market Funds [Member]
Cash equivalents:
Cash equivalents	26,648	35,480
Commercial Paper [Member]
Cash equivalents:
Cash equivalents	9,911
Investments:
Investments	13,347	12,343
Commercial Paper [Member] \| Fair Value, Measurements, Recurring [Member]
Cash equivalents:
Cash equivalents		10,313
Investments:
Investments	13,347	12,343
Corporate Bonds [Member]
Investments:
Investments	46,748	68,289
Corporate Bonds [Member] \| Fair Value, Measurements, Recurring [Member]
Cash equivalents:
Cash equivalents		2,014
Investments:
Investments	46,748	68,289
Certificates of Deposit [Member]
Investments:
Investments	2,272	2,272
Certificates of Deposit [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	2,272	2,272
Government Securities [Member]
Investments:
Investments	63,348	104,488
Government Securities [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	63,348	104,488
Level 1 [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	26,648	35,480
Level 1 [Member] \| Fair Value, Measurements, Recurring [Member] \| Money Market Funds [Member]
Cash equivalents:
Cash equivalents	26,648	35,480
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	135,626	199,719
Level 2 [Member] \| Commercial Paper [Member]
Cash equivalents:
Cash equivalents	9,911
Level 2 [Member] \| Commercial Paper [Member] \| Fair Value, Measurements, Recurring [Member]
Cash equivalents:
Cash equivalents		10,313
Investments:
Investments	13,347	12,343
Level 2 [Member] \| Corporate Bonds [Member] \| Fair Value, Measurements, Recurring [Member]
Cash equivalents:
Cash equivalents		2,014
Investments:
Investments	46,748	68,289
Level 2 [Member] \| Certificates of Deposit [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	2,272	2,272
Level 2 [Member] \| Government Securities [Member] \| Fair Value, Measurements, Recurring [Member]
Investments:
Investments	$ 63,348	$ 104,488

Fair Value Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair value, assets transfers from Level 1 to Level 2 measurement	$ 0		$ 0
Fair value, assets transfers from Level 2 to Level 1 measurement	0		$ 0
Restricted investments	$ 2,150,000	$ 1,400,000

Investments - Schedule of Investments by Security Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 125,704	$ 187,439
Gross Unrealized Gain	19	14
Gross Unrealized Loss	(8)	(61)
Fair Value	125,715	187,392
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,347	12,343
Fair Value	13,347	12,343
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	46,742	68,333
Gross Unrealized Gain	12	8
Gross Unrealized Loss	(6)	(52)
Fair Value	46,748	68,289
Certificates of Deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,272	2,272
Fair Value	2,272	2,272
US Government Agencies Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	63,343	104,491
Gross Unrealized Gain	7	6
Gross Unrealized Loss	(2)	(9)
Fair Value	$ 63,348	$ 104,488

Investments - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Investments [Abstract]
Maximum maturity days for cash equivalents	90 days
Restricted investments	$ 2,150	$ 1,400

Investments - Schedule of Amortized Cost and Fair Value of Investments by Contractual Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Available-for-sale, amortized cost
Due in 1-year or less	$ 119,915	$ 137,588
Due after 1-year through 5-years	5,789	49,851
Amortized Cost	125,704	187,439
Available-for-sale, fair value
Due in 1-year or less	119,927	137,567
Due after 1-year through 5-years	5,788	49,825
Fair value	$ 125,715	$ 187,392

Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 56,071	$ 48,217
Less: Accumulated depreciation and amortization	(38,716)	(34,320)
Property and equipment, net	17,355	13,897
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	18,261	15,985
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,139	2,874
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,096	1,033
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	32,555	27,977
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,020	$ 348

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$ 1,493	$ 1,576	$ 4,395	$ 5,069

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($)
$ in Thousands

Sep. 30, 2021

Dec. 31, 2020

Payables And Accruals [Abstract]

Development and clinical manufacturing costs

$ 13,530

$ 6,339

Payroll and payroll-related costs

7,006

6,734

26,734

Facility and other

1,630

1,153

Total accrued expenses and other current liabilities

^[1]

$ 48,900

$ 14,226

[1]	Includes related party amounts of $26,734 and $0 at September 30, 2021 and December 31, 2020, respectively (see Note 10)

Note Payable - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Oct. 29, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Interest expense		$ 744,000	$ 730,000	$ 2,172,000	$ 2,165,000
Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Interest expense		744,000	$ 730,000	$ 2,172,000	$ 2,165,000
Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit facility, interest rate	9.65%
Credit facility, payment terms				The Company will make interest only payments through December 1, 2021. Following the interest only period, the Company will repay the principal balance and interest of the advances in equal monthly installments through November 1, 2023.
Percentage of prepayment amount during first year	3.00%
Percentage of prepayment amount during second year	2.00%
Percentage of prepayment amount during third year	1.00%
Prepayment or repayment percentage	4.85%
Additional advance prepayment or repayment percentage	4.85%
Carrying value of debt		25,462,000		$ 25,462,000		$ 25,093,000
Loan and Security Agreement [Member] \| Term Loan Facility [Member] \| Current Liability [Member]
Debt Instrument [Line Items]
Carrying value of debt		9,345,000		9,345,000		454,000
Loan and Security Agreement [Member] \| Term Loan Facility [Member] \| Non Current Liability [Member]
Debt Instrument [Line Items]
Carrying value of debt		$ 16,117,000		$ 16,117,000		$ 24,639,000
Loan and Security Agreement [Member] \| Term Loan Facility [Member] \| Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, variable rate	4.40%
Hercules Capital, Inc. [Member] \| Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit facility, aggregate principal amount	$ 50,000,000
First Tranche [Member] \| Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Prepayment or repayment charge	1,213,000
Carrying value of debt	$ 24,575,000
Debt instrument, interest rate effective percentage	11.47%
First Tranche [Member] \| Hercules Capital, Inc. [Member] \| Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Gross proceeds from debt	$ 25,000,000
Second Tranche Unavailable to Borrow Due to Not Met Milestone Requirements [Member] \| Hercules Capital, Inc. [Member] \| Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit facility, aggregate principal amount	12,500,000
Third Tranche Available Upon Approval Until June 30, 2021 [Member] \| Hercules Capital, Inc. [Member] \| Loan and Security Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit facility, aggregate principal amount	$ 12,500,000

Note Payable - Summary of Future Principal Payments Due Under Arrangement, Excluding Interest and End of Term Charge (Detail) $ in Thousands	Sep. 30, 2021 USD ($)
Debt Disclosure [Abstract]
2021 (remaining 3 months)	$ 949
2022	11,970
2023	12,081
Total	$ 25,000

Common Stock and Stock-Based Awards - Additional Information (Details) - USD ($)		9 Months Ended
	May 21, 2021	Sep. 30, 2021	Dec. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued		91,841,974	91,459,239
At The Market Equity Offering Program [Member] \| Sales Agreement [Member] \| Cowen And Company, LLC [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued		0
At The Market Equity Offering Program [Member] \| Sales Agreement [Member] \| Cowen And Company, LLC [Member] \| Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Gross proceeds from sale of common stock	$ 150,000,000

Common Stock and Stock-Based Awards - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Equity [Abstract]
Number of Shares, Beginning Balance \| shares	10,037,130
Number of Shares, Granted \| shares	2,825,431
Number of Shares, Exercised \| shares	(281,668)
Number of Shares, Forfeited \| shares	(1,677,450)
Number of Shares, Ending Balance \| shares	10,903,443	10,037,130
Number of Shares, Options exercisable \| shares	5,197,692
Weighted Average Exercise Price, Beginning Balance \| $ / shares	$ 9.54
Weighted Average Exercise Price, Granted \| $ / shares	22.27
Weighted Average Exercise Price, Exercised \| $ / shares	3.89
Weighted Average Exercise Price, Forfeited \| $ / shares	12.11
Weighted Average Exercise Price, Ending Balance \| $ / shares	11.28	$ 9.54
Weighted Average Exercise Price, Options exercisable \| $ / shares	$ 8.34
Weighted Average Remaining Contractual Term, Outstanding	7 years 6 months 14 days	7 years 10 months 13 days
Weighted Average Remaining Contractual Term, Options exercisable	6 years 2 months 26 days
Aggregate Intrinsic Value, Outstanding \| $	$ 19,879,702	$ 156,627
Aggregate Intrinsic Value, Options exercisable \| $	$ 10,950,342

Common Stock and Stock-Based Awards - Stock Options - Additional Information (Detail) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2019	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of stock options	$ 10.08		$ 18.12		$ 17.89	$ 3.03
Performance-based stock options to granted					2,825,431
Stock based compensation expense for stock options	$ 5,846,000		$ 2,249,000		$ 14,548,000	$ 6,122,000
Number of Shares, Granted					2,825,431
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of stock options		$ 14.93		$ 4.58
Performance-based stock options to granted		440,000		1,100,000
Percentage of performance-based stock options with modified determination date		50.00%
Percentage of performance-based stock options with no modified determination date		50.00%
Stock options expiration date					Apr. 01, 2021
Stock options exercisable	0				0
Stock based compensation expense for stock options	$ 0				$ 0
Number of Shares, Granted		440,000		1,100,000

Common Stock and Stock-Based Awards - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Unvested restricted stock units, Beginning balance \| shares	6,500
Number of Shares, Granted \| shares	565,798
Number of Shares, Vested \| shares	(650)
Number of Shares, Forfeited \| shares	(13,452)
Number of Shares, Unvested restricted stock units, Ending balance \| shares	558,196
Weighted Average Grant Date Fair Value, Unvested restricted stock units, Beginning balance \| $ / shares	$ 25.36
Weighted Average Grant Date Fair Value, Granted \| $ / shares	21.17
Weighted Average Grant Date Fair Value, Vested \| $ / shares	25.36
Weighted Average Grant Date Fair Value, Forfeited \| $ / shares	24.88
Weighted Average Grant Date Fair Value, Unvested restricted stock units, Ending balance \| $ / shares	$ 21.12

Common Stock and Stock-Based Awards - Restricted Stock Units - Additional Information (Detail) - Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted	565,798
Vesting period	4 years
Vesting After One Year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	25.00%
Vesting Quarterly Over Next 3 Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	75.00%

Common Stock and Stock-Based Awards - Summary of Stock Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 5,846	$ 2,249	$ 14,548	$ 6,122
Research and development expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	2,718	1,368	7,564	3,358
General and administrative expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 3,128	$ 881	$ 6,984	$ 2,764

Net Income (Loss) per Share - Basic and Diluted Net Income (Loss) per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 68,218	$ (48,330)	$ (35,465)	$ (30,280)	$ (20,714)	$ (19,881)	$ (15,577)	$ (70,875)
Income (loss) attributable to common stockholders - basic	$ 68,218			$ (30,280)			$ (15,577)	$ (70,875)
Denominator:
Weighted-average shares outstanding	91,757,614			83,531,617			91,649,035	75,914,361
Net income (loss) per share applicable to common stockholders - basic	$ 0.74			$ (0.36)			$ (0.17)	$ (0.93)
Numerator:
Net loss	$ 68,218	$ (48,330)	$ (35,465)	$ (30,280)	$ (20,714)	$ (19,881)	$ (15,577)	$ (70,875)
Income (loss) attributable to common stockholders - diluted	$ 68,218			$ (30,280)			$ (15,577)	$ (70,875)
Denominator:
Weighted-average shares outstanding	91,757,614			83,531,617			91,649,035	75,914,361
Dilutive impact from:
Stock options to purchase common stock	3,186,762
Unvested restricted stock units	8,741
Weighted-average shares outstanding - diluted	94,953,117			83,531,617			91,649,035	75,914,361
Net income (loss) per share applicable to common stockholders - diluted	$ 0.72			$ (0.36)			$ (0.17)	$ (0.93)
Stock Options to Purchase Common Stock [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share:
Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share	7,716,681			9,802,633			10,903,443	9,802,633
Unvested Restricted Stock Units [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share:
Anti-dilutive potential common stock equivalents excluded from the calculation of net income (loss) per share	549,455						558,196

Collaboration Revenue - Additional Information (Detail)				1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
Collaboration Revenue - Additional Information (Detail)	Jul. 21, 2021 USD ($)	Jul. 01, 2021 USD ($)	Jan. 31, 2016 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2019 USD ($) Installment	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 30, 2018 USD ($)	Feb. 29, 2016 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration profit (loss)						$ 1,127,000		$ 1,127,000
Change in collaboration revenue-related party						(4,618,000)		4,028,000	$ 11,837,000
Upfront collaboration/license fee			$ 120,000,000
Collaboration revenue - related party						126,725,000	$ 80,000	136,636,000	10,728,000
Collaboration revenue						0	0	$ 0	2,016,000
2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration product, percentage of commercial profit		50.00%
Collaborative arrangement, sharing of pre-launch costs, percentage		50.00%
Research Agreement [Member] \| AstraZeneca Inc. [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront collaboration milestone payments receivable					$ 20,000,000
Transaction price allocated to remaining performance obligations				$ 23,377,000						$ 23,377,000
Minimum exclusivity period					3 years
Number of installments \| Installment					3
Option exercise period from exclusivity period								90 days
Terms of the definitive license agreement good faith negotiation period								6 months
Other terms of definitive license agreement period								1 year
Termination date				Apr. 02, 2021
Termination notice period				120 days
Research and development fixed consideration				$ 20,000,000	$ 20,000,000					20,000,000
Research and development estimated reimbursement costs								$ 13,900,000
Reimbursement of research and development costs incurred										3,376,000
Collaboration revenue						0	0	0	2,016,000	15,145,000
Nestle Health Science [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment				108,174,000		104,146,000		104,146,000		108,174,000					$ 120,000,000
Maximum development milestone payments to be received						285,000,000		285,000,000
Maximum regulatory payments to be received						375,000,000		375,000,000
Maximum amount to be received on achievement of certain commercial milestones						1,125,000,000		1,125,000,000
Proceeds on achievement of development milestone											$ 40,000,000	$ 20,000,000	$ 10,000,000
Transaction price allocated to remaining performance obligations						200,000,000		200,000,000
Transaction price of milestone payment to be received										10,000,000
Collaboration revenue - related party						(5,883,000)	$ 80,000	4,028,000	$ 10,728,000
Deferred revenue				$ 108,174,000		104,146,000		104,146,000		$ 108,174,000
Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration product, percentage of commercial profit		50.00%
Upfront payment received	$ 175,000,000
Maximum amount to be received on achievement of regulatory and sales milestones		$ 360,000,000
Maximum amount to be received on achievement of sales milestones		225,000,000
Collaboration profit (loss)						1,127,000		1,127,000
Change in collaboration revenue-related party						(5,883,000)
Maximum regulatory payments to be received		$ 135,000,000
Transaction price allocated to remaining performance obligations	$ 139,500,000
Collaboration revenue - related party						131,343,000		131,343,000
Termination notice period	60 days
Nestle Health Science [Member] \| Phase 2 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront collaboration milestone payments receivable			20,000,000
Nestle Health Science [Member] \| Phase 3 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront collaboration milestone payments receivable			$ 20,000,000
Nestle Health Science [Member] \| Phase 2b [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront collaboration milestone payments receivable														$ 40,000,000
Proceeds on achievement of development milestone											$ 40,000,000
Topic 808 [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated under collaborative arrangement	$ 35,500,000
Topic 808 [Member] \| Total Liabilities [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated under collaborative arrangement	$ 35,500,000
Topic 808 [Member] \| Other Long-term Liabilities [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated under collaborative arrangement						7,075,000		7,075,000
Topic 808 [Member] \| Accrued Expenses and Other Current Liabilities [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated under collaborative arrangement						26,734,000		26,734,000
Research and Development Expenses [Member] \| Topic 808 [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cost associated with pre-launch activities						$ 1,117,000
General and Administrative Expenses [Member] \| Topic 808 [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cost associated with pre-launch activities								$ 1,701,000

Collaboration Revenue - Changes in Contract Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue - related party, Deductions	$ 4,618	$ (4,028)	$ (11,837)
ASU 2014-09 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue - related party, Balance at beginning of period		108,174	110,071
Deferred revenue - related party, Additions		8,157
Deferred revenue - related party, Deductions		(5,294)	(10,728)
Deferred revenue - related party, Balance at end of period	$ 111,037	$ 111,037	99,343
Deferred revenue, Balance at beginning of period			9,668
Deferred revenue, Additions			827
Deferred revenue, Deductions			(2,016)
Deferred revenue, Balance at end of period			$ 8,479

Collaboration Revenue - Schedule of Revenue Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Revenue recognized in the period from:
Amounts included in the contract liability at the beginning of the period	$ (4,618)	$ 4,028	$ 11,837

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Indemnification Agreement [Member]
Other Commitments [Line Items]
Obligations accrued	$ 0	$ 0
Legal Contingencies [Member]
Other Commitments [Line Items]
Obligations accrued	$ 0	$ 0

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 0	$ 0	$ 0	$ 0
Accrued interest or tax penalties	$ 0		$ 0		$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Related Party Transactions - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Feb. 29, 2016
Related Party Transaction [Line Items]
Collaboration revenue - related party		$ 126,725,000	$ 80,000	$ 136,636,000	$ 10,728,000
Aggregate net proceeds from offering of common stock					244,020,000
Nestle Health Science [Member]
Related Party Transaction [Line Items]
Collaboration revenue - related party		(5,883,000)	80,000	4,028,000	10,728,000
Deferred revenue		104,146,000		104,146,000		$ 108,174,000	$ 120,000,000
Payments under agreements with related party		0	0	0	0
Due from related party for the reimbursement of development costs		0		0
Nestle Health Science [Member] \| 2021 License Agreement [Member]
Related Party Transaction [Line Items]
Collaboration revenue - related party		132,608,000		132,608,000
Deferred revenue		6,891,000		6,891,000
Payments under agreements with related party		0		0
Due from related party for the reimbursement of development costs		0		$ 0
Nestlé [Member] \| Securities Purchase Agreement [Member] \| Concurrent Placement [Member]
Related Party Transaction [Line Items]
Common stock, shares issued	959,002
Common stock, share price	$ 20.855
Aggregate net proceeds from offering of common stock	$ 19,900,000
Flagship Pioneering [Member] \| Sublease Agreement [Member]
Related Party Transaction [Line Items]
Lessee, term of operating sublease, description				The term of the sublease agreement commenced in July 2019 and ends on the last day of the 24th calendar month following commencement. In the second quarter of 2021, the sublease agreement was extended to November 2021.
Sub lease commencement date				2019-07
Cash received from related party transaction		437,000	458,000	$ 1,361,000	1,357,000
Flagship Pioneering [Member] \| Sublease Agreement [Member] \| Other Income [Member]
Related Party Transaction [Line Items]
Sublease income		437,000	$ 458,000	1,361,000	$ 1,357,000
Other Long Term Liabilities [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Related Party Transaction [Line Items]
Transaction price allocated under collaborative arrangement		7,075,000		7,075,000
Accrued Expenses and Other Liabilities [Member] \| Nestle Health Science [Member] \| 2021 License Agreement [Member]
Related Party Transaction [Line Items]
Transaction price allocated under collaborative arrangement		$ 26,734,000		$ 26,734,000

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member] SFr in Thousands, $ in Thousands	Nov. 08, 2021 CHF (SFr)	Nov. 08, 2021 USD ($)	Nov. 04, 2021 USD ($)
David Ege, Ph.D. [Member]
Subsequent Event [Line Items]
One-time special cash bonus to be paid			$ 131
One-time special cash bonus payment date			Dec. 04, 2021
Minimum employment duration required after special bonus to avoid repayment of bonus			2 years
Time period to repay special bonus after termination			10 days
Bacthera Agreement [Member]
Subsequent Event [Line Items]
Payments to acquire under agreement	SFr 240,000	$ 262,000
Long-term manufacturing agreement, additional term period thereafter	3 years	3 years
Bacthera Agreement [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Long-term manufacturing agreement term period	16 years	16 years