Synlogic (SYBX) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 05, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	SYBX
Entity Registrant Name	SYNLOGIC, INC.
Security Exchange Name	NASDAQ
Entity Central Index Key	0001527599
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Title of 12(b) Security	Common Stock
Entity Common Stock, Shares Outstanding		32,290,814
Entity Address, State or Province	MA
Entity File Number	001-37566
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1824804
Entity Address, Address Line One	301 Binney St.
Entity Address, Address Line Two	Suite 402
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	02142
City Area Code	617
Local Phone Number	401-9975
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 27,458	$ 11,252
Short-term marketable securities	92,808	111,477
Prepaid expenses	10,531	1,221
Other current assets	522	388
Total current assets	131,319	124,338
Long-term marketable securities	18,396
Property and equipment, net	13,289	14,841
Right of use asset - operating lease	17,674
Restricted cash	1,097	1,097
Prepaid research and development, net of current portion	20,570
Other assets	64	64
Total assets	202,409	140,340
Current liabilities:
Accounts payable	2,351	2,421
Accrued expenses	4,028	4,993
Deferred revenue	1,775	268
Deferred rent		393
Lease liability - operating lease	1,925
Finance lease obligations	258	266
Total current liabilities	10,337	8,341
Long-term liabilities:
Deferred rent, net of current portion		7,691
Lease liability - operating lease, net of current portion	23,385
Finance lease obligations, net of current portion	20	210
Total long-term liabilities	23,405	7,901
Commitments and contingencies (Note 11)
Stockholders' Equity
Preferred stock, $0.001 par value 5,000,000 shares authorized, none issued and outstanding as of September 30, 2019 and December 31, 2018
Common stock, $0.001 par value 250,000,000 shares authorized as of September 30, 2019 and December 31, 2018. 32,290,814 and 25,401,479 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively.	33	25
Additional paid-in capital	326,860	243,903
Accumulated other comprehensive loss	114	(65)
Accumulated deficit	(158,340)	(119,765)
Total stockholders' equity	168,667	124,098
Total liabilities and stockholders' equity	$ 202,409	$ 140,340

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, Shares Authorized	5,000,000	5,000,000
Preferred stock, Shares Issued	0	0
Preferred stock, Shares Outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	250,000,000	250,000,000
Common stock, Issued	32,290,814	25,401,479
Common stock, outstanding	32,290,814	25,401,479

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 305	$ 1,801	$ 993	$ 2,409
Operating expenses:
Research and development	10,564	9,934	30,651	29,167
General and administrative	3,879	3,401	11,272	11,764
Total operating expenses	14,443	13,335	41,923	40,931
Loss from operations	(14,138)	(11,534)	(40,930)	(38,522)
Other income (expense):
Interest and investment income	857	797	2,373	2,059
Interest expense	(5)	(10)	(17)	(36)
Other expense	1	(1)	(1)	(5)
Other income (expense), net	853	786	2,355	2,018
Net loss	$ (13,285)	$ (10,748)	$ (38,575)	$ (36,504)
Net loss per share attributable to common shareholders - basic and diluted	$ (0.39)	$ (0.43)	$ (1.33)	$ (1.56)
Weighted-average common shares used in computing net loss per share attributable to common shareholders - basic and diluted	34,213,096	25,208,117	28,956,280	23,415,242
Comprehensive loss:
Net loss	$ (13,285)	$ (10,748)	$ (38,575)	$ (36,504)
Net unrealized gains (losses) on marketable securities	46	28	179	(38)
Comprehensive loss	$ (13,239)	$ (10,720)	$ (38,396)	$ (36,542)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock $0.001 Par	Additional Paid-in Capital	Other Accumulated Comprehensive Income	Accumulated Deficit
Balance at Dec. 31, 2017	$ 85,038	$ 16	$ 156,685	$ (9)	$ (71,654)
Balance (in Shares) at Dec. 31, 2017		16,272,617
Effect of adoption of ASU | ASU 2014-09 (ASC 606)	324				324
Sale of common stock, net of issuance costs	82,666	$ 9	82,657
Sale of common stock, net of issuance costs, shares		9,179,500
Exercise of options	103		103
Exercise of options,shares		9,393
Cancellation of restricted stock		(21,169)
Equity-based compensation expense	3,445		3,445
Unrealized gain (loss) on securities	(38)			(38)
Net loss	(36,504)				(36,504)
Balance at Sep. 30, 2018	135,034	$ 25	242,890	(47)	(107,834)
Balance (in Shares) at Sep. 30, 2018		25,440,341
Balance at Jun. 30, 2018	144,620	$ 25	241,756	(75)	(97,086)
Balance (in Shares) at Jun. 30, 2018		25,432,849
Exercise of options	103		103
Exercise of options,shares		9,393
Cancellation of restricted stock		(1,901)
Equity-based compensation expense	1,031		1,031
Unrealized gain (loss) on securities	28			28
Net loss	(10,748)				(10,748)
Balance at Sep. 30, 2018	135,034	$ 25	242,890	(47)	(107,834)
Balance (in Shares) at Sep. 30, 2018		25,440,341
Balance at Dec. 31, 2018	124,098	$ 25	243,903	(65)	(119,765)
Balance (in Shares) at Dec. 31, 2018		25,401,479
Issuance of restricted stock		$ 1	(1)
Issuance of restricted stock, shares		585,600
Sale of common stock, net of issuance costs	56,997	$ 7	56,990
Sale of common stock, net of issuance costs, shares		6,340,771
Proceeds from pre-funded common stock warrants, net of issuance costs	22,874		22,874
Cancellation of restricted stock		(37,036)
Equity-based compensation expense	3,094		3,094
Unrealized gain (loss) on securities	179			179
Net loss	(38,575)				(38,575)
Balance at Sep. 30, 2019	168,667	$ 33	326,860	114	(158,340)
Balance (in Shares) at Sep. 30, 2019		32,290,814
Balance at Jun. 30, 2019	180,823	$ 32	325,778	68	(145,055)
Balance (in Shares) at Jun. 30, 2019		31,719,719
Issuance of restricted stock		$ 1	(1)
Issuance of restricted stock, shares		585,600
Cancellation of restricted stock		(14,505)
Adjustment to accrued common stock issuance costs	14		14
Equity-based compensation expense	1,069		1,069
Unrealized gain (loss) on securities	46			46
Net loss	(13,285)				(13,285)
Balance at Sep. 30, 2019	$ 168,667	$ 33	$ 326,860	$ 114	$ (158,340)
Balance (in Shares) at Sep. 30, 2019		32,290,814

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (38,575)	$ (36,504)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,989	1,789
Loss on disposal of property and equipment		2
Equity-based compensation expense	3,094	3,445
Accretion/amortization of investment securities	(1,177)	(958)
Changes in operating assets and liabilities:
Accounts receivable		(2,000)
Prepaid expenses and other current assets	(9,444)	190
Accounts payable and accrued expenses	(670)	(592)
Deferred revenue	1,507	(410)
Operating lease liability and right of use asset	(1,407)
Deferred rent		1,364
Prepaid research and development, net of current portion	(20,571)
Other assets		167
Net cash used in operating activities	(64,254)	(33,507)
Cash flows from investing activities:
Purchases of marketable securities	(129,517)	(144,594)
Proceeds from maturity of marketable securities	131,146	58,730
Purchases of property and equipment	(842)	(4,254)
Net cash provided by (used in) investing activities	787	(90,118)
Cash flows from financing activities:
Proceeds from exercise of stock options		103
Payments on finance lease obligations	(198)	(330)
Proceeds from sale of common stock, net of issuance costs	56,997	82,666
Proceeds from sale of pre-funded warrants, net of issuance costs	22,874
Net cash provided by financing activities	79,673	82,439
Net increase (decrease) in cash, cash equivalents and restricted cash	16,206	(41,186)
Cash, cash equivalents and restricted cash at beginning of period	12,349	59,537
Cash, cash equivalents and restricted cash at end of period	28,555	18,351
Supplemental disclosure of non-cash investing activities:
Landlord funded allowance for tenant improvements		1,654
Property and equipment purchases included in accounts payable and accrued expenses	(365)	976
Assets acquired under operating lease obligation	2,714
Supplemental disclosure of non-cash financing activities:
Issuance costs included in accounts payable and accrued expenses	26
Purchase under finance lease		12
Cash paid for interest	$ 17	$ 35

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	(1) Nature of Business Organization Synlogic, Inc., together with its wholly owned and consolidated subsidiaries (“Synlogic” or the “Company”), is a clinical-stage biopharmaceutical company focused on advancing its proprietary drug discovery and development platform to create Synthetic Biotic™ medicines which are designed using synthetic biology to genetically reprogram beneficial microbes to treat metabolic and inflammatory diseases and cancer Synthetic Biotic medicines are generated by applying the principles and tools of synthetic biology to engineer beneficial microbes to perform or deliver critical therapeutic functions. Synlogic, Inc. (“Private Synlogic” when referred to prior to the Merger (as defined below)) was founded and began operations on March 14, 2014, as TMC Therapeutics, Inc., located in Cambridge, Massachusetts. On July 15, 2014, TMC Therapeutics, Inc. changed its name to Synlogic, Inc. On July 2, 2015, the common and preferred stockholders of Private Synlogic executed the Synlogic, LLC Contribution Agreement (the “Contribution Agreement”), pursuant to which such common and preferred stockholders contributed such stockholders’ equity interests in Private Synlogic in exchange for common and preferred units in a newly formed parent company named Synlogic, LLC. In addition, Synlogic IBDCo, Inc. (“IBDCo”) was formed as a subsidiary of Synlogic, LLC (the “2015 Reorganization”). In conjunction with the 2015 Reorganization, Private Synlogic entered into a license, option and merger agreement with AbbVie S.à.r.l. (“AbbVie”), for the development of treatments for inflammatory bowel disease (“IBD”). See Note 9, AbbVie Collaboration Agreement In May 2017, Private Synlogic completed a reorganization (the “2017 Reorganization”) pursuant to which Synlogic, LLC merged with and into Private Synlogic, with Private Synlogic continuing as the surviving corporation. On August 28, 2017, Synlogic, Inc., formerly known as Mirna Therapeutics, Inc. (NASDAQ: MIRN) (“Mirna”), completed its business combination with Private Synlogic pursuant to the Agreement and Plan of Merger and Reorganization, dated as of May 15, 2017, by and among Mirna, Meerkat Merger Sub, Inc. (“Merger Sub”), and Private Synlogic (the “Merger Agreement”), pursuant to which Merger Sub merged with and into Private Synlogic, with Private Synlogic surviving as a wholly owned subsidiary of Mirna (the “Merger”). Immediately after completion of the Merger, Mirna changed its name to “Synlogic, Inc.” (NASDAQ: SYBX). Risks and Uncertainties At September 30, 2019, the Company had approximately $120.3 million in cash, cash equivalents, and short-term marketable securities, $18.4 million of long-term marketable securities, $1.1 million of restricted cash and an accumulated deficit of approximately $158.3 million. Since its inception through September 30, 2019, the Company has primarily financed its operations through the issuance of preferred stock, units and warrants, the sale of its common stock, the AbbVie collaboration, and cash received in the Merger. In June 2019, the Company issued to Ginkgo Bioworks, Inc. (“Ginkgo”), a privately held high-throughput synthetic biology company, 6,340,771 shares of common stock at a purchase price per share of $9.00, and pre-funded warrants (the “Pre-Funded Warrants”) As an early-stage company, the Company is subject to a number of risks common to other life science companies, including, but not limited to, raising additional capital, development by its competitors of new technological innovations, risk of failure in preclinical and clinical studies, safety and efficacy of its product candidates in clinical trials, the risk of relying on external parties such as contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), the regulatory approval process, market acceptance of the Company’s products once approved, lack of marketing and sales history, dependence on key personnel and protection of proprietary technology. The Company’s therapeutic programs are currently pre-commercial, spanning discovery through early development and will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization of any product candidates. These efforts require significant amounts of additional capital, adequate personnel, infrastructure, and extensive compliance-reporting capabilities. 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, that any products developed will obtain necessary regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate revenue from product sales. The Company may never achieve profitability, and unless and until it does, it will continue to need to raise additional capital or obtain financing from other sources, such as strategic collaborations or partnerships.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	( 2) Summary of Significant Accounting Policies The significant accounting policies described in the Company’s audited financial statements as of and for the year ended December 31, 2018, and the notes thereto, which are included in the Company’s 2018 Annual Report for the year ended December 31, 2018, filed with the Securities and Exchange Commission (“SEC”) on March 12, 2019 (the “2018 Annual Report”), have had no material changes during the three and nine months ended September 30, 2019, other than our adoption of ASU 2016-02 (as defined below). The updated accounting policy and the impact of adoption are discussed in the “Recently Adopted Accounting Pronouncements” section in this note. Basis of Presentation The accompanying consolidated financial statements and the related disclosures as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and the rules and regulations of the SEC for interim financial statements. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. These interim consolidated financial statements should be read in conjunction with the Company’s 2018 and 2017 audited consolidated financial statements and notes included in the Company’s 2018 Annual Report. The December 31, 2018 consolidated balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments, consisting of normal and recurring adjustments, necessary for the fair presentation of the Company’s financial position and results of operations for the three and nine months ended September 30, 2019 and 2018. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or any other interim period or future year or period. Principles of Consolidation The accompanying consolidated financial statements include the accounts of Synlogic and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 – Leases (Topic 842), which replaces the existing accounting guidance for leases. This standard requires entities that lease assets to recognize the assets and liabilities for the rights and obligations created by those leases on the balance sheet. The standard is effective for fiscal years and the interim periods within those fiscal years beginning after December 15, 2018. The guidance is required to be applied by the modified retrospective transition approach and early adoption is permitted. In July 2018, the FASB issued ASU 2018-11 Leases – Targeted Improvements, intended to ease the implementation of the new lease standard for financial statement preparers by, among other things, allowing for an additional transition method. In lieu of presenting transition requirements to comparative periods, as previously required, an entity may now elect to show a cumulative effect adjustment on the date of adoption without the requirement to recast prior period financial statements or disclosures presented in accordance with ASU 2016-02. The Company adopted the new standard using the cumulative effect adjustment transition option effective January 1, 2019, which is the initial date of application per ASU 2018-11. The Company elected the available package of practical expedients which allows the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of our leases, and the treatment of initial direct costs. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. T he Company adopted ASU 2016-02: Leases (Topic 842) as of January 1, 2019. The Company uses judgement to assess if an arrangement is a lease at contract inception. An arrangement is a lease if the contract involves the use of a distinct identified asset, the lessor does not have substantive substitution rights and the Company obtains control of the asset throughout the period by obtaining substantially all of the economic benefit of the asset and the right to direct the use of the asset. Leases classified as operating leases are included in operating lease right-of-use (ROU) assets, current operating lease liabilities and noncurrent operating lease liabilities in our consolidated balance sheet. Finance leases are included in property and equipment and finance lease obligations, in our consolidated balance sheet. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. The Company utilizes its incremental borrowing rate to determine the present value of lease payments. The incremental borrowing rate is the rate incurred to borrow similar funds, on a collateralized basis, over a comparable term in a similar economic environment. For new and amended leases beginning in 2019 and after, the Company has elected to account for the lease and non-lease components for leases as a single component for classes of all underlying assets and allocate all of the contract consideration to the lease component only. Lease cost for operating leases is recognized on a straight-line basis over the lease term and is included in operating expenses on the statements of operations and comprehensive loss. Variable lease payments are included in lease operating expenses. The lease term includes options to extend the lease when it is reasonably certain that option will be exercised. Leases with a term of 12 months or less are not recorded on the Company’s consolidated balance sheet. The adoption had a material impact on the consolidated balance sheet related to the recognition of a transition adjustment on January 1, 2019 of a right-of-use asset of $15.9 million and lease liability of $24.0 million for an operating lease and the derecognition of deferred rent originally accounted for under legacy guidance. The adoption did not have a material impact on the consolidated statement of operations. The Company has designed and implemented changes to related processes, controls and disclosures. Refer to the Commitments and Contingencies footnote for further information on the adoption of this standard and the Company’s accounting for leases. In February 2018, the FASB issued ASU 2018-02 – Income Statement – Reporting Comprehensive Income (Topic 220), which provides amended guidance on income tax accounting. The amended guidance permits the reclassification of the income tax effect on amounts recorded within other comprehensive income impacted by the Tax Cuts and Jobs Act (the “TCJA”) into retained earnings. The amended guidance is effective for periods beginning after December 15, 2018 and applies only to those amounts remaining in other comprehensive income at the date of enactment of the TCJA. The amended guidance may be adopted on either a retrospective basis or at the beginning of the period of adoption. The amended standard had an immaterial impact on the Company’s consolidated financial statements and as such the Company did not reclassify the income tax effects of the TCJA from other comprehensive income to retained earnings. In June 2018, the FASB issued ASU 2018-07- Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of ASC 606. The standard expands the scope of ASC 718 to include all share-based payment arrangements related to the acquisition of goods and services from both nonemployees and employees. Under the amended guidance, equity-classified share-based payment awards issued to nonemployees will be measured at grant date fair value. Upon transition, the entity is required to remeasure these nonemployee awards at fair value as of the adoption date. The Company adopted the new guidance on January 1, 2019 which had an immaterial impact on its consolidated financial statements. Recently Issued Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13 - Fair Value Measurement - Disclosure Framework (Topic 820). The standard modifies the disclosure requirements for fair value measurements. The standard is effective for public companies for annual and interim periods beginning after December 15, 2019. Early adoption is permitted for any removed or modified disclosures. Management is currently assessing the impact adoption will have on the Company, but it is not expected to have a material impact on the Company’s financial statement disclosures. In August 2018, the FASB issued ASU 2018-15 - Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract. The standard requires implementation costs incurred by customers in cloud computing arrangements to be deferred over the noncancelable term of the cloud computing arrangements plus any optional renewal periods (1) that are reasonably certain to be exercised by the customer or (2) for which exercise of the renewal option is controlled by the cloud service provider. The effective date of this pronouncement is for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, and early adoption is permitted. The standard can be adopted either using the prospective or retrospective transition approach. The Company is currently evaluating the impact of this standard on the Company's consolidated financial statements and disclosures. In November 2018, the FASB issued ASU 2018-18 - Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606, which, among other things, provides guidance on how to assess whether certain collaborative arrangement transactions should be accounted for under Topic 606. The amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the impact of this standard on the Company’s consolidated financial statements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	( 3 ) Fair Value of Financial Instruments The tables below present information about the Company’s assets that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value, as described under Note 2 , Summary of Significant Accounting Policies, The Company’s investment portfolio includes many fixed income securities that do not always trade on a daily basis. As a result, the pricing services used by the Company applied other available information as applicable through processes such as benchmark yields, benchmarking of like securities, sector groupings and matrix pricing to prepare evaluations. In addition, model processes were used to assess interest rate impact and develop prepayment scenarios. These models take into consideration relevant credit information, perceived market movements, sector news and economic events. The inputs into these models may include benchmark yields, reported trades, broker-dealer quotes, issuer spreads and other relevant data. At September 30, 2019 and December 31, 2018, the Company has classified assets measured at fair value on a recurring basis as follows (in thousands): Fair Value Measurements at September 30, 2019 September 30, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description 2019 (Level 1) (Level 2) (Level 3) Money market funds (included in cash and cash equivalents) $ 16,691 $ 16,691 $ — $ — Commercial paper (included in short-term investments) 36,205 — 36,205 — Corporate debt securities (included short-term investments) 56,603 — 56,603 — Corporate debt securities (included in long-term investments) 17,388 — 17,388 — U.S. government agency securities and treasuries (included in long-term investments) 1,008 — 1,008 — Total $ 127,895 $ 16,691 $ 111,204 $ — Fair Value Measurements at December 31, 2018 December 31, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description 2018 (Level 1) (Level 2) (Level 3) Money market funds (included in cash and cash equivalents) $ 265 $ 265 $ — $ — Commercial paper (included in short-term investments) 57,453 — 57,453 — Corporate debt securities (included in short-term investments) 50,052 — 50,052 — U.S. government agency securities and treasuries (included in short-term investments) 3,972 1,987 1,985 — Total $ 111,742 $ 2,252 $ 109,490 $ — Cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses at September 30, 2019 and December 31, 2018 are carried at amounts that approximate fair value due to their short-term maturities. Finance lease obligations at September 30, 2019 and December 31, 2018 approximate fair value as they bear interest at a rate approximating a market interest rate.

Available-for-Sale Investments

Available-for-Sale Investments	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Available-for-Sale Investments	( 4 ) Available-for-Sale Investments The following tables summarize the available-for-sale securities held at September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 Amortized cost Gross unrealized gains Gross unrealized losses Fair Value Commercial paper $ 36,175 $ 30 $ — $ 36,205 Corporate debt securities 73,909 86 (4 ) 73,991 U.S. government agency securities 1,006 2 — 1,008 Total $ 111,090 $ 118 $ (4 ) $ 111,204 December 31, 2018 Amortized cost Gross unrealized gains Gross unrealized losses Fair Value Commercial paper $ 53,549 $ — $ (47 ) $ 53,502 Corporate debt securities 54,022 4 (23 ) 54,003 U.S. government agency securities 3,971 1 — 3,972 Total $ 111,542 $ 5 $ (70 ) $ 111,477 The contractual maturity of all securities held at September 30, 2019 was 17 months or less. There were 4 and 37 investments in an unrealized loss position at September 30, 2019 and December 31, 2018, respectively, none of which had been in an unrealized loss position for more than twelve months. The aggregate fair value of the securities in an unrealized loss position at September 30, 2019 and December 31, 2018 was $9.5 million and $96.5 million, respectively. The Company reviews its investments for other-than-temporary impairment whenever the fair value of an investment is less than amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. To determine whether an impairment is other-than-temporary, the Company considers whether it has the ability and intent to hold the investment until a market price recovery and considers whether evidence indicating the cost of the investment is recoverable outweighs evidence to the contrary. The Company did not hold any securities with an other-than-temporary impairment at September 30, 2019. Gross realized gains and losses on the sales of investments have not been material to the Company’s consolidated statement of operations.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment, Net	( 5 ) Property and Equipment, net Property and equipment, net consists of the following (in thousands): September 30, December 31, 2019 2018 Laboratory equipment $ 7,467 $ 7,111 Computer and office equipment 840 781 Furniture and fixtures 413 413 Leasehold improvements 9,514 9,484 Construction in progress 72 39 18,306 17,828 Less accumulated depreciation (5,017 ) (2,987 ) $ 13,289 $ 14,841

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	( 6 ) Accrued Expenses Accrued expenses consist of the following (in thousands): September 30, December 31, 2019 2018 Payroll related $ 2,116 $ 2,906 Professional fees 427 306 Research and development 1,322 1,585 Other 163 196 $ 4,028 $ 4,993

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stockholders' Equity	( 7 ) Stockholders’ Equity In June 2019, the Company issued to Ginkgo an aggregate of 6,340,771 shares of common stock at a purchase price per share of $9.00, and Pre-Funded Warrants to purchase an aggregate of 2,548,117 shares of common stock at an exercise price of $9.00 per share, with $8.99 of such exercise price paid at the closing of the offering. The net proceeds to the Company were approximately $79.9 million. The Pre-Funded Warrants may be exercised at any time until all of the Pre-Funded Warrants are exercised in full to the extent that, after giving effect to such issuance after exercise, Ginkgo would not beneficially own in excess of 19.99% of the number of shares of common stock outstanding immediately after giving effect to the issuance. The Pre-Funded Warrants were classified as a component of permanent equity and were recorded at the issuance date using a relative fair value allocation method. The Pre-Funded Warrants are equity classified because they are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of common shares upon exercise. In addition, such warrants do not provide any guarantee of value or return.

Equity-based Compensation and E

Equity-based Compensation and Equity Incentive Plans	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity-based Compensation and Equity Incentive Plans	( 8 ) Equity‑based Compensation and Equity Incentive Plans The Company is displaying all equity in its post-Merger amounts. Equity Plans The Company has a number of equity plans, two of which are currently active. The 2015 Equity Incentive Award Plan (the “2015 Plan”) was adopted by Mirna in 2015 and remains active after the Merger, now functioning as the primary equity plan for the Company. The 2015 Plan provides for the granting of a variety of stock‑based compensation awards, including stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, deferred stock awards, dividend equivalent awards, stock payment awards, performance awards and other stock‑based awards. Pursuant to the evergreen provision of the 2015 Plan, which allows for an annual increase in the number of shares of common stock available for issuance, the Company added 1,270,073 shares to the 2015 Plan on January 1, 2019. The 2017 Stock Incentive Plan (the “2017 Plan”) was adopted by Private Synlogic in 2017 at the time of the 2017 Reorganization and assumed by the Company during the Merger. The 2017 Plan provides for the grant of incentive stock options, non-qualified stock options, restricted and unrestricted stock awards and other stock-based awards. As of September 30, 2019, there were 536,808 shares available for future grant under the Company’s two active equity incentive plans, the 2017 Plan and the 2015 Plan. For a full description of the Company’s equity plans, refer to Note 12, Equity-based Compensation and Equity Incentive Plans Stock Options The following table summarizes stock option activity during the nine months ended September 30, 2019 under the 2015 Plan and the 2017 Plan. Stock options outstanding Weighted Weighted average Aggregate average remaining Intrinsic Number of exercise contractual value (a) options price term (in years) (in thousands) Outstanding at December 31, 2018 1,739,884 $ 11.92 9.0 $ — Granted 1,171,030 8.08 Exercised — Forfeited (508,915 ) 11.76 25 Outstanding at September 30, 2019 2,401,999 10.08 8.8 $ — Vested or expected to vest at September 30, 2019 2,401,999 10.08 8.8 — Exercisable at September 30, 2019 805,772 11.86 8.3 $ — (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the options and the fair market value of the underlying common stock for the options that were in the money at September 30, 2019 and December 31, 2018. As of September 30, 2019, there was $8.7 million of unrecognized share-based compensation related to unvested stock option grants which is expected to be recognized over a weighted average period of 2.6 years. The total unrecognized share-based compensation cost will be adjusted for actual forfeitures as they occur. Restricted Common Stock The following table shows restricted stock activity during the nine months ended September 30, 2019: Restricted stock awards Grant date Number of fair value shares (per share) Unvested at December 31, 2018 118,679 $ 13.54 Granted 585,600 2.49 Vested (46,606 ) 13.53 Forfeited (37,036 ) 13.53 Unvested at September 30, 2019 620,637 $ 3.12 As of September 30, 2019, there was approximately $1.5 million of unrecognized share-based compensation related to restricted stock awards granted, which is expected to be recognized over a weighted average period of 1.5 years. The total unrecognized share-based compensation cost will be adjusted for actual forfeitures as they occur. Equity Compensation The Company recorded total equity-based compensation expense of $1.1 million and $3.1 million during the three and nine months ended September 30, 2019, respectively and $1.0 million and $3.4 million during the three and nine months ended September 30, 2018, respectively. The following table summarizes equity‑based compensation expense within the Company’s consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2019 and 2018 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 353 $ 386 $ 986 $ 1,115 General and administrative 716 645 2,108 2,330 $ 1,069 $ 1,031 $ 3,094 $ 3,445 The following table summarizes equity‑based compensation expense by type of award for the three and nine months ended September 30, 2019 and 2018 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock options $ 1,026 $ 890 $ 2,999 $ 2,500 Restricted stock awards 43 141 95 945 $ 1,069 $ 1,031 $ 3,094 $ 3,445

AbbVie Collaboration Agreement

AbbVie Collaboration Agreement	9 Months Ended
	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
AbbVie Collaboration Agreement	( 9 ) AbbVie Collaboration Agreement In July 2015, the Company entered into the AbbVie Agreement under which the Company granted AbbVie an exclusive option to purchase IBDCo and, in exchange, agreed to collaborate in researching and developing an Investigational New Drug (“IND”) candidate for the treatment of IBD. The AbbVie Agreement sets forth the Company’s and AbbVie’s respective obligations for development and delivery of an IND candidate package using reasonable commercial efforts. In exchange for the exclusive option to acquire IBDCo, initial research and development services for drug discovery and pre-clinical development, and participation on the joint research committee (“JRC”), AbbVie agreed to pay IBDCo an upfront, non-refundable cash payment of $2.0 million, which IBDCo received in December 2015. AbbVie also agreed to pay IBDCo up to $16.5 million in milestone payments associated with specified research and pre-clinical events, which were determined to represent customer options for accounting purposes, as well as an option exercise fee upon the execution of their option to buy IBDCo and other royalty and milestone payments. The upfront cash payment and any payments for option fees and royalties are non-refundable, non-creditable and not subject to set-off. The research and development is performed by the Company over four phases of research defined in the research plan. The Company is eligible to receive payments from AbbVie upon the election to continue the research and development at the achievement of certain milestone events. The JRC will make a determination as to the continuation of the collaboration at the achievement of research and pre-clinical milestones, except for the final milestone, which AbbVie has the discretion to determine achievement without the approval of the JRC. If the parties make the determination to continue on with the AbbVie Agreement upon achievement of each milestone event, then AbbVie will pay the consideration associated with that milestone and the collaboration will continue through the remaining term of the option to purchase IBDCo, which was initially considered to be approximately 54 months. However, AbbVie has the right to terminate the contract at any time with 90 days’ notice. The Company assessed this arrangement in accordance with ASC 606 and concluded that the contract counterparty, AbbVie, is a customer. The Company identified the following material promises at the outset of the arrangement: (1) a non-exclusive royalty-free research and development license; (2) research and development services for pre-clinical activities under the research plan through to the first research and development phase (or an estimated 17 months); (3) three option rights for AbbVie to continue the collaboration as related to three phases of research and development; (4) participation on the JRC; and (5) the transfer of ownership of IBDCo upon exercise of the option to buy IBDCo. The Company determined that the license and research and development activities were not distinct from one another. Participation on the JRC to oversee the research and development activities was determined to be quantitatively and qualitatively immaterial and therefore is excluded from performance obligations. As such, the Company determined that the license and research and development services should be combined into a single performance obligation. The Company evaluated the milestone payments, which represent customer options as described above, and the option to purchase IBDCo, to determine whether they provide AbbVie with any material rights. The Company concluded that the options were not issued at a significant and incremental discount, and therefore do not provide material rights. As such, they were excluded as performance obligations at the outset of the arrangement. If AbbVie elects to exercise the options, the additional consideration will be added to the transaction price and allocated to the resulting performance obligations. Based on these assessments, the Company identified one performance obligation at the outset of the AbbVie Agreement, which consists of: (1) the non-exclusive license and (2) the research and development activities through the first research and development phase. At the outset of the arrangement, the transaction price included only the $2.0 million up-front consideration received . The option exercise fees ($16.5 million for the milestones and the IBDCo purchase option exercise fee) that may be received are excluded from the transaction price until each customer option is exercised. The Company reevaluates the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, and, if necessary, adjust its estimate of the transaction price. In May 2017, the Company completed the research and development services for the first phase of the research plan and was paid $2.0 million to commence the second phase of the research plan. At this time, the $2.0 million was added to the transaction price and allocated to a new performance obligation consisting of the underlying license and research and development services to be performed over the second phase of the research plan. On September 27, 2018, AbbVie and the Company signed an amendment (the “Amendment”) to the AbbVie Agreement. The Amendment clarified the requirements necessary to complete the second phase which resulted in additional time and effort in the second phase of the research plan. Additionally, the Amendment split the next milestone payment under the AbbVie Agreement into two payments: a milestone payment of $2.0 million earned by the Company upon execution of the Amendment and the remaining milestone payment of the balance due upon the successful achievement of specified research and pre-clinical events and the advancement to the third phase of the research plan. On December 18, 2018, AbbVie and the Company signed an amendment (the “Third Amendment”) to the AbbVie Agreement. The Third Amendment provides that in the event AbbVie determines that it is necessary to enter into license agreements with certain third parties in a particular country or other jurisdiction which, but for such license, would be infringed by the manufacture, use or sale of any product governed by the AbbVie Agreement, AbbVie would be entitled to deduct certain expenses related to such license agreements from particular payments made to the Company. The Company determined that the Amendment represented a modification to the AbbVie Agreement. The additional research and development services are not distinct from the remaining research and development services under the second phase of the research plan of the AbbVie Agreement. The Amendment was accounted for as part of the original AbbVie Agreement and the services form part of the single performance obligation that was partially satisfied as of the date of the contract modification. As a result, the transaction price for the current performance obligation associated with the second phase of the research plan increased by $2.0 million. The impact of the contract modification on the transaction price and the measure of progress toward completion of the performance obligation was recognized as an adjustment to revenue upon execution of the Amendment on a cumulative catch-up basis. On February 28, 2019, the JRC concluded that the remaining milestone of $2.5 million under the Second Amendment was achieved upon the achievement of specified research and pre-clinical events under the second phase of the research plan and the advancement to the third phase of the research plan. For the three months ended September 30, 2019 and 2018, the Company recognized revenue of $0.3 nine months ended September 30, 2019

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Loss per Share	( 10 ) Net Loss per Share Basic net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed using the sum of the weighted-average number of shares of common stock outstanding during the period and if dilutive, the weighted-average number of potential shares of common stock, including unvested restricted common stock and outstanding stock options. In June 2019, the Company sold 6,340,771 shares of common stock and Pre-Funded Warrants to purchase an aggregate of 2,548,117 shares of common stock at an exercise price of $9.00 per share, with $8.99 of such exercise price paid at the closing of the offering (see Note 7). The shares of common stock into which the warrants may be exercised are considered outstanding for the purposes of computing net loss per share. The Company computed basic and diluted net loss per share using the two-class method, which gives effect to the impact of outstanding participating securities. As the three and nine months ended September 30, 2019 and 2018 resulted in net losses attributable to common stockholders, there is no income allocation required under the two-class method or dilution attributed to weighted-average shares outstanding in the calculation of diluted net loss per share because the preferred stockholders do not participate in losses of the Company. Accordingly, for 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 stock are not assumed to have been issued if their effect is anti-dilutive. The Company’s potentially dilutive shares, which include outstanding stock options and unvested restricted common stock/units, are considered to be common share equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of the diluted net loss per share attributable to common stockholders for the period indicated because including them would have had an anti-dilutive effect. As of September 30, 2019 2018 Unvested restricted common stock awards 620,637 203,063 Outstanding options to purchase common stock 2,401,999 1,654,656

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	( 11 ) Commitments and Contingencies In the ordinary course of business, the Company may be subject to legal proceedings, claims and litigation as the Company operates in an industry susceptible to patent legal claims. The Company accounts for estimated losses with respect to legal proceedings and claims when such losses are probable and estimable. Legal costs associated with these matters are expensed when incurred. The Company is not currently a party to any material legal proceedings. In July 2017, the Company entered into an agreement to lease approximately 41,346 square feet of laboratory and office space at 301 Binney Street in Cambridge, Massachusetts. Annual rent is approximately $3.2 million. The ten-year lease commenced in January 2018 and contains provisions for a free-rent period, annual rent increases and an allowance for tenant improvements. Additionally, we have paid for a tenant improvement investment of approximately $1.6 million. The Company was determined to be the accounting owner and recorded tenant improvements as leasehold improvements which reduce the initial measurement of the ROU asset. In conjunction with the lease, we established a letter of credit of approximately $1.0 million. Variable payments based on our portion of the operating expenses, including real estate taxes and insurance, are recorded as a period expense when incurred. The Company has an option to extend the term by five years and an option to terminate the agreement if a similar agreement is executed with the landlord or an affiliate of the landlord. Neither option is reasonably certain of exercise and are excluded from the lease liability calculation. On December 7, 2018, Synlogic Operating Company, Inc., a wholly-owned subsidiary of Synlogic, Inc., entered into a Statement of Work (the “SOW”) with Azzur Group, LLC (“Azzur”) pursuant to a Master Contract Services Agreement (the “Master Services Agreement”), dated September 8, 2018, between the Company and Azzur. Pursuant to the SOW, Azzur has agreed to provide the Company with access to, and the use of, an approximately 700 square foot cleanroom space to be constructed in Waltham, Massachusetts (the “Azzur Suite”), for a period of 44 months, from May 1, 2019 to December 31, 2022 (the “Term”). Azzur has also agreed to provide the Company with storage space and personnel support at the Azzur Suite. The total estimated project cost during the Term for access to, and use of, the cleanroom and storage space, and the personnel support and other services, is up to $4.8 million. The Company may terminate the SOW on four months’ prior written notice at any time during the Term. In addition, either party may terminate the Master Services Agreement (including the SOW) due to a breach by the other party and failure to cure. The Company is reasonably certain not to exercise the termination option through December 31, 2022. Therefore, the Company used a term of May 1, 2019 through December 31, 2022 for purposes of the calculation of the ROU asset and lease liability. The Company’s estimate of the termination date changed between the reporting periods for June 30, 2019 to September 2019 from June 30, 2021 to December 31, 2022, respectively. The change estimate increased the ROU asset and long-term lease liability by $1.1 million and $1.2 million, respectively, the current lease liability was decreased by $0.1 million. The operating lease right-of-use assets and operating lease liabilities represent the Binney Street and Azzur leases. Finance leases are made up of laboratory and office equipment. Cash paid for amounts included in the present value of operating lease liabilities were $1.0 million and $2.7 million during the three and nine months ended September 30, 2019, respectively, which is included in operating cash flows. The components of lease cost for operating and finance leases were (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, Operating leases 2019 Operating lease cost $ 907 $ 2,437 Short-term lease cost 2 160 Variable lease cost 268 794 1,177 3,391 Finance leases Depreciation on finance leases 47 141 Interest on finance leases 5 17 52 158 Total lease cost $ 1,229 $ 3,549 The right-of-use asset for the operating leases is disclosed on the consolidated balance sheet. The right-of-use asset for finance leases are classified within property and equipment, net. The total right-of-use asset for finance leases is $0.9 million. The weighted average remaining lease term and the weighted average discount rate for operating and finance leases at September 30, 2019 was: Operating Lease Finance Leases Weighted average discount rate 8.0 % 6.0 % Weighted average remaining lease term (years) 8.4 1.3 The following table reconciles the undiscounted cash flows for the operating and finance leases at September 30, 2019 to the operating and finance lease liabilities recorded on the balance sheet: Maturity of lease liabilities Operating Leases Finance Leases (in thousands) 2019 $ 1,003 $ 72 2020 3,892 214 2021 4,236 2 2022 4,389 — 2023 3,574 — Thereafter 18,067 — Total lease payments 35,161 288 Less: imputed interest 9,851 10 Total lease liabilities $ 25,310 $ 278 Current lease liabilities 1,925 258 Long-term lease liabilities 23,385 20 The aggregate future lease payments for operating and capital leases as of December 31, 2018 are as follows: Operating Lease Finance Leases (in thousands) 2019 $ 3,175 $ 287 2020 3,270 214 2021 3,369 2 2022 3,470 — 2023 3,574 — Thereafter 18,067 — Total future minimum lease payments $ 34,925 $ 503 Less amounts representing interest 27 Capital lease obligations at December 31, 2018 476 Less current portion of capital lease obligations 266 Capital lease obligations, net of current portion $ 210

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	(12) Related Party Transactions In June 2019, the Company issued to Ginkgo an aggregate of 6,340,771 shares of common stock at a purchase price per share of $9.00, and Pre-Funded Warrants to purchase an aggregate of 2,548,117 shares of common stock at an exercise price of $9.00 per share, with $8.99 of such exercise price paid at the closing of the offering. The net proceeds to the Company were approximately $79.9 million. The Pre-Funded Warrants may be exercised at any time until all of the Pre-Funded Warrants are exercised in full to the extent that, after giving effect to such issuance after exercise, Ginkgo would not beneficially own in excess of 19.99% of the number of shares of common stock outstanding immediately after giving effect to the issuance. See Note 7 for further details of the transaction. In 2017, the Company established a technology collaboration with Ginkgo, to enable the discovery of new living medicines. In June 2019 the Company expanded its collaboration and entered into an agreement with Ginkgo for the research and development of engineered microbial therapeutic products. Under the agreement the Company made a prepayment to Ginkgo of $30.0 million for its foundry services that will be provided to the Company over an initial term of five years. At September 30, 2019, the Company had remaining balances of $9.2 million and $20.5 million of current and non-current pre-paid research and development related to this transaction. Upon the expiration of such initial term and, if applicable, such additional period, any portion of the prepayment that has not been used to purchase services from Ginkgo will be retained by Ginkgo. For the three and nine months ended September 30, 2019, the Company used $0.3 million of the pre-paid research and development expenses.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Event	(13) Subsequent Event On October 21, 2019, the Company appointed Gregg Beloff as Interim Chief Financial Officer, principal accounting officer and principal financial officer while it commenced a search for a successor to its prior Chief Financial Officer, Todd Shegog. Mr. Beloff is the co-founder and Managing Director of Danforth Advisors, LLC. Mr. Beloff has more than 20 years of experience in the life science industry, ranging from venture-backed start-ups to publicly traded companies. Mr. Beloff’s prior experience includes serving as CFO of several public and privately held companies, during which time he managed finance, accounting, corporate communications, human resources, IT, facilities, legal, IP, business development and manufacturing functions. He holds a BA from Middlebury College, JD from the University of Pittsburgh School of Law and an MBA from Carnegie Mellon University.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements and the related disclosures as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and the rules and regulations of the SEC for interim financial statements. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. These interim consolidated financial statements should be read in conjunction with the Company’s 2018 and 2017 audited consolidated financial statements and notes included in the Company’s 2018 Annual Report. The December 31, 2018 consolidated balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments, consisting of normal and recurring adjustments, necessary for the fair presentation of the Company’s financial position and results of operations for the three and nine months ended September 30, 2019 and 2018. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or any other interim period or future year or period.
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of Synlogic and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 – Leases (Topic 842), which replaces the existing accounting guidance for leases. This standard requires entities that lease assets to recognize the assets and liabilities for the rights and obligations created by those leases on the balance sheet. The standard is effective for fiscal years and the interim periods within those fiscal years beginning after December 15, 2018. The guidance is required to be applied by the modified retrospective transition approach and early adoption is permitted. In July 2018, the FASB issued ASU 2018-11 Leases – Targeted Improvements, intended to ease the implementation of the new lease standard for financial statement preparers by, among other things, allowing for an additional transition method. In lieu of presenting transition requirements to comparative periods, as previously required, an entity may now elect to show a cumulative effect adjustment on the date of adoption without the requirement to recast prior period financial statements or disclosures presented in accordance with ASU 2016-02. The Company adopted the new standard using the cumulative effect adjustment transition option effective January 1, 2019, which is the initial date of application per ASU 2018-11. The Company elected the available package of practical expedients which allows the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of our leases, and the treatment of initial direct costs. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. T he Company adopted ASU 2016-02: Leases (Topic 842) as of January 1, 2019. The Company uses judgement to assess if an arrangement is a lease at contract inception. An arrangement is a lease if the contract involves the use of a distinct identified asset, the lessor does not have substantive substitution rights and the Company obtains control of the asset throughout the period by obtaining substantially all of the economic benefit of the asset and the right to direct the use of the asset. Leases classified as operating leases are included in operating lease right-of-use (ROU) assets, current operating lease liabilities and noncurrent operating lease liabilities in our consolidated balance sheet. Finance leases are included in property and equipment and finance lease obligations, in our consolidated balance sheet. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. The Company utilizes its incremental borrowing rate to determine the present value of lease payments. The incremental borrowing rate is the rate incurred to borrow similar funds, on a collateralized basis, over a comparable term in a similar economic environment. For new and amended leases beginning in 2019 and after, the Company has elected to account for the lease and non-lease components for leases as a single component for classes of all underlying assets and allocate all of the contract consideration to the lease component only. Lease cost for operating leases is recognized on a straight-line basis over the lease term and is included in operating expenses on the statements of operations and comprehensive loss. Variable lease payments are included in lease operating expenses. The lease term includes options to extend the lease when it is reasonably certain that option will be exercised. Leases with a term of 12 months or less are not recorded on the Company’s consolidated balance sheet. The adoption had a material impact on the consolidated balance sheet related to the recognition of a transition adjustment on January 1, 2019 of a right-of-use asset of $15.9 million and lease liability of $24.0 million for an operating lease and the derecognition of deferred rent originally accounted for under legacy guidance. The adoption did not have a material impact on the consolidated statement of operations. The Company has designed and implemented changes to related processes, controls and disclosures. Refer to the Commitments and Contingencies footnote for further information on the adoption of this standard and the Company’s accounting for leases. In February 2018, the FASB issued ASU 2018-02 – Income Statement – Reporting Comprehensive Income (Topic 220), which provides amended guidance on income tax accounting. The amended guidance permits the reclassification of the income tax effect on amounts recorded within other comprehensive income impacted by the Tax Cuts and Jobs Act (the “TCJA”) into retained earnings. The amended guidance is effective for periods beginning after December 15, 2018 and applies only to those amounts remaining in other comprehensive income at the date of enactment of the TCJA. The amended guidance may be adopted on either a retrospective basis or at the beginning of the period of adoption. The amended standard had an immaterial impact on the Company’s consolidated financial statements and as such the Company did not reclassify the income tax effects of the TCJA from other comprehensive income to retained earnings. In June 2018, the FASB issued ASU 2018-07- Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of ASC 606. The standard expands the scope of ASC 718 to include all share-based payment arrangements related to the acquisition of goods and services from both nonemployees and employees. Under the amended guidance, equity-classified share-based payment awards issued to nonemployees will be measured at grant date fair value. Upon transition, the entity is required to remeasure these nonemployee awards at fair value as of the adoption date. The Company adopted the new guidance on January 1, 2019 which had an immaterial impact on its consolidated financial statements.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13 - Fair Value Measurement - Disclosure Framework (Topic 820). The standard modifies the disclosure requirements for fair value measurements. The standard is effective for public companies for annual and interim periods beginning after December 15, 2019. Early adoption is permitted for any removed or modified disclosures. Management is currently assessing the impact adoption will have on the Company, but it is not expected to have a material impact on the Company’s financial statement disclosures. In August 2018, the FASB issued ASU 2018-15 - Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract. The standard requires implementation costs incurred by customers in cloud computing arrangements to be deferred over the noncancelable term of the cloud computing arrangements plus any optional renewal periods (1) that are reasonably certain to be exercised by the customer or (2) for which exercise of the renewal option is controlled by the cloud service provider. The effective date of this pronouncement is for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, and early adoption is permitted. The standard can be adopted either using the prospective or retrospective transition approach. The Company is currently evaluating the impact of this standard on the Company's consolidated financial statements and disclosures. In November 2018, the FASB issued ASU 2018-18 - Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606, which, among other things, provides guidance on how to assess whether certain collaborative arrangement transactions should be accounted for under Topic 606. The amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the impact of this standard on the Company’s consolidated financial statements.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Company's Classified Assets Measured at Fair Value on Recurring Basis	At September 30, 2019 and December 31, 2018, the Company has classified assets measured at fair value on a recurring basis as follows (in thousands): Fair Value Measurements at September 30, 2019 September 30, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description 2019 (Level 1) (Level 2) (Level 3) Money market funds (included in cash and cash equivalents) $ 16,691 $ 16,691 $ — $ — Commercial paper (included in short-term investments) 36,205 — 36,205 — Corporate debt securities (included short-term investments) 56,603 — 56,603 — Corporate debt securities (included in long-term investments) 17,388 — 17,388 — U.S. government agency securities and treasuries (included in long-term investments) 1,008 — 1,008 — Total $ 127,895 $ 16,691 $ 111,204 $ — Fair Value Measurements at December 31, 2018 December 31, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description 2018 (Level 1) (Level 2) (Level 3) Money market funds (included in cash and cash equivalents) $ 265 $ 265 $ — $ — Commercial paper (included in short-term investments) 57,453 — 57,453 — Corporate debt securities (included in short-term investments) 50,052 — 50,052 — U.S. government agency securities and treasuries (included in short-term investments) 3,972 1,987 1,985 — Total $ 111,742 $ 2,252 $ 109,490 $ —

Available-for-Sale Investments

Available-for-Sale Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Summary of Available-for-Sale Securities Held	The following tables summarize the available-for-sale securities held at September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 Amortized cost Gross unrealized gains Gross unrealized losses Fair Value Commercial paper $ 36,175 $ 30 $ — $ 36,205 Corporate debt securities 73,909 86 (4 ) 73,991 U.S. government agency securities 1,006 2 — 1,008 Total $ 111,090 $ 118 $ (4 ) $ 111,204 December 31, 2018 Amortized cost Gross unrealized gains Gross unrealized losses Fair Value Commercial paper $ 53,549 $ — $ (47 ) $ 53,502 Corporate debt securities 54,022 4 (23 ) 54,003 U.S. government agency securities 3,971 1 — 3,972 Total $ 111,542 $ 5 $ (70 ) $ 111,477

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): September 30, December 31, 2019 2018 Laboratory equipment $ 7,467 $ 7,111 Computer and office equipment 840 781 Furniture and fixtures 413 413 Leasehold improvements 9,514 9,484 Construction in progress 72 39 18,306 17,828 Less accumulated depreciation (5,017 ) (2,987 ) $ 13,289 $ 14,841

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): September 30, December 31, 2019 2018 Payroll related $ 2,116 $ 2,906 Professional fees 427 306 Research and development 1,322 1,585 Other 163 196 $ 4,028 $ 4,993

Equity-based Compensation and_2

Equity-based Compensation and Equity Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Schedule of Restricted Common Stock Activity	The following table shows restricted stock activity during the nine months ended September 30, 2019: Restricted stock awards Grant date Number of fair value shares (per share) Unvested at December 31, 2018 118,679 $ 13.54 Granted 585,600 2.49 Vested (46,606 ) 13.53 Forfeited (37,036 ) 13.53 Unvested at September 30, 2019 620,637 $ 3.12
Schedule of Equity-based Compensation Expenses	The following table summarizes equity‑based compensation expense within the Company’s consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2019 and 2018 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 353 $ 386 $ 986 $ 1,115 General and administrative 716 645 2,108 2,330 $ 1,069 $ 1,031 $ 3,094 $ 3,445
Schedule of Equity-based Compensation Expenses by Award Type	The following table summarizes equity‑based compensation expense by type of award for the three and nine months ended September 30, 2019 and 2018 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock options $ 1,026 $ 890 $ 2,999 $ 2,500 Restricted stock awards 43 141 95 945 $ 1,069 $ 1,031 $ 3,094 $ 3,445
2015 and 2017 Plan
Schedule of Stock Option Activity	The following table summarizes stock option activity during the nine months ended September 30, 2019 under the 2015 Plan and the 2017 Plan. Stock options outstanding Weighted Weighted average Aggregate average remaining Intrinsic Number of exercise contractual value (a) options price term (in years) (in thousands) Outstanding at December 31, 2018 1,739,884 $ 11.92 9.0 $ — Granted 1,171,030 8.08 Exercised — Forfeited (508,915 ) 11.76 25 Outstanding at September 30, 2019 2,401,999 10.08 8.8 $ — Vested or expected to vest at September 30, 2019 2,401,999 10.08 8.8 — Exercisable at September 30, 2019 805,772 11.86 8.3 $ — (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the options and the fair market value of the underlying common stock for the options that were in the money at September 30, 2019 and December 31, 2018.

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Potentially Common Shares Excluded from Calculation of Net Loss Per share	The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of the diluted net loss per share attributable to common stockholders for the period indicated because including them would have had an anti-dilutive effect. As of September 30, 2019 2018 Unvested restricted common stock awards 620,637 203,063 Outstanding options to purchase common stock 2,401,999 1,654,656

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Components of Lease Cost for Operating and Finance Leases	The components of lease cost for operating and finance leases were (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, Operating leases 2019 Operating lease cost $ 907 $ 2,437 Short-term lease cost 2 160 Variable lease cost 268 794 1,177 3,391 Finance leases Depreciation on finance leases 47 141 Interest on finance leases 5 17 52 158 Total lease cost $ 1,229 $ 3,549
Summary of Weighted Average Remaining Lease Term and Weighted Average Discount Rate for Operating and Finance Leases	The weighted average remaining lease term and the weighted average discount rate for operating and finance leases at September 30, 2019 was: Operating Lease Finance Leases Weighted average discount rate 8.0 % 6.0 % Weighted average remaining lease term (years) 8.4 1.3
Summary of Maturity of Lease Liabilities for Operating and Finance Leases	The following table reconciles the undiscounted cash flows for the operating and finance leases at September 30, 2019 to the operating and finance lease liabilities recorded on the balance sheet: Maturity of lease liabilities Operating Leases Finance Leases (in thousands) 2019 $ 1,003 $ 72 2020 3,892 214 2021 4,236 2 2022 4,389 — 2023 3,574 — Thereafter 18,067 — Total lease payments 35,161 288 Less: imputed interest 9,851 10 Total lease liabilities $ 25,310 $ 278 Current lease liabilities 1,925 258 Long-term lease liabilities 23,385 20
Schedule of Aggregate Future Lease Payments for Operating and Capital Leases	The aggregate future lease payments for operating and capital leases as of December 31, 2018 are as follows: Operating Lease Finance Leases (in thousands) 2019 $ 3,175 $ 287 2020 3,270 214 2021 3,369 2 2022 3,470 — 2023 3,574 — Thereafter 18,067 — Total future minimum lease payments $ 34,925 $ 503 Less amounts representing interest 27 Capital lease obligations at December 31, 2018 476 Less current portion of capital lease obligations 266 Capital lease obligations, net of current portion $ 210

Nature of Business - Additional

Nature of Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Nature Of Business [Line Items]
Cash, cash equivalents, and short-term marketable securities	$ 120,300		$ 120,300
Long-term marketable securities	18,400		18,400
Restricted cash	1,097		1,097		$ 1,097
Accumulated deficit	$ (158,340)		$ (158,340)		$ (119,765)
Common Stock
Nature Of Business [Line Items]
Number of shares sold		6,340,771	6,340,771	9,179,500
Pre-Funded Warrants
Nature Of Business [Line Items]
Warrants to purchase shares of common stock		2,548,117
Warrants exercise price per share		$ 9
Warrants exercise price per share paid at closing of offering		8.99
Ginkgo Bioworks, Inc.
Nature Of Business [Line Items]
Exercise price of warrants, per share	$ 9	9	$ 9
Warrants exercise price per share		$ 9
Proceeds from issuance of common stock and pre-funded warrants	$ 79,900	$ 79,900
Ginkgo Bioworks, Inc. | Common Stock
Nature Of Business [Line Items]
Number of shares sold	6,340,771	6,340,771
Ginkgo Bioworks, Inc. | Pre-Funded Warrants
Nature Of Business [Line Items]
Warrants to purchase shares of common stock	2,548,117	2,548,117	2,548,117
Warrants exercise price per share	$ 9	$ 9	$ 9
Warrants exercise price per share paid at closing of offering	$ 8.99	$ 8.99	$ 8.99

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jul. 31, 2017	Sep. 30, 2019	Jan. 01, 2019
Accounting Policies [Abstract]
Lease, practical expedients, package		true
Lessee, operating lease, existence of option to extend	true	true
Lessee, operating lease, option to extend		options to extend the lease when it is reasonably certain that option will be exercised
Operating lease, right-of-use asset		$ 17,674	$ 15,900
Operating lease, lease liability		$ 25,310	$ 24,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Company's Classified Assets Measured at Fair Value on Recurring Basis (Detail) - Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Asset Measured On Recurring Basis [Line Items]
Total assets	$ 127,895	$ 111,742
Money market funds
Fair Value Asset Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents	16,691	265
Corporate debt securities
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	56,603	50,052
Long-term investments	17,388
Commercial paper
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	36,205	57,453
U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Long-term investments	1,008
U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments		3,972
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Asset Measured On Recurring Basis [Line Items]
Total assets	16,691	2,252
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value Asset Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents	16,691	265
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments		1,987
Significant Other Observable Inputs (Level 2)
Fair Value Asset Measured On Recurring Basis [Line Items]
Total assets	111,204	109,490
Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	56,603	50,052
Long-term investments	17,388
Significant Other Observable Inputs (Level 2) | Commercial paper
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	36,205	57,453
Significant Other Observable Inputs (Level 2) | U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Long-term investments	1,008
Significant Other Observable Inputs (Level 2) | U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments		1,985
Significant Unobservable Inputs (Level 3)
Fair Value Asset Measured On Recurring Basis [Line Items]
Total assets	0	0
Significant Unobservable Inputs (Level 3) | Money market funds
Fair Value Asset Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents	0	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	0	0
Long-term investments	0
Significant Unobservable Inputs (Level 3) | Commercial paper
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments	0	0
Significant Unobservable Inputs (Level 3) | U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Long-term investments	$ 0
Significant Unobservable Inputs (Level 3) | U.S. Government Agency Securities and Treasuries
Fair Value Asset Measured On Recurring Basis [Line Items]
Short-term investments		$ 0

Available-for-Sale Investment_2

Available-for-Sale Investments - Summary of Available-for-Sale Securities Held (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 111,090	$ 111,542
Gross unrealized gains	118	5
Gross unrealized losses	(4)	(70)
Fair Value	111,204	111,477
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	36,175	53,549
Gross unrealized gains	30
Gross unrealized losses		(47)
Fair Value	36,205	53,502
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	73,909	54,022
Gross unrealized gains	86	4
Gross unrealized losses	(4)	(23)
Fair Value	73,991	54,003
U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,006	3,971
Gross unrealized gains	2	1
Fair Value	$ 1,008	$ 3,972

Available-for-Sale Investment_3

Available-for-Sale Investments - Additional Information (Detail) $ in Millions	Sep. 30, 2019USD ($)InvestmentSecurity	Dec. 31, 2018USD ($)Investment
Investments Debt And Equity Securities [Abstract]
Number of investments in unrealized loss position	4	37
Number of investments in unrealized loss position, more than twelve months	0	0
Aggregate fair value of securities in unrealized loss position | $	$ 9.5	$ 96.5
Number of securities with other than temporary impairment | Security	0

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 18,306	$ 17,828
Less accumulated depreciation	(5,017)	(2,987)
Property and equipment, net	13,289	14,841
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	7,467	7,111
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	840	781
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	413	413
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	9,514	9,484
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 72	$ 39

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Payroll related	$ 2,116	$ 2,906
Professional fees	427	306
Research and development	1,322	1,585
Other	163	196
Total accrued expenses	$ 4,028	$ 4,993

Stockholders Equity - Additiona

Stockholders Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Common Stock
Class Of Stock [Line Items]
Number of shares sold		6,340,771	6,340,771	9,179,500
Pre-Funded Warrants
Class Of Stock [Line Items]
Warrants to purchase shares of common stock		2,548,117
Warrants exercise price per share		$ 9
Warrants exercise price per share paid at closing of offering		8.99
Ginkgo Bioworks, Inc.
Class Of Stock [Line Items]
Exercise price of warrants, per share	$ 9	9	$ 9
Warrants exercise price per share		$ 9
Proceeds from issuance of common stock and pre-funded warrants	$ 79.9	$ 79.9
Ginkgo Bioworks, Inc. | Common Stock
Class Of Stock [Line Items]
Number of shares sold	6,340,771	6,340,771
Ginkgo Bioworks, Inc. | Pre-Funded Warrants | Maximum
Class Of Stock [Line Items]
Unbeneficial percentage of ownership after exercise of common stock outstanding effect to issuance			19.99%
Ginkgo Bioworks, Inc. | Pre-Funded Warrants
Class Of Stock [Line Items]
Warrants to purchase shares of common stock	2,548,117	2,548,117	2,548,117
Warrants exercise price per share	$ 9	$ 9	$ 9
Warrants exercise price per share paid at closing of offering	$ 8.99	$ 8.99	$ 8.99

Equity-based Compensation and_3

Equity-based Compensation and Equity Incentive Plans - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee unrecognized compensation expense		$ 8,700		$ 8,700
Employee unrecognized compensation cost, period of recognition				2 years 7 months 6 days
Equity-based compensation expense		1,069	$ 1,031	$ 3,094	$ 3,445
Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee unrecognized compensation expense		1,500		$ 1,500
Employee unrecognized compensation cost, period of recognition				1 year 6 months
Equity-based compensation expense		$ 43	$ 141	$ 95	$ 945
Plan 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares available for issuance (in shares)	1,270,073
2015 and 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants		536,808		536,808

Equity-based Compensation and_4

Equity-based Compensation and Equity Incentive Plans - Schedule of Stock Option Activity Under 2015 and 2017 Plan (Detail) - 2015 and 2017 Plan - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Beginning balance, Number of options	1,739,884
Granted, Number of options	1,171,030
Forfeited, Number of options	(508,915)
Outstanding Ending balance, Number of options	2,401,999	1,739,884
Number of options, Vested or expected to vest	2,401,999
Number of options, Exercisable	805,772
Beginning balance, Weighted-average price	$ 11.92
Granted, Weighted-average price	8.08
Forfeited, Weighted-average price	11.76
Ending balance, Weighted-average price	10.08	$ 11.92
Weighted-average price Vested or expected to vest	10.08
Weighted-average price, Exercisable	$ 11.86
Outstanding, weighted average remaining contractual term (Year)	8 years 9 months 18 days	9 years
Weighted average remaining contractual term, Vested or expected to vest	8 years 9 months 18 days
Weighted average remaining contractual term, Exercisable	8 years 3 months 18 days
Forfeited, Aggregate Intrinsic value	$ 25

Equity-based Compensation and_5

Equity-based Compensation and Equity Incentive Plans - Schedule of Restricted Common Stock Activity (Detail) - Restricted Common Stock	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Beginning balance, Number of unvested shares/units | shares	118,679
Granted, Number of shares/units | shares	585,600
Vested, Number of shares/units | shares	(46,606)
Forfeited, Number of shares/units | shares	(37,036)
Ending balance, Number of unvested shares/units | shares	620,637
Beginning balance, Unvested Grant date fair value | $ / shares	$ 13.54
Granted, Grant date fair value | $ / shares	2.49
Vested, Grant date fair value | $ / shares	13.53
Forfeited, Grant date fair value | $ / shares	13.53
Ending balance, Unvested Grant date fair value | $ / shares	$ 3.12

Equity-based Compensation and_6

Equity-based Compensation and Equity Incentive Plans - Schedule of Equity-based Compensation Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 1,069	$ 1,031	$ 3,094	$ 3,445
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	353	386	986	1,115
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 716	$ 645	$ 2,108	$ 2,330

Equity-based Compensation and_7

Equity-based Compensation and Equity Incentive Plans - Schedule of Equity-based Compensation Expenses by Award Type (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 1,069	$ 1,031	$ 3,094	$ 3,445
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	1,026	890	2,999	2,500
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 43	$ 141	$ 95	$ 945

AbbVie Collaboration Agreement

AbbVie Collaboration Agreement - Additional Information (Detail) $ in Thousands	Dec. 18, 2018USD ($)	Sep. 27, 2018USD ($)Milestone	May 31, 2017USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Feb. 28, 2019USD ($)	Dec. 31, 2018USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognition of revenue					$ 305	$ 1,801	$ 993	$ 2,409
Current deferred revenue					1,775		1,775			$ 268
AbbVie Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of mile stone payments under second phase | Milestone		2
Initial milestone payment upon execution of amendment		$ 2,000
Increase in transaction price of performance obligation of second phase	$ 2,000
Remaining milestone achieved									$ 2,500
Recognition of revenue					300	$ 1,800	1,000	$ 2,400
Current deferred revenue					$ 1,800		1,800
AbbVie Agreement | IBDCo
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront non-refundable payment				$ 2,000
Potential milestone payment							$ 16,500
Collaboration in research and development							54 months
Milestone payment			$ 2,000

Net Loss per Share - Additional

Net Loss per Share - Additional Information (Detail) - $ / shares	1 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Common Stock
Number of shares sold	6,340,771	6,340,771	9,179,500
Pre-Funded Warrants
Warrants to purchase shares of common stock	2,548,117
Warrants exercise price per share	$ 9
Warrants exercise price per share paid at closing of offering	$ 8.99

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Potentially Common Shares Excluded from Calculation of Net Loss Per share (Detail) - shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Unvested Restricted Common Stock Awards
Potentially Common Shares Excluded from Calculation of Net Loss Per share	620,637	203,063
Stock Options
Potentially Common Shares Excluded from Calculation of Net Loss Per share	2,401,999	1,654,656

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Dec. 07, 2018USD ($)ft²	Jul. 31, 2017USD ($)ft²	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Commitments And Contingencies [Line Items]
Laboratory and office space to be leased | ft²		41,346
Operating lease annual rent		$ 3,200,000
Term of lease		10 years
Tenant improvement investment		$ 1,600,000
Letter of credit		$ 1,000,000
Renewal term of lease		5 years
Lessee, operating lease, existence of option to extend		true		true
Lessee, operating lease, existence of option to terminate		true
Cash paid included in operating cash flows			$ 1,000,000	$ 2,700,000
Total right-of-use asset for finance leases			900,000	$ 900,000
Master Services Agreement | Azzur Group, LLC
Commitments And Contingencies [Line Items]
Access and use of space under agreement | ft²	700
Term of agreement	44 months
Agreement expiration date	Dec. 31, 2022
Term of prior terminate written notice	4 months
Increase in ROU asset			1,100,000
Increase in long-term lease liability			1,200,000
Decrease in current lease liability			$ (100,000)
Master Services Agreement | Maximum | Azzur Group, LLC
Commitments And Contingencies [Line Items]
Estimated project costs	$ 4,800,000

Commitments and Contingencies_2

Commitments and Contingencies - Components of Lease Cost for Operating and Finance Leases (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating leases
Operating lease cost	$ 907	$ 2,437
Short-term lease cost	2	160
Variable lease cost	268	794
Operating and variable lease cost	1,177	3,391
Finance leases
Depreciation on finance leases	47	141
Interest on finance leases	5	17
Finance lease cost	52	158
Total lease cost	$ 1,229	$ 3,549

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Weighted Average Remaining Lease Term and Weighted Average Discount Rate for Operating and Finance Leases (Detail)	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating Lease, Weighted average discount rate	8.00%
Operating Lease, Weighted average remaining lease term (years)	8 years 4 months 24 days
Finance Leases, Weighted average discount rate	6.00%
Finance Leases, Weighted average remaining lease term (years)	1 year 3 months 18 days

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Maturity of Lease Liabilities for Operating and Finance Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases
2019	$ 1,003
2020	3,892
2021	4,236
2022	4,389
2023	3,574
Thereafter	18,067
Total lease payments	35,161
Less: imputed interest	9,851
Total lease liabilities	25,310	$ 24,000
Current lease liabilities	1,925
Long-term lease liabilities	23,385
Finance Leases
2019	72
2020	214
2021	2
Total lease payments	288
Less: imputed interest	10
Total lease liabilities	278
Current lease liabilities	258		$ 266
Long-term lease liabilities	$ 20		$ 210

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Aggregate Future Lease Payments for Operating and Capital Leases (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating lease
2019	$ 3,175
2020	3,270
2021	3,369
2022	3,470
2023	3,574
Thereafter	18,067
Total future minimum lease payments	34,925
Capital leases
2019	287
2020	214
2021	2
Total future minimum lease payments	503
Less amounts representing interest	27
Capital lease obligations at December 31, 2018	476
Less current portion of capital lease obligations	266
Capital lease obligations, net of current portion	$ 210

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Common Stock
Related Party Transaction [Line Items]
Number of shares sold		6,340,771		6,340,771	9,179,500
Pre-Funded Warrants
Related Party Transaction [Line Items]
Warrants exercise price per share		$ 9
Warrants to purchase shares of common stock		2,548,117
Warrants exercise price per share paid at closing of offering		$ 8.99
Ginkgo Bioworks, Inc.
Related Party Transaction [Line Items]
Warrants exercise price per share		$ 9
Proceeds from issuance of common stock and pre-funded warrants	$ 79.9	$ 79.9
Prepayment to related party for collaboration agreement		$ 30
Related party transaction collaboration agreement, initial term		5 years
Current Pre-Paid Research and Development	9.2		$ 9.2	$ 9.2
Non Current Pre-Paid Research and Development	$ 20.5		20.5	20.5
Prepaid research and development expenses			$ 0.3	$ 0.3
Ginkgo Bioworks, Inc. | Common Stock
Related Party Transaction [Line Items]
Number of shares sold	6,340,771	6,340,771
Ginkgo Bioworks, Inc. | Pre-Funded Warrants | Maximum
Related Party Transaction [Line Items]
Unbeneficial percentage of ownership after exercise of common stock outstanding effect to issuance				19.99%
Ginkgo Bioworks, Inc. | Pre-Funded Warrants
Related Party Transaction [Line Items]
Warrants exercise price per share	$ 9	$ 9	$ 9	$ 9
Warrants to purchase shares of common stock	2,548,117	2,548,117	2,548,117	2,548,117
Warrants exercise price per share paid at closing of offering	$ 8.99	$ 8.99	$ 8.99	$ 8.99

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail)	Oct. 21, 2019
Minimum | Gregg Beloff | Subsequent Event
Subsequent Event [Line Items]
Work experience	20 years