Arvinas (ARVN) 10-Q 5 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 30, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	ARVN
Entity Registrant Name	ARVINAS, INC.
Entity Central Index Key	0001655759
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-38672
Entity Tax Identification Number	472566120
Entity Address, Address Line One	5 Science Park
Entity Address, Address Line Two	395 Winchester Ave
Entity Address, City or Town	New Haven
Entity Address, State or Province	Connecticut
Entity Address, Postal Zip Code	06511
City Area Code	203
Local Phone Number	535-1456
Entity Common Stock, Shares Outstanding		33,717,343

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 11,342,178	$ 3,190,056
Marketable securities	147,831,005	184,637,640
Account receivable		2,775,831
Other receivables	1,402,085	2,255,966
Prepaid expenses and other current assets	2,685,820	2,818,286
Total current assets	163,261,088	195,677,779
Property, equipment and leasehold improvements, net	6,366,491	3,583,036
Operating lease right of use assets	2,397,789
Other assets	20,760	20,760
Total assets	172,046,128	199,281,575
Current liabilities:
Accounts payable	1,411,471	2,758,184
Accrued expenses	3,998,974	4,001,276
Deferred revenue	14,815,957	16,065,957
Current portion of long-term debt	71,499	154,461
Current portion of operating lease liability	647,872
Total current liabilities	20,945,773	22,979,878
Deferred revenue	30,701,736	37,484,714
Long term debt, net of current portion	2,000,000	2,000,000
Operating lease liability	1,893,359
Other noncurrent liability		150,000
Total liabilities	55,540,868	62,614,592
Commitments and Contingencies
Stockholders’ equity:
Common stock, $0.001 par value; 31,523,474 and 31,235,458 shares issued and outstanding as of June 30, 2019 and December 31, 2018, respectively	31,524	31,236
Accumulated deficit	(333,833,758)	(302,264,619)
Additional paid-in capital	450,007,344	439,118,089
Accumulated other comprehensive income (loss)	300,150	(217,723)
Total stockholders’ equity	116,505,260	136,666,983
Total liabilities and stockholders’ equity	$ 172,046,128	$ 199,281,575

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common Stock Par Or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock Shares Issued	31,523,474	31,235,458
Common Stock Shares Outstanding	31,523,474	31,235,458

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue	$ 4,016,489	$ 3,399,895	$ 8,032,979	$ 7,508,491
Operating expenses:
Research and development	16,000,638	10,337,835	30,190,996	17,481,652
General and administrative	6,440,779	1,579,605	12,081,409	2,826,492
Total operating expenses	22,441,417	11,917,440	42,272,405	20,308,144
Loss from operations	(18,424,928)	(8,517,545)	(34,239,426)	(12,799,653)
Other income (expenses)
Other income, net	191,729	130,945	434,850	258,394
Change in fair value of preferred unit warrant	0	2,516	0	(193,779)
Interest income	1,091,331	539,413	2,281,853	750,650
Interest expense	(22,778)	(9,871)	(46,416)	(20,540)
Total other income	1,260,282	663,003	2,670,287	794,725
Net loss	(17,164,646)	(7,854,542)	(31,569,139)	(12,004,928)
Change in fair value of redeemable convertible preferred units	0	(14,834,049)	0	(86,316,147)
Net loss attributable to common shares/units	$ (17,164,646)	$ (22,688,591)	$ (31,569,139)	$ (98,321,075)
Net loss per common share/unit, basic and diluted	$ (0.55)	$ (11.96)	$ (1.01)	$ (51.81)
Weighted average common shares/units outstanding, basic and diluted	31,440,051	1,897,544	31,408,658	1,897,544

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (17,164,646)	$ (7,854,542)	$ (31,569,139)	$ (12,004,928)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	220,119	(28,831)	517,873	(86,863)
Comprehensive loss	$ (16,944,527)	$ (7,883,373)	$ (31,051,266)	$ (12,091,791)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Redeemable Convertible Preferred Units/Shares and Changes in Members'/Stockholders' Equity (unaudited) - USD ($)	Total	Accumulated Deficit	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Series A Redeemable Convertible Preferred Units	Series B Redeemable Convertible Preferred Units	Series C Redeemable Convertible Preferred Units	Common UnitsMember Units	Common Shares	Incentive UnitsMember Units
Balance at Dec. 31, 2017					$ 19,768,025	$ 41,712,407
Balance, Units/Shares at Dec. 31, 2017					22,463,665	24,977,489
Balance at Dec. 31, 2017	$ (61,234,562)	$ (62,417,397)		$ (9,751)				$ 6,167		$ 1,186,419
Balance, Units at Dec. 31, 2017								1,897,544		3,669,963
Incentive unit-based compensation	1,126,603									$ 1,126,603
Incentive unit-based compensation, Units/Shares										1,669,110
Issuance of Series C redeemable convertible preferred units							$ 55,000,001
Issuance of Series C redeemable convertible preferred units, Units							16,467,066
Net loss	(12,004,928)	(12,004,928)
Change in redemption value of redeemable convertible preferred units	(86,316,147)	(86,316,147)			$ 46,050,513	$ 37,466,233	$ 2,799,401
Unrealized gain (loss) on available-for-sale securities	(86,863)			(86,863)
Balance at Jun. 30, 2018					$ 65,818,538	$ 79,178,640	$ 57,799,402
Balance, Units/Shares at Jun. 30, 2018					22,463,665	24,977,489	16,467,066
Balance at Jun. 30, 2018	(158,515,897)	(160,738,472)		(96,614)				$ 6,167		$ 2,313,022
Balance, Units/Shares at Jun. 30, 2018								1,897,544		5,339,073
Balance at Mar. 31, 2018					$ 59,528,712	$ 73,433,818
Balance, Units/Shares at Mar. 31, 2018					22,463,665	24,977,489
Balance at Mar. 31, 2018	(136,778,348)	(138,049,881)		(67,783)				$ 6,167		$ 1,333,149
Balance, Units at Mar. 31, 2018								1,897,544		3,829,223
Incentive unit-based compensation	979,873									$ 979,873
Incentive unit-based compensation, Units/Shares										1,509,850
Issuance of Series C redeemable convertible preferred units							$ 55,000,001
Issuance of Series C redeemable convertible preferred units, Units							16,467,066
Net loss	(7,854,542)	(7,854,542)
Change in redemption value of redeemable convertible preferred units	(14,834,049)	(14,834,049)			$ 6,289,826	$ 5,744,822	$ 2,799,401
Unrealized gain (loss) on available-for-sale securities	(28,831)			(28,831)
Balance at Jun. 30, 2018					$ 65,818,538	$ 79,178,640	$ 57,799,402
Balance, Units/Shares at Jun. 30, 2018					22,463,665	24,977,489	16,467,066
Balance at Jun. 30, 2018	(158,515,897)	(160,738,472)		(96,614)				$ 6,167		$ 2,313,022
Balance, Units/Shares at Jun. 30, 2018								1,897,544		5,339,073
Balance at Dec. 31, 2018	136,666,983	(302,264,619)	$ 439,118,089	(217,723)					$ 31,236
Balance, Units at Dec. 31, 2018									31,235,458
Stock-based compensation	10,490,055		10,490,055
Net loss	(31,569,139)	(31,569,139)
Restricted stock vesting			(263)						$ 263
Restricted stock vesting, Shares									263,048
Proceeds from exercise of stock options	399,488		399,463						$ 25
Proceeds from exercise of stock options, Shares									24,968
Unrealized gain (loss) on available-for-sale securities	517,873			517,873
Balance at Jun. 30, 2019	116,505,260	(333,833,758)	450,007,344	300,150					$ 31,524
Balance, Units/Shares at Jun. 30, 2019									31,523,474
Balance at Mar. 31, 2019	127,737,692	(316,669,112)	444,295,404	80,031					$ 31,369
Balance, Units at Mar. 31, 2019									31,368,864
Stock-based compensation	5,312,607		5,312,607
Net loss	(17,164,646)	(17,164,646)
Restricted stock vesting			(130)						$ 130
Restricted stock vesting, Shares									129,642
Proceeds from exercise of stock options	399,488		399,463						$ 25
Proceeds from exercise of stock options, Shares									24,968
Unrealized gain (loss) on available-for-sale securities	220,119			220,119
Balance at Jun. 30, 2019	$ 116,505,260	$ (333,833,758)	$ 450,007,344	$ 300,150					$ 31,524
Balance, Units/Shares at Jun. 30, 2019									31,523,474

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (31,569,139)	$ (12,004,928)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of debt discount	8,982	4,491
Change in fair value of preferred unit warrant liability	0	193,779
Depreciation and amortization	556,619	291,504
Net accretion of bond discounts/premiums	(88,852)	117,583
Amortization of right to use assets	366,610	0
Non-cash compensation	10,490,055	1,126,603
Changes in operating assets and liabilities:
Account receivable	2,775,831	25,000,000
Other receivables	853,881	(921,973)
Prepaid expenses and other current assets	(17,534)	(1,674,044)
Accounts payable	(1,419,457)	1,060,051
Accrued expenses	(2,302)	(1,561,132)
Deferred revenue	(8,032,978)	(4,508,491)
Operating lease liabilities	(223,168)	0
Net cash provided by (used in) operating activities	(26,301,452)	7,123,443
Cash flows from investing activities:
Purchase of marketable securities	(37,852,640)	(106,321,225)
Maturities of marketable securities	75,266,000	17,989,000
Purchase of property, equipment and leasehold improvements	(3,267,330)	(1,270,222)
Net cash provided by (used in) investing activities	34,146,030	(89,602,447)
Cash flows from financing activities:
Repayments of long-term debt	(91,944)	(80,829)
Proceeds from sale of redeemable convertible preferred units	0	55,000,001
Proceeds from exercise of stock options	399,488	0
Net cash provided by financing activities	307,544	54,919,172
Net increase in cash and cash equivalents	8,152,122	(27,559,832)
Cash and cash equivalents, beginning of the period	3,190,056	30,912,391
Cash and cash equivalents, end of the period	11,342,178	3,352,559
Supplemental disclosure of cash flow information:
Purchases of property, equipment and leasehold improvements unpaid at period end	72,744	0
Cash paid for interest	37,434	11,558
Change in fair value of redeemable convertible preferred units	$ 0	$ (86,316,147)

Nature of Business

Nature of Business	6 Months Ended
	Jun. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Arvinas, Inc. and subsidiaries (the Company) is a biopharmaceutical company dedicated to improving the lives of patients suffering from debilitating and life-threatening diseases throughout the discovery, development and commercialization of therapies to degrade disease-causing proteins. The Company expects to incur additional operating losses and negative operating cash flows for the foreseeable future. On October 1, 2018, the Company completed an initial public offering (IPO) in which the Company issued and sold 7,500,000 shares On October 1, 2018, all of the outstanding shares of convertible preferred stock automatically converted into 19,697,928 shares of common stock at the applicable conversion ratio then in effect. Subsequent to the closing of the IPO, there were no shares of preferred stock outstanding.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Unaudited Interim Financial Statements The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and pursuant to the rules and regulations of the Securities and Exchange Commission. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but does not include all disclosures required by U.S. GAAP. These condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the years ended December 31, 2018 and 2017 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on March 26, 2019 (the Annual Report). The condensed consolidated financial statements, in the opinion of management, reflect all normal and recurring adjustments necessary for a fair statement of the Company’s financial position and results of operations. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases In June 2018, the FASB issued ASU No. 2018-07 , Improvements in Nonemployee Share-Based Payment Accounting The Company adopted ASU 2018-07 in the first quarter of 2019. During the three months ended June 30, 2019, there were no other changes to the Company’s significant accounting policies as described in Note 2 to the financial statements included in the Company’s condensed consolidated financial statements as of December 31, 2018 and 2017 and for the years then ended included in the Annual Report.

Research Collaboration and Lice

Research Collaboration and License Agreements	6 Months Ended
	Jun. 30, 2019
Research Collaboration And License Agreements [Abstract]
Research Collaboration and License Agreements	3. Research Collaboration and License Agreements In December 2017, the Company entered into a Research Collaboration and License Agreement with Pfizer, Inc. (Pfizer) (the Pfizer Agreement). Under the terms of the Pfizer Agreement, the Company received an upfront non-refundable payment and certain additional payments totaling $28.0 million in 2018 in exchange for use of the Company’s technology license and to fund Pfizer-related research as defined within the agreement. These payments are being recognized as revenue over the total estimated period of performance. The Company is also eligible to receive up to an additional $37.5 million in non-refundable option payments if Pfizer exercises its options for all targets under the agreement. Pfizer exercised an option for $2.5 million in December 2018 and the amount was included in accounts receivable at December 31, 2018. The option will be recognized as revenue over the estimated period of performance. In September 2015, the Company entered into an Option and License Agreement with Genentech, Inc. and F. Hoffman-La Roche Ltd. (together, Genentech) (the Genentech Agreement). During 2015, the Company received an upfront non-refundable payment of $11.0 million in exchange for use of the Company’s technology license and to fund Genentech-related research as defined within the Genentech Agreement. In November 2017, the Company entered into an Amended and Restated Option, License, and Collaboration Agreement with Genentech, Inc. and F. Hoffman-La Roche Ltd. (the Genentech Modification), amending the Genentech Agreement. Under the Genentech Modification, the Company received additional upfront non-refundable payments of $34.5 million to fund Genentech-related research and Genentech has the right to designate up to ten targets. The Company is eligible to receive up to $27.5 million in additional expansion target payments if Genentech exercises its options on all remaining targets. Upfront non-refundable payments are recognized as revenue over the total estimated period of performance. The Company is eligible to receive up to $44.0 million per target in development milestone payments, $52.5 million in regulatory milestone payments and $60.0 million in commercial milestones based on sales thresholds as well as tiered royalties based on sales. Information about contract liabilities is as follows: June 30, December 31, 2019 2018 Contract liabilities $ 45,517,693 $ 53,550,671 Revenues recognized in the period from: Amounts included in deferred revenue in previous periods $ 8,032,979 $ 13,553,136 Changes in deferred revenue from December 31, 2018 to June 30, 2019 were due to $8.0 million of revenue recognized on the research collaboration and license agreements. The aggregate amount of the transaction price allocated to performance obligations that are unsatisfied as of June 30, 2019 was $45.5 million, which is expected to be recognized as revenue for the years ending December 31 are: Remainder of 2019 $ 8.0 2020 13.6 2021 13.5 2022 8.6 2023 1.8 $ 45.5

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements Accounting Standards Codification (ASC) Topic 820, Fair Value Measurements and Disclosures Financial Instruments Level 1—Inputs are based upon observable or quoted prices for identical instruments traded in active markets. Level 2—Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities. Level 3—Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models, and similar techniques. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. The Company’s marketable securities consist of corporate bonds and a government bond which are adjusted to fair value each balance sheet date, based on quoted prices, which are considered Level 2 inputs. The fair value of the preferred unit warrant liability was measured on a recurring basis and was considered a Level 3 instrument in the fair value hierarchy. See Note 8 for a description and terms of the warrant, the valuation method used and significant assumptions used in the valuation. The following is a summary of the Company’s available-for-sale securities as of June 30, 2019 and December 31, 2018: June 30, 2019 Gross Gross Description Effective Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value Corporate bonds 2019-2020 $ 128,081,144 178,163 — $ 128,259,307 Government bonds 2019 2,984,544 7,956 — 2,992,500 Corporate bonds 2020 16,465,166 114,032 — 16,579,198 $ 147,530,854 $ 300,151 $ — $ 147,831,005 December 31, 2018 Gross Gross Description Effective Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value Corporate bonds 2019 $ 154,859,427 — (165,630 ) $ 154,693,797 Government bonds 2019 2,966,262 2,778 — 2,969,040 Corporate bonds 2020 27,029,673 — (54,870 ) 26,974,803 $ 184,855,362 2,778 (220,500 ) $ 184,637,640 The following tables summarize the fair values and levels within the fair value hierarchy in which the fair value measurements fall for assets and liabilities measured on a recurring basis: June 30, 2019 Description Level 1 Level 2 Level 3 Total Assets: Corporate bonds $ — $ 144,838,505 $ — $ 144,838,505 Government bonds $ — $ 2,992,500 $ — $ 2,992,500 December 31, 2018 Description Level 1 Level 2 Level 3 Total Assets: Corporate bonds $ — $ 181,668,600 $ — $ 181,668,600 Government bonds $ — $ 2,969,040 $ — $ 2,969,040

Property, Equipment and Leaseho

Property, Equipment and Leasehold Improvements	6 Months Ended
	Jun. 30, 2019
Property Plant And Equipment [Abstract]
Property, Equipment and Leasehold Improvements	5. Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements consist of the following at: June 30, 2019 December 31, 2018 Laboratory equipment $ 5,968,924 $ 3,757,265 Office equipment 728,821 577,418 Leasehold improvements 1,945,289 981,884 8,643,034 5,316,567 Less: accumulated depreciation and amortization (2,276,543 ) (1,733,531 ) Property, equipment and leasehold improvements, net $ 6,366,491 $ 3,583,036 Depreciation and amortization expense totaled $310,461 and $168,476 for the three months ended June 30, 2019 and 2018, respectively, and $556,619 and $291,504 for the six months ended June 30, 2019 and 2018, respectively.

Right to Use Assets and Liabili

Right to Use Assets and Liabilities	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Right to Use Assets and Liabilities	6. Right to Use Assets and Liabilities The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (ROU) assets and operating lease liabilities in the condensed consolidated balance sheets. 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. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate was 5.1%. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Some of our leases include options to extend or terminate the lease. The Company includes these options in the recognition of the Company’s ROU assets and lease liabilities when it is reasonably certain that the Company will exercise the option. The Company has operating leases for its corporate office and certain equipment, which expire no later than December 31, 2022. The leases have a weighted average remaining term of 3.5 years. Maturities of lease liabilities for the years ending December 31 are: 2019 $ 450,816 2020 839,555 2021 840,498 2022 823,403 Total lease payments 2,954,272 Less: imputed interest (282,895 ) Total $ 2,671,377 The amortization of the ROU assets for the three and six months ended June 30, 2019 was $186,212 and $366,610, respectively. Prior to January 1, 2019, the Company accounted for its leases in accordance with ASC Topic 840, Leases

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	7. Accrued Expenses Accrued expenses consisted of the following at: June 30, 2019 December 31, 2018 Employee expenses $ 2,512,324 $ 2,795,205 Research and development expenses 675,964 357,148 Professional fees and other 810,686 848,923 $ 3,998,974 $ 4,001,276

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	8. Long-Term Debt In August 2013, the Company entered into a Loan Agreement (Loan) and a Stock Subscription Warrant, with Connecticut Innovations, Incorporated (CII). Under the Loan, the Company can draw up to $750,000 for the purpose of purchasing laboratory equipment, information technology equipment and leasehold improvements. Leasehold improvements are limited to $100,000. Interest on the Loan is compounded on a monthly basis at a rate of 7.50% per annum and is required to be paid on a monthly basis beginning on the date of the first draw of funds for 10 months, then with principal payments beginning on June 1, 2015 and payable monthly until the maturity date of July 31, 2019. The Company has the ability to prepay the amount due at any time prior to the maturity date without premium or penalty. The Loan is secured by substantially all of the Company’s assets. As of June 30, 2019 and December 31, 2018, the amount outstanding under the Loan was $77,667 and $169,610, respectively. The Company paid the loan in full in July 2019. At June 30, 2019 and December 31, 2018, the total unamortized debt discount on the Loan totaled $1,030 and $7,210, respectively. Interest expense recorded related to the amortization of the debt discount in each of the six months ended June 30, 2019 and 2018 was $6,180. In connection with the issuance of the Loan, and as additional consideration, the Company granted CII a warrant to purchase 110,116 shares of the Company’s Series A Preferred Stock at a purchase price of $0.6811 per share, with a term of 7 years from the date of issuance (CII Series A Preferred Stock Warrant). Effective January 1, 2015, the CII Series A Preferred Stock Warrant was exchanged for a warrant to purchase 110,116 units of the Company’s Series A redeemable convertible preferred units (CII Series A Preferred Unit Warrant). In July 2018, CII exercised the CII Series A Preferred Unit Warrant. In connection with an Assistance Agreement with the State of Connecticut (Assistance Agreement) entered into in 2014, under which all the borrowings by the Company were forgiven in accordance with the Assistance Agreement, the Company is required to be located in the State of Connecticut through January 2024, with a default penalty of repayment of the full original funding amount of $2.5 million plus liquidated damages of 7.5%. In June 2018, the Company entered into an Assistance Agreement with the State of Connecticut (2018 Assistance Agreement) to provide funding for the expansion and renovation of laboratory and office space (Project). Under the terms of the 2018 Assistance Agreement, the Company could borrow from the State of Connecticut a maximum of $2.0 million, provided that the funding does not exceed more than 50% of the total Project costs. In September 2018, the Company borrowed $2.0 million under the 2018 Assistance Agreement, bearing interest at 3.25% per annum and interest payments will be required for the first 60 months from the funding date. Thereafter, the loan amortizes over the next sixty months, maturing in September 2028. According to the terms of the 2018 Assistance Agreement, up to $1.0 million of the funding thereunder can be forgiven if the Company meets certain employment conditions, as defined therein. The Company may also be required to prepay a portion of the loan if the employment conditions are not met. The 2018 Assistance Agreement requires that the Company be located in the State of Connecticut through June 2028 with a default penalty of repayment of the full original funding amount of $2.0 million plus liquidated damages of 7.5% of the total amount of funding received. Anticipated future minimum payments on long-term debt for the years ending December 31 are: 2019 $ 77,667 2023 92,480 2024 377,516 Beyond 1,530,004 Total $ 2,077,667 During the three months ended June 30, 2019 and 2018, interest expense was $22,778 and $10,669, respectively. During the six months ended June 30, 2019 and 2018, interest expense was $46,416 and $20,540, respectively.

Incentive Equity Plans

Incentive Equity Plans	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Incentive Equity Plans	9. Incentive Equity Plans In the Fourth Amendment to the Company’s Incentive Share Plan (the Incentive Plan) adopted in March 2018, the Company was authorized to issue up to an aggregate of 6,199,477 incentive units pursuant to the Incentive Plan. Generally, incentive units were granted at no less than fair value as determined by the board of managers and had vesting periods ranging from one to four years. The Incentive Plan was terminated in September 2018. In September 2018, the Company’s board of directors adopted and the Company’s stockholders approved the 2018 Stock Incentive Plan (the 2018 Plan), which became effective upon the effectiveness of the registration statement on Form S-1 for the Company’s IPO. The number of common shares initially available for issuance under the 2018 Plan is the sum of (1) 4,067,007 shares of common stock; plus (2) the number of shares of common stock (up to 1,277,181) issued in respect of incentive units granted under the Incentive Plan that are subject to vesting immediately prior to the effectiveness of the registration statement that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase on the first day of each fiscal year beginning with the fiscal year ending December 31, 2019 and continuing to, and including, the fiscal year ending December 31, 2028, equal to the lowest of 4,989,593 shares of the Company’s common stock, 4% of the number of shares of the Company’s common stock outstanding on the first day of the fiscal year and an amount determined by the Company’s board of directors. The increase in the number of authorized shares for the fiscal year ending December 31, 2019 was 1,293,510. During the six months ended June 30, 2019, the Company granted 1,195,988 stock options to purchase shares of common stock to employees and directors at a weighted average fair value of $12.58 per share. During the six months ended June 30, 2019, the Company also granted 176,841 restricted stock units, which vest annually over four years. During the six months ended June 30, 2019, the Company recognized compensation expense of $9,807,362 relating to the issuance of employee and director incentive awards, and at June 30, 2019, there was $19,543,078 of compensation expense that is expected to be amortized over a weighted average period of approximately two years. During the six months ended June 30, 2019, the Company recognized compensation expense of $682,693 relating to incentive share awards for consultants and at June 30, 2019, there was $873,277 of compensation expense remaining to be amortized over a weighted average period of approximately 1.4 years. The fair value of the incentive units granted during the six months ended June 30, 2018 was determined using the Black-Scholes option pricing model with the following assumptions: June 30, 2018 Expected volatility 66.0-71.0% Expected term (years) 5.6-6.1 Risk free interest rate 2.5-2.9% Expected dividend yield 0 % Fair value of underlying common units $1.08-8.48 The fair value of the underlying common units was utilized as the exercise price within the Black-Scholes option pricing model. The fair value of the stock options granted during the six months ended June 30, 2019 was determined using the Black-Scholes option pricing model with the following assumptions: June 30, 2019 Expected volatility 70.2-70.5% Expected term (years) 5.5-7.0 Risk free interest rate 1.9-2.7% Expected dividend yield 0 % Exercise price $17.29-22.25 Given the Company’s common stock has not been trading for a sufficient period of time, the Company utilizes a collection of volatilities of peer companies to estimate the expected volatility of its common stock. The expected term is calculated utilizing the simplified method. The following table provides a summary of the restricted stock grant activity under the Incentive Plan during the six months ended June 30, 2019. These amounts include restricted stock granted to employees, directors and consultants. Shares Weighted Average Grant Date Fair Value Per Share Unvested restricted stock at December 31, 2018 1,102,289 $ 16.00 Vested (263,366 ) $ 16.00 Forfeited (16,246 ) $ 16.00 Unvested restricted stock at June 30, 2019 822,677 $ 16.00 The following table provides a summary of the stock option activity under the 2018 Plan during the six months ended June 30, 2019. These amounts include stock options granted to employees, directors and consultants. Options Weighted Average Fair Value Outstanding at December 31, 2018 2,273,024 $ 9.88 Granted 1,195,988 $ 12.58 Exercised (24,968 ) $ 9.41 Forfeited (39,638 ) $ 10.23 Outstanding at June 30, 2019 3,404,406 $ 10.82 Exercisable at June 30, 2019 802,057 $ 9.75 The following table provides a summary of the restricted stock unit activity under the 2018 Plan during the six months ended June 30, 2019. These amounts include restricted stock units granted to employees. Shares Weighted Average Grant Date Fair Value Per Share Unvested restricted stock units at December 31, 2018 — $ — Granted 176,841 $ 19.36 Unvested restricted stock units at June 30, 2019 176,841 $ 19.36 At June 30, 2019, there were 677,215 restricted shares under the Incentive Plan and 2,984,885 stock options under the 2018 Plan that vested and are expected to vest.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company’s effective tax rate was 0.0% for the six months ended June 30, 2019 and 2018. The primary reconciling items between the federal statutory rate of 21.0% and 34.0% for the six months ended June 30, 2019 and 2018, respectively, and the Company’s overall effective tax rate of 0.0% was the effect of equity compensation and the valuation allowance recorded against the full amount of its net deferred tax assets. Valuation allowance is established when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company is subject to tax in the U.S. Federal jurisdiction and the states of Connecticut and Massachusetts. The Company pays franchise tax in the states mentioned above due to its loss position. As a result, there is no state income tax provision recorded for the six months ended June 30, 2019 and 2018.

Net Loss Per Common Share_Unit

Net Loss Per Common Share/Unit	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Loss Per Common Share/Unit	11. Net Loss Per Common Share/Unit Basic and diluted loss per common share/unit were calculated as follows: For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 Net loss $ (17,164,646 ) $ (7,854,542 ) $ (31,569,139 ) $ (12,004,928 ) Change in redemption value of preferred units — (14,834,049 ) — (86,316,147 ) Net loss attributable to common shares/units—basic and diluted $ (17,164,646 ) $ (22,688,591 ) $ (31,569,139 ) $ (98,321,075 ) Weighted average number of common shares/units outstanding, basic and diluted 31,440,051 1,897,544 31,408,658 1,897,544 Net loss per common share/unit $ (0.55 ) $ (11.96 ) $ (1.01 ) $ (51.81 ) The Company’s potential dilutive securities have been excluded from the computation of diluted net loss per common share/unit as the effect would be to reduce the net loss per common share/unit. The incentive units that converted into restricted shares have been excluded from basic loss per unit given that the incentive units had no obligation to share in losses and have been excluded from dilutive loss per share due to their anti-dilutive effect. The following common share/unit equivalents have been excluded from the calculations of diluted loss per common share/unit because their inclusion would have been antidilutive for the periods ended June 30: 2019 2018 Redeemable convertible preferred units — 19,664,047 Incentive units — 3,829,224 Restricted stock 822,677 — Stock options 3,404,406 — Restricted stock units 176,841 — Preferred unit warrant — 33,881 4,403,924 23,527,152

Related Parties

Related Parties	6 Months Ended
	Jun. 30, 2019
Related Party Transactions [Abstract]
Related Parties	12. Related Parties Dr. Craig Crews, founder of the Company and the Chief Scientific Advisor to the Company, is a common shareholder in the Company and has a consulting agreement with the Company. The Company entered into an amendment to the amended and restated consulting agreement with Professor Crews, which became effective upon the closing of the IPO and continues in effect for three years, until September 26, 2021. Pursuant to the amendment, Professor Crews will be paid $20,833 per month for his services. During the six months ended June 30, 2019 and 2018, the Company paid Professor Crews $125,000 and $75,000, respectively, related to his consulting agreement. In connection with the conversion of incentive units, the Company also granted Professor Crews 235,150 options to purchase common stock at an exercise price of $16.00 per share, vesting over three years. In July 2016, the Company entered into a Corporate Sponsored Research Agreement (SRA) with Yale University (Yale), under the direction of Professor Crews, which was amended in April 2018. The amended SRA extended the agreement until April 2021 and amended the scope of work. The amended SRA requires quarterly payments of $250,000 through the end of the agreement. The total payments made under the SRA for the six months ended June 30, 2019 and 2018 were $500,000 and $351,161, respectively. During the six months ended June 30, 2019 and 2018, the Company also paid Yale $208,774 and $37,473, respectively, for reimbursable patent costs. During the six months ended June 30, 2019, in connection with the Company’s license agreement with Yale, the Company met a milestone triggering a $50,000 payment to Yale upon the initiation of the Phase 1 clinical trial for ARV-110.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events Bayer Collaboration Agreement In June 2019, the Company and Bayer AG (together with its controlled affiliates, Bayer), directly or through one or more wholly owned subsidiaries, entered into a Collaboration and License Agreement (the Collaboration Agreement) setting forth the Company’s collaboration to identify or optimize proteolysis targeting chimeras, or PROTAC® targeted protein degraders, that mediate for degradation of target proteins (Targets), using the Company’s proprietary platform technology, which Targets will be selected by Bayer, subject to certain exclusions and limitations. The Collaboration Agreement became effective in July 2019 upon the occurrence of the JV Closing (as defined below). Under the terms of the Collaboration Agreement , the Company is entitled to receive an aggregate upfront payment of $17.5 million, plus an additional $1.5 million in research funding payments within 30 days following Bayer’s receipt of an invoice therefor after the date of closing. The Company is entitled to receive up to an additional $10.5 million in research funding payments. The Company is also eligible to receive up to $197.5 million in development milestone payments and up to $490.0 million in sales-based milestone payments for all designated Targets. In addition, the Company is eligible to receive, on net sales of PROTAC targeted protein degrader-related products, mid-single digit to low-double digit tiered royalties, which may be subject to reductions. Bayer Joint Venture Also in June 2019, the Company and Bayer entered into a Commitment Agreement (the Commitment Agreement) relating to the formation of a joint venture for the purpose of researching, developing and commercializing PROTAC targeted protein degraders for applications in the field of agriculture (JV Entity). The parties consummated the formation of the joint venture as contemplated by the Commitment Agreement in July 2019 (the JV Closing), upon the expiration of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, with respect to the reportable transactions and the satisfaction of the other applicable closing conditions. Pursuant to the terms of the Commitment Agreement and certain other agreements entered into at the JV Closing, the Company and Bayer each made an in-kind intellectual property contribution to the JV Entity at the JV Closing. In addition, Bayer has made a $56.0 million total cash commitment to the JV Entity, $16.0 million of which Bayer contributed to the JV Entity in connection with the JV Closing. The Company and Bayer each hold an ownership interest in the JV Entity initially representing 50% of the ownership interests. A 15% ownership interest of the JV Entity is reserved for the future grant of incentive units to service providers of the JV Entity. Bayer Stock Purchase Agreement In June 2019, the Company entered into a Stock Purchase Agreement with Bayer pursuant to which, in connection with the JV Closing in July 2019, the Company issued and sold to Bayer 1,346,313 shares of the Company’s common stock (the Shares) for an aggregate purchase price of approximately $32.5 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Unaudited Interim Financial Statements	Unaudited Interim Financial Statements The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and pursuant to the rules and regulations of the Securities and Exchange Commission. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but does not include all disclosures required by U.S. GAAP. These condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the years ended December 31, 2018 and 2017 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on March 26, 2019 (the Annual Report). The condensed consolidated financial statements, in the opinion of management, reflect all normal and recurring adjustments necessary for a fair statement of the Company’s financial position and results of operations.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases In June 2018, the FASB issued ASU No. 2018-07 , Improvements in Nonemployee Share-Based Payment Accounting The Company adopted ASU 2018-07 in the first quarter of 2019.

Research Collaboration and Li_2

Research Collaboration and License Agreements (Tables)	6 Months Ended
	Jun. 30, 2019
Research Collaboration And License Agreements [Abstract]
Summary of Contract Liabilities	Information about contract liabilities is as follows: June 30, December 31, 2019 2018 Contract liabilities $ 45,517,693 $ 53,550,671 Revenues recognized in the period from: Amounts included in deferred revenue in previous periods $ 8,032,979 $ 13,553,136
Transaction Price Allocated to Performance Obligations	The aggregate amount of the transaction price allocated to performance obligations that are unsatisfied as of June 30, 2019 was $45.5 million, which is expected to be recognized as revenue for the years ending December 31 are: Remainder of 2019 $ 8.0 2020 13.6 2021 13.5 2022 8.6 2023 1.8 $ 45.5

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Company's Available for Sale Securities	The following is a summary of the Company’s available-for-sale securities as of June 30, 2019 and December 31, 2018: June 30, 2019 Gross Gross Description Effective Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value Corporate bonds 2019-2020 $ 128,081,144 178,163 — $ 128,259,307 Government bonds 2019 2,984,544 7,956 — 2,992,500 Corporate bonds 2020 16,465,166 114,032 — 16,579,198 $ 147,530,854 $ 300,151 $ — $ 147,831,005 December 31, 2018 Gross Gross Description Effective Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value Corporate bonds 2019 $ 154,859,427 — (165,630 ) $ 154,693,797 Government bonds 2019 2,966,262 2,778 — 2,969,040 Corporate bonds 2020 27,029,673 — (54,870 ) 26,974,803 $ 184,855,362 2,778 (220,500 ) $ 184,637,640
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables summarize the fair values and levels within the fair value hierarchy in which the fair value measurements fall for assets and liabilities measured on a recurring basis: June 30, 2019 Description Level 1 Level 2 Level 3 Total Assets: Corporate bonds $ — $ 144,838,505 $ — $ 144,838,505 Government bonds $ — $ 2,992,500 $ — $ 2,992,500 December 31, 2018 Description Level 1 Level 2 Level 3 Total Assets: Corporate bonds $ — $ 181,668,600 $ — $ 181,668,600 Government bonds $ — $ 2,969,040 $ — $ 2,969,040

Property, Equipment and Lease_2

Property, Equipment and Leasehold Improvements (Tables)	6 Months Ended
	Jun. 30, 2019
Property Plant And Equipment [Abstract]
Schedule of Property, Equipment and Leasehold Improvements	Property, equipment and leasehold improvements consist of the following at: June 30, 2019 December 31, 2018 Laboratory equipment $ 5,968,924 $ 3,757,265 Office equipment 728,821 577,418 Leasehold improvements 1,945,289 981,884 8,643,034 5,316,567 Less: accumulated depreciation and amortization (2,276,543 ) (1,733,531 ) Property, equipment and leasehold improvements, net $ 6,366,491 $ 3,583,036

Right to Use Assets and Liabi_2

Right to Use Assets and Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities for the years ending December 31 are 2019 $ 450,816 2020 839,555 2021 840,498 2022 823,403 Total lease payments 2,954,272 Less: imputed interest (282,895 ) Total $ 2,671,377

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Payables And Accruals [Abstract]
Components of Accrued Expenses	Accrued expenses consisted of the following at: June 30, 2019 December 31, 2018 Employee expenses $ 2,512,324 $ 2,795,205 Research and development expenses 675,964 357,148 Professional fees and other 810,686 848,923 $ 3,998,974 $ 4,001,276

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Schedule of Anticipated Future Minimum Payments on Long-Term Debt Excluding Discount on Debt	Anticipated future minimum payments on long-term debt for the years ending December 31 are: 2019 $ 77,667 2023 92,480 2024 377,516 Beyond 1,530,004 Total $ 2,077,667

Incentive Equity Plans (Tables)

Incentive Equity Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of Assumptions Used to Determine Fair Value of Incentive Common Units Granted	The fair value of the incentive units granted during the six months ended June 30, 2018 was determined using the Black-Scholes option pricing model with the following assumptions: June 30, 2018 Expected volatility 66.0-71.0% Expected term (years) 5.6-6.1 Risk free interest rate 2.5-2.9% Expected dividend yield 0 % Fair value of underlying common units $1.08-8.48
Schedule of Assumptions Used to Determine Fair Value of Stock Options Granted	The fair value of the stock options granted during the six months ended June 30, 2019 was determined using the Black-Scholes option pricing model with the following assumptions: June 30, 2019 Expected volatility 70.2-70.5% Expected term (years) 5.5-7.0 Risk free interest rate 1.9-2.7% Expected dividend yield 0 % Exercise price $17.29-22.25
Summary of Restricted Stock Grant Activity	The following table provides a summary of the restricted stock grant activity under the Incentive Plan during the six months ended June 30, 2019. These amounts include restricted stock granted to employees, directors and consultants. Shares Weighted Average Grant Date Fair Value Per Share Unvested restricted stock at December 31, 2018 1,102,289 $ 16.00 Vested (263,366 ) $ 16.00 Forfeited (16,246 ) $ 16.00 Unvested restricted stock at June 30, 2019 822,677 $ 16.00
Summary of Stock Option Activity	The following table provides a summary of the stock option activity under the 2018 Plan during the six months ended June 30, 2019. These amounts include stock options granted to employees, directors and consultants. Options Weighted Average Fair Value Outstanding at December 31, 2018 2,273,024 $ 9.88 Granted 1,195,988 $ 12.58 Exercised (24,968 ) $ 9.41 Forfeited (39,638 ) $ 10.23 Outstanding at June 30, 2019 3,404,406 $ 10.82 Exercisable at June 30, 2019 802,057 $ 9.75
Restricted Stock Units
Summary of Restricted Stock Grant Activity	The following table provides a summary of the restricted stock unit activity under the 2018 Plan during the six months ended June 30, 2019. These amounts include restricted stock units granted to employees. Shares Weighted Average Grant Date Fair Value Per Share Unvested restricted stock units at December 31, 2018 — $ — Granted 176,841 $ 19.36 Unvested restricted stock units at June 30, 2019 176,841 $ 19.36

Net Loss Per Common Share_Unit

Net Loss Per Common Share/Unit (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Basic and Diluted Loss per Common Share/Unit	Basic and diluted loss per common share/unit were calculated as follows: For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 Net loss $ (17,164,646 ) $ (7,854,542 ) $ (31,569,139 ) $ (12,004,928 ) Change in redemption value of preferred units — (14,834,049 ) — (86,316,147 ) Net loss attributable to common shares/units—basic and diluted $ (17,164,646 ) $ (22,688,591 ) $ (31,569,139 ) $ (98,321,075 ) Weighted average number of common shares/units outstanding, basic and diluted 31,440,051 1,897,544 31,408,658 1,897,544 Net loss per common share/unit $ (0.55 ) $ (11.96 ) $ (1.01 ) $ (51.81 )
Common Share/Unit Equivalents Excluded from the Calculations of Diluted Loss Per Common Share/Unit	The following common share/unit equivalents have been excluded from the calculations of diluted loss per common share/unit because their inclusion would have been antidilutive for the periods ended June 30: 2019 2018 Redeemable convertible preferred units — 19,664,047 Incentive units — 3,829,224 Restricted stock 822,677 — Stock options 3,404,406 — Restricted stock units 176,841 — Preferred unit warrant — 33,881 4,403,924 23,527,152

Nature of Business - Additional

Nature of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 01, 2018	Oct. 31, 2018
Nature Of Business [Line Items]
Underwriting fees and expenses	$ 12
Preferred stock outstanding	0
Common Stock
Nature Of Business [Line Items]
Gross proceeds from sale of shares in Initial public offering before fees and expenses	$ 123.2
Common stock issued for conversion of convertible preferred stock	19,697,928
Common Stock | Initial Public Offering
Nature Of Business [Line Items]
Shares issued and sold	7,500,000
Share price, issued and sold	$ 16
Common Stock | Over-Allotment Option
Nature Of Business [Line Items]
Shares issued and sold		200,482
Share price, issued and sold		$ 16

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	Jun. 30, 2019	Jan. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Operating lease right of use assets	$ 2,397,789
Lease liabilities	$ 2,671,377
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Operating lease right of use assets		$ 2,400,000
Lease liabilities		$ 2,400,000

Research Collaboration and Li_3

Research Collaboration and License Agreements - Additional Information (Details)	1 Months Ended	4 Months Ended	6 Months Ended
	Nov. 30, 2017USD ($)Target	Dec. 31, 2015USD ($)	Jun. 30, 2019USD ($)
Research Collaboration And License Agreements [Line Items]
Revenue recognized on research collaboration and license agreements			$ 8,000,000
Unsatisfied performance obligations expected to be recognized as revenue			45,500,000
Pfizer, Inc.
Research Collaboration And License Agreements [Line Items]
Upfront non-refundable payment and certain additional payments received			28,000,000
Pfizer, Inc. | Option Exercised
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised			2,500,000
Pfizer, Inc. | Option Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised			37,500,000
Pfizer, Inc. | Development Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised			225,000,000
Pfizer, Inc. | Sales-based Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised			$ 550,000,000
Genentech, Inc. and F. Hoffman-La Roche Ltd.
Research Collaboration And License Agreements [Line Items]
Upfront non-refundable payment and certain additional payments received	$ 34,500,000	$ 11,000,000
Number of designated targets | Target	10
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Option Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	$ 27,500,000
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Development Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	44,000,000
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Regulatory Milestone Payments
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	52,500,000
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Commercial Milestones
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	$ 60,000,000

Research Collaboration and Li_4

Research Collaboration and License Agreements - Summary of Contract Liabilities (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Contract liabilities	$ 45,517,693	$ 53,550,671
Amounts included in deferred revenue in previous periods	$ 8,032,979	$ 13,553,136

Research Collaboration and Li_5

Research Collaboration and License Agreements - Transaction Price Allocated to Performance Obligations (Details) $ in Millions	Jun. 30, 2019USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 45.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-07-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 8
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 13.6
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 13.5
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 8.6
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 1.8
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Research Collaboration and Li_6

Research Collaboration and License Agreements - Transaction Price Allocated to Performance Obligations (Details1) $ in Millions	Jun. 30, 2019USD ($)
Revenue From Contract With Customer [Abstract]
Revenue, remaining performance obligation	$ 45.5

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Company's Available for Sale Securities (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 147,530,854	$ 184,855,362
Gross Unrealized Gains	300,151	2,778
Gross Unrealized Losses		(220,500)
Fair Value	147,831,005	$ 184,637,640
Corporate Bonds | 2019-2020
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	128,081,144
Gross Unrealized Gains	178,163
Fair Value	$ 128,259,307
Corporate Bonds | 2019
Schedule Of Available For Sale Securities [Line Items]
Effective Maturity		2019
Amortized Cost		$ 154,859,427
Gross Unrealized Losses		(165,630)
Fair Value		$ 154,693,797
Corporate Bonds | 2020
Schedule Of Available For Sale Securities [Line Items]
Effective Maturity	2020	2020
Amortized Cost	$ 16,465,166	$ 27,029,673
Gross Unrealized Gains	114,032
Gross Unrealized Losses		(54,870)
Fair Value	$ 16,579,198	$ 26,974,803
Corporate Bonds | Minimum | 2019-2020
Schedule Of Available For Sale Securities [Line Items]
Effective Maturity	2019
Corporate Bonds | Maximum | 2019-2020
Schedule Of Available For Sale Securities [Line Items]
Effective Maturity	2020
Government Securities | 2019
Schedule Of Available For Sale Securities [Line Items]
Effective Maturity	2019	2019
Amortized Cost	$ 2,984,544	$ 2,966,262
Gross Unrealized Gains	7,956	2,778
Fair Value	$ 2,992,500	$ 2,969,040

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Assets:
Fair value measurements of assets	$ 147,831,005	$ 184,637,640
Corporate Bonds | Fair Value, Measurements, Recurring
Assets:
Fair value measurements of assets	144,838,505	181,668,600
Corporate Bonds | Fair Value, Measurements, Recurring | Level 2
Assets:
Fair value measurements of assets	144,838,505	181,668,600
Government Securities | Fair Value, Measurements, Recurring
Assets:
Fair value measurements of assets	2,992,500	2,969,040
Government Securities | Fair Value, Measurements, Recurring | Level 2
Assets:
Fair value measurements of assets	$ 2,992,500	$ 2,969,040

Property, Equipment and Lease_3

Property, Equipment and Leasehold Improvements - Schedule of Property, Equipment and Leasehold Improvements (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 8,643,034	$ 5,316,567
Less: accumulated depreciation and amortization	(2,276,543)	(1,733,531)
Property, equipment and leasehold improvements, net	6,366,491	3,583,036
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	5,968,924	3,757,265
Office Equipment
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	728,821	577,418
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 1,945,289	$ 981,884

Property, Equipment and Lease_4

Property, Equipment and Leasehold Improvements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$ 310,461	$ 168,476	$ 556,619	$ 291,504

Right to Use Assets and Liabi_3

Right to Use Assets and Liabilities - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Leases [Abstract]
Percentage of incremental borrowing for lease Payments	5.10%	5.10%
Operating lease, existence of option to extend		true
Operating lease, existence of option to terminate		true
Operating lease, weighted average remaining lease term	3 years 6 months	3 years 6 months
Operating lease expiration date		Dec. 31, 2022
Amortization of right to use assets	$ 186,212	$ 366,610	$ 0
Future minimum annual lease payments, 2019				$ 705,606
Future minimum annual lease payments, 2020				731,541
Future minimum annual lease payments, 2021				731,541
Future minimum annual lease payments, 2022				716,906
Future minimum lease payments , Total				$ 2,885,594

Right to Use Assets and Liabi_4

Right to Use Assets and Liabilities - Schedule of Maturities of Lease Liabilities (Details)	Jun. 30, 2019USD ($)
Leases [Abstract]
2019	$ 450,816
2020	839,555
2021	840,498
2022	823,403
Total lease payments	2,954,272
Less: imputed interest	(282,895)
Lease liabilities	$ 2,671,377

Accrued Expenses - Components o

Accrued Expenses - Components of Accrued Expenses (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Employee expenses	$ 2,512,324	$ 2,795,205
Research and development expenses	675,964	357,148
Professional fees and other	810,686	848,923
Accrued expenses	$ 3,998,974	$ 4,001,276

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Aug. 31, 2013	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2014	Dec. 31, 2018	Jan. 01, 2015
Debt Instrument [Line Items]
Debt instrument, outstanding amount				$ 2,077,667		$ 2,077,667
Total unamortized debt discount on Loan				1,030		1,030			$ 7,210
Amortization of debt discount						6,180	$ 6,180
Interest expense, Debt				22,778	$ 10,669	$ 46,416	20,540
2014 Assistance Agreement | State of Connecticut
Debt Instrument [Line Items]
Debt instrument maturity month and year								2024-01
Debt instrument face amount								$ 2,500,000
Percentage of liquidated damages								7.50%
2018 Assistance Agreement | State of Connecticut
Debt Instrument [Line Items]
Debt instrument, interest rate per annum	3.25%
Debt instrument maturity month and year	2028-09
Debt instrument face amount	$ 2,000,000
Percentage of liquidated damages	7.50%
Percentage of maximum funding on total project costs		50.00%
Debt instrument interest payments term	60 months
Debt instrument amortization period after interest payments period	60 months
2018 Assistance Agreement | State of Connecticut | Maximum
Debt Instrument [Line Items]
Debt instrument face amount		$ 2,000,000			$ 2,000,000		$ 2,000,000
Forgiveness of funding on achieving certain employment conditions	$ 1,000,000
Series A Preferred Unit Warrant
Debt Instrument [Line Items]
Warrant to purchase of stock			110,116
Warrant purchase price per share			$ 0.6811
Term of warrant from the date of issuance			7 years
Series A Redeemable Convertible Preferred Units
Debt Instrument [Line Items]
Warrant to purchase of stock										110,116
Loan Agreement | Connecticut Innovations, Inc. | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maximum borrowing capacity			$ 750,000
Debt instrument, frequency of periodic payment						monthly
Debt instrument, interest rate per annum			7.50%
Debt instrument, interest only payment period upon first draw of funds			10 months
Debt instrument, date of first required payment			Jun. 1, 2015
Debt instrument, maturity date			Jul. 31, 2019
Debt instrument, outstanding amount				$ 77,667		$ 77,667			$ 169,610
Loan Agreement | Connecticut Innovations, Inc. | Secured Debt | Leasehold Improvements
Debt Instrument [Line Items]
Debt instrument, maximum borrowing capacity			$ 100,000

Long-Term Debt - Schedule of An

Long-Term Debt - Schedule of Anticipated Future Minimum Payments on Long-Term Debt Excluding Discount on Debt (Details)	Jun. 30, 2019USD ($)
Long Term Debt By Maturity [Abstract]
2019	$ 77,667
2023	92,480
2024	377,516
Beyond	1,530,004
Total	$ 2,077,667

Incentive Equity Plans - Additi

Incentive Equity Plans - Additional Information (Details) - USD ($)	1 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Dec. 31, 2019
Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incentive units authorized for issuance		6,199,477
Share-based award, expiration date		Sep. 30, 2018
Weighted average fair value of stock options granted			$ 12.58
Incentive Plan | Employees And Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense			$ 9,807,362
Compensation expense not yet recognized			$ 19,543,078
Compensation expense not yet recognized, period of recognition			2 years
Incentive Plan | Consultants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense			$ 682,693
Compensation expense not yet recognized			$ 873,277
Compensation expense not yet recognized, period of recognition			1 year 4 months 24 days
Incentive Plan | Incentive Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based award, stock options granted			1,195,988
Incentive Plan | Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based award, vesting period			4 years
Share-based award, non-option equity instruments granted			176,841
Incentive Plan | Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted shares vested and expected to vest			677,215
Incentive Plan | Scenario Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incentive units authorized for issuance				1,293,510
Incentive Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based award, vesting period		1 year
Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based award, vesting period		4 years
Available for issuance of common stock	1,277,181
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Available for issuance of common stock	4,067,007
Annual increase in reserved shares as percentage of outstanding common stock	4.00%
Share-based award, stock options granted			1,195,988
Weighted average fair value of stock options granted			$ 12.58
Stock options vested and expected to vest			2,984,885
2018 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase in reserved shares of common stock	4,989,593

Incentive Equity Plans - Schedu

Incentive Equity Plans - Schedule of Assumptions Used to Determine Fair Value of Incentive Common Units Granted (Details) - Incentive Common Units	6 Months Ended
	Jun. 30, 2018$ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	66.00%
Expected volatility, maximum	71.00%
Risk free interest rate, minimum	2.50%
Risk free interest rate, maximum	2.90%
Expected dividend yield	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 7 months 6 days
Fair value of underlying common units	$ 1.08
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 years 1 month 6 days
Fair value of underlying common units	$ 8.48

Incentive Equity Plans - Sche_2

Incentive Equity Plans - Schedule of Assumptions Used to Determine Fair Value of and Stock Options Granted (Details) - Stock Options	6 Months Ended
	Jun. 30, 2019$ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	70.20%
Expected volatility, maximum	70.50%
Risk free interest rate, minimum	1.90%
Risk free interest rate, maximum	2.70%
Expected dividend yield	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months
Fair value of underlying common units	$ 17.29
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	7 years
Fair value of underlying common units	$ 22.25

Incentive Equity Plans - Summar

Incentive Equity Plans - Summary of Restricted Stock Grant Activity (Details) - Incentive Plan	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Restricted Stock | Employees, Directors and Consultants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested Restricted Stock, Shares, Beginning Balance	1,102,289
Restricted Shares, Vested	(263,366)
Restricted Shares, Forfeited	(16,246)
Unvested Restricted Stock, Shares, Ending Balance	822,677
Weighted Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares	$ 16
Weighted Average Grant Date Fair Value Per Share, Granted | $ / shares	16
Weighted Average Grant Date Fair Value Per Share, Forfeited | $ / shares	16
Weighted Average Grant Date Fair Value Per Share, Ending Balance | $ / shares	$ 16
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Shares, Granted	176,841
Restricted Stock Units | Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested Restricted Stock, Shares, Beginning Balance	0
Restricted Shares, Granted	176,841
Unvested Restricted Stock, Shares, Ending Balance	176,841
Weighted Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares	$ 0
Weighted Average Grant Date Fair Value Per Share, Granted | $ / shares	19.36
Weighted Average Grant Date Fair Value Per Share, Ending Balance | $ / shares	$ 19.36

Incentive Equity Plans - Summ_2

Incentive Equity Plans - Summary of Stock Option Activity (Details) - 2018 Plan	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, Outstanding, Beginning Balance | shares	2,273,024
Options, Granted | shares	1,195,988
Options, Exercised | shares	(24,968)
Options, Forfeited | shares	(39,638)
Options, Outstanding, Ending Balance | shares	3,404,406
Options, Exercisable, Ending Balance | shares	802,057
Weighted Average Fair Value, Outstanding, Beginning Balance | $ / shares	$ 9.88
Weighted Average Fair Value, Granted | $ / shares	12.58
Weighted Average Fair Value, Exercised | $ / shares	9.41
Weighted Average Fair Value, Forfeited | $ / shares	10.23
Weighted Average Fair Value, Outstanding, Ending Balance | $ / shares	10.82
Weighted Average Fair Value, Exercisable, Ending Balance | $ / shares	$ 9.75

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Effective tax rate, percentage	0.00%	0.00%
Federal statutory rate, percentage	21.00%	34.00%
Effect of equity compensation valuation allowance recorded against net deferred tax assets, percentage	0.00%
State income tax provision	$ 0	$ 0

Net Loss Per Common Share_Uni_2

Net Loss Per Common Share/Unit - Basic and Diluted Loss per Common Share/Unit (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net loss	$ (17,164,646)	$ (7,854,542)	$ (31,569,139)	$ (12,004,928)
Change in redemption value of preferred units	0	(14,834,049)	0	(86,316,147)
Net loss attributable to common shares/units—basic and diluted	$ (17,164,646)	$ (22,688,591)	$ (31,569,139)	$ (98,321,075)
Weighted average number of common shares/units outstanding, basic and diluted	31,440,051	1,897,544	31,408,658	1,897,544
Net loss per common share/unit	$ (0.55)	$ (11.96)	$ (1.01)	$ (51.81)

Net Loss Per Common Share_Uni_3

Net Loss Per Common Share/Unit - Common Share/Unit Equivalents Excluded from the Calculations of Diluted Loss Per Common Share/Unit (Details) - shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit	4,403,924	23,527,152
Redeemable Convertible Preferred Stock/Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit		19,664,047
Incentive Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit		3,829,224
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit	822,677
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit	3,404,406
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit	176,841
Preferred Unit Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common share/unit equivalents excluded from the calculations of diluted loss per common share/unit		33,881

Related Parties - Additional In

Related Parties - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Yale University
Related Party Transaction [Line Items]
Reimbursable patent costs	$ 208,774	$ 37,473
Milestone payment	$ 50,000
Consulting Agreement
Related Party Transaction [Line Items]
Consulting agreement maturity date	Sep. 26, 2021
Consulting Agreement | Dr. Craig Crews
Related Party Transaction [Line Items]
Payment for consulting service	$ 125,000	75,000
Monthly consulting services fee	$ 20,833
Consulting agreement term	3 years
Share-based award, stock options granted	235,150
Exercise price of stock options	$ 16
Incentive units vesting period	3 years
Amended Corporate Sponsored Research Agreement | Yale University
Related Party Transaction [Line Items]
Quarterly research payments	$ 250,000
Corporate Sponsored Research Agreement (SRA) | Yale University
Related Party Transaction [Line Items]
Total research payments	$ 500,000	$ 351,161
Related party agreement, description	In July 2016, the Company entered into a Corporate Sponsored Research Agreement (SRA) with Yale University (Yale), under the direction of Professor Crews, which was amended in April 2018. The amended SRA extended the agreement until April 2021 and amended the scope of work. The amended SRA requires quarterly payments of $250,000 through the end of the agreement. The total payments made under the SRA for the six months ended June 30, 2019 and 2018 were $500,000 and $351,161, respectively.

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event	1 Months Ended
	Jul. 31, 2019USD ($)shares
JV Entity
Subsequent Event [Line Items]
Ownership interest in joint venture	50.00%
Future grant of incentive units to service providers, percentage	15.00%
Bayer A G
Subsequent Event [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	$ 17,500,000
Shares issued and sold | shares	1,346,313
Common stock issued in period	$ 32,500,000
Bayer A G | JV Entity
Subsequent Event [Line Items]
Cash commitment	56,000,000
Contributed to joint venture entity	$ 16,000,000
Ownership interest in joint venture	50.00%
Bayer A G | Research Funding Payments
Subsequent Event [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	$ 1,500,000
Bayer A G | Research Funding Payments | Maximum
Subsequent Event [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	10,500,000
Bayer A G | Development Milestone Payments | Maximum
Subsequent Event [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	197,500,000
Bayer A G | Sales-based Milestone Payments | Maximum
Subsequent Event [Line Items]
Contract revenue receivable if milestones achieved or options for all targets exercised	$ 490,000,000