Editas Medicine (EDIT) 10-Q 7 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2020
Entity File Number	001-37687
Entity Registrant Name	EDITAS MEDICINE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-4097528
Entity Address, Address Line One	11 Hurley Street
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02141
City Area Code	617
Local Phone Number	401-9000
Title of 12(b) Security	Common Stock
Trading Symbol	EDIT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		62,269,906
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001650664
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 485,819	$ 238,183
Marketable securities	112,901	218,957
Accounts receivable	1,865	418
Prepaid expenses and other current assets	9,541	6,286
Total current assets	610,126	463,844
Property and equipment, net	12,895	10,887
Right-of-use assets	28,569	28,761
Restricted cash and other non-current assets	3,891	5,393
Total assets	655,481	508,885
Current liabilities:
Accounts payable	6,339	5,843
Accrued expenses	10,194	22,120
Deferred revenue, current	40,940	23,514
Operating lease liabilities	6,650	5,804
Other current liabilities	4,027	2,682
Total current liabilities	68,150	59,963
Operating lease liabilities, net of current portion	22,153	23,277
Deferred revenue, net of current portion	138,406	163,207
Other non-current liabilities		1
Total liabilities	228,709	246,448
Stockholders' equity
Preferred stock, $0.0001 par value per share: 5,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.0001 par value per share: 195,000,000 shares authorized; 62,265,649 and 54,533,798 shares issued, and 62,103,649 and 54,355,798 shares outstanding at June 30, 2020 and December 31, 2019, respectively	6	5
Additional paid-in capital	1,037,100	811,546
Accumulated other comprehensive income	183	107
Accumulated deficit	(610,517)	(549,221)
Total stockholders' equity	426,772	262,437
Total liabilities and stockholders' equity	$ 655,481	$ 508,885

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
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 (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	195,000,000	195,000,000
Common stock, shares issued	62,265,649	54,533,798
Common stock, shares outstanding	62,103,649	54,355,798

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Condensed Consolidated Statements of Operations
Collaboration and other research and development revenues	$ 10,749	$ 2,330	$ 16,472	$ 4,399
Revenue type	us-gaap:ServiceMember	us-gaap:ServiceMember	us-gaap:ServiceMember	us-gaap:ServiceMember
Operating expenses:
Research and development	$ 28,007	$ 23,565	$ 62,576	$ 39,408
General and administrative	14,081	14,414	31,852	31,903
Total operating expenses	42,088	37,979	94,428	71,311
Operating loss	(31,339)	(35,649)	(77,956)	(66,912)
Other income, net:
Other income (expense), net	7,175	(68)	14,509	(111)
Interest income, net	592	1,931	2,151	3,988
Total other income, net	7,767	1,863	16,660	3,877
Net loss	$ (23,572)	$ (33,786)	$ (61,296)	$ (63,035)
Net loss per share basic and diluted	$ (0.43)	$ (0.69)	$ (1.12)	$ (1.29)
Weighted-average common shares outstanding, basic and diluted	55,346,052	49,070,574	54,968,123	48,955,043

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (23,572)	$ (33,786)	$ (61,296)	$ (63,035)
Other comprehensive income:
Unrealized gain (loss) on marketable debt securities	(511)	16	76	74
Comprehensive loss	$ (24,083)	$ (33,770)	$ (61,220)	$ (62,961)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Other Accumulated Deficit	Total
Balance, beginning of period at Dec. 31, 2018	$ 5	$ 652,464	$ (29)	$ (416,278)	$ 236,162
Balance, beginning of period (in shares) at Dec. 31, 2018	48,758,951
Statement of Stockholders' Equity (Deficit)
Exercise of stock options		1,533			1,533
Exercise of stock options (in shares)	146,171
Vesting of restricted common stock awards (in shares)	18,000
Stock-based compensation expense		7,855			7,855
Unrealized gain (loss) on marketable debt securities			58		58
Net loss				(29,249)	(29,249)
Balance, end of period at Mar. 31, 2019	$ 5	661,852	29	(444,724)	217,162
Balance, end of period (in shares) at Mar. 31, 2019	48,923,122
Balance, beginning of period at Dec. 31, 2018	$ 5	652,464	(29)	(416,278)	236,162
Balance, beginning of period (in shares) at Dec. 31, 2018	48,758,951
Statement of Stockholders' Equity (Deficit)
Net loss					(63,035)
Balance, end of period at Jun. 30, 2019	$ 5	671,522	45	(478,510)	193,062
Balance, end of period (in shares) at Jun. 30, 2019	49,241,093
Statement of Stockholders' Equity (Deficit)
Cumulative effect adjustment for adoption of new accounting guidance				803	803
Balance, beginning of period at Mar. 31, 2019	$ 5	661,852	29	(444,724)	217,162
Balance, beginning of period (in shares) at Mar. 31, 2019	48,923,122
Statement of Stockholders' Equity (Deficit)
Exercise of stock options		2,894			2,894
Exercise of stock options (in shares)	277,259
Vesting of restricted common stock awards		410			410
Vesting of restricted common stock awards (in shares)	24,486
Purchase of common stock under benefit plans		283			283
Purchase of common stock under benefit plans (in shares)	16,226
Stock-based compensation expense		6,083			6,083
Unrealized gain (loss) on marketable debt securities			16		16
Net loss				(33,786)	(33,786)
Balance, end of period at Jun. 30, 2019	$ 5	671,522	45	(478,510)	193,062
Balance, end of period (in shares) at Jun. 30, 2019	49,241,093
Balance, beginning of period at Dec. 31, 2019	$ 5	811,546	107	(549,221)	262,437
Balance, beginning of period (in shares) at Dec. 31, 2019	54,355,798
Statement of Stockholders' Equity (Deficit)
Exercise of stock options		3,047			3,047
Exercise of stock options (in shares)	233,208
Vesting of restricted common stock awards (in shares)	213,393
Stock-based compensation expense		6,220			6,220
Unrealized gain (loss) on marketable debt securities			587		587
Net loss				(37,724)	(37,724)
Balance, end of period at Mar. 31, 2020	$ 5	820,813	694	(586,945)	234,567
Balance, end of period (in shares) at Mar. 31, 2020	54,802,399
Balance, beginning of period at Dec. 31, 2019	$ 5	811,546	107	(549,221)	262,437
Balance, beginning of period (in shares) at Dec. 31, 2019	54,355,798
Statement of Stockholders' Equity (Deficit)
Net loss					(61,296)
Balance, end of period at Jun. 30, 2020	$ 6	1,037,100	183	(610,517)	426,772
Balance, end of period (in shares) at Jun. 30, 2020	62,103,649
Balance, beginning of period at Mar. 31, 2020	$ 5	820,813	694	(586,945)	234,567
Balance, beginning of period (in shares) at Mar. 31, 2020	54,802,399
Statement of Stockholders' Equity (Deficit)
Exercise of stock options		6,839			6,839
Exercise of stock options (in shares)	355,812
Vesting of restricted common stock awards (in shares)	30,194
Issuance of common stock for public offering	$ 1	203,681			203,682
Issuance of common stock for public offering (in shares)	6,900,000
Purchase of common stock under benefit plans		350			350
Purchase of common stock under benefit plans (in shares)	15,244
Stock-based compensation expense		5,417			5,417
Unrealized gain (loss) on marketable debt securities			(511)		(511)
Net loss				(23,572)	(23,572)
Balance, end of period at Jun. 30, 2020	$ 6	$ 1,037,100	$ 183	$ (610,517)	$ 426,772
Balance, end of period (in shares) at Jun. 30, 2020	62,103,649

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flow from operating activities
Net loss	$ (61,296)	$ (63,035)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	11,637	14,348
Depreciation	1,669	1,321
Unrealized gain on corporate equity securities	(14,525)
Other non-cash items, net	(289)	(1,959)
Changes in operating assets and liabilities:
Accounts receivable	(1,447)	18
Prepaid expenses and other current assets	(3,254)	301
Right-of-use assets	192	1,984
Other non-current assets	93
Accounts payable	1,026	(1,459)
Accrued expenses	(12,439)	(4,627)
Deferred revenue	(7,375)	621
Operating lease liabilities	(278)	(2,325)
Other current and non-current liabilities	1,344	3
Net cash used in operating activities	(84,942)	(54,809)
Cash flow from investing activities
Purchases of property and equipment	(3,993)	(2,231)
Proceeds from the sale of equipment	14	36
Purchases of marketable securities	(66,384)	(106,569)
Proceeds from maturities of marketable securities	191,000	235,500
Net cash provided by investing activities	120,637	126,736
Cash flow from financing activities
Proceeds from offering of common stock, net of issuance costs	203,964
Proceeds from exercise of stock options	9,886	3,619
Issuance of common stock under benefit plans	350	283
Net cash provided by financing activities	214,200	3,902
Net increase in cash, cash equivalents, and restricted cash	249,895	75,829
Cash, cash equivalents, and restricted cash, beginning of period	239,802	136,395
Cash, cash equivalents, and restricted cash, end of period	489,697	212,224
Supplemental disclosure of cash and non-cash activities:
Fixed asset additions included in accounts payable and accrued expenses	429	96
Cash paid in connection with operating lease liabilities	5,125	3,089
Offering costs included in accounts payable and accrued expenses	282
Right-of-use assets obtained in exchange of operating lease obligations	$ 3,319	$ 19,461

Nature of Business

Nature of Business	6 Months Ended
	Jun. 30, 2020
Nature of Business
Nature of Business	1. Nature of Business ​ Editas Medicine, Inc. (the “Company”) is a leading, clinical stage genome editing company dedicated to developing potentially transformative genomic medicines to treat a broad range of serious diseases. The Company was incorporated in the state of Delaware in September 2013. Its principal offices are in Cambridge, Massachusetts. Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, and raising capital. The Company has primarily financed its operations through various equity financings, payments received under a research collaboration with Juno Therapeutics, Inc., a wholly-owned subsidiary of the Bristol-Myers Squibb Company (“Juno Therapeutics”), and payments received under a strategic alliance with Allergan Pharmaceuticals International Limited (which was acquired by AbbVie, Inc. in May 2020 and is referred to together with its affiliates as “Allergan”). In August 2020, the collaboration with Allergan was terminated. See Note 11, “Subsequent Events”. The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations and ability to transition from pilot-scale manufacturing to large-scale production of products. Liquidity ​ In May 2020, the Company entered into a sales agreement with Cowen and Company, LLC (“Cowen”), under which the Company from time to time can issue and sell shares of its common stock through Cowen in at-the-market offerings for aggregate gross sale proceeds of up to $150.0 million ( the “ATM Facility”). As of June 30, 2020, the Company has not sold any shares of its common stock under the ATM Facility. In June 2020, the Company completed a public offering whereby the Company sold 6,900,000 shares of its common stock, inclusive of 900,000 shares of common stock sold by the Company pursuant to the full exercise of an option granted to the underwriters in connection with the offering and received net proceeds of approximately $203.7 million. As of June 30, 2020, the Company has raised an aggregate of $648.7 million in net proceeds through the sale of shares of its common stock in public offerings and at-the-market offerings. ​ The Company has incurred annual net operating losses in every year since its inception. The Company expects that its existing cash, cash equivalents and marketable securities at June 30, 2020 and anticipated interest income will enable it to fund its operating expenses and capital expenditure requirements into 2023 . The Company had an accumulated deficit of $610.5 million at June 30, 2020, and will require substantial additional capital to fund its operations. The Company has never generated any product revenue. There can be no assurance that the Company will be able to obtain additional debt or equity financing or generate product revenue or revenues from collaborative partners, on terms acceptable to the Company, on a timely basis or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company’s business, results of operations, and financial condition.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies ​ Unaudited Interim Financial Information ​ The condensed consolidated financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (the “Annual Report”). ​ The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Editas Securities Corporation. All intercompany transactions and balances of the subsidiary have been eliminated in consolidation. In the opinion of management, the information furnished reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended June 30, 2020 and 2019 are referred to as the second quarter of 2020 and 2019, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. ​ Summary of Significant Accounting Policies ​ The Company’s significant accounting policies are described in Note 2, “Summary of significant accounting policies,” to the consolidated financial statements included in the Annual Report. There have been no material changes to the significant accounting policies previously disclosed in the Annual Report, other than as noted below. ​ Corporate Equity Securities ​ The Company classifies investments in equity securities that have a readily determinable fair value as marketable securities in the Company’s condensed consolidated balance sheets. The Company’s marketable securities are stated at fair value. Typically, the fair value of these securities is based on a quoted price for an identical equity security. If the equity security has a restriction that is determined to be an attribute of the security that would transfer to a market participant, the fair value of the security is measured based on the quoted price for an otherwise identical unrestricted equity security, adjusted for the effect of the restriction. The adjustment reflects the discount that a market participant would demand for the risk relating to the inability to dispose of the security for a specified period of time. That adjustment is based on the nature and duration of the restriction and the limitations imposed by the restriction to a buyer. The Company records changes in the fair value of its equity securities in “Other Income (Expense), net” in the Company’s condensed consolidated statement of operations. ​ Recent Accounting Pronouncements – Recently Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Statement Update (“ASU”) 2016-13, Financial Instruments-Credit Losses ASU 2016-13 requires evaluation of credit loss based on historical experience, current conditions and reasonable and supportable forecasts. current conditions and reasonable and supportable forecasts results in an expectation that nonpayment of the amortized cost basis is zero. At each reporting date, the Company will record an allowance for credit losses and reports it as credit loss expense which is included in “Other income (expense), net” in the Company’s condensed consolidated statement of operations. However subsequent increases or decreases in the fair value of available-for-sale securities that do not result in recognition or reversal of an allowance for credit loss or write-down will continue to be recorded in other comprehensive loss. The Company adopted the new standard and the related amendments on January 1, 2020 using a modified retrospective approach. The modified retrospective approach requires the Company to record a one-time adjustment to opening accumulated deficit as of the effective date. The Company concluded that there are no indicators of credit loss with respect to its available-for-sale debt securities which consist of U.S Treasury securities and government-agency bonds. The Company therefore did not record an allowance for credit losses or doubtful accounts upon adoption or during the first quarter of 2020. The adoption of ASU 2016-13 had no impact on the Company’s condensed consolidated financial statements. ​ In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . - ​ In 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which eliminates, adds, and modifies the disclosure requirements for fair value measurements. ASU 2018-13 was effective on January 1, 2020. The adoption of ASU 2018-13 results in additional disclosures related to the Company’s assets and liabilities that are valued based on Level 3 inputs and transfers between Level 1 and Level 2 fair value measurements. ​

Cash Equivalents, Marketable Se

Cash Equivalents, Marketable Securities and Equity Securities	6 Months Ended
	Jun. 30, 2020
Cash Equivalents, Marketable Securities and Equity Securities
Cash Equivalents, Marketable Securities and Equity Securities	3. Cash Equivalents, Marketable Securities and Equity Securities ​ Cash equivalents and marketable securities consisted of the following at June 30, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ for Credit ​ ​ Unrealized ​ Unrealized ​ Fair June 30, 2020 ​ Cost ​ Losses ​ ​ Gains ​ Losses ​ Value Cash equivalents and marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 485,819 ​ $ — ​ ​ $ — ​ $ — ​ $ 485,819 U.S. Treasuries ​ ​ 26,961 ​ ​ — ​ ​ ​ 36 ​ ​ — ​ ​ 26,997 Government agency securities ​ ​ 67,565 ​ ​ — ​ ​ ​ 147 ​ ​ — ​ ​ 67,712 Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ ​ 14,525 ​ ​ — ​ ​ 18,192 Total ​ $ 584,012 ​ $ — ​ ​ $ 14,708 ​ $ — ​ $ 598,720 ​ Cash equivalents, marketable securities and equity securities consisted of the following at December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair December 31, 2019 ​ Cost ​ Gains ​ Losses ​ Value Cash equivalents and marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 230,201 ​ $ — ​ $ — ​ $ 230,201 U.S. Treasuries ​ ​ 71,348 ​ ​ 20 ​ ​ — ​ ​ 71,368 Government agency securities ​ ​ 155,484 ​ ​ 87 ​ ​ — ​ ​ 155,571 Equity securities included in other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ — ​ ​ 3,667 Total ​ $ 460,700 ​ $ 107 ​ $ — ​ $ 460,807 ​ As of June 30, 2020, the Company did not hold any marketable securities in an unrealized loss position. Furthermore, the Company has determined that there were no material changes in the credit risk of the debt securities. ​ There were no realized gains or losses on available-for-sale securities during the six months ended June 30, 2020 or 2019.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Measurements
Fair Value Measurements	4. Fair Value Measurements ​ Assets measured at fair value on a recurring basis as of June 30, 2020 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices Significant ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ June 30, ​ Identical Assets ​ Inputs ​ Inputs Financial Assets ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 485,819 ​ $ 485,819 ​ $ — ​ $ — Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Treasuries ​ ​ 26,997 ​ ​ 26,997 ​ ​ — ​ ​ — Government agency securities ​ ​ 67,712 ​ ​ 67,712 ​ ​ — ​ ​ — Corporate equity securities ​ ​ 18,192 ​ ​ — ​ ​ 18,192 ​ ​ — Restricted cash and other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ 3,877 ​ ​ 3,877 ​ ​ — ​ ​ — Total financial assets ​ $ 602,597 ​ $ 584,405 ​ $ 18,192 ​ $ — ​ Assets measured at fair value on a recurring basis as of December 31, 2019 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices Significant ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ December 31, ​ Identical Assets ​ Inputs ​ Inputs Financial Assets ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 230,201 ​ $ 230,201 ​ $ — ​ $ — U.S. Treasuries ​ ​ 7,982 ​ ​ 7,982 ​ ​ — ​ ​ — Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Treasuries ​ ​ 63,386 ​ ​ 63,386 ​ ​ — ​ ​ — Government agency securities ​ ​ 155,571 ​ ​ 155,571 ​ ​ — ​ ​ — Restricted cash and other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ 3,667 ​ ​ — Money market funds ​ ​ 1,619 ​ ​ 1,619 ​ ​ — ​ ​ — Total financial assets ​ $ 462,426 ​ $ 458,759 ​ $ 3,667 ​ $ — ​ The Company holds an investment in Beam Therapeutics Inc. (“Beam Therapeutics”) consisting of shares of Beam Therapeutics’ common stock. Prior to Beam Therapeutics’ initial public offering in February 2020, the Company valued such investment based on the cost of the equity securities adjusted for any observable market transactions. Following the initial public offering, the equity securities have a readily determinable fair value, and are included in marketable securities on the condensed consolidated balance sheet with a fair value based on Level 2 inputs due to transfer restrictions associated with the securities. Upon the expiration of the transfer restrictions the Company expects to transfer the value of these equity securities from Level 2 to Level 1. During the three and six months ended June 30, 2020, the Company recorded unrealized gains of $7.2 million and $14.5 million, respectively in other income (expense), net on the consolidated statements of operations.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2020
Accrued Expenses
Accrued Expenses	5. Accrued Expenses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ December 31, ​ 2020 2019 Employee related expenses ​ $ 4,179 ​ $ 4,971 Process and platform development expenses ​ ​ 2,266 ​ 735 Intellectual property and patent related fees ​ ​ 1,598 ​ ​ 3,725 Sublicensing expenses ​ ​ 813 ​ ​ 11,416 Professional service expenses ​ ​ 609 ​ ​ 674 Other expenses ​ ​ 729 ​ ​ 599 Total accrued expenses ​ $ 10,194 ​ $ 22,120 ​ ​ ​ ​ ​ ​ ​ ​

Property and Equipment, net

Property and Equipment, net	6 Months Ended
	Jun. 30, 2020
Property and Equipment, net
Property and Equipment, net	6. Property and Equipment, net ​ Property and equipment, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ December 31, ​ 2020 2019 Laboratory equipment ​ $ 16,656 ​ $ 14,571 Leasehold improvements ​ ​ 3,393 ​ ​ 1,042 Computer equipment ​ 858 ​ 858 Construction-in-progress ​ ​ 550 ​ ​ 1,336 Furniture and office equipment ​ ​ 166 ​ ​ 166 Software ​ 118 ​ 118 Total property and equipment ​ 21,741 ​ 18,091 Less: accumulated depreciation ​ (8,846) ​ (7,204) Property and equipment, net ​ $ 12,895 ​ $ 10,887 ​

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies
Commitments and Contingencies	7. Commitments and Contingencies ​ ​ Licensor Expense Reimbursement ​ The Company is obligated to reimburse The Broad Institute, Inc. (“Broad”) and the President and Fellows of Harvard College (“Harvard”) for expenses incurred by each of them associated with the prosecution and maintenance of the patent rights that the Company licenses from them pursuant to the license agreement by and among the Company, Broad and Harvard, including the interference and opposition proceedings involving patents licensed to the Company under the license agreement, and other license agreements between the Company and Broad. As such, the Company anticipates that it has a substantial commitment in connection with these proceedings until such time as these proceedings have been resolved, but the amount of such commitment is not determinable. The Company incurred an aggregate of $2.8 million and $6.6 million in expense during the three and six months ended June 30, 2020, respectively, for such reimbursement. The Company incurred an aggregate of $3.5 million and $6.9 million in expense during the three and six months ended June 30, 2019, respectively, for such reimbursement.

Collaboration and Profit-Sharin

Collaboration and Profit-Sharing Agreements	6 Months Ended
	Jun. 30, 2020
Collaboration and Profit-Sharing Agreements
Collaboration and Profit-Sharing Agreements	8 Collaboration and Profit-Sharing Agreements ​ The Company has entered into multiple collaborations, out-licenses and strategic alliances with third parties that typically involve payments to or from the Company, including up-front payments, payments for research and development services, option payments, milestone payments and royalty payments to or from the Company. The terms and conditions as well as the accounting analysis for the Company’s significant collaborations, out-licenses and strategic alliances are described in Note 9, “Collaboration and Profit-Sharing Agreements” to the consolidated financial statements included in the Annual Report. There have been no material changes to the terms and conditions, or the accounting conclusions previously disclosed in the Annual Report. ​ ​ ​ Collaboration Revenue ​ As of June 30, 2020, the Company’s contract liabilities were primarily related to the Company’s collaboration with Juno Therapeutics and its strategic alliance with Allergan. The following table presents changes in the Company’s accounts receivable and contract liabilities for the six months ended June 30, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the six months ended June 30, 2020 Balance at December 31, 2019 ​ Additions ​ Deductions ​ Balance at June 30, 2020 Accounts receivable $ 418 ​ $ 1,447 ​ $ ​ ​ $ 1,865 Contract liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred revenue $ 186,721 ​ $ 508 ​ $ (7,883) ​ $ 179,346 ​ During the three and six months ended June 30, 2020, the Company recognized the following collaboration revenue (in thousands): ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended Revenue recognized in the period from: June 30, 2020 Amounts included in deferred revenue at the beginning of the period $ 3,066 ​ $ 7,883 Performance obligations satisfied in previous periods $ — ​ $ 60 ​

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2020
Stock-based Compensation
Stock-based Compensation	9 Stock-based Compensation ​ Total compensation cost recognized for all stock-based compensation awards in the condensed consolidated statements of operations was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 ​ Research and development ​ $ 2,673 ​ $ 3,853 ​ $ 5,730 ​ $ 7,235 ​ General and administrative ​ 2,744 ​ 2,640 ​ 5,907 ​ 7,113 ​ Total stock-based compensation expense ​ $ 5,417 ​ $ 6,493 ​ $ 11,637 ​ $ 14,348 ​ ​ Restricted Stock and Restricted Stock Unit Awards ​ The following is a summary of restricted stock and restricted stock unit awards activity for the six months ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ ​ Fair Value ​ ​ Shares ​ Per Share Unvested restricted stock and restricted stock unit awards as of December 31, 2019 581,408 ​ $ 24.03 Issued 283,319 ​ $ 27.91 Vested (243,587) ​ $ 22.65 Forfeited ​ (105,009) ​ $ 24.07 Unvested restricted stock and restricted stock unit awards as of June, 30 2020 516,131 ​ $ 26.60 ​ As of June 30, 2020, total unrecognized compensation expense related to unvested restricted stock and restricted stock unit awards was $12.0 million, which the Company expects to recognize over a remaining weighted-average period of 3.0 years. ​ Stock Options ​ The following is a summary of stock option activity for the six months ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Remaining Aggregate Intrinsic ​ ​ Shares ​ Exercise Price ​ Contractual Life (years) ​ Value (in thousands) Outstanding at December 31, 2019 4,358,291 ​ $ 25.40 ​ 7.4 ​ $ 26,060 Granted ​ 1,228,749 ​ $ 27.84 ​ ​ ​ ​ ​ Exercised ​ (589,020) ​ $ 16.78 ​ ​ ​ ​ ​ Cancelled ​ (1,018,295) ​ $ 30.83 ​ ​ ​ ​ ​ Outstanding at June 30, 2020 3,979,725 ​ $ 26.04 ​ 8.0 ​ $ 17,695 Exercisable at June 30, 2020 1,367,908 ​ $ 23.94 ​ 6.7 ​ $ 10,035 ​ As of June 30, 2020, total unrecognized compensation expense related to stock options was $40.0 million, which the Company expects to recognize over a remaining weighted-average period of 2.8 years.

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2020
Net Loss per Share
Net Loss per Share	10. Net Loss per Share ​ Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock and potentially dilutive securities outstanding for the period determined using the treasury stock and if converted methods. Contingently issuable shares are included in the calculation of basic loss per share as of the beginning of the period in which all the necessary conditions have been satisfied. Contingently issuable shares are included in diluted loss per share based on the number of shares, if any, that would be issuable under the terms of the arrangement if the end of the reporting period was the end of the contingency period, if the results are dilutive. ​ For purposes of the diluted net loss per share calculation, stock options are considered to be common stock equivalents, but they were excluded from the Company’s calculation of diluted net loss per share allocable to common stockholders because their inclusion would have been anti-dilutive. Therefore, basic and diluted net loss per share applicable to common stockholders was the same for all periods presented. ​ The following common stock equivalents were excluded from the calculation of diluted net loss per share allocable to common stockholders because their inclusion would have been anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ ​ 2020 2019 Unvested restricted stock and restricted stock unit awards ​ 516,131 591,473 Outstanding stock options ​ 3,979,725 4,452,878 Total ​ 4,495,856 5,044,351 ​

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events
Subsequent Events	11. Subsequent Events ​ On August 5, 2020, the Company and Allergan Pharmaceuticals International Limited (which was acquired by AbbVie, Inc. in May 2020 and is referred to together with its affiliates as “Allergan”) agreed to terminate the strategic alliance and option agreement that was entered into in May 2017 and the profit-sharing arrangement to equally split U.S profit and losses of EDIT-101, an experimental medicine for Leber congenital amaurosis 10 (“LCA10”) that was originally licensed to Allergan under the strategic alliance and option agreement (the “Termination Agreement”). In addition, in connection with the termination, the Company entered into a transition services agreement with Allergan (together with the Termination Agreement, the “Termination Agreements”), primarily to facilitate the transfer of EDIT-101 back to the Company. ​ Pursuant to the Termination Agreements, the Company has regained full global rights to research, develop, manufacture, and commercialize its ocular medicines, including EDIT-101. Allergan has no further obligations pursuant to the initial agreements, all unexercised options and contingent payments contemplated under the initial agreements have terminated, which includes their worldwide developmental and commercialization rights of EDIT-101. Under the Termination Agreements, Allergan granted the Company a non-exclusive license to certain know-how that is necessary to develop, manufacture and commercialize EDIT-101 and will transfer to the Company certain materials produced under the initial agreement. The Company expects the transition services to be completed within four months. ​ Pursuant to the Termination Agreements, the Company will continue to use commercially reasonable efforts to develop and commercialize a product directed at four collaboration targets, one of which is LCA10. The Termination Agreements also obligate the Company to make a payment to Allergan, as well as certain payments based on the achievement of clinical and regulatory milestones for each target program, aggregated sales milestones for all products covered by the Termination Agreement, and pay royalties on net sales of specified products. The Company is also obligated to pay for a portion of the transition services. ​ ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Summary of Significant Accounting Policies
Unaudited Interim Financial Information	Unaudited Interim Financial Information ​ The condensed consolidated financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (the “Annual Report”). ​ The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Editas Securities Corporation. All intercompany transactions and balances of the subsidiary have been eliminated in consolidation. In the opinion of management, the information furnished reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended June 30, 2020 and 2019 are referred to as the second quarter of 2020 and 2019, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.
Corporate Equity Securities	Corporate Equity Securities ​ The Company classifies investments in equity securities that have a readily determinable fair value as marketable securities in the Company’s condensed consolidated balance sheets. The Company’s marketable securities are stated at fair value. Typically, the fair value of these securities is based on a quoted price for an identical equity security. If the equity security has a restriction that is determined to be an attribute of the security that would transfer to a market participant, the fair value of the security is measured based on the quoted price for an otherwise identical unrestricted equity security, adjusted for the effect of the restriction. The adjustment reflects the discount that a market participant would demand for the risk relating to the inability to dispose of the security for a specified period of time. That adjustment is based on the nature and duration of the restriction and the limitations imposed by the restriction to a buyer. The Company records changes in the fair value of its equity securities in “Other Income (Expense), net” in the Company’s condensed consolidated statement of operations.
Recent Accounting Pronouncements - Recently Adopted	Recent Accounting Pronouncements – Recently Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Statement Update (“ASU”) 2016-13, Financial Instruments-Credit Losses ASU 2016-13 requires evaluation of credit loss based on historical experience, current conditions and reasonable and supportable forecasts. current conditions and reasonable and supportable forecasts results in an expectation that nonpayment of the amortized cost basis is zero. At each reporting date, the Company will record an allowance for credit losses and reports it as credit loss expense which is included in “Other income (expense), net” in the Company’s condensed consolidated statement of operations. However subsequent increases or decreases in the fair value of available-for-sale securities that do not result in recognition or reversal of an allowance for credit loss or write-down will continue to be recorded in other comprehensive loss. The Company adopted the new standard and the related amendments on January 1, 2020 using a modified retrospective approach. The modified retrospective approach requires the Company to record a one-time adjustment to opening accumulated deficit as of the effective date. The Company concluded that there are no indicators of credit loss with respect to its available-for-sale debt securities which consist of U.S Treasury securities and government-agency bonds. The Company therefore did not record an allowance for credit losses or doubtful accounts upon adoption or during the first quarter of 2020. The adoption of ASU 2016-13 had no impact on the Company’s condensed consolidated financial statements. ​ In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . - ​ In 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which eliminates, adds, and modifies the disclosure requirements for fair value measurements. ASU 2018-13 was effective on January 1, 2020. The adoption of ASU 2018-13 results in additional disclosures related to the Company’s assets and liabilities that are valued based on Level 3 inputs and transfers between Level 1 and Level 2 fair value measurements.

Cash Equivalents, Marketable _2

Cash Equivalents, Marketable Securities and Corporate Equity Securities (Tables)	6 Months Ended
	Jun. 30, 2020
Cash Equivalents, Marketable Securities and Equity Securities
Schedule of cash equivalents, marketable securities and corporate equity securities	Cash equivalents and marketable securities consisted of the following at June 30, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ for Credit ​ ​ Unrealized ​ Unrealized ​ Fair June 30, 2020 ​ Cost ​ Losses ​ ​ Gains ​ Losses ​ Value Cash equivalents and marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 485,819 ​ $ — ​ ​ $ — ​ $ — ​ $ 485,819 U.S. Treasuries ​ ​ 26,961 ​ ​ — ​ ​ ​ 36 ​ ​ — ​ ​ 26,997 Government agency securities ​ ​ 67,565 ​ ​ — ​ ​ ​ 147 ​ ​ — ​ ​ 67,712 Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ ​ 14,525 ​ ​ — ​ ​ 18,192 Total ​ $ 584,012 ​ $ — ​ ​ $ 14,708 ​ $ — ​ $ 598,720 ​ Cash equivalents, marketable securities and equity securities consisted of the following at December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair December 31, 2019 ​ Cost ​ Gains ​ Losses ​ Value Cash equivalents and marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 230,201 ​ $ — ​ $ — ​ $ 230,201 U.S. Treasuries ​ ​ 71,348 ​ ​ 20 ​ ​ — ​ ​ 71,368 Government agency securities ​ ​ 155,484 ​ ​ 87 ​ ​ — ​ ​ 155,571 Equity securities included in other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ — ​ ​ 3,667 Total ​ $ 460,700 ​ $ 107 ​ $ — ​ $ 460,807

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Measurements
Schedule of assets measured at fair value on a recurring basis	Assets measured at fair value on a recurring basis as of June 30, 2020 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices Significant ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ June 30, ​ Identical Assets ​ Inputs ​ Inputs Financial Assets ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 485,819 ​ $ 485,819 ​ $ — ​ $ — Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Treasuries ​ ​ 26,997 ​ ​ 26,997 ​ ​ — ​ ​ — Government agency securities ​ ​ 67,712 ​ ​ 67,712 ​ ​ — ​ ​ — Corporate equity securities ​ ​ 18,192 ​ ​ — ​ ​ 18,192 ​ ​ — Restricted cash and other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ 3,877 ​ ​ 3,877 ​ ​ — ​ ​ — Total financial assets ​ $ 602,597 ​ $ 584,405 ​ $ 18,192 ​ $ — ​ Assets measured at fair value on a recurring basis as of December 31, 2019 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices Significant ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ December 31, ​ Identical Assets ​ Inputs ​ Inputs Financial Assets ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 230,201 ​ $ 230,201 ​ $ — ​ $ — U.S. Treasuries ​ ​ 7,982 ​ ​ 7,982 ​ ​ — ​ ​ — Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Treasuries ​ ​ 63,386 ​ ​ 63,386 ​ ​ — ​ ​ — Government agency securities ​ ​ 155,571 ​ ​ 155,571 ​ ​ — ​ ​ — Restricted cash and other non-current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate equity securities ​ ​ 3,667 ​ ​ — ​ ​ 3,667 ​ ​ — Money market funds ​ ​ 1,619 ​ ​ 1,619 ​ ​ — ​ ​ — Total financial assets ​ $ 462,426 ​ $ 458,759 ​ $ 3,667 ​ $ —

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2020
Accrued Expenses
Schedule of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ December 31, ​ 2020 2019 Employee related expenses ​ $ 4,179 ​ $ 4,971 Process and platform development expenses ​ ​ 2,266 ​ 735 Intellectual property and patent related fees ​ ​ 1,598 ​ ​ 3,725 Sublicensing expenses ​ ​ 813 ​ ​ 11,416 Professional service expenses ​ ​ 609 ​ ​ 674 Other expenses ​ ​ 729 ​ ​ 599 Total accrued expenses ​ $ 10,194 ​ $ 22,120 ​ ​ ​ ​ ​ ​ ​

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	6 Months Ended
	Jun. 30, 2020
Property and Equipment, net
Schedule of property and equipment, net	Property and equipment, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ December 31, ​ 2020 2019 Laboratory equipment ​ $ 16,656 ​ $ 14,571 Leasehold improvements ​ ​ 3,393 ​ ​ 1,042 Computer equipment ​ 858 ​ 858 Construction-in-progress ​ ​ 550 ​ ​ 1,336 Furniture and office equipment ​ ​ 166 ​ ​ 166 Software ​ 118 ​ 118 Total property and equipment ​ 21,741 ​ 18,091 Less: accumulated depreciation ​ (8,846) ​ (7,204) Property and equipment, net ​ $ 12,895 ​ $ 10,887

Collaboration and Profit-Shar_2

Collaboration and Profit-Sharing Agreements (Tables)	6 Months Ended
	Jun. 30, 2020
Collaboration and Profit-Sharing Agreements
Schedule of accounts receivable and contract liabilities	The following table presents changes in the Company’s accounts receivable and contract liabilities for the six months ended June 30, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the six months ended June 30, 2020 Balance at December 31, 2019 ​ Additions ​ Deductions ​ Balance at June 30, 2020 Accounts receivable $ 418 ​ $ 1,447 ​ $ ​ ​ $ 1,865 Contract liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred revenue $ 186,721 ​ $ 508 ​ $ (7,883) ​ $ 179,346
Schedule of change in contract assets and contract liabilities	During the three and six months ended June 30, 2020, the Company recognized the following collaboration revenue (in thousands): ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended Revenue recognized in the period from: June 30, 2020 Amounts included in deferred revenue at the beginning of the period $ 3,066 ​ $ 7,883 Performance obligations satisfied in previous periods $ — ​ $ 60

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Stock-based Compensation
Schedule of stock-based compensation expense	Total compensation cost recognized for all stock-based compensation awards in the condensed consolidated statements of operations was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 ​ Research and development ​ $ 2,673 ​ $ 3,853 ​ $ 5,730 ​ $ 7,235 ​ General and administrative ​ 2,744 ​ 2,640 ​ 5,907 ​ 7,113 ​ Total stock-based compensation expense ​ $ 5,417 ​ $ 6,493 ​ $ 11,637 ​ $ 14,348 ​
Schedule of changes in unvested restricted stock	The following is a summary of restricted stock and restricted stock unit awards activity for the six months ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ ​ Fair Value ​ ​ Shares ​ Per Share Unvested restricted stock and restricted stock unit awards as of December 31, 2019 581,408 ​ $ 24.03 Issued 283,319 ​ $ 27.91 Vested (243,587) ​ $ 22.65 Forfeited ​ (105,009) ​ $ 24.07 Unvested restricted stock and restricted stock unit awards as of June, 30 2020 516,131 ​ $ 26.60
Schedule of stock option activity	The following is a summary of stock option activity for the six months ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Remaining Aggregate Intrinsic ​ ​ Shares ​ Exercise Price ​ Contractual Life (years) ​ Value (in thousands) Outstanding at December 31, 2019 4,358,291 ​ $ 25.40 ​ 7.4 ​ $ 26,060 Granted ​ 1,228,749 ​ $ 27.84 ​ ​ ​ ​ ​ Exercised ​ (589,020) ​ $ 16.78 ​ ​ ​ ​ ​ Cancelled ​ (1,018,295) ​ $ 30.83 ​ ​ ​ ​ ​ Outstanding at June 30, 2020 3,979,725 ​ $ 26.04 ​ 8.0 ​ $ 17,695 Exercisable at June 30, 2020 1,367,908 ​ $ 23.94 ​ 6.7 ​ $ 10,035

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2020
Net Loss per Share
Schedule of anti-dilutive common stock equivalents	The following common stock equivalents were excluded from the calculation of diluted net loss per share allocable to common stockholders because their inclusion would have been anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ ​ 2020 2019 Unvested restricted stock and restricted stock unit awards ​ 516,131 591,473 Outstanding stock options ​ 3,979,725 4,452,878 Total ​ 4,495,856 5,044,351

Nature of Business (Details)

Nature of Business (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended	28 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2020	May 31, 2020	Dec. 31, 2019
Liquidity
Number of common stock issued	6,900,000
Proceeds from offering of common stock, net of issuance costs	$ 203,700	$ 203,964
Accumulated deficit	$ 610,517	$ 610,517	$ 610,517		$ 549,221
At Market Offering | Cowen and Company LLC ("Cowen")
Liquidity
Sales agreement amount of aggregate sale proceeds of common stock agreed to be issued				$ 150,000
Overallotment Option
Liquidity
Number of common stock issued	900,000
Public and Market Offering
Liquidity
Aggregate net proceeds			$ 648,700

Cash Equivalents, Marketable _3

Cash Equivalents, Marketable Securities and Corporate Equity Securities (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Equity securities included in other non-current assets:
Gross Unrealized Gains	$ 14,525
Cash Equivalents, Marketable Securities and Equity Securities
Amortized Cost	584,012		$ 460,700
Gross Unrealized Gains	14,708		107
Fair Value	598,720		460,807
Realized gains (losses) on available-for-sale securities	0	$ 0
Corporate equity securities
Cash Equivalents, Marketable Securities and Corporate Equity Securities
Amortized Cost	3,667
Gross Unrealized Gains	14,525
Fair Value	18,192
Equity securities included in other non-current assets:
Amortized Cost			3,667
Fair Value			3,667
Money market funds
Cash Equivalents, Marketable Securities and Corporate Equity Securities
Amortized Cost	485,819		230,201
Fair Value	485,819		230,201
U.S. Treasuries
Cash Equivalents, Marketable Securities and Corporate Equity Securities
Amortized Cost	26,961		71,348
Gross Unrealized Gains	36		20
Fair Value	26,997		71,368
Government agency securities
Cash Equivalents, Marketable Securities and Corporate Equity Securities
Amortized Cost	67,565		155,484
Gross Unrealized Gains	147		87
Fair Value	$ 67,712		$ 155,571

Fair Value Measurements - Recur

Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Corporate equity securities
Financial Assets
Equity securities		$ 3,667
Marketable securities	$ 18,192
Money market funds
Financial Assets
Marketable securities	485,819	230,201
U.S. Treasuries
Financial Assets
Marketable securities	26,997	71,368
Government agency securities
Financial Assets
Marketable securities	67,712	155,571
Recurring
Financial Assets
Total financial assets	602,597	462,426
Recurring | U.S. Treasuries
Financial Assets
Marketable securities	26,997	63,386
Recurring | Government agency securities
Financial Assets
Marketable securities	67,712	155,571
Recurring | Corporate equity securities
Financial Assets
Equity securities		3,667
Marketable securities	18,192
Recurring | Money market funds
Financial Assets
Cash and cash equivalents	485,819	230,201
Restricted cash	3,877	1,619
Recurring | U.S. Treasuries
Financial Assets
Cash and cash equivalents		7,982
Recurring | Level 1
Financial Assets
Total financial assets	584,405	458,759
Recurring | Level 1 | U.S. Treasuries
Financial Assets
Marketable securities	26,997	63,386
Recurring | Level 1 | Government agency securities
Financial Assets
Marketable securities	67,712	155,571
Recurring | Level 1 | Money market funds
Financial Assets
Cash and cash equivalents	485,819	230,201
Restricted cash	3,877	1,619
Recurring | Level 1 | U.S. Treasuries
Financial Assets
Cash and cash equivalents		7,982
Recurring | Level 2
Financial Assets
Total financial assets	18,192	3,667
Recurring | Level 2 | Corporate equity securities
Financial Assets
Equity securities		$ 3,667
Marketable securities	$ 18,192

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Fair Value Measurements
Unrealized gain on corporate equity securities		$ 14,525
Other income (expense), net
Fair Value Measurements
Unrealized gain on corporate equity securities	$ 7,200	$ 14,500

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accrued Expenses
Employee related expenses	$ 4,179	$ 4,971
Process and platform development expenses	2,266	735
Intellectual property and patent related fees	1,598	3,725
Sublicensing expenses	813	11,416
Professional service expenses	609	674
Other expenses	729	599
Total	$ 10,194	$ 22,120

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property and equipment disclosures
Total property and equipment	$ 21,741	$ 18,091
Less: accumulated depreciation	(8,846)	(7,204)
Property and equipment, net	12,895	10,887
Laboratory equipment
Property and equipment disclosures
Total property and equipment	16,656	14,571
Leasehold improvements
Property and equipment disclosures
Total property and equipment	3,393	1,042
Computer equipment
Property and equipment disclosures
Total property and equipment	858	858
Construction-in-progress
Property and equipment disclosures
Total property and equipment	550	1,336
Furniture and office equipment
Property and equipment disclosures
Total property and equipment	166	166
Software
Property and equipment disclosures
Total property and equipment	$ 118	$ 118

Commitments and Contingencies -

Commitments and Contingencies - Licensor Expense Reimbursement (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Licensor Expense Reimbursement
Commitments and contingencies
Expense for prosecution and maintenance of patent rights	$ 2.8	$ 3.5	$ 6.6	$ 6.9

Collaboration and Profit-Shar_3

Collaboration and Profit-Sharing Agreements - Revenue Recognition (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)
Accounts receivable
Accounts receivable, Balance at Beginning of Period	$ 418
Accounts Receivable, Additions	1,447
Accounts receivable, Balance at End of Period	1,865
Contract liabilities:
Deferred Revenue, Balance at Beginning of Period	186,721
Deferred revenue, Additions	508
Deferred revenue, Deductions	(7,883)
Deferred Revenue, Balance at End of Period	$ 179,346

Collaboration and Profit-Shar_4

Collaboration and Profit-Sharing Agreements - Contract Assets and Liability (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Change in contract asset and contract liability balances
Amounts included in deferred revenue at the beginning of the period	$ 3,066	$ 7,883
Performance obligations satisfied in previous periods		$ 60

Stock-based Compensation - Expe

Stock-based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Stock-based compensation disclosures
Compensation expense	$ 5,417	$ 6,493	$ 11,637	$ 14,348
Research and development
Stock-based compensation disclosures
Compensation expense	2,673	3,853	5,730	7,235
General and administrative
Stock-based compensation disclosures
Compensation expense	$ 2,744	$ 2,640	$ 5,907	$ 7,113

Stock-based Compensation - Rest

Stock-based Compensation - Restricted Stock and Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Weighted Average Grant Date Fair Value
Compensation expense	$ 5,417	$ 6,493	$ 11,637	$ 14,348
Restricted Stock
Changes in unvested restricted stock
Unvested restricted shares, beginning of period (in shares)			581,408
Issued (in shares)			283,319
Vested (in shares)			(243,587)
Forfeited (in shares)			(105,009)
Unvested restricted shares, end of period(in shares)	516,131		516,131		581,408
Weighted Average Grant Date Fair Value
Balance, beginning of period			$ 24.03
Issued (in dollars per share)			27.91
Vested (in dollars per share)			22.65
Forfeited (in dollars per share)			24.07
Balance, ending of period	$ 26.60		$ 26.60		$ 24.03
Unrecognized stock-based compensation expense	$ 12,000		$ 12,000
Period for recognition			3 years
Stock options
Weighted Average Grant Date Fair Value
Unrecognized stock-based compensation expense	$ 40,000		$ 40,000
Period for recognition			2 years 9 months 18 days
Changes in unvested stock options
Outstanding, beginning of period (in shares)			4,358,291
Granted (in shares)			1,228,749
Exercised (in shares)			(589,020)
Cancelled (in shares)			(1,018,295)
Outstanding, end of period (in shares)	3,979,725		3,979,725		4,358,291
Exercisable (in shares)	1,367,908		1,367,908
Outstanding, beginning of period (in dollars per share)			$ 25.40
Granted (in dollars per share)			27.84
Exercised (in dollars per share)			16.78
Cancelled (in dollars per share)			30.83
Outstanding, end of period (in dollars per share)	$ 26.04		26.04		$ 25.40
Exercisable (in dollar per share)	$ 23.94		$ 23.94
Remaining contractual life			8 years		7 years 4 months 24 days
Exercisable, remaining contractual life			6 years 8 months 12 days
Aggregate intrinsic value	$ 17,695		$ 17,695		$ 26,060
Exercisable, aggregated intrinsic value	$ 10,035		$ 10,035

Net Loss per Share (Details)

Net Loss per Share (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Potentially dilutive securities
Anti-dilutive common stock equivalent shares	4,495,856	5,044,351
Restricted Stock
Potentially dilutive securities
Anti-dilutive common stock equivalent shares	516,131	591,473
Stock options
Potentially dilutive securities
Anti-dilutive common stock equivalent shares	3,979,725	4,452,878