Dicerna Pharmaceuticals (DRNA) 10-Q 5 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 02, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	DRNA
Entity Registrant Name	DICERNA PHARMACEUTICALS INC
Entity Central Index Key	1,399,529
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 Common Stock, Shares Outstanding		62,731,942

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 46,399	$ 68,789
Held-to-maturity investments	133,980	44,889
Withholding tax receivable		1,583
Prepaid expenses and other current assets	3,107	3,415
Total current assets	183,486	118,676
NONCURRENT ASSETS:
Property and equipment, net	1,212	1,512
Restricted cash equivalents	744	744
Other noncurrent assets	66	70
Total noncurrent assets	2,022	2,326
TOTAL ASSETS	185,508	121,002
CURRENT LIABILITIES:
Accounts payable	3,595	4,920
Accrued expenses and other current liabilities	8,101	5,726
Litigation settlement payable	12,797
Current portion of deferred revenue	4,635	6,180
Total current liabilities	29,128	16,826
NONCURRENT LIABILITIES:
Deferred revenue, net of current portion		3,090
Total noncurrent liabilities		3,090
TOTAL LIABILITIES	29,128	19,916
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.0001 par value – 5,000,000 shares authorized; no shares issued or outstanding at September 30, 2018 or December 31, 2017
Common stock, $0.0001 par value – 150,000,000 shares authorized; 61,889,206 and 51,644,841 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	6	5
Additional paid-in capital	542,572	417,037
Accumulated deficit	(386,198)	(315,956)
Total stockholders’ equity	156,380	101,086
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 185,508	$ 121,002

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 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	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	61,889,206	51,644,841
Common stock, shares outstanding	61,889,206	51,644,841

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue from collaborative arrangements	$ 1,545		$ 4,635
Operating expenses:
Research and development	11,695	$ 8,527	31,927	$ 26,338
General and administrative	5,354	4,137	14,449	12,324
Litigation expense	3,694	2,548	29,122	6,157
Total operating expenses	20,743	15,212	75,498	44,819
Loss from operations	(19,198)	(15,212)	(70,863)	(44,819)
Other income (expense):
Interest income	401	179	1,020	360
Interest expense	(223)		(399)
Total other income, net	178	179	621	360
Net loss	(19,020)	(15,033)	(70,242)	(44,459)
Dividends on redeemable convertible preferred stock		(4,111)		(6,733)
Deemed dividend related to beneficial conversion feature of redeemable convertible preferred stock				(6,144)
Net loss attributable to common stockholders	$ (19,020)	$ (19,144)	$ (70,242)	$ (57,336)
Net loss per share attributable to common stockholders – basic and diluted	$ (0.35)	$ (0.92)	$ (1.32)	$ (2.76)
Weighted average common shares outstanding – basic and diluted	54,799,644	20,841,728	53,037,516	20,809,372

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (70,242)	$ (44,459)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash litigation expense	10,315
Stock-based compensation expense	5,673	6,003
Depreciation expense	580	571
Loss on disposal of property and equipment	9	51
Amortization of premium on investments	(390)	(106)
Changes in operating assets and liabilities:
Litigation settlement payable	12,797
Deferred revenue	(4,635)
Prepaid expenses and other assets	312	(1,963)
Accounts payable	(1,389)	1,114
Withholding tax receivable	1,583
Accrued expenses and other liabilities	2,045	(584)
Net cash used in operating activities	(43,342)	(39,373)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(245)	(133)
Maturities of held-to-maturity investments	50,000	45,000
Purchases of held-to-maturity investments	(138,699)	(64,853)
Net cash used in investing activities	(88,944)	(19,986)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of underwriters' commissions	108,099
Proceeds from issuance of redeemable convertible preferred stock		70,000
Redeemable convertible preferred stock issuance costs		(750)
Proceeds from stock option exercises and issuances under Employee Stock Purchase Plan	1,832	215
Settlement of restricted stock for tax withholding	(35)	(11)
Net cash provided by financing activities	109,896	69,454
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH EQUIVALENTS	(22,390)	10,095
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH EQUIVALENTS — Beginning of period	69,533	21,981
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH EQUIVALENTS — End of period	47,143	32,076
NONCASH FINANCING ACTIVITIES:
Dividends on redeemable convertible preferred stock		6,733
Deemed dividend related to beneficial conversion feature of redeemable preferred stock		$ 6,144
Common stock issuance costs included in accounts payable and accrued expenses	349
NONCASH INVESTING ACTIVITIES:
Property and equipment purchases included in accounts payable	$ 44

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Operating Cash Flows Direct Method [Abstract]
Cash and cash equivalents	$ 46,399	$ 68,789	$ 30,960
Restricted cash equivalents	744	744	1,116
Cash, cash equivalents and restricted cash equivalents presented above	$ 47,143	$ 69,533	$ 32,076	$ 21,981

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Business Dicerna Pharmaceuticals, Inc. (“Dicerna” or the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative subcutaneously delivered ribonucleic acid (“RNA”) interference (“RNAi”)-based pharmaceuticals using its GalXC TM Basis of presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial information. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP to constitute a complete set of financial statements. These condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position at September 30, 2018 and results of operations and cash flows for the interim periods ended September 30, 2018 and 2017. These unaudited condensed consolidated interim financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The results of the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018 or for any other interim period or for any other future year. Stockholders’ Equity Changes in stockholders’ equity for the nine months ended September 30, 2018 are as follows: Common Stock Total Description Number of shares Amount Additional Paid-in Capital Accumulated Deficit Stockholders' Equity BALANCE – 51,644,841 $ 5 $ 417,037 $ (315,956 ) $ 101,086 Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs 8,832,565 1 107,749 — 107,750 Issuance of common stock to Alnylam Pharmaceuticals, Inc. 983,208 — 10,315 — 10,315 Exercise of common stock options 258,417 — 1,444 — 1,444 Sale of common stock related to Employee Stock Purchase Plan 118,239 — 309 — 309 Exercise of warrants to common stock 45,710 — 45 — 45 Settlement of restricted stock for stock withholding 6,226 — — — — Stock-based compensation expense — — 5,673 — 5,673 Net loss — — — (70,242 ) (70,242 ) BALANCE – September 30, 2018 61,889,206 $ 6 $ 542,572 $ (386,198 ) $ 156,380 Significant judgments and estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the Company’s condensed consolidated financial statements, as well as the revenues and expenses incurred during the reporting periods. On an ongoing basis, the Company evaluates judgments and estimates, including those related to revenue recognition and accrued expenses. The Company bases its estimates on historical experience and on various other factors that the Company believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not apparent from other sources. Changes in estimates are reflected in reported results for the period in which they become known. Actual results could differ materially from those estimates. Grants The Company records income from various grants as an offset to research and development expenses. Liquidity Based on the Company’s current operating plan and liquidity, management believes that, subject to the closing of the transactions contemplated by the Collaboration and License Agreement (the “Lilly Collaboration Agreement”) between the Company and Eli Lilly and Company (“Lilly”) and the share issuance agreement (the “Lilly Share Issuance Agreement”) between the Company and Lilly, available cash, cash equivalents, and held-to-maturity investments will be sufficient to fund the Company’s planned level of operations beyond the year ended December 31, 2020. Subsequent to that period, if the Company is unable to generate funding from one or more sources within a reasonable timeframe, it may have to delay, reduce, or terminate its research and development programs, pre-clinical or clinical trials, limit strategic opportunities, or undergo reductions in its workforce or other corporate restructuring activities. Summary of Significant Accounting Policies – There have been no changes to the significant accounting policies disclosed in the Company’s most recent Annual Report on Form 10-K, except as a result of adopting the Financial Accounting Standards Board (“FASB”)’s Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) , as discussed below. Revenue recognition The Company generates revenue from research collaboration and license agreements with third-party customers. Goods and services in the agreements typically include (i) the grant of licenses for the use of the Company’s technology and (ii) the provision of services associated with the research and development of customer product candidates. Such agreements may provide for consideration to the Company in the form of upfront payments, research and development services, option payments, milestone payments, and royalty payments on licensed products. The Company accounts for a contract when the Company has approval and commitment from both parties, when the rights of the parties are identified, when payment terms are identified, when the contract has commercial substance, and when collectability of consideration is probable. In determining the appropriate amount of revenue to be recognized as the Company fulfills its obligations under each of its agreements, management completes the following steps: (i) identifies the promised goods or services in the contract; (ii) determines whether the promised goods or services are performance obligations; (iii) measures the transaction price, including whether there are any constraints on variable consideration; (iv) allocates the transaction price to the performance obligations; and (v) recognizes revenue when (or as) the Company satisfies each performance obligation. In order to account for its contracts with customers, the Company identifies the promised goods or services in the contract and evaluates whether such promised goods or services represent performance obligations. The Company accounts for those components as separate performance obligations when the following criteria are met: • the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and • the Company’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract. This evaluation requires subjective determinations and requires the Company to make judgments about the promised goods and services and whether such goods and services are separable from the other aspects of the contractual relationship. In determining the performance obligations, the Company evaluates certain criteria, including whether the promised good or service is capable of being distinct and whether such good or service is distinct within the context of the contract, based on consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research, manufacturing, and commercialization capabilities of the partner; the availability of research and manufacturing expertise in the general marketplace; and the level of integration, interrelation, and interdependence among the promises to transfer goods or services. As part of the accounting for the relevant arrangements, the Company makes key assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the underlying contract, which may include, as applicable, relevant market data, forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates, and probabilities of technical and regulatory success. The transaction price is allocated among the performance obligations using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate performance obligations. At contract inception, the Company determines the standalone selling price for each performance obligation identified in the contract. If an observable price of the promised good or service sold separately is not readily available, the Company utilizes assumptions that require judgment to estimate the standalone selling price, which may include development timelines, probabilities of technical and regulatory success, reimbursement rates for personnel costs, forecasted revenues, potential limitations to the selling price of the product, expected technological life of the product, and discount rates. Licenses of intellectual property: If a license granted to a customer to use the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from consideration allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company applies judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, to conclude upon the appropriate method of measuring progress for purposes of recognizing revenue related to consideration allocated to the performance obligation. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone payments: At the inception of each contract with a customer that includes development or regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or of the licensee, such as regulatory approvals, are assessed as to the probability of achieving the related milestones. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of all milestones and any related constraint, and, if necessary, adjusts the estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis and are recorded as revenue and through earnings in the period of adjustment. Options: Customer options, such as options granted to allow a licensee to choose to research and develop product candidates against target genes to be identified in the future, generally do not provide a material right to the customer and therefore do not give rise to a separate performance obligation. As such, the additional consideration that would result from a customer exercising an option in the future is not included in the transaction price for the current contract. Instead, additional option fee payments are recognized or begin being recognized as revenue when the licensee exercises the options, and the exercise of the option would be treated as a separate contract for accounting purposes. Research and development services: Arrangements that include a promise to provide research or development services at the licensee’s discretion are assessed to determine whether the services provide a material right to the licensee and are capable of being distinct, are not highly interdependent or do not significantly modify one another, and if so, the services are accounted for as separate performance obligations as the services are provided to the customer. Otherwise, when research or development services are determined not to be capable of being distinct or distinct within the context of the contract, those services are added to the performance obligation that includes the underlying license. Royalties: For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and when the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any out-licensing arrangement. The Company receives payments from its licensees as established in each contract. Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Where applicable, amounts are recorded as contracts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract with a customer has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less. Recent Accounting Pronouncements Adopted in 2018 Revenue recognition In May 2014, the FASB issued Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Revenue Recognition Statement of cash flows In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash Not yet adopted Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements “ ” and evaluating the impact of the new guidance on its condensed consolidated financial statements and related disclosures; however,

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	2. NET LOSS PER SHARE The Company computes basic net loss per common share by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding. In periods of net income, the Company’s accounting policy includes allocating a proportional share of net income to participating securities, as determined by dividing total weighted average participating securities by the sum of the total weighted average common shares and participating securities (the “two-class method”). The Company’s vested restricted shares participated in any dividends declared by the Company and were therefore considered to be participating securities. Participating securities have the effect of diluting both basic and diluted earnings per share during periods of income. During periods when the Company incurred a net loss, the Company did not allocate a loss to participating securities because they had no contractual obligation to share in the losses of the Company. The outstanding securities presented below were excluded from the calculation of net loss per share, because such securities would have been anti-dilutive due to the Company’s net loss per share during the periods ending on the dates presented. September 30, 2018 2017 Options to purchase common stock 7,573,698 6,134,301 Warrants to purchase common stock 2,198 87,901 Unvested restricted common stock — 10,000 Redeemable convertible preferred stock — 740,126 Total 7,575,896 6,972,328

Held-to-maturity Investments

Held-to-maturity Investments	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Held-to-maturity Investments	3. HELD-TO-MATURITY INVESTMENTS The following tables provide information regarding the Company’s held-to-maturity investments. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value As of September 30, 2018: Held-to-maturity investments U.S. treasury securities maturing in one year or less $ 133,980 $ — $ (57 ) $ 133,923 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value As of December 31, 2017: Held-to-maturity investments U.S. treasury securities maturing in one year or less $ 44,889 $ — $ (30 ) $ 44,859 The Company’s investment policy mandates that, at the time of purchase, the maturity of each investment within its portfolio shall not exceed 24 months. In addition, the weighted average maturity of the investment portfolio must not exceed 12 months.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	4. STOCK-BASED COMPENSATION During the three and nine months ended September 30, 2018, the Company granted stock options to purchase 175,500 and 1,936,850 shares, respectively, of common stock with aggregate grant date fair values of $1.7 million and $14.9 million, respectively, compared to stock options to purchase 304,500 and 1,635,497 shares of common stock granted with aggregate grant date fair values of $0.7 million and $3.5 million, for the three and nine months ended September 30, 2017, respectively. The assumptions used to estimate the grant date fair value using the Black-Scholes option pricing model were as follows: Three Months Ended Nine Months Ended September 30, 2018 Common stock price $12.74 - $15.74 $9.14 - $15.74 Expected option term (in years) 6.00 - 6.25 5.50 - 6.25 Expected volatility 77.0% - 77.9% 75.9% - 90.9% Risk-free interest rate 2.78% - 2.90% 2.32% - 2.90% Expected dividend yield 0.00% 0.00% Three Months Ended Nine Months Ended September 30, 2017 Common stock price $3.24 - $3.99 $2.49 - $3.99 Expected option term (in years) 5.50 - 6.25 5.50 - 6.25 Expected volatility 79.6% - 90.8% 79.4% - 90.8% Risk-free interest rate 1.87% - 2.04% 1.86% - 2.07% Expected dividend yield 0.00% 0.00% The Company has classified stock-based compensation in its condensed consolidated statements of operations as follows: Three Months Ended Nine Months Ended Three Months Ended Nine Months Ended September 30, 2018 September 30, 2017 Research and development expense $ 718 $ 2,275 $ 899 $ 2,816 General and administrative expenses 1,430 3,398 1,071 3,187 Total $ 2,148 $ 5,673 $ 1,970 $ 6,003

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. FAIR VALUE MEASUREMENTS A summary of the Company’s financial assets that are measured or disclosed at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 are presented below. Description September 30, 2018 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 29,459 $ 29,459 $ — $ — Held-to-maturity investments U.S. treasury securities 133,923 — 133,923 — Restricted cash equivalents Money market fund 744 — 744 — Total $ 164,126 $ 29,459 $ 134,667 $ — Description December 31, 2017 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 51,441 $ 51,441 $ — $ — Held-to-maturity investments U.S. treasury securities 44,859 — 44,859 — Restricted cash equivalents Money market fund 744 — 744 — Total $ 97,044 $ 51,441 $ 45,603 $ — The Company’s cash equivalents, which are in money market funds, are classified within Level 1 of the fair value hierarchy because they are valued using quoted prices as of September 30, 2018 and December 31, 2017. The Company’s held-to-maturity investments and restricted cash equivalents bore interest at the prevailing market rates for instruments with similar characteristics and therefore approximated fair value. These financial instruments were classified within Level 2 of the fair value hierarchy because the inputs to the fair value measurement are valued using observable inputs as of September 30, 2018 and December 31, 2017. As of September 30, 2018 and December 31, 2017, the Company’s accounts payable and accrued expenses approximated their estimated fair values because of the short-term nature of these financial instruments. As of December 31, 2017, the carrying amount of the withholding tax receivable also approximated its estimated fair value due to the short-term nature of the instrument. Th e Company Alnylam Pharmaceuticals, Inc. (“Alnylam”). The Company’s policy is to recognize transfers between levels of the fair value hierarchy, if any, at the end of the reporting period; however, there have been no

Collaborative Research and Lice

Collaborative Research and License Agreement	9 Months Ended
	Sep. 30, 2018
Collaborative Research And License Agreement [Abstract]
Collaborative Research and License Agreement	6. COLLABORATIVE RESEARCH AND LICENSE AGREEMENT On October 27, 2017, the Company entered into a collaborative research and license agreement (the “BI Agreement”) with Boehringer Ingelheim International GmbH (“BI”), pursuant to which the Company and BI jointly research and develop product candidates for the treatment of chronic liver disease using the GalXC platform, Dicerna’s proprietary RNAi-based technology. The BI Agreement is for the development of product candidates against one target gene with an option for BI to add the development of product candidates that target a second gene. Pursuant to the BI Agreement, Dicerna granted BI a worldwide license in connection with the research and development of such product candidates and has transferred to BI certain intellectual property rights of the product candidates selected by BI for clinical development and commercialization. Dicerna also may provide assistance to BI in order to help BI further develop selected product candidates. Under the terms of the BI Agreement, BI agreed to pay Dicerna a non-refundable upfront payment of $10.0 million for the first target, less a refundable withholding tax in Germany of $1.6 million. The German withholding tax was withheld by BI and remitted to the German tax authorities in accordance with local tax law; the Company received reimbursement of this tax in July 2018. During the term of the research program, BI will reimburse Dicerna the cost of certain materials and third-party expenses that have been included in the preclinical studies. The Company is eligible to receive up to $191.0 million in potential development and commercial milestones related to the initial target. Dicerna is also eligible to receive royalty payments on potential global net sales, subject to certain adjustments, tiered from high single digits up to low double digits. BI’s option to add a second target would provide for an option fee payment and success-based development and commercialization milestones and royalty payments to Dicerna. Milestone payments that are contingent upon the Company’s performance under the BI Agreement include potential developmental milestones totaling $99.0 million, including milestones for the first commercial sale. The Company has excluded the amounts from allocable consideration at the outset of the arrangement, as described below. All potential net sales milestones, totaling $95.0 million, will be accounted for in the same manner as royalties and recorded as revenue at the later of the achievement of the milestone or the satisfaction of the performance obligation. The Company assessed the BI Agreement in accordance with ASC 606 and concluded that BI is a customer. The Company identified the following performance obligations under the contract: the license of intellectual property and conducting agreed-upon research program services. The Company has concluded that the license and research and development services do not have standalone value and are not capable of being distinct; therefore, the Company considers these to be one performance obligation. The Company concluded the option underlying the transfer of future licenses and potential associated research for any not-yet-known target gene is not a performance obligation of the contract at inception because the option fee reflects the standalone selling price of the option, and therefore, the option is not considered to be a material right. The Company considered the level of BI’s therapeutic expertise specifically related to RNAi, as well as BI’s know-how vis-à-vis the Company’s GalXC conjugates, and concluded that BI cannot currently benefit from the granted license on its own or together with other resources that are readily available to BI, including relationships with oligonucleotide vendors who synthesize GalXC conjugates under contract with the Company. As a result, the combination of the license of intellectual property together with the provision of research and development support services together represent the highest level of goods and services that can be deemed distinct. Based on management’s evaluation, the non-refundable upfront fee and the agreed-upon reimbursable third-party expenses constituted the amount of the consideration to be included in the transaction price and has been allocated to the performance obligation identified based on the Company’s best estimate of the relative standalone selling price via application of a market assessment approach. None of the development milestones have been included in the transaction price, since none of such milestone amounts are within the control of the Company and are not considered probable to occur until confirmed by BI, at BI’s sole discretion. Any consideration related to commercial sales-based milestones (including royalties) will be recognized when the related sales occur, since these amounts have been determined to relate predominantly to the license granted to BI and therefore are recognized at the later of when the performance obligation is satisfied or the related sales occur. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The $10.3 million transaction price is being recognized over the current research term, which is estimated to extend through June 30, 2019, which represents the Company’s best estimate of the period of the obligation to provide research support services to BI, and is the expected period over which the Company estimates the deferred revenue balance will be recognized in revenue. Related revenue is being recognized on a straight-line basis, which is in management’s judgment an appropriate measure of progress toward satisfying the performance obligation, largely in absence of evidence that obligations are fulfilled in a specific pattern. The following table presents changes in the Company’s deferred revenue accounts during the nine months ended September 30, 2018. Nine months ended September 30, 2018 Balance at beginning of period Additions Deductions Balance at end of period Current portion of deferred revenue $ 6,180 $ — $ (1,545 ) $ 4,635 Deferred revenue, net of current portion $ 3,090 $ — $ (3,090 ) $ — The Company recognized revenues of $1.5 million and $4.6 million for the three and nine months ended September 30, 2018, as a result of changes in the deferred revenue balances. There was no activity related to the Company’s deferred revenue accounts during the three and nine months ended September 30, 2017.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES Facility lease Future minimum lease payments on the Company’s non-cancelable operating lease for office and laboratory space are as follows: Years Ending December 31, Operating Lease Remaining 2018 $ 409 2019 1,678 2020* 1,581 Total $ 3,668 * The end of the lease term is November 30, 2020. Litigation On June 10, 2015, Alnylam filed a complaint against the Company in the Superior Court of Middlesex County, Massachusetts (the “Court”). The complaint alleged misappropriation of confidential, proprietary, and trade secret information, as well as other related claims, in connection with the Company’s hiring of a number of former employees of Merck & Co., Inc. (“Merck”) and its discussions with Merck regarding the acquisition of its subsidiary, Sirna Therapeutics, Inc., which was subsequently acquired by Alnylam. On April 18, 2018, the Company and Alnylam entered into a Confidential Settlement Agreement and General Release (the “Settlement Agreement”), resolving all ongoing litigation between the Company and Alnylam. The terms of the Settlement Agreement include mutual releases and dismissals with prejudice of all claims and counterclaims in the following litigation between the parties: (i) Alnylam Pharmaceuticals, Inc. v. Dicerna Pharmaceuticals, Inc. Dicerna Pharmaceuticals, Inc., v. Alnylam Pharmaceuticals, Inc. Under the Settlement Agreement, for periods ranging from 18 months up to four years, the Company will be restricted in its development and other activities relating to oligonucleotide-based therapeutics directed toward a defined set of eight Alnylam targets (the “Oligo Restrictions”). The Oligo Restrictions pertain to targets where Dicerna does not have, or does not currently intend to have, a therapeutic program, or are expected to be consistent with Dicerna’s execution on programs in the normal course of business. The Settlement Agreement does not include any admission of liability or wrongdoing by either party or any licenses to any intellectual property from either party. On April 20, 2018, the Company and Alnylam entered into the Share Issuance Agreement, pursuant to which the Company agreed to issue to Alnylam 983,208 Shares in satisfaction of the Company’s obligation under the Settlement Agreement to deliver Shares to Alnylam. The Share Issuance Agreement contains customary representations and warranties of each party. Pursuant to the terms of the Share Issuance Agreement, Alnylam may not, without the prior approval of the Company, dispose of any of the Shares for a six-month period commencing on the closing date of the Share issuance. Thereafter, through the fifth anniversary of the closing date of the Share issuance, Alnylam will only dispose of the maximum number of Shares that it would be permitted to dispose if the Shares were subject to the volume restrictions set forth in Rule 144(e) of the Securities Act of 1933, as amended. The Company paid the upfront payment of $2.0 million dollars in May 2018 and recorded the cash obligation of $13.0 million as a liability discounted to the estimated present value of $8.7 million at an effective interest rate of 10.0%. Ten percent of any first year or upfront consideration or proceeds paid to the Company arising from any new collaboration agreements are payable to Alnylam until the cash obligation is satisfied. If the entire obligation is not paid by the fourth-year anniversary of the agreement, the balance is payable to Alnylam in cash at that time. Upon signing the agreement, the Company recorded a liability equal to the estimated present value of the obligation at that time. The Company applies the effective interest method, as the present value is accreted through maturity. As of September 30, 2018, $0.4 million of interest expense had been recorded on this liability. Upon receipt of certain upfront cash payments owed to the Company resulting from signing the Alexion and Lilly agreements in October 2018, the Company anticipates that the $13.0 million cash obligation will become payable in the fourth quarter of 2018. As a result, the estimated present value of $12.8 million, which was revised based on the expected timing of the remaining payments, is recorded in current liabilities. The impact of revising the expected timing of repayment is recorded as a component of litigation expense in the condensed consolidated statement of operations. The 983,208 shares issued pursuant to the Share Issuance Agreement was recorded at fair market value of $10.3 million based on the Company’s closing share price on April 18, 2018, the date the Settlement Agreement was executed. The Company did not assign any value to the Oligo Restrictions as the Company did not incur additional losses or give up any value as a result of the restrictions. Total litigation expense was $3.7 million and $29.1 million for the three and nine months ended September 30, 2018, respectively, all of which related to the litigation and settlement agreement with Alnylam. The litigation expense for the nine months ended September 30, 2018 includes $24.7 million related to the Settlement Agreement. The Company recorded litigation expenses, also related to the Alnylam litigation, of $2.5 million and $6.2 million for three and nine months ended September 30, 2017, respectively, which was previously included as a component of general and administrative expenses and recast to litigation expense for comparative purposes. From time to time, the Company may be subject to various claims and legal proceedings. If the potential loss from any claim, asserted or unasserted, or legal proceeding is considered probable and the amount is reasonably estimable, the Company will accrue a liability for the estimated loss. There were no contingent liabilities recorded as of September 30, 2018 and December 31, 2017.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	8. SUBSEQUENT EVENTS Alexion Alexion Collaborative Research and License Agreement On October 22, 2018, the Company and Alexion Pharma Holding Unlimited Company (“Alexion Pharma Holding”), an affiliate of Alexion Pharmaceuticals, Inc. (“Alexion Pharmaceuticals” and together with Alexion Pharma Holding, “Alexion”) entered into a Collaborative Research and License Agreement (the “Alexion Collaboration Agreement”). The Alexion Collaboration Agreement is for the joint discovery and development of RNAi therapies for complement-mediated diseases. Under the terms of the Alexion Collaboration Agreement, the Company and Alexion will collaborate on the discovery and development of subcutaneously delivered GalXC candidates, currently in pre-clinical development, for the treatment of complement-mediated diseases with potential global commercialization by Alexion. The Company will lead the joint discovery and research efforts through the pre-clinical stage, and Alexion will lead development efforts beginning with Phase 1 studies. The Company will be responsible for manufacturing of the GalXC candidates through the completion of Phase 1, the costs of which will be paid by Alexion. Alexion will be solely responsible for the manufacturing of any product candidate subsequent to the completion of Phase 1. The Alexion Collaboration Agreement provides Alexion with exclusive worldwide licenses as well as development and commercial rights for two of the Company’s pre-clinical, subcutaneously delivered GalXC RNAi candidates and an exclusive option for the discovery and development of GalXC RNAi candidates against two additional complement pathway targets. Under the terms of the Alexion Collaboration Agreement, Alexion will pay the Company a non-refundable, non-reimbursable, and non-creditable upfront payment of $22.0 million, with Alexion Pharmaceuticals making a concurrent $15.0 million equity investment at a premium in Dicerna pursuant to a share issuance agreement between the Company and Alexion Pharmaceuticals (the “Alexion Share Issuance Agreement”). The Alexion Collaboration Agreement also provides for potential additional payments to the Company of up to $600.0 million, which is comprised of option exercise fees of up to $20.0 million, representing $10.0 million for each of the candidates selected; development milestones of up to $105.0 million for each product; and aggregate sales milestones of up to $160.0 million. Under the agreement, Alexion will also pay to the Company mid-single to low-double digit royalties on potential product sales on a country-by-country, product-by-product basis until the later of the expiration of patent rights in a country, the expiration of market or regulatory exclusivity in such country, or 10 years after the first product sale in such country, subject to certain royalty step-down provisions set forth in the agreement The Alexion Collaboration Agreement includes various representations, warranties, covenants, indemnities, and other customary provisions. Alexion may terminate the Alexion Collaboration Agreement at any time without cause following a 90-day notice period. Alexion Share Issuance Agreement In connection with the Alexion Collaboration Agreement, the Company and Alexion entered into the Alexion Share Issuance Agreement on October 22, 2018, pursuant to which the Company agreed to issue to Alexion 835,834 shares of the Company’s common stock Pursuant to the terms of the Alexion Share Issuance Agreement, Alexion may not, without the prior approval of the Company, dispose of any of the Alexion Shares for a six-month period of time commencing on the closing date of the Alexion Share issuance. Lilly Lilly Collaboration and License Agreement On October 25, 2018, the Company and Lilly entered into a Collaboration and License Agreement the Lilly Collaboration Agreement. The Lilly Collaboration Agreement is for The Lilly Collaboration Agreement provides that the Company will work exclusively with Lilly in the neurodegeneration and pain fields with the exception of mutually agreed upon orphan indications. Additionally, the Company will work exclusively with Lilly on select targets in the cardio-metabolic field. Under the Lilly Collaboration Agreement, the Company will provide Lilly with exclusive and non-exclusive licenses to support the companies’ activities and to enable Lilly to commercialize products derived from or containing compounds developed pursuant to such agreement. The Lilly Collaboration Agreement contemplates in excess of 10 targets. Under the terms of the Lilly Collaboration Agreement, Lilly will pay the Company a non-refundable, non-creditable upfront payment of $100.0 million, with Lilly making a concurrent $100.0 million equity investment in the Company pursuant to the Lilly Share Issuance Agreement. Under the Lilly Collaboration Agreement, the Company is also eligible to potentially receive up to approximately $350.0 million per target in development and commercialization milestones, in addition to a $5.0 million payment due when the first non-hepatocyte target achieves proof of principle. In addition, the Lilly Collaboration Agreement also provides that Lilly will pay to the Company mid-single to low-double digit royalties on potential product sales on a country-by-country and product-by-product basis until the later of expiration of patent rights in a country, the expiration of data or regulatory exclusivity in such country, or 10 years after the first product sale in such country, subject to certain royalty step-down provisions set forth in the agreement. The Lilly Collaboration Agreement includes various representations, warranties, covenants, indemnities, and other customary provisions. Lilly may terminate the Lilly Collaboration Agreement at any time without cause following a 90-day notice period. The Lilly Collaboration Agreement is subject to clearance under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”), and other customary closing conditions. Lilly Share Issuance Agreement In connection with the Lilly Collaboration Agreement, the Company and Lilly entered into the Lilly Share Issuance Agreement on October 25, 2018, pursuant to which the Company agreed to issue to Lilly 5,414,185 shares of the Company’s common stock at a purchase price of $18.47 per share, for an aggregate purchase price of approximately $100.0 million. The issuance of shares of common stock under the Lilly Share Issuance Agreement is subject to clearance under the HSR Act and other customary closing conditions. The Lilly Share Issuance Agreement contains customary representations, warranties, and covenants of each party. The Lilly Share Issuance Agreement will automatically terminate if the Lilly Collaboration Agreement is terminated prior to the closing of the transactions contemplated by the Lilly Share Issuance Agreement. Pursuant to the terms of the Lilly Share Issuance Agreement, Lilly may not, without the prior approval of the Company or except in the case of a third party tender offer, dispose of any of the Lilly Shares for a nine-month period of time commencing on the closing date of the Lilly Share issuance. Alnylam As a result of the recently executed partnership agreements with Alexion and Lilly, the Company believes that its cash obligation of $13.0 million payable to Alnylam will become due and that it will make this payment during the fourth quarter of 2018. As a result, the estimated present value of $12.8 million, which was revised based on the expected timing of the remaining payments, is recorded in current liabilities. The impact of revising the expected timing of repayment was recorded as a $3.7 million charge to litigation expense in the condensed consolidated statement of operations for three and nine months ended September 30, 2018.

Description of Business and B_2

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Business	Business Dicerna Pharmaceuticals, Inc. (“Dicerna” or the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative subcutaneously delivered ribonucleic acid (“RNA”) interference (“RNAi”)-based pharmaceuticals using its GalXC TM
Basis of presentation	Basis of presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial information. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP to constitute a complete set of financial statements. These condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position at September 30, 2018 and results of operations and cash flows for the interim periods ended September 30, 2018 and 2017. These unaudited condensed consolidated interim financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The results of the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018 or for any other interim period or for any other future year.
Stockholders' Equity	Stockholders’ Equity Changes in stockholders’ equity for the nine months ended September 30, 2018 are as follows: Common Stock Total Description Number of shares Amount Additional Paid-in Capital Accumulated Deficit Stockholders' Equity BALANCE – 51,644,841 $ 5 $ 417,037 $ (315,956 ) $ 101,086 Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs 8,832,565 1 107,749 — 107,750 Issuance of common stock to Alnylam Pharmaceuticals, Inc. 983,208 — 10,315 — 10,315 Exercise of common stock options 258,417 — 1,444 — 1,444 Sale of common stock related to Employee Stock Purchase Plan 118,239 — 309 — 309 Exercise of warrants to common stock 45,710 — 45 — 45 Settlement of restricted stock for stock withholding 6,226 — — — — Stock-based compensation expense — — 5,673 — 5,673 Net loss — — — (70,242 ) (70,242 ) BALANCE – September 30, 2018 61,889,206 $ 6 $ 542,572 $ (386,198 ) $ 156,380
Significant judgments and estimates	Significant judgments and estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the Company’s condensed consolidated financial statements, as well as the revenues and expenses incurred during the reporting periods. On an ongoing basis, the Company evaluates judgments and estimates, including those related to revenue recognition and accrued expenses. The Company bases its estimates on historical experience and on various other factors that the Company believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not apparent from other sources. Changes in estimates are reflected in reported results for the period in which they become known. Actual results could differ materially from those estimates.
Grants	Grants The Company records income from various grants as an offset to research and development expenses.
Liquidity	Liquidity Based on the Company’s current operating plan and liquidity, management believes that, subject to the closing of the transactions contemplated by the Collaboration and License Agreement (the “Lilly Collaboration Agreement”) between the Company and Eli Lilly and Company (“Lilly”) and the share issuance agreement (the “Lilly Share Issuance Agreement”) between the Company and Lilly, available cash, cash equivalents, and held-to-maturity investments will be sufficient to fund the Company’s planned level of operations beyond the year ended December 31, 2020. Subsequent to that period, if the Company is unable to generate funding from one or more sources within a reasonable timeframe, it may have to delay, reduce, or terminate its research and development programs, pre-clinical or clinical trials, limit strategic opportunities, or undergo reductions in its workforce or other corporate restructuring activities.
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies – There have been no changes to the significant accounting policies disclosed in the Company’s most recent Annual Report on Form 10-K, except as a result of adopting the Financial Accounting Standards Board (“FASB”)’s Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) , as discussed below.
Revenue recognition	Revenue recognition The Company generates revenue from research collaboration and license agreements with third-party customers. Goods and services in the agreements typically include (i) the grant of licenses for the use of the Company’s technology and (ii) the provision of services associated with the research and development of customer product candidates. Such agreements may provide for consideration to the Company in the form of upfront payments, research and development services, option payments, milestone payments, and royalty payments on licensed products. The Company accounts for a contract when the Company has approval and commitment from both parties, when the rights of the parties are identified, when payment terms are identified, when the contract has commercial substance, and when collectability of consideration is probable. In determining the appropriate amount of revenue to be recognized as the Company fulfills its obligations under each of its agreements, management completes the following steps: (i) identifies the promised goods or services in the contract; (ii) determines whether the promised goods or services are performance obligations; (iii) measures the transaction price, including whether there are any constraints on variable consideration; (iv) allocates the transaction price to the performance obligations; and (v) recognizes revenue when (or as) the Company satisfies each performance obligation. In order to account for its contracts with customers, the Company identifies the promised goods or services in the contract and evaluates whether such promised goods or services represent performance obligations. The Company accounts for those components as separate performance obligations when the following criteria are met: • the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and • the Company’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract. This evaluation requires subjective determinations and requires the Company to make judgments about the promised goods and services and whether such goods and services are separable from the other aspects of the contractual relationship. In determining the performance obligations, the Company evaluates certain criteria, including whether the promised good or service is capable of being distinct and whether such good or service is distinct within the context of the contract, based on consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research, manufacturing, and commercialization capabilities of the partner; the availability of research and manufacturing expertise in the general marketplace; and the level of integration, interrelation, and interdependence among the promises to transfer goods or services. As part of the accounting for the relevant arrangements, the Company makes key assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the underlying contract, which may include, as applicable, relevant market data, forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates, and probabilities of technical and regulatory success. The transaction price is allocated among the performance obligations using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate performance obligations. At contract inception, the Company determines the standalone selling price for each performance obligation identified in the contract. If an observable price of the promised good or service sold separately is not readily available, the Company utilizes assumptions that require judgment to estimate the standalone selling price, which may include development timelines, probabilities of technical and regulatory success, reimbursement rates for personnel costs, forecasted revenues, potential limitations to the selling price of the product, expected technological life of the product, and discount rates. Licenses of intellectual property: If a license granted to a customer to use the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from consideration allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company applies judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, to conclude upon the appropriate method of measuring progress for purposes of recognizing revenue related to consideration allocated to the performance obligation. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone payments: At the inception of each contract with a customer that includes development or regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or of the licensee, such as regulatory approvals, are assessed as to the probability of achieving the related milestones. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of all milestones and any related constraint, and, if necessary, adjusts the estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis and are recorded as revenue and through earnings in the period of adjustment. Options: Customer options, such as options granted to allow a licensee to choose to research and develop product candidates against target genes to be identified in the future, generally do not provide a material right to the customer and therefore do not give rise to a separate performance obligation. As such, the additional consideration that would result from a customer exercising an option in the future is not included in the transaction price for the current contract. Instead, additional option fee payments are recognized or begin being recognized as revenue when the licensee exercises the options, and the exercise of the option would be treated as a separate contract for accounting purposes. Research and development services: Arrangements that include a promise to provide research or development services at the licensee’s discretion are assessed to determine whether the services provide a material right to the licensee and are capable of being distinct, are not highly interdependent or do not significantly modify one another, and if so, the services are accounted for as separate performance obligations as the services are provided to the customer. Otherwise, when research or development services are determined not to be capable of being distinct or distinct within the context of the contract, those services are added to the performance obligation that includes the underlying license. Royalties: For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and when the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any out-licensing arrangement. The Company receives payments from its licensees as established in each contract. Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Where applicable, amounts are recorded as contracts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract with a customer has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted in 2018 Revenue recognition In May 2014, the FASB issued Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Revenue Recognition Statement of cash flows In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash Not yet adopted Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements “ ” and evaluating the impact of the new guidance on its condensed consolidated financial statements and related disclosures; however,

Description of Business and B_3

Description of Business and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Changes in Stockholders' Equity	Changes in stockholders’ equity for the nine months ended September 30, 2018 are as follows: Common Stock Total Description Number of shares Amount Additional Paid-in Capital Accumulated Deficit Stockholders' Equity BALANCE – 51,644,841 $ 5 $ 417,037 $ (315,956 ) $ 101,086 Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs 8,832,565 1 107,749 — 107,750 Issuance of common stock to Alnylam Pharmaceuticals, Inc. 983,208 — 10,315 — 10,315 Exercise of common stock options 258,417 — 1,444 — 1,444 Sale of common stock related to Employee Stock Purchase Plan 118,239 — 309 — 309 Exercise of warrants to common stock 45,710 — 45 — 45 Settlement of restricted stock for stock withholding 6,226 — — — — Stock-based compensation expense — — 5,673 — 5,673 Net loss — — — (70,242 ) (70,242 ) BALANCE – September 30, 2018 61,889,206 $ 6 $ 542,572 $ (386,198 ) $ 156,380

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Outstanding Securities excluded from Calculation of Net Loss Per Share	The outstanding securities presented below were excluded from the calculation of net loss per share, because such securities would have been anti-dilutive due to the Company’s net loss per share during the periods ending on the dates presented. September 30, 2018 2017 Options to purchase common stock 7,573,698 6,134,301 Warrants to purchase common stock 2,198 87,901 Unvested restricted common stock — 10,000 Redeemable convertible preferred stock — 740,126 Total 7,575,896 6,972,328

Held-to-maturity Investments (T

Held-to-maturity Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Schedule of Held-To-Maturity Investments	The following tables provide information regarding the Company’s held-to-maturity investments. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value As of September 30, 2018: Held-to-maturity investments U.S. treasury securities maturing in one year or less $ 133,980 $ — $ (57 ) $ 133,923 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value As of December 31, 2017: Held-to-maturity investments U.S. treasury securities maturing in one year or less $ 44,889 $ — $ (30 ) $ 44,859

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Valuation Assumptions	The assumptions used to estimate the grant date fair value using the Black-Scholes option pricing model were as follows: Three Months Ended Nine Months Ended September 30, 2018 Common stock price $12.74 - $15.74 $9.14 - $15.74 Expected option term (in years) 6.00 - 6.25 5.50 - 6.25 Expected volatility 77.0% - 77.9% 75.9% - 90.9% Risk-free interest rate 2.78% - 2.90% 2.32% - 2.90% Expected dividend yield 0.00% 0.00% Three Months Ended Nine Months Ended September 30, 2017 Common stock price $3.24 - $3.99 $2.49 - $3.99 Expected option term (in years) 5.50 - 6.25 5.50 - 6.25 Expected volatility 79.6% - 90.8% 79.4% - 90.8% Risk-free interest rate 1.87% - 2.04% 1.86% - 2.07% Expected dividend yield 0.00% 0.00%
Stock-Based Compensation Expense	The Company has classified stock-based compensation in its condensed consolidated statements of operations as follows: Three Months Ended Nine Months Ended Three Months Ended Nine Months Ended September 30, 2018 September 30, 2017 Research and development expense $ 718 $ 2,275 $ 899 $ 2,816 General and administrative expenses 1,430 3,398 1,071 3,187 Total $ 2,148 $ 5,673 $ 1,970 $ 6,003

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets Measured or Disclosed at Fair Value	A summary of the Company’s financial assets that are measured or disclosed at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 are presented below. Description September 30, 2018 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 29,459 $ 29,459 $ — $ — Held-to-maturity investments U.S. treasury securities 133,923 — 133,923 — Restricted cash equivalents Money market fund 744 — 744 — Total $ 164,126 $ 29,459 $ 134,667 $ — Description December 31, 2017 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 51,441 $ 51,441 $ — $ — Held-to-maturity investments U.S. treasury securities 44,859 — 44,859 — Restricted cash equivalents Money market fund 744 — 744 — Total $ 97,044 $ 51,441 $ 45,603 $ —

Collaborative Research and Li_2

Collaborative Research and License Agreement (Tables)	9 Months Ended
	Sep. 30, 2018
Collaborative Research And License Agreement [Abstract]
Schedule of Changes in Deferred Revenue Accounts	The following table presents changes in the Company’s deferred revenue accounts during the nine months ended September 30, 2018. Nine months ended September 30, 2018 Balance at beginning of period Additions Deductions Balance at end of period Current portion of deferred revenue $ 6,180 $ — $ (1,545 ) $ 4,635 Deferred revenue, net of current portion $ 3,090 $ — $ (3,090 ) $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments on Company's Non-cancelable Operating Lease	Future minimum lease payments on the Company’s non-cancelable operating lease for office and laboratory space are as follows: Years Ending December 31, Operating Lease Remaining 2018 $ 409 2019 1,678 2020* 1,581 Total $ 3,668 * The end of the lease term is November 30, 2020.

Description of Business and B_4

Description of Business and Basis of Presentation- Changes in Stockholder's Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary Of Significant Accounting Policies [Line Items]
BALANCE – December 31, 2017			$ 101,086
Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs			107,750
Issuance of common stock to Alnylam Pharmaceuticals, Inc.			10,315
Exercise of common stock options			1,444
Sale of common stock related to Employee Stock Purchase Plan			309
Exercise of warrants to common stock			45
Stock-based compensation expense			5,673
Net loss	$ (19,020)	$ (15,033)	(70,242)	$ (44,459)
BALANCE – September 30, 2018	156,380		156,380
Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
BALANCE – December 31, 2017			$ 5
BALANCE - December 31, 2017 (in shares)			51,644,841
Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs			$ 1
Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs, shares			8,832,565
Issuance of common stock to Alnylam Pharmaceuticals, Inc., shares			983,208
Exercise of common stock options, shares			258,417
Sale of common stock related to employee stock purchase plan, shares			118,239
Exercise of warrants to common stock, shares			45,710
Settlement of restricted stock for stock withholding, shares			6,226
BALANCE – September 30, 2018	$ 6		$ 6
BALANCE - September 30, 2018 (in shares)	61,889,206		61,889,206
Additional Paid in Capital [Member]
Summary Of Significant Accounting Policies [Line Items]
BALANCE – December 31, 2017			$ 417,037
Proceeds from issuance of common stock from public offering, net of underwriting fees and issuance costs			107,749
Issuance of common stock to Alnylam Pharmaceuticals, Inc.			10,315
Exercise of common stock options			1,444
Sale of common stock related to Employee Stock Purchase Plan			309
Exercise of warrants to common stock			45
Stock-based compensation expense			5,673
BALANCE – September 30, 2018	$ 542,572		542,572
Accumulated Deficit [Member]
Summary Of Significant Accounting Policies [Line Items]
BALANCE – December 31, 2017			(315,956)
Net loss			(70,242)
BALANCE – September 30, 2018	$ (386,198)		$ (386,198)

Description of Business and B_5

Description of Business and Basis of Presentation- Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Availability of current operating plan and liquidity, date	Dec. 31, 2020

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail)	Sep. 30, 2018USD ($)
Earnings Per Share [Abstract]
Contractual obligation to share in losses of the company	$ 0

Net Loss Per Share - Outstandin

Net Loss Per Share - Outstanding Securities excluded from Calculation of Net Loss Per Share (Detail) - shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	7,575,896	6,972,328
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	7,573,698	6,134,301
Hercules Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	2,198	87,901
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities		10,000
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities		740,126

Held-to-maturity Investments -

Held-to-maturity Investments - Schedule of Held-To-Maturity Investments (Detail) - US Treasury Securities [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity investments, Amortized Cost	$ 133,980	$ 44,889
Held-to-maturity investments, Gross Unrealized Gains	0	0
Held-to-maturity investments, Gross Unrealized Losses	(57)	(30)
Held-to-maturity investments, Fair Value, Total	$ 133,923	$ 44,859

Held-to-maturity Investments _2

Held-to-maturity Investments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity investments portfolio maximum period	24 months
Maximum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Weighted average maturity investment portfolio period	12 months

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - Employee Stock Option [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, granted	175,500	304,500	1,936,850	1,635,497
Fair value of stock options	$ 1.7	$ 0.7	$ 14.9	$ 3.5

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Valuation Assumptions (Detail) - Employee Stock Option [Member] - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price	$ 12.74	$ 3.24	$ 9.14	$ 2.49
Expected option term (in years)	6 years	5 years 6 months	5 years 6 months	5 years 6 months
Expected volatility	77.00%	79.60%	75.90%	79.40%
Risk-free interest rate	2.78%	1.87%	2.32%	1.86%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price	$ 15.74	$ 3.99	$ 15.74	$ 3.99
Expected option term (in years)	6 years 3 months	6 years 3 months	6 years 3 months	6 years 3 months
Expected volatility	77.90%	90.80%	90.90%	90.80%
Risk-free interest rate	2.90%	2.04%	2.90%	2.07%

Stock-Based Compensation - Clas

Stock-Based Compensation - Classification of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,148	$ 1,970	$ 5,673	$ 6,003
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	718	899	2,275	2,816
General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,430	$ 1,071	$ 3,398	$ 3,187

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets Measured or Disclosed at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Restricted cash equivalents
Total	$ 164,126	$ 97,044
Money Market Fund [Member]
Cash equivalents
Money market fund	29,459	51,441
Restricted cash equivalents
Money market fund	744	744
US Treasury Securities [Member]
Held-to-maturity investments
U.S. treasury securities	133,923	44,859
Level 1 [Member]
Restricted cash equivalents
Total	29,459	51,441
Level 1 [Member] | Money Market Fund [Member]
Cash equivalents
Money market fund	29,459	51,441
Level 2 [Member]
Restricted cash equivalents
Total	134,667	45,603
Level 2 [Member] | Money Market Fund [Member]
Restricted cash equivalents
Money market fund	744	744
Level 2 [Member] | US Treasury Securities [Member]
Held-to-maturity investments
U.S. treasury securities	$ 133,923	$ 44,859

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Estimated present value of cash obligation	$ 12,797,000
Litigation settlement, liability		$ 0
Alnylam [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash obligation payable as part of litigation settlement	13,000,000
Estimated present value of cash obligation	$ 12,800,000

Collaborative Research and Li_3

Collaborative Research and License Agreement - Additional Information (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)PerformanceObligation	Dec. 31, 2017USD ($)	Oct. 27, 2017USD ($)
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Proceeds from income tax refunds			$ 1,583
Number of performance obligation | PerformanceObligation		1
Revenue recognized	$ 1,500	$ 4,600
Foreign Tax Authority [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Proceeds from income tax refunds				$ 1,600
BI Agreement [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Initial non-refundable upfront payment				$ 10,000
Additional payments upon potential development and commercial milestones	191,000	191,000
Potential Developmental Milestone	99,000	99,000
Net Sales Milestone	95,000	95,000
BI Agreement [Member] | Over Current Research Term [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Recognition of transaction price	$ 10,300	$ 10,300

Collaborative Research and Li_4

Collaborative Research and License Agreement - Schedule of Changes in Deferred Revenue Accounts (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Revenue Recognition And Deferred Revenue [Abstract]
Balance at beginning of period	$ 6,180
Additions	0
Deductions	(1,545)
Balance at end of period	4,635
Balance at beginning of period	3,090
Additions	0
Deductions	(3,090)
Balance at end of period	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Summary of Future Minimum Lease Payments on Company's Non-cancelable Operating Lease (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remaining 2,018	$ 409
2,019	1,678
2,020	1,581	[1]
Total	$ 3,668
[1]	The end of the lease term is November 30, 2020.

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments on Company's Non-cancelable Operating Lease (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Lease Expiration Date	Nov. 30, 2020

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Detail)	Apr. 18, 2018USD ($)shares	May 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Apr. 20, 2018shares	Dec. 31, 2017USD ($)
Loss Contingencies [Line Items]
Litigation settlement expense			$ 3,694,000	$ 2,548,000	$ 29,122,000	$ 6,157,000
Alnylam [Member]
Loss Contingencies [Line Items]
Cash obligation payable as part of litigation settlement			13,000,000		13,000,000
Settled Litigation [Member]
Loss Contingencies [Line Items]
Contingent liabilities			0		$ 0			$ 0
Settled Litigation [Member] | Alnylam [Member]
Loss Contingencies [Line Items]
Settlement agreement date	April 18, 2018
Settlement agreement terms					The terms of the Settlement Agreement include mutual releases and dismissals with prejudice of all claims and counterclaims in the following litigation between the parties: (i) Alnylam Pharmaceuticals, Inc. v. Dicerna Pharmaceuticals, Inc., No. 15-4126 pending in the Massachusetts Superior Court for Middlesex County and (ii) Dicerna Pharmaceuticals, Inc., v. Alnylam Pharmaceuticals, Inc. No.1:17-cv-11466 pending in the United States District Court for the District of Massachusetts.
Litigation settlement upfront payment payable	$ 2,000,000
Litigation settlement upfront payment		$ 2,000,000
Percentage of consideration receivable related to future collaboration	10.00%
Additional litigation settlement payment	$ 13,000,000		13,000,000		$ 13,000,000
Additional litigation settlement payment date	Apr. 28, 2022
Loss contingency settlement agreement counterparty's name	Alnylam Pharmaceuticals, Inc.
Number of Oligo Restrictions target	8
Issuance of shares under shares issuance agreement | shares	983,208						983,208
Cash obligation payable as part of litigation settlement		13,000,000	13,000,000		13,000,000
Litigation settlement discounted estimated present value of liability		$ 8,700,000	12,800,000		12,800,000
Debt instrument effective interest percentage		10.00%
Interest expense					400,000
Share issued at fair market value	$ 10,300,000
Litigation settlement expense			$ 3,700,000	$ 2,500,000	29,100,000	$ 6,200,000
Settled Litigation [Member] | Alnylam [Member] | Settlement Agreement [Member]
Loss Contingencies [Line Items]
Litigation settlement expense					$ 24,700,000
Settled Litigation [Member] | Alnylam [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Loss contingency settlement agreement period	18 months
Settled Litigation [Member] | Alnylam [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Loss contingency settlement agreement period	4 years

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)	Oct. 25, 2018	Oct. 22, 2018	Sep. 30, 2018	Sep. 30, 2018	Apr. 18, 2018
Subsequent Event [Line Items]
Estimated present value of cash obligation			$ 12,797,000	$ 12,797,000
Alnylam [Member]
Subsequent Event [Line Items]
Estimated present value of cash obligation			12,800,000	12,800,000
Charge to litigation expenses due to revising the expected timing of repayment			3,700,000	3,700,000
Alnylam [Member] | Settled Litigation [Member]
Subsequent Event [Line Items]
Additional litigation settlement payment			$ 13,000,000	$ 13,000,000	$ 13,000,000
Subsequent Event [Member] | Alexion Collaborative Research and License Agreement [Member]
Subsequent Event [Line Items]
Non refundable upfront payment receivable		$ 22,000,000
Equity investment under share issuance agreement		15,000,000
Option exercise fee for each candidates selected		10,000,000
Aggregate sales milestones receivable		$ 160,000,000
Royalty payment, description		Under the agreement, Alexion will also pay to the Company mid-single to low-double digit royalties on potential product sales on a country-by-country, product-by-product basis until the later of the expiration of patent rights in a country, the expiration of market or regulatory exclusivity in such country, or 10 years after the first product sale in such country, subject to certain royalty step-down provisions set forth in the agreement.
Collaboration agreement termination, notice period		90 days
Subsequent Event [Member] | Alexion Collaborative Research and License Agreement [Member] | Maximum [Member]
Subsequent Event [Line Items]
Potential additional payment receivable		$ 600,000,000
Option exercise fee		20,000,000
Potential development milestones receivable		$ 105,000,000
Subsequent Event [Member] | Alexion Share Issuance Agreement [Member]
Subsequent Event [Line Items]
Number of common stock issuable		835,834
Purchase price per share		$ 17.95
Aggregate purchase price		$ 15,000,000
Share dispose, description		Pursuant to the terms of the Alexion Share Issuance Agreement, Alexion may not, without the prior approval of the Company, dispose of any of the Alexion Shares for a six-month period of time commencing on the closing date of the Alexion Share issuance.
Subsequent Event [Member] | Lilly Collaboration and License Agreement [Member]
Subsequent Event [Line Items]
Non refundable upfront payment receivable	$ 100,000,000
Equity investment under share issuance agreement	$ 100,000,000
Royalty payment, description	Lilly Collaboration Agreement also provides that Lilly will pay to the Company mid-single to low-double digit royalties on potential product sales on a country-by-country and product-by-product basis until the later of expiration of patent rights in a country, the expiration of data or regulatory exclusivity in such country, or 10 years after the first product sale in such country, subject to certain royalty step-down provisions set forth in the agreement.
Collaboration agreement termination, notice period	90 days
Payment due on first non-hepatocyte target achievement	$ 5,000,000
Subsequent Event [Member] | Lilly Collaboration and License Agreement [Member] | Maximum [Member]
Subsequent Event [Line Items]
Development and commercialization milestones receivable	$ 350,000,000
Subsequent Event [Member] | Lilly ShareIssuance Agreement [Member]
Subsequent Event [Line Items]
Number of common stock issuable	5,414,185
Purchase price per share	$ 18.47
Aggregate purchase price	$ 100,000,000
Share dispose, description	Pursuant to the terms of the Lilly Share Issuance Agreement, Lilly may not, without the prior approval of the Company or except in the case of a third party tender offer, dispose of any of the Lilly Shares for a nine-month period of time commencing on the closing date of the Lilly Share issuance.