Dicerna Pharmaceuticals (DRNA) 10-Q 10 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 09, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
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	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		20,844,429

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 38,777	$ 20,865
Held-to-maturity investments (Note 3)	49,953	25,009
Prepaid expenses and other current assets	2,966	1,952
Total current assets	91,696	47,826
NONCURRENT ASSETS:
Property and equipment-net	1,837	2,234
Restricted cash equivalents	1,116	1,116
Other noncurrent assets	74	76
Total noncurrent assets	3,027	3,426
TOTAL ASSETS	94,723	51,252
CURRENT LIABILITIES:
Accounts payable	4,129	4,318
Accrued expenses and other current liabilities	5,454	5,726
Total current liabilities	9,583	10,044
TOTAL LIABILITIES	9,583	10,044
Commitments and contingencies (Note 6)
Redeemable convertible preferred stock, $0.0001 par value-5,000,000 shares authorized; 718,404 and no shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively (aggregate liquidation preference of $71,841 and $0 at June 30, 2017 and December 31, 2016, respectively) (Note 4)	71,872	0
STOCKHOLDERS' EQUITY:
Common stock, $0.0001 par value-150,000,000 shares authorized at June 30, 2017 and December 31, 2016; 20,794,427 shares and 20,753,001 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	2	2
Additional paid-in capital	298,448	296,962
Accumulated deficit	(285,182)	(255,756)
Total stockholders' equity	13,268	41,208
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 94,723	$ 51,252

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Redeemable convertible preferred stock, par value	$ 0.0001
Redeemable convertible preferred stock, shares authorized	5,000,000
Redeemable convertible preferred stock, shares issued	718,404
Redeemable convertible preferred stock, shares outstanding	718,404
Aggregate liquidation preference value	$ 71,841	$ 0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	20,794,427	20,753,001
Common stock, shares outstanding	20,794,427	20,753,001

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenue	$ 252		$ 385
Operating expenses:
Research and development	9,320	$ 11,032	18,196	$ 22,296
General and administrative	6,300	4,656	11,796	9,140
Total operating expenses	15,620	15,688	29,992	31,436
Loss from operations	(15,368)	(15,688)	(29,607)	(31,436)
Interest income	143	66	181	121
Net loss	(15,225)	(15,622)	(29,426)	(31,315)
Dividends on redeemable convertible preferred stock	(2,622)		(2,622)
Deemed dividend related to beneficial conversion feature of redeemable convertible preferred stock	(6,144)		(6,144)
Net loss attributable to common stockholders	$ (23,991)	$ (15,622)	$ (38,192)	$ (31,315)
Net loss per share attributable to common stockholders-basic and diluted	$ (1.15)	$ (0.75)	$ (1.84)	$ (1.51)
Weighted average common shares outstanding-basic and diluted	20,794,193	20,726,108	20,792,925	20,706,388

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (29,426)	$ (31,315)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	4,033	4,795
Depreciation and amortization	363	414
Net amortization of premium/discount on investments	(35)	64
Loss on disposal of property and equipment	51
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,013)	53
Accounts payable	(599)	580
Accrued expenses and other liabilities	(276)	(181)
Deferred rent	4	48
Net cash used in operating activities	(26,898)	(25,542)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(58)	(279)
Maturities of held-to-maturity investments	25,000	18,500
Purchases of held-to-maturity investments	(49,908)	(20,016)
Net cash used in investing activities	(24,966)	(1,795)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	70,000
Redeemable convertible preferred stock issuance costs	(300)
Proceeds from stock option exercises and issuances under employee stock purchase plan	87	493
Settlement of restricted stock for tax withholding	(11)	(27)
Net cash provided by financing activities	69,776	466
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	17,912	(26,871)
CASH AND CASH EQUIVALENTS - Beginning of period	20,865	56,058
CASH AND CASH EQUIVALENTS - End of period	38,777	29,187
NONCASH FINANCING ACTIVITIES:
Dividends on redeemable convertible preferred stock	2,622
Deemed dividend related to beneficial conversion feature of redeemable convertible preferred stock	6,144
Redeemable convertible preferred stock issuance costs included in accounts payable	$ 450
NONCASH INVESTING ACTIVITIES:
Property and equipment purchases included in accounts payable		$ 29

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Business Dicerna Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative subcutaneously delivered ribonucleic acid 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. Accordingly, these condensed consolidated financial statements do not include all of the information and notes 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 June 30, 2017 and results of operations and cash flows for the interim periods ended June 30, 2017 and 2016. 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 Significant judgments and estimates The preparation of 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 consolidated financial statements, as well as the revenue and expenses incurred during the reporting periods. On an ongoing basis, the Company evaluates judgments and estimates, including those related to accrued expenses, stock-based compensation and in relation to the accounting for, including cumulative dividends on, the Redeemable Convertible Preferred, as defined below. 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. Liquidity risk Based on the Company’s current operating plan and liquidity, including the receipt of gross proceeds of $70.0 million from the issuance of the Company’s Redeemable Convertible Preferred, as defined below, on April 11, 2017 (see Note 4), management believes that available cash, cash equivalents and held-to-maturity 12-month Summary of Significant Accounting Policies 10-K, Recent Accounting Pronouncements Adopted in 2017 Stock-based compensation In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting 2016-09”), 2016-09 2016-09. Not yet adopted Revenue recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), Revenue Recognition Revenue from Contracts with Customers Income taxes In October 2016, the FASB issued ASU No. 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory 2016-16”), 2016-16 pre-tax 2016-16 Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02”), which 2016-02 2016-02 2016-02 Statement of cash flows In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) 2016-15”), 2016-15 2016-15 2016-15 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash 2016-18”), 2016-18 2016-18 Stock-based compensation In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09”), 2017-09, 2017-19

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	2. Net Loss per Share Attributable to Common Stockholders The outstanding securities presented below were excluded from the calculation of net loss per share attributable to common stockholders, because such securities would have been anti-dilutive due to the Company’s net loss per share attributable to common stockholders during the periods ending on the dates presented. June 30, 2017 June 30, Options to purchase common stock 6,212,437 4,888,522 Warrants to purchase common stock 87,901 87,901 Unvested restricted common stock 10,000 25,859 Redeemable convertible preferred stock 718,404 —

Held-to-maturity Investments

Held-to-maturity Investments	6 Months Ended
	Jun. 30, 2017
Text Block [Abstract]
Held-to-maturity Investments	3. Held-to-maturity The following tables provide information relating to the Company’s held-to-maturity As of June 30, 2017: Amortized Gross Gross Fair Held-to-maturity U.S. treasury securities maturing in one year or less $ 49,953 $ — $ (22 ) $ 49,931 As of December 31, 2016: Amortized Gross Gross Fair Held-to-maturity U.S. treasury securities maturing in one year or less $ 25,009 $ — $ (5 ) $ 25,004

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	6 Months Ended
	Jun. 30, 2017
Text Block [Abstract]
Redeemable Convertible Preferred Stock	4. Redeemable Convertible Preferred Stock On April 11, 2017, pursuant to a redeemable convertible preferred stock purchase agreement (“SPA”) with seven institutional investors (“Investors”), led by funds advised by Bain Capital Life Sciences L.P. (“Lead Investor”), the Company issued and sold in a private placement 700,000 shares of its newly designated Redeemable Convertible Preferred Stock, par value $0.0001 per share (“Redeemable Convertible Preferred”), at a purchase price of $100.00 per share, for total gross proceeds of $70.0 million (“Private Placement”), less issuance costs of $0.8 million. The shares of Redeemable Convertible Preferred and the shares of common stock issuable upon conversion of the Redeemable Convertible Preferred were offered and sold by the Company pursuant to an exemption from the registration requirements of the Securities Act provided by Section 4(a)(2) thereunder. In addition to the Lead Investor, other participants in the Private Placement included Cormorant Asset Management, Domain Associates, EcoR1 Capital, RA Capital and Skyline Ventures, among others. Domain Associates, RA Capital and Skyline Ventures are entities that are affiliated or were formerly affiliated with certain members of the Company’s board of directors. The Redeemable Convertible Preferred has the rights and preferences set forth in a Certificate of Designation, which was filed with the Secretary of State of the State of Delaware. Those rights and preferences are summarized below. Conversion The Company has the right to require the Investors to convert the Redeemable Convertible Preferred into common stock at any time following the earlier of the second anniversary of the closing of the Private Placement or the occurrence of certain agreed-upon milestone events, provided, that, in each case, the trading price of the Company’s common stock exceeds 200% of $3.19 (the “Conversion Price”) for 45 out of 60 consecutive trading days. The Company’s ability to require conversion shall be subject to (i) a 19.99% blocker provision to comply with NASDAQ Listing Rules (“19.99% Conversion Blocker”), (ii) for certain Investors, a 9.99% blocker provision (“9.99% Conversion Blocker”) that will prohibit beneficial ownership of more than 9.99% of the outstanding shares of the Company’s common stock or voting power at any time, or (iii) applicable regulatory restrictions. The 19.99% Conversion Blocker and the 9.99% Conversion Blocker are hereinafter referred to as the “Conversion Blockers.” The Conversion Price is subject to proportionate adjustment for any stock split, stock dividend, combination or other similar recapitalization event. At any time and from time to time at their election, the holders of Redeemable Convertible Preferred will have the option to convert the Redeemable Convertible Preferred into shares of the Company’s common stock by dividing (i) the sum of the Accrued Value plus an amount equal to all accrued or declared and unpaid dividends on the Redeemable Convertible Preferred that have not previously been added to the Accrued Value by (ii) the Conversion Price in effect at the time of such conversion. The conversion of shares of Redeemable Convertible Preferred into shares of common stock is subject to the Conversion Blockers. “Accrued Value” means, with respect to each share of Redeemable Convertible Preferred, the sum of (i) $100.00 plus (ii) on each quarterly dividend date, an additional amount equal to the dollar value of any dividends on a share of Redeemable Convertible Preferred which have accrued on any dividend payment date and have not previously been added to such Accrued Value. Redemption On or at any time following the seventh anniversary of the closing of the Private Placement, (i) the Company shall have the right to redeem the Redeemable Convertible Preferred for a cash consideration equal to the sum of the Accrued Value, as of the date of redemption, plus an amount equal to all accrued or declared and unpaid dividends on the Redeemable Convertible Preferred that have not previously been added to the Accrued Value, and (ii) the holders of a majority of the Redeemable Convertible Preferred shall also have the right to cause the Company to redeem the Redeemable Convertible Preferred at the same price. Upon consummation of a specified change of control transaction, each holder of Redeemable Convertible Preferred will be entitled to receive in preference to the holders of common stock and any junior preferred stock, an amount equal to the greater of (i) 101% of the sum of the Accrued Value plus an amount equal to all accrued or declared and unpaid dividends on the Redeemable Convertible Preferred that have not previously been added to the Accrued Value, or (ii) the amount that such shares would have been entitled to receive if they had converted into common stock immediately prior to such event. Liquidation preferences In the event of the Company’s liquidation, dissolution or winding up, the holder of each share of Redeemable Convertible Preferred will be entitled to receive, in preference to the holders of the common stock and any junior preferred stock, an amount per share equal to the greater of (i) the sum of the Accrued Value plus an amount equal to all accrued or declared and unpaid dividends on the Redeemable Convertible Preferred that have not previously been added to the Accrued Value, or (ii) the amount that such shares would have been entitled to receive if they had converted into common stock immediately prior to such liquidation, dissolution or winding up. Voting and other rights Except as set forth above or as otherwise required by law, holders of shares of Redeemable Convertible Preferred are entitled to vote together with shares of common stock (based on one vote per share of common stock into which the shares of Redeemable Convertible Preferred are convertible on the applicable record date) on any matter on which the holders of common stock are entitled to vote. Additionally, for so long as any shares of Redeemable Convertible Preferred remain outstanding, without the approval of holders of a majority of the Redeemable Convertible Preferred, the Company may not, among other things, (i) amend, modify or fail to give effect to any right of holders of the Redeemable Convertible Preferred, (ii) change the authorized number of Redeemable Convertible Preferred or issue additional Redeemable Convertible Preferred or create a new class or series of equity securities or securities convertible into equity securities with equal or superior rights, preferences or privileges to those of the Redeemable Convertible Preferred in terms of liquidation preference, dividend rights or certain governance rights, (iii) issue shares of common stock or securities convertible into common stock while the Company has insufficient shares to effect the conversion of the Redeemable Convertible Preferred into common stock, (iv) declare or pay dividends or redeem or repurchase any capital stock (other than certain repurchases from employees, directors, advisors or consultants upon termination of service) or (v) incur certain indebtedness in excess of $10 million. On March 28, 2017, in accordance with the terms of the SPA, the Company increased the size of its board of directors from eight to nine directors and approved the appointment of Adam M. Koppel, M.D., Ph.D., a managing director of the Lead Investor, as a director of the Company, effective as of the closing of the Private Placement on April 11, 2017. To the extent that such director is not re-elected The Company also entered into an amended and restated registration rights agreement, by and among the Company and the Investors (“Registration Rights Agreement”). Pursuant to the Registration Rights Agreement, the Investors will be entitled to certain demand, shelf and “piggyback” registration rights with respect to the shares of common stock issuable upon conversion of the Redeemable Convertible Preferred, subject to the limitations set forth in the Registration Rights Agreement. Dividends Each holder of Redeemable Convertible Preferred is entitled to receive cumulative dividends on the Accrued Value of each share of Redeemable Convertible Preferred at an initial rate of 12% per annum, compounded quarterly and subject to two rate reductions, of 4% each, upon the occurrence of certain agreed-upon milestone events. Dividends on the Redeemable Convertible Preferred are payable in kind and will accrue on the Accrued Value of each share of Redeemable Convertible Preferred until the earlier of conversion, redemption, consummation of a change of control, a liquidation event, or upon failure to mandatorily convert due to the Conversion Blockers or applicable regulatory restrictions. For accounting purposes, in accordance with the FASB’s Accounting Standard Codification (“ASC”) Topic 480-10-S99, Distinguishing Liabilities from Equity SEC Materials 480-10-S99”), paid-in The lattice model used to determine fair value used an adjusted risk rate of 18.0%, a 6.75-year Classification and measurement At the date of issuance, the Redeemable Convertible Preferred was classified as temporary equity in the mezzanine section of the Company’s consolidated balance sheet, since the underlying preferred shares are subject to redemption upon the occurrence of uncertain events not solely within the Company’s control, pursuant to ASC 480-10-S99. In accordance with ASC Topic 470-20, Debt with Conversion and Other Options paid-in non-cash The following table reflects the changes in Redeemable Convertible Preferred. Balance at January 1, 2017 $ — Issuance of Redeemable Convertible Preferred 70,000 Share issuance costs (750 ) Net proceeds 69,250 Discount resulting from the BCF at issuance (6,144 ) Accretion of the discount resulting from the BCF (deemed dividend) 6,144 Dividends accrued at the stated rate 1,841 Accretion of share issuance costs (additional dividends) 750 Liquidation preference 71,841 Fair value in excess of dividends accrued at the stated rate 31 Balance at June 30, 2017 $ 71,872 No shares of Redeemable Convertible Preferred were converted since the original issuance thereof through June 30, 2017. As of June 30, 2017, 42,774,585 shares of common stock were issuable assuming full conversion of all outstanding shares of the Redeemable Convertible Preferred, representing approximately 71% ownership of the Company by the Investors on an as-converted

Stock Option Plan and Stock-Bas

Stock Option Plan and Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Plan and Stock-Based Compensation	5. Stock Option Plan and Stock-Based Compensation During the three and six month periods ended June 30, 2017, the Company granted stock options to purchase 352,500 and 1,330,997 shares of common stock to employees with aggregate grant date fair values of $0.7 million and $2.7 million, respectively, compared to stock options to purchase 517,500 and 1,445,275 shares of common stock granted to employees with aggregate grant date fair values of $1.6 million and $6.8 million, for the comparable three and six month periods in 2016. The assumptions used to estimate the grant date fair value using the Black-Scholes option pricing model were as follows: Three Months Ended Six Months Ended Stock price $2.91 – $3.47 $2.49 – $3.47 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 79.7% – 80.8% 79.4% – 80.8% Risk-free interest rate 1.86% – 1.89% 1.86% – 2.07% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $3.26 – $5.55 $3.26 – $9.09 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 75.1% – 75.3% 70.9% – 75.3% Risk-free interest rate 1.20% – 1.46% 1.20% – 1.71% Expected dividend yield 0.00% 0.00% The Company has classified stock based compensation in its condensed consolidated statements of operations as follows: Three June 30, Six June 30, Three June 30, Six June 30, 2017 2017 2016 2016 Research and development expenses $ 972 $ 1,917 $ 1,126 $ 2,301 General and administrative expenses 1,053 2,116 1,284 2,494 Total $ 2,025 $ 4,033 $ 2,410 $ 4,795

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements A summary of the Company’s assets that are measured or disclosed at fair value as of June 30, 2017 and December 31, 2016 are presented below: Description At June 30, 2017 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 26,040 $ 26,040 $ — $ — Held-to-maturity U.S. treasury securities 49,931 — 49,931 — Restricted cash equivalents Money market fund 1,116 — 1,116 — Total $ 77,087 $ 26,040 $ 51,047 $ — Description At December 31, Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 12,853 $ 12,853 $ — $ — Held-to-maturity U.S. treasury securities 25,004 — 25,004 — Restricted cash equivalents Money market fund 1,116 — 1,116 — Total $ 38,973 $ 12,853 $ 26,120 $ — 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 June 30, 2017 and December 31, 2016. The Company’s restricted cash equivalents bore interest at the prevailing market rates for instruments with similar characteristics and, accordingly, the carrying value of these instruments also approximated their 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 June 30, 2017 and December 31, 2016. The Company’s held-to-maturity As of June 30, 2017 and December 31, 2016, the carrying amounts of accounts payable and accrued expenses approximated their estimated fair values because of the short-term nature of these financial instruments. For the three and six month periods ended June 30, 2017 and 2016 there were no transfers between Level 1 and Level 2.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Facility lease Future minimum lease payments on the Company’s non-cancelable 12-Month Operating 2018 $ 1,606 2019 1,654 2020 1,703 2021* 718 Total $ 5,681 * The end of the lease term is November 30, 2020. Litigation On June 10, 2015, Alnylam Pharmaceuticals, Inc. (“Alnylam”) filed a complaint against the Company in the Superior Court of Middlesex County, Massachusetts (the “Court”). The complaint alleges 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. The complaint seeks among other things, unspecified damages, attorneys’ fees, and an order permanently enjoining the Company from disclosing or using any of Alnylam’s confidential information or trade secrets. The Court has set a trial date of April 23, 2018. The Company believes that these allegations lack merit, has filed an answer denying all liability and intends to continue to vigorously defend all claims asserted. At this time, the Company has not recorded a liability in connection with these matters because management believes that any potential loss is neither probable nor reasonably estimable. 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 litigation liabilities recorded as of June 30, 2017 or December 31, 2016.

Description of Business and B13

Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Business	Business Dicerna Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative subcutaneously delivered ribonucleic acid 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. Accordingly, these condensed consolidated financial statements do not include all of the information and notes 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 June 30, 2017 and results of operations and cash flows for the interim periods ended June 30, 2017 and 2016. 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
Significant judgments and estimates	Significant judgments and estimates The preparation of 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 consolidated financial statements, as well as the revenue and expenses incurred during the reporting periods. On an ongoing basis, the Company evaluates judgments and estimates, including those related to accrued expenses, stock-based compensation and in relation to the accounting for, including cumulative dividends on, the Redeemable Convertible Preferred, as defined below. 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.
Liquidity risk	Liquidity risk Based on the Company’s current operating plan and liquidity, including the receipt of gross proceeds of $70.0 million from the issuance of the Company’s Redeemable Convertible Preferred, as defined below, on April 11, 2017 (see Note 4), management believes that available cash, cash equivalents and held-to-maturity 12-month
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies 10-K,
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted in 2017 Stock-based compensation In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting 2016-09”), 2016-09 2016-09. Not yet adopted Revenue recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), Revenue Recognition Revenue from Contracts with Customers Income taxes In October 2016, the FASB issued ASU No. 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory 2016-16”), 2016-16 pre-tax 2016-16 Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02”), which 2016-02 2016-02 2016-02 Statement of cash flows In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) 2016-15”), 2016-15 2016-15 2016-15 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash 2016-18”), 2016-18 2016-18 Stock-based compensation In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09”), 2017-09, 2017-19

Net Loss per Share Attributab14

Net Loss per Share Attributable to Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule of Dilutive Securities Outstanding	The outstanding securities presented below were excluded from the calculation of net loss per share attributable to common stockholders, because such securities would have been anti-dilutive due to the Company’s net loss per share attributable to common stockholders during the periods ending on the dates presented. June 30, 2017 June 30, Options to purchase common stock 6,212,437 4,888,522 Warrants to purchase common stock 87,901 87,901 Unvested restricted common stock 10,000 25,859 Redeemable convertible preferred stock 718,404 —

Held-to-maturity Investments (T

Held-to-maturity Investments (Tables)	6 Months Ended
	Jun. 30, 2017
Text Block [Abstract]
Schedule of Held-To-Maturity Investments	The following tables provide information relating to the Company’s held-to-maturity As of June 30, 2017: Amortized Gross Gross Fair Held-to-maturity U.S. treasury securities maturing in one year or less $ 49,953 $ — $ (22 ) $ 49,931 As of December 31, 2016: Amortized Gross Gross Fair Held-to-maturity U.S. treasury securities maturing in one year or less $ 25,009 $ — $ (5 ) $ 25,004

Redeemable Convertible Prefer16

Redeemable Convertible Preferred Stock (Tables)	6 Months Ended
	Jun. 30, 2017
Text Block [Abstract]
Summary of Changes in Redeemable Convertible Preferred	The following table reflects the changes in Redeemable Convertible Preferred. Balance at January 1, 2017 $ — Issuance of Redeemable Convertible Preferred 70,000 Share issuance costs (750 ) Net proceeds 69,250 Discount resulting from the BCF at issuance (6,144 ) Accretion of the discount resulting from the BCF (deemed dividend) 6,144 Dividends accrued at the stated rate 1,841 Accretion of share issuance costs (additional dividends) 750 Liquidation preference 71,841 Fair value in excess of dividends accrued at the stated rate 31 Balance at June 30, 2017 $ 71,872

Stock Option Plan and Stock-B17

Stock Option Plan and Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Stock-Based Compensation Expense	The Company has classified stock based compensation in its condensed consolidated statements of operations as follows: Three June 30, Six June 30, Three June 30, Six June 30, 2017 2017 2016 2016 Research and development expenses $ 972 $ 1,917 $ 1,126 $ 2,301 General and administrative expenses 1,053 2,116 1,284 2,494 Total $ 2,025 $ 4,033 $ 2,410 $ 4,795
Stock Options Granted to Non-Employees [Member]
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 Six Months Ended Stock price $2.91 – $3.47 $2.49 – $3.47 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 79.7% – 80.8% 79.4% – 80.8% Risk-free interest rate 1.86% – 1.89% 1.86% – 2.07% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $3.26 – $5.55 $3.26 – $9.09 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 75.1% – 75.3% 70.9% – 75.3% Risk-free interest rate 1.20% – 1.46% 1.20% – 1.71% Expected dividend yield 0.00% 0.00%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Assets Measured or Disclosed at Fair Value	A summary of the Company’s assets that are measured or disclosed at fair value as of June 30, 2017 and December 31, 2016 are presented below: Description At June 30, 2017 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 26,040 $ 26,040 $ — $ — Held-to-maturity U.S. treasury securities 49,931 — 49,931 — Restricted cash equivalents Money market fund 1,116 — 1,116 — Total $ 77,087 $ 26,040 $ 51,047 $ — Description At December 31, Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 12,853 $ 12,853 $ — $ — Held-to-maturity U.S. treasury securities 25,004 — 25,004 — Restricted cash equivalents Money market fund 1,116 — 1,116 — Total $ 38,973 $ 12,853 $ 26,120 $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
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 12-Month Operating 2018 $ 1,606 2019 1,654 2020 1,703 2021* 718 Total $ 5,681

Description of Business and B20

Description of Business and Basis of Presentation - Additional Information (Detail) $ in Millions	Apr. 11, 2017USD ($)
Collaboration Arrangement Disclosure [Abstract]
Proceeds from private placement	$ 70

Net Loss Per Share Attributab21

Net Loss Per Share Attributable to Common Stockholders - Schedule of Dilutive Securities Outstanding (Detail) - shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	6,212,437	4,888,522
Hercules Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	87,901	87,901
Unvested Restricted Stock Common [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	10,000	25,859
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	718,404

Held-to-maturity Investments -

Held-to-maturity Investments - Schedule of Held-To-Maturity Investments (Detail) - US Treasury Securities [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity investments, Amortized Cost	$ 49,953	$ 25,009
Held-to-maturity investments, Gross Unrealized Gains	0	0
Held-to-maturity investments, Gross Unrealized Losses	(22)	(5)
Held-to-maturity investments, Fair Value, Total	$ 49,931	$ 25,004

Redeemable Convertible Prefer23

Redeemable Convertible Preferred Stock - Additional Information (Detail)	Apr. 11, 2017USD ($)d$ / sharesshares	Mar. 28, 2017Director	Jun. 30, 2017USD ($)$ / sharesshares	Jun. 30, 2017USD ($)$ / sharesshares
Temporary Equity [Line Items]
Redeemable convertible preferred stock, issued | shares	700,000		718,404	718,404
Redeemable convertible preferred stock, par value | $ / shares	$ 0.0001		$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, price per share | $ / shares	$ 100
Proceeds from private placement	$ 70,000,000
Issuance costs related to private placement	$ 800,000			$ 300,000
Initial conversion price | $ / shares	$ 3.19
Redeemable convertible preferred stock, terms of conversion				The Company's ability to require conversion shall be subject to (i) a 19.99% blocker provision to comply with NASDAQ Listing Rules ("19.99% Conversion Blocker"), (ii) for certain Investors, a 9.99% blocker provision ("9.99% Conversion Blocker") that will prohibit beneficial ownership of more than 9.99% of the outstanding shares of the Company's common stock or voting power at any time, or (iii) applicable regulatory restrictions.
Percentage of redeemable convertible preferred stock conversion blocker provision	19.99%
Percentage of redeemable convertible preferred stock ownership limit conversion blocker provision	9.99%
Conversion price percentage of company's common stock	200.00%
Number of trading days | d	45
Number of consecutive trading days applicable conversion price | d	60
Liquidation preference percentage	101.00%
Maximum borrowings under securitization facility	$ 10,000,000
Existing number of directors | Director		8
Increased number of directors | Director		9
Cumulative dividends rate	12.00%
Percentage of rate reduction	4.00%
Number of interest rate reductions	2
Redeemable convertible preferred stock additional share issued as payment in kind of cumulative dividend | shares			18,404	18,404
Redeemable Preferred Dividend			$ 2,622,000	$ 2,622,000
Deemed dividend related to beneficial conversion feature of redeemable convertible preferred stock				$ 6,144,000
Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Fair value assumption risk free rate			18.00%	18.00%
Fair value assumption expected term				6 years 9 months
Fair value assumption expected volatility rate				70.00%
Fair value assumption change in liquidity preference			$ 30,000
Fair value estimate of dividend declared			$ 1,870,000
Common stock issued from conversion of redeemable convertible preferred stock | shares			42,774,585	42,774,585
Percentage Ownership of Investor			71.00%	71.00%
Director [Member]
Temporary Equity [Line Items]
Minimum required ownership percentage		25.00%

Redeemable Convertible Prefer24

Redeemable Convertible Preferred Stock - Summary of Changes in Redeemable Convertible Preferred (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Temporary Equity Disclosure [Abstract]
Balance at January 1, 2017	$ 0
Issuance of Redeemable Convertible Preferred	70,000
Share issuance costs	(750)
Net proceeds	69,250
Discount resulting from the BCF at issuance	(6,144)
Accretion of the discount resulting from the BCF (deemed dividend)	6,144
Dividends accrued at the stated rate	1,841
Accretion of share issuance costs (additional dividends)	750
Liquidation preference	71,841
Fair value in excess of dividends accrued at the stated rate	31
Balance at June 30, 2017	$ 71,872

Stock Option Plan and Stock-B25

Stock Option Plan and Stock-Based Compensation - Additional Information (Detail) - Employee Stock Option [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, granted	352,500	517,500	1,330,997	1,445,275
Fair value of stock options	$ 0.7	$ 1.6	$ 2.7	$ 6.8

Stock Option Plan and Stock-B26

Stock Option Plan and Stock-Based Compensation - Schedule of Valuation Assumptions (Detail) - Employee Stock Option [Member] - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
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]
Stock price	$ 2.91	$ 3.26	$ 2.49	$ 3.26
Expected option term (in years)	5 years 6 months	5 years 6 months	5 years 6 months	5 years 6 months
Expected volatility	79.70%	75.10%	79.40%	70.90%
Risk-free interest rate	1.86%	1.20%	1.86%	1.20%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 3.47	$ 5.55	$ 3.47	$ 9.09
Expected option term (in years)	6 years 2 months 30 days	6 years 2 months 30 days	6 years 2 months 30 days	6 years 2 months 30 days
Expected volatility	80.80%	75.30%	80.80%	75.30%
Risk-free interest rate	1.89%	1.46%	2.07%	1.71%

Stock Option Plan and Stock-B27

Stock Option Plan and Stock-Based Compensation - Classification of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,025	$ 2,410	$ 4,033	$ 4,795
Research and Development Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	972	1,126	1,917	2,301
General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,053	$ 1,284	$ 2,116	$ 2,494

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets Measured or Disclosed at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Restricted cash equivalents
Total	$ 77,087	$ 38,973
Money Market Fund [Member]
Cash equivalents
Money market fund	26,040	12,853
Restricted cash equivalents
Restricted investments, at fair value	1,116	1,116
US Treasury Securities [Member]
Held-to-maturity investments
U.S. treasury securities	49,931	25,004
Level 1 [Member]
Restricted cash equivalents
Total	26,040	12,853
Level 1 [Member] | Money Market Fund [Member]
Cash equivalents
Money market fund	26,040	12,853
Level 2 [Member]
Restricted cash equivalents
Total	51,047	26,120
Level 2 [Member] | Money Market Fund [Member]
Restricted cash equivalents
Restricted investments, at fair value	1,116	1,116
Level 2 [Member] | US Treasury Securities [Member]
Held-to-maturity investments
U.S. treasury securities	$ 49,931	$ 25,004

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Jun. 30, 2017	Jun. 30, 2016
Debt Instrument Fair Value Carrying Value [Abstract]
Transfers between Level 1 and Level 2	$ 0	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Summary of Future Minimum Lease Payments on Company's Non-cancelable Operating Lease (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 1,606
2,019	1,654
2,020	1,703
2,021	718	[1]
Total	$ 5,681
[1]	The end of the lease term is November 30, 2020.

Commitments and Contingencies31

Commitments and Contingencies - Summary of Future Minimum Lease Payments on Company's Non-cancelable Operating Lease (Parenthetical) (Detail)	12 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Lease Expiration Date	Nov. 30, 2020

Commitments and Contingencies32

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Outstanding litigation liabilities	$ 0	$ 0