Document and Entity Information
| Document and Entity Information - shares | 6 Months Ended | |
| Jun. 30, 2015 | Aug. 05, 2015 | |
| Document And Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Jun. 30, 2015 | |
| Document Fiscal Year Focus | 2,015 | |
| 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 | Non-accelerated Filer | |
| Entity Common Stock, Shares Outstanding | 20,593,117 |
Condensed Consolidated Balance
| Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014 |
| CURRENT ASSETS: | ||
| Cash and cash equivalents | $ 25,908 | $ 26,067 |
| Held-to-maturity investments | 69,100 | 70,055 |
| Prepaid expenses and other current assets | 1,733 | 1,194 |
| Total current assets | 96,741 | 97,316 |
| NONCURRENT ASSETS: | ||
| Held-to-maturity investments | 27,033 | 2,501 |
| Property and equipment-net | 2,584 | 2,165 |
| Assets held in restriction | 1,116 | 1,380 |
| Other noncurrent assets | 188 | 243 |
| Total noncurrent assets | 30,921 | 6,289 |
| TOTAL ASSETS | 127,662 | 103,605 |
| CURRENT LIABILITIES: | ||
| Accounts payable | 1,637 | 1,237 |
| Accrued expenses and other current liabilities | 7,344 | 3,845 |
| Deferred rent | 77 | |
| Total current liabilities | 8,981 | 5,159 |
| NONCURRENT LIABILITIES: | ||
| Security deposit | 106 | |
| Total noncurrent liabilities | 106 | |
| TOTAL LIABILITIES | $ 8,981 | $ 5,265 |
| STOCKHOLDERS' EQUITY: | ||
| Preferred stock, $0.0001 par value-5,000,000 shares authorized, no shares issued and outstanding at June 30, 2015 and December 31, 2014 | ||
| Common stock, $0.0001 par value-150,000,000 shares authorized at June 30, 2015 and December 31, 2014; 20,580,375 shares and 17,786,867 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively | $ 2 | $ 3 |
| Additional paid-in capital | 282,342 | 231,741 |
| Accumulated deficit | (163,663) | (133,404) |
| Total stockholders' equity | 118,681 | 98,340 |
| TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY | $ 127,662 | $ 103,605 |
Condensed Consolidated Balance3
| Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Jun. 30, 2015 | Dec. 31, 2014 |
| 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 | 20,580,375 | 17,786,867 |
| Common stock, shares outstanding | 20,580,375 | 17,786,867 |
Condensed Consolidated Statemen
| Condensed Consolidated Statements of Operations - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
| Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Income Statement [Abstract] | ||||
| Revenues | $ 184 | $ 184 | ||
| Operating expenses: | ||||
| Research and development | 11,875 | $ 6,806 | 20,567 | $ 12,057 |
| General and administrative | 4,519 | 4,372 | 9,964 | 7,213 |
| Total operating expenses | 16,394 | 11,178 | 30,531 | 19,270 |
| Loss from operations | (16,210) | (11,178) | (30,347) | (19,270) |
| Other income (expense): | ||||
| Interest income | 34 | 8 | 87 | 12 |
| Interest expense | (42) | (199) | ||
| Preferred stock warrant remeasurement | (2,559) | |||
| Loss on extinguishment of debt | (143) | (143) | ||
| Total net other income (expense) | 34 | (177) | 87 | (2,889) |
| Net loss | (16,176) | (11,355) | (30,260) | (22,159) |
| Less: Accretion and dividends on redeemable convertible preferred stock | 204 | |||
| Net loss attributable to common stockholders | $ (16,176) | $ (11,355) | $ (30,260) | $ (22,363) |
| Net loss per share attributable to common stockholders-basic and diluted | $ (0.86) | $ (0.64) | $ (1.65) | $ (1.57) |
| Weighted average shares outstanding-basic and diluted | 18,852,814 | 17,684,563 | 18,337,030 | 14,272,401 |
Condensed Consolidated Stateme5
| Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 6 Months Ended | |
| Jun. 30, 2015 | Jun. 30, 2014 | |
| CASH FLOWS FROM OPERATING ACTIVITIES: | ||
| Net loss | $ (30,260) | $ (22,159) |
| Adjustments to reconcile net loss to net cash used in operating activities: | ||
| Depreciation and amortization | 339 | 261 |
| Net amortization of premium/discount on investments | 53 | |
| Stock-based compensation | 4,981 | 4,617 |
| Loss on extinguishment of debt | 143 | |
| Increase in fair value of preferred stock warrant liability | 2,559 | |
| Changes in operating assets and liabilities: | ||
| Prepaid expenses and other assets | (564) | (944) |
| Accounts payable | 400 | (272) |
| Accrued expenses and other liabilities | 2,776 | 1,542 |
| Deferred rent | 60 | (18) |
| Net cash used in operating activities | (22,215) | (14,271) |
| CASH FLOWS FROM INVESTING ACTIVITIES: | ||
| Changes in assets held in restriction | 264 | (1,116) |
| Purchases of property and equipment | (639) | (808) |
| Maturities of held-to-maturity investments | 12,500 | |
| Purchases of held-to-maturity investments | (36,130) | (42,552) |
| Net cash used in investing activities | (24,005) | (44,476) |
| CASH FLOWS FROM FINANCING ACTIVITIES: | ||
| Proceeds from exercised stock options | 252 | 762 |
| Settlement of restricted stock for tax withholding | (75) | |
| Proceeds from public offering of common stock, net of costs | 45,884 | 94,148 |
| Repayments of long-term debt principal | (5,026) | |
| Net cash provided by financing activities | 46,061 | 89,884 |
| (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS | (159) | 31,137 |
| CASH AND CASH EQUIVALENTS - Beginning of period | 26,067 | 46,595 |
| CASH AND CASH EQUIVALENTS - End of period | $ 25,908 | 77,732 |
| SUPPLEMENTAL CASH FLOW INFORMATION: | ||
| Warrant conversion to common stock | $ 3,088 | |
Description of Business and Bas
| Description of Business and Basis of Presentation | 6 Months Ended |
| Jun. 30, 2015 | |
| Accounting Policies [Abstract] | |
| Description of Business and Basis of Presentation | 1. Description of Business and Basis of Presentation Nature of business Dicerna Pharmaceuticals, Inc. and its subsidiaries (the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative treatments for rare inherited diseases involving the liver and for cancers that are genetically defined. The Company is using its proprietary RNA interference (RNAi) technology platform to build a broad pipeline in these therapeutic areas. The Company intends to discover, develop and commercialize novel therapeutics either on its own or in collaboration with pharmaceutical partners. The Company continues to be subject to a number of risks common to companies in similar stages of development. Principal among these risks are the uncertainties of technological innovations, which are particularly high in the field of drug discovery and development, dependence on key individuals, development of the same or similar technological innovations by the Company’s competitors and protection of proprietary technology. The Company’s ability to fund its planned preclinical and clinical operations, including completion of its clinical trials, is expected to depend on the amount and timing of cash receipts under its existing collaboration agreement, as well as any future collaboration or product sales and/or financing transactions. In February 2014, the Company completed the sale of 6,900,000 shares of common stock in an initial public offering of its common stock (the IPO) at a price to the public of $15.00 per share, resulting in proceeds to the Company of $92,750 after deducting underwriting discounts and commissions of approximately $7,245 and offering expenses paid by the Company of approximately $3,506. In connection with the close of the IPO, all of the outstanding shares of Series A mandatorily redeemable, convertible preferred stock (Series A preferred stock), Series B mandatorily redeemable, convertible preferred stock (Series B preferred stock) and Series C mandatorily redeemable, convertible preferred stock (Series C preferred stock) were converted into shares of common stock on a one-for-one basis immediately prior to the closing of the IPO. In May 2015, the Company completed the sale of 2,750,000 shares of common stock in a public offering of its common stock at a price to the public of $17.75 per share, resulting in proceeds to the Company of $45,438 after deducting underwriting discounts and commissions of approximately $2,929 and offering cost accrued by the Company of approximately $446. Basis of presentation and consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the U.S. (GAAP) and in accordance with the rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information and notes required by GAAP for a complete set of financial statements. The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the annual 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, 2015 and results of operations and cash flows for the interim periods ended June 30, 2015 and 2014. These unaudited condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. The results of the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2014 or for any other interim period or for any other future year. Summary of Significant Accounting Policies Revenue Recognition Grant revenue is recognized in the period during in which the related grant research and activities are incurred, provided that the conditions under which the grant was provided have been met and the Company only has perfunctory obligations outstanding. Any amounts received in advance of revenue recognition are classified as deferred revenue in the consolidated balance sheets. Costs associated with grants are included in research and development expenses in the consolidated statements of operations. |
Revenue Recognition
| Revenue Recognition | 6 Months Ended |
| Jun. 30, 2015 | |
| Text Block [Abstract] | |
| Revenue Recognition | 2. Revenue Recognition NIH Grants In April 2015, the National Cancer Institute (NCI), a division of the National Institutes of Health (NIH), awarded the Company a grant related to cancer treatment research. The project period for this grant covers a three month period which commenced in April 2015, with total funds available of approximately $184. The payment of the NIH grant award was based upon subcontractor and internal costs incurred that are specifically covered by the grant, and where applicable, a facilities and administrative rate that provides funding for overhead expenses. During the three and six month periods ended June 30, 2015, the Company recognized $184 of revenue associated with the NIH grant award. |
Net Loss Per Share Attributable
| Net Loss Per Share Attributable to Common Stockholders | 6 Months Ended |
| Jun. 30, 2015 | |
| Earnings Per Share [Abstract] | |
| Net Loss Per Share Attributable to Common Stockholders | 3. Net Loss Per Share Attributable to Common Stockholders The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Net loss $ (16,176 ) $ (11,355 ) $ (30,260 ) $ (22,159 ) Less: Accretion and dividends on redeemable convertible preferred stock — — — 204 Net loss attributable to common stockholders (16,176 ) (11,355 ) (30,260 ) (22,363 ) Net loss per share attributable to common stockholders—basic and diluted $ (0.86 ) $ (0.64 ) $ (1.65 ) $ (1.57 ) Weighted average shares outstanding—basic and diluted 18,852,814 17,684,563 18,337,030 14,272,401 The following potentially dilutive securities outstanding during the period, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average common stock outstanding, because such securities had an anti-dilutive impact since the Company has a net loss attributable to common stockholders: Three months Ended June 30, Six months Ended June 30, 2015 2014 2015 2014 Options to purchase common stock 4,194,171 2,831,125 4,164,904 2,159,551 Warrants to purchase common stock 87,901 87,901 87,901 73,424 Warrants to purchase redeemable convertible preferred stock — — — 25,738 Redeemable convertible preferred stock — — — 2,047,682 Unvested restricted stock 72,772 109,859 78,436 87,141 |
Held-to-maturity investments
| Held-to-maturity investments | 6 Months Ended |
| Jun. 30, 2015 | |
| Text Block [Abstract] | |
| Held-to-maturity investments | 4. Held-to-maturity investments The Company invests its excess cash balances in short-term and long-term fixed-income investments. The Company determines the appropriate classification of investments at the time of purchase and re-evaluates such designation as of each balance sheet date. Debt securities carried at amortized cost are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. The following tables provide information relating to held-to-maturity investments: At June 30, 2015: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity investments U.S. Government treasury and agency securities $ 96,133 $ 32 $ (2 ) $ 96,163 Total held-to-maturity investments $ 96,133 $ 32 $ (2 ) $ 96,163 At December 31, 2014: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity investments U.S. Government treasury and agency securities $ 72,556 $ 2 $ (26 ) $ 72,532 Total held-to-maturity investments $ 72,556 $ 2 $ (26 ) $ 72,532 The amortized cost and fair value of held-to-maturity investments by contractual maturities at June 30, 2015, are as follows (in thousands): Held-to-Maturity Amortized Fair Maturing in one year or less $ 69,100 $ 69,111 Maturing after one year through two years 27,033 27,052 Total $ 96,133 $ 96,163 |
Long-term Debt
| Long-term Debt | 6 Months Ended |
| Jun. 30, 2015 | |
| Debt Disclosure [Abstract] | |
| Long-term Debt | 5. Long-term Debt On March 26, 2009, the Company entered into a loan and security agreement with an independent finance company, Hercules Technology II, LP (Hercules), for up to $7,000 (Hercules loan). The Hercules loan, which has since been repaid, was collateralized by a security interest in all tangible assets. On June 28, 2011, the Company and Hercules executed a second amendment to the loan and security agreement, which increased the maximum loan amount to $12,000. Upon execution of the second amendment, the Company drew a $7,000 advance, a portion of which the Company used to repay the outstanding balance of principal and interest under the original loan and security agreement. On December 15, 2011, the Company drew down the remaining $5,000. Interest was payable monthly and principal was to be repaid in equal monthly installments beginning April 1, 2012 through January 2, 2015. The applicable annual interest rate was 10.15% at December 31, 2013. On April 7, 2014, the Company repaid the remaining amount of the Hercules loan in full in a total amount of $3,590. In connection with the Hercules loan, the Company issued warrants to Hercules for the purchase of an aggregate of 21,000 shares of Series A preferred stock and 26,400 shares of Series B preferred stock each at an exercise price of $25.00 per share. Immediately prior to the closing of the IPO on February 4, 2014, all of the outstanding shares of Series A, Series B and Series C preferred stock were automatically converted into shares of common stock on a one-for-one basis. The fair value of the warrants was classified as a liability in the balance sheet as of December 31, 2013. After the conversion of Series A and Series B preferred stock, the fair value of the warrants was reclassified as a part of stockholders’ equity. The remeasurement of the liability continued until the date of the closing of the IPO. The fair value of the outstanding Hercules warrants as of the IPO closing date was $765 and was determined using the Black-Scholes option-pricing model with the following assumptions: February 4, Stock price $ 32.66 Expected option term (in years) 3.00 Expected volatility 62 % Risk-free interest rate 0.69 % Expected dividend yield 0.00 % On February 11, 2014, Hercules net exercised the warrants in exchange for a total of 12,702 shares of common stock. There were no Series A and Series B warrants outstanding at June 30, 2015 and December 31, 2014. The adjustment to this preferred stock warrant liability related to the Hercules warrants was recorded in other income (expense) and amounted to $0 for the three and six month periods ended June 30, 2015 compared to $0 and $(671) for the same periods in the prior year. |
Stock-Based Compensation
| Stock-Based Compensation | 6 Months Ended |
| Jun. 30, 2015 | |
| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
| Stock-Based Compensation | 6. Stock-Based Compensation Stock options granted to nonemployees Stock-based compensation expense related to stock options granted to nonemployees is recognized as the consulting services are rendered, generally on a straight-line basis. The Company believes that the fair value of the stock options is more reliably measurable than the fair value of the services received. Compensation expense is subject to re-measurement until the options vest. In September 2013, the Company granted stock options to purchase 132,500 shares of common stock to nonemployees with an initial fair value of $337. Based on the terms of the nonemployee stock option agreements the Company recorded nonemployee stock-based compensation of $64 and $155 for the three and six month periods ended June 30, 2015, as compared to $50 and $1,661 in the comparable 2014 periods. The assumptions used to estimate fair value were as follows: Three Months Ended June 30, 2015 Six Months Ended June 30, 2015 Stock price $13.95 – $20.07 $13.95 – $24.43 Expected option term (in years) 4.83 – 5.01 4.37 – 5.29 Expected volatility 66% – 67% 66% – 68% Risk-free interest rate 1.43% – 1.57% 1.21% – 1.57% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $16.16 – $22.57 $16.16 – $41.12 Expected option term (in years) 6.11 – 6.40 0.25 – 6.86 Expected volatility 73% 56% – 73% Risk-free interest rate 2.12% – 2.27% 0.08% – 2.29% Expected dividend yield 0.00% 0.00% As of June 30, 2015, there were 35,000 unvested stock options held by nonemployees. Stock option grants to employees During the three and six month periods ended June 30, 2015, the Company granted stock options to purchase 210,500 and 849,926 shares of common stock to employees with grant date fair values of $1,776 and $9,303, respectively, compared to 1,810,806 shares with grant date fair values of $19,622, for the three and six month periods in 2014. Employee stock-based compensation for the three and six month periods ended June 30, 2015 were $2,597 and $4,826 as compared to $2,355 and $2,956, respectively, for the comparable 2014 periods. The assumptions used to estimate the grant date fair value for 2015 grants were as follows: Three Months Ended Six Months Ended Stock price $13.87 – $13.95 $13.87 – $24.03 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 67% 67 – 69% Risk-free interest rate 1.77% –1.81% 1.51% –1.81% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $16.30 – $18.73 $16.30 – $18.73 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 73% – 74% 73% – 74% Risk-free interest rate 1.92% – 2.00% 1.92% – 2.00% Expected dividend yield 0.00% 0.00% |
Redeemable Convertible Preferre
| Redeemable Convertible Preferred Stock | 6 Months Ended |
| Jun. 30, 2015 | |
| Text Block [Abstract] | |
| Redeemable Convertible Preferred Stock | 7. Redeemable Convertible Preferred Stock The consummation of the IPO on February 4, 2014 resulted in the conversion of all of the shares of the Company’s Series A, Series B and Series C preferred stock into shares of common stock. Each share of Series A, Series B and Series C preferred stock was automatically converted into common stock on a one-for-one basis. The conversion of Series A, Series B and Series C preferred stock resulted in the issuance of 10,589,434 shares of common stock. After the conversion of Series C preferred stock, the fair value of the warrants related to Series C preferred stock outstanding immediately prior to the closing of the IPO was reclassified as a part of stockholders’ equity. The remeasurement of the Series C preferred stock warrant liability continued until the closing date of the IPO. The fair value of the Series C preferred stock warrants as of the IPO closing date was $2,323 and was determined using the Black-Scholes option-pricing model with the following assumptions: February 4, Stock price $ 32.66 Expected option term (in years) 4.39 Expected volatility 65 % Risk-free interest rate 1.52 % Expected dividend yield 0.00 % The adjustment to the Series C preferred stock warrant liability was recorded in other income (expense) and amounted to $0 for the three and six month periods ended June 30, 2015, compared to $0 and ($1,888) for the same periods in 2014. |
Fair Value Measurements
| Fair Value Measurements | 6 Months Ended |
| Jun. 30, 2015 | |
| Fair Value Disclosures [Abstract] | |
| Fair Value Measurements | 8. Fair Value Measurements Fair value is an exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumption the accounting literature establishes a three-tier value hierarchy which prioritizes the inputs used in measuring fair value as follows: (Level 1) observable inputs, such as quoted prices in active markets; (Level 2) inputs other than the quoted prices in active markets that are observable either directly or indirectly; and (Level 3) unobservable inputs for which there is little or no market data, which requires the Company to develop its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. A summary of the Company’s assets that are measured or disclosed at fair value as of June 30, 2015 and December 31, 2014 are presented below: Description At June 30, 2015 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 17,845 $ 17,845 $ — $ — Held-to-maturity investments U.S. treasury securities and government agency bonds 96,163 — 96,163 — Assets held in restriction Money market fund 1,116 — 1,116 — Total $ 115,124 $ 17,845 $ 97,279 $ — Description At December 31, 2014 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 20,425 $ 20,425 $ — $ — Held-to-maturity investments U.S. treasury securities and government agency bonds 72,532 — 72,532 — Assets held in restriction Money market fund and certificate of deposit 1,380 — 1,380 — Total $ 94,337 $ 20,425 $ 73,912 $ — The Company’s cash equivalents, primarily money market accounts are classified within Level 1 of the fair value hierarchy because they are valued using quoted prices as of June 30, 2015 and December 31, 2014, respectively. The Company’s assets held in restriction 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 and the 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, 2015 and December 31, 2014, respectively. The Company’s held-to-maturity investments bore interest at the prevailing market rates for instruments with similar characteristics. The 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, 2015 and December 31, 2014, respectively. For the three and six month periods ended June 30, 2015 and 2014, there were no transfers between Level 1 and Level 2. The fair value of the preferred stock warrant liability was determined using the Black-Scholes option-pricing model until the IPO conversion date of February 4, 2014. After the closing of the IPO, the remaining preferred stock warrant liability was no longer subject to remeasurement as the warrants to purchase the Company’s preferred stock became warrants to purchase shares of the Company’s common stock. As of the IPO closing date, the fair value of the preferred stock warrants was based significantly on the fair value of the Company’s publicly traded common stock and other observable inputs and was reclassified to Level 2. The fair value of the preferred stock warrant prior to the closing of the IPO was based significantly on the fair value of the preferred stock, which was developed using unobservable inputs, and was classified within Level 3. The following table provides a roll-forward of the Company’s liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3): BALANCE—January 1, 2014 $ 529 Change in fair value of warrant liability 2,559 Transfers to Level 2 (3,088 ) BALANCE— June 30, 2014 $ — There were no preferred stock warrants outstanding as of June 30, 2015 and December 31, 2014. |
Commitments and Contingencies
| Commitments and Contingencies | 6 Months Ended |
| Jun. 30, 2015 | |
| Commitments and Contingencies Disclosure [Abstract] | |
| Commitments and Contingencies | 9. Commitments and Contingencies Facility lease On July 11, 2014, the Company executed a non-cancelable operating lease for office and laboratory space in Cambridge, Massachusetts. The lease agreement obligates the Company to future minimum payments totaling $9,498 over a six-year lease term. The lease commenced on December 1, 2014. As part of the lease agreement, the Company established a $1,116 letter of credit, secured by a money market account which is included in assets held in restriction at June 30, 2015 and December 31, 2014. On April 9, 2015, the Company terminated its lease and sub-lease at 480 Arsenal Street in Watertown. The transactions did not have a material impact on the Company’s financial statements. The associated letter of credit was cancelled by the bank during the second quarter of 2015. A $264 certificate of deposit, which secured the letter of credit, was redeemed and is included in the Company’s cash and cash equivalents at June 30, 2015. City of Hope license agreement In September 2007, the Company entered into a license agreement with City of Hope, an independent academic research and medical center (the “Medical Center”). In consideration for the right to develop, manufacture, and commercialize products based on certain of the Medical Center’s intellectual property, the Company paid a one-time, non-refundable license fee and issued shares of common stock as consideration for the license. The Company is required to pay an annual license maintenance fee, reimburse the Medical Center for patent costs incurred, and pay an amount within the range of $5,000 to $10,000 upon the achievement of certain milestones, and royalties on future sales, if any. The license agreement will remain in effect until the expiration of the last patents or copyrights licensed under the agreement or until all obligations under the agreement with respect to payment of milestones have terminated or expired. The Company may terminate the license agreement at any time upon 90 days written notice to the Medical Center. There were no expenses related to this agreement for the three and six month periods ended June 30, 2015 and the comparable prior year periods. Plant Bioscience Limited license agreement In September 2013, the Company entered into a commercial license agreement with Plant Bioscience Limited (PBL), pursuant to which PBL has granted to the Company a license to certain of its U.S. patents and patent applications to research, discover, develop, manufacture, sell, import and export, products incorporating one or more short RNA molecules (SRMs). The Company has paid PBL a one-time, non-refundable signature fee and will pay PBL a nomination fee for any additional SRMs nominated by the Company under the agreement. The Company is further obligated to pay PBL milestone payments upon achievement of certain clinical and regulatory milestones. During 2014, the Company paid $100 to PBL based on meeting a clinical milestone. In addition, PBL is entitled to receive royalties of any net sale revenue of any licensed product candidates sold by the Company. Research and development expense for the three and six month periods ended June 30, 2015 related to this agreement was $0 as compared to $100 in the comparable 2014 periods. Tekmira Pharmaceuticals Corporation license agreement In November 2014, the Company signed a licensing and collaboration agreement with Tekmira Pharmaceuticals Corporation (Tekmira) to license Tekmira’s LNP delivery technology for exclusive use in the Company’s primary hyperoxaluria type 1 (PH1) development program. The Company will use Tekmira’s LNP technology to deliver DCR-PH1, for the treatment of PH1. As of June 30, 2015, the Company had paid $3,000 in cumulative license fees. Tekmira is entitled to receive additional payments of $22,000 in aggregate development milestones, plus a mid-single-digit royalty on future PH1 sales. This partnership also includes a supply agreement with Tekmira providing clinical drug supply and regulatory support. |
Litigation
| Litigation | 6 Months Ended |
| Jun. 30, 2015 | |
| Commitments and Contingencies Disclosure [Abstract] | |
| Litigation | 10. Litigation On June 10, 2015, Alnylam Pharmaceuticals, Inc. (Alnylam) filed a complaint against the Company in the Superior Court of Middlesex County, Massachusetts. 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 Sirna Therapeutics, Inc. (Sirna), which at the time was a subsidiary of Merck & Co., Inc., and in connection with our discussions with Merck to acquire Sirna, which was subsequently acquired by Alnylam. The complaint seeks, among other things, damages, attorneys’ fees, and an order permanently enjoining the Company from disclosing or using any of Alnylam’s confidential information or trade secrets. The Company believes that these allegations lack merit, and intends to vigorously defend all claims asserted. At this time, the Company has not recorded a liability in connection with these matters because it 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 outstanding as of June 30, 2015 and December 31, 2014. |
Description of Business and B16
| Description of Business and Basis of Presentation (Policies) | 6 Months Ended |
| Jun. 30, 2015 | |
| Accounting Policies [Abstract] | |
| Nature of business | Nature of business Dicerna Pharmaceuticals, Inc. and its subsidiaries (the “Company”) is a biopharmaceutical company focused on the discovery and development of innovative treatments for rare inherited diseases involving the liver and for cancers that are genetically defined. The Company is using its proprietary RNA interference (RNAi) technology platform to build a broad pipeline in these therapeutic areas. The Company intends to discover, develop and commercialize novel therapeutics either on its own or in collaboration with pharmaceutical partners. The Company continues to be subject to a number of risks common to companies in similar stages of development. Principal among these risks are the uncertainties of technological innovations, which are particularly high in the field of drug discovery and development, dependence on key individuals, development of the same or similar technological innovations by the Company’s competitors and protection of proprietary technology. The Company’s ability to fund its planned preclinical and clinical operations, including completion of its clinical trials, is expected to depend on the amount and timing of cash receipts under its existing collaboration agreement, as well as any future collaboration or product sales and/or financing transactions. In February 2014, the Company completed the sale of 6,900,000 shares of common stock in an initial public offering of its common stock (the IPO) at a price to the public of $15.00 per share, resulting in proceeds to the Company of $92,750 after deducting underwriting discounts and commissions of approximately $7,245 and offering expenses paid by the Company of approximately $3,506. In connection with the close of the IPO, all of the outstanding shares of Series A mandatorily redeemable, convertible preferred stock (Series A preferred stock), Series B mandatorily redeemable, convertible preferred stock (Series B preferred stock) and Series C mandatorily redeemable, convertible preferred stock (Series C preferred stock) were converted into shares of common stock on a one-for-one basis immediately prior to the closing of the IPO. In May 2015, the Company completed the sale of 2,750,000 shares of common stock in a public offering of its common stock at a price to the public of $17.75 per share, resulting in proceeds to the Company of $45,438 after deducting underwriting discounts and commissions of approximately $2,929 and offering cost accrued by the Company of approximately $446. |
| Basis of presentation and consolidation | Basis of presentation and consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the U.S. (GAAP) and in accordance with the rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information and notes required by GAAP for a complete set of financial statements. The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the annual 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, 2015 and results of operations and cash flows for the interim periods ended June 30, 2015 and 2014. These unaudited condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. The results of the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2014 or for any other interim period or for any other future year. |
| Summary of Significant Accounting Policies | Summary of Significant Accounting Policies |
| Revenue Recognition | Revenue Recognition Grant revenue is recognized in the period during in which the related grant research and activities are incurred, provided that the conditions under which the grant was provided have been met and the Company only has perfunctory obligations outstanding. Any amounts received in advance of revenue recognition are classified as deferred revenue in the consolidated balance sheets. Costs associated with grants are included in research and development expenses in the consolidated statements of operations. |
Net Loss Per Share Attributab17
| Net Loss Per Share Attributable to Common Stockholders (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| Earnings Per Share [Abstract] | |
| Summary of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders | The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Net loss $ (16,176 ) $ (11,355 ) $ (30,260 ) $ (22,159 ) Less: Accretion and dividends on redeemable convertible preferred stock — — — 204 Net loss attributable to common stockholders (16,176 ) (11,355 ) (30,260 ) (22,363 ) Net loss per share attributable to common stockholders—basic and diluted $ (0.86 ) $ (0.64 ) $ (1.65 ) $ (1.57 ) Weighted average shares outstanding—basic and diluted 18,852,814 17,684,563 18,337,030 14,272,401 |
| Schedule of Dilutive Securities Outstanding | The following potentially dilutive securities outstanding during the period, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average common stock outstanding, because such securities had an anti-dilutive impact since the Company has a net loss attributable to common stockholders: Three months Ended June 30, Six months Ended June 30, 2015 2014 2015 2014 Options to purchase common stock 4,194,171 2,831,125 4,164,904 2,159,551 Warrants to purchase common stock 87,901 87,901 87,901 73,424 Warrants to purchase redeemable convertible preferred stock — — — 25,738 Redeemable convertible preferred stock — — — 2,047,682 Unvested restricted stock 72,772 109,859 78,436 87,141 |
Held-to-maturity investments (T
| Held-to-maturity investments (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| Text Block [Abstract] | |
| Schedule of Held-To-Maturity Investments | The following tables provide information relating to held-to-maturity investments: At June 30, 2015: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity investments U.S. Government treasury and agency securities $ 96,133 $ 32 $ (2 ) $ 96,163 Total held-to-maturity investments $ 96,133 $ 32 $ (2 ) $ 96,163 At December 31, 2014: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity investments U.S. Government treasury and agency securities $ 72,556 $ 2 $ (26 ) $ 72,532 Total held-to-maturity investments $ 72,556 $ 2 $ (26 ) $ 72,532 |
| Amortized Cost and Fair Value of Held-To-Maturity Investments | The amortized cost and fair value of held-to-maturity investments by contractual maturities at June 30, 2015, are as follows (in thousands): Held-to-Maturity Amortized Fair Maturing in one year or less $ 69,100 $ 69,111 Maturing after one year through two years 27,033 27,052 Total $ 96,133 $ 96,163 |
Long-term Debt (Tables)
| Long-term Debt (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| Debt Disclosure [Abstract] | |
| Summary of Estimated Fair Values of Outstanding Warrants Using Black-Scholes Option-Pricing Model | The fair value of the outstanding Hercules warrants as of the IPO closing date was $765 and was determined using the Black-Scholes option-pricing model with the following assumptions: February 4, Stock price $ 32.66 Expected option term (in years) 3.00 Expected volatility 62 % Risk-free interest rate 0.69 % Expected dividend yield 0.00 % |
Stock-Based Compensation (Table
| Stock-Based Compensation (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| Stock Options Granted to Nonemployees [Member] | |
| Schedule of Valuation Assumptions | The assumptions used to estimate fair value were as follows: Three Months Ended June 30, 2015 Six Months Ended June 30, 2015 Stock price $13.95 – $20.07 $13.95 – $24.43 Expected option term (in years) 4.83 – 5.01 4.37 – 5.29 Expected volatility 66% – 67% 66% – 68% Risk-free interest rate 1.43% – 1.57% 1.21% – 1.57% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $16.16 – $22.57 $16.16 – $41.12 Expected option term (in years) 6.11 – 6.40 0.25 – 6.86 Expected volatility 73% 56% – 73% Risk-free interest rate 2.12% – 2.27% 0.08% – 2.29% Expected dividend yield 0.00% 0.00% |
| Employee Stock Option | |
| Schedule of Valuation Assumptions | The assumptions used to estimate the grant date fair value for 2015 grants were as follows: Three Months Ended Six Months Ended Stock price $13.87 – $13.95 $13.87 – $24.03 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 67% 67 – 69% Risk-free interest rate 1.77% –1.81% 1.51% –1.81% Expected dividend yield 0.00% 0.00% Three Months Ended Six Months Ended Stock price $16.30 – $18.73 $16.30 – $18.73 Expected option term (in years) 5.50 – 6.25 5.50 – 6.25 Expected volatility 73% – 74% 73% – 74% Risk-free interest rate 1.92% – 2.00% 1.92% – 2.00% Expected dividend yield 0.00% 0.00% |
Redeemable Convertible Prefer21
| Redeemable Convertible Preferred Stock (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| Series C Redeemable Convertible Preferred Stock [Member] | |
| Summary of Estimated Fair Values of Outstanding Warrants Using Black-Scholes Option-Pricing Model | The fair value of the Series C preferred stock warrants as of the IPO closing date was $2,323 and was determined using the Black-Scholes option-pricing model with the following assumptions: February 4, Stock price $ 32.66 Expected option term (in years) 4.39 Expected volatility 65 % Risk-free interest rate 1.52 % Expected dividend yield 0.00 % |
Fair Value Measurements (Tables
| Fair Value Measurements (Tables) | 6 Months Ended |
| Jun. 30, 2015 | |
| 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, 2015 and December 31, 2014 are presented below: Description At June 30, 2015 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 17,845 $ 17,845 $ — $ — Held-to-maturity investments U.S. treasury securities and government agency bonds 96,163 — 96,163 — Assets held in restriction Money market fund 1,116 — 1,116 — Total $ 115,124 $ 17,845 $ 97,279 $ — Description At December 31, 2014 Level 1 Level 2 Level 3 Cash equivalents Money market fund $ 20,425 $ 20,425 $ — $ — Held-to-maturity investments U.S. treasury securities and government agency bonds 72,532 — 72,532 — Assets held in restriction Money market fund and certificate of deposit 1,380 — 1,380 — Total $ 94,337 $ 20,425 $ 73,912 $ — |
| Schedule of Roll-Forward of Company's Liabilities Measured at Fair Value on Recurring Basis Using Unobservable Inputs (Level 3) | The fair value of the preferred stock warrant prior to the closing of the IPO was based significantly on the fair value of the preferred stock, which was developed using unobservable inputs, and was classified within Level 3. The following table provides a roll-forward of the Company’s liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3): BALANCE—January 1, 2014 $ 529 Change in fair value of warrant liability 2,559 Transfers to Level 2 (3,088 ) BALANCE— June 30, 2014 $ — |
Description of Business and B23
| Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 6 Months Ended | ||
| May. 31, 2015 | Feb. 28, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Organization Consolidation And Presentation Of Financial Statements [Line Items] | ||||
| Proceeds from issuance of common stock | $ 45,884 | $ 94,148 | ||
| Preferred stock conversion basis | In connection with the close of the IPO, all of the outstanding shares of Series A mandatorily redeemable, convertible preferred stock (Series A preferred stock), Series B mandatorily redeemable, convertible preferred stock (Series B preferred stock) and Series C mandatorily redeemable, convertible preferred stock (Series C preferred stock) were converted into shares of common stock on a one-for-one basis immediately prior to the closing of the IPO. | |||
| IPO [Member] | ||||
| Organization Consolidation And Presentation Of Financial Statements [Line Items] | ||||
| Common stock shares issued | 2,750,000 | 6,900,000 | ||
| Sale of stock price per share | $ 17.75 | $ 15 | ||
| Proceeds from issuance of common stock | $ 45,438 | $ 92,750 | ||
| Underwriting discounts and commissions | 2,929 | 7,245 | ||
| Offering expenses | $ 3,506 | |||
| Offering cost accrued | $ 446 | |||
Revenue Recognition - Additiona
| Revenue Recognition - Additional Information (Detail) - Jun. 30, 2015 - National Institutes of Health [Member] - USD ($) $ in Thousands | Total | Total |
| Revenue Recognition, Multiple-deliverable Arrangements [Line Items] | ||
| Funds available under revenue recognition grant | $ 184 | |
| Revenue associated with NIH grant award | $ 184 | $ 184 |
Net Loss Per Share Attributab25
| Net Loss Per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 6 Months Ended | ||
| Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Earnings Per Share [Abstract] | ||||
| Net loss | $ (16,176) | $ (11,355) | $ (30,260) | $ (22,159) |
| Less: Accretion and dividends on redeemable convertible preferred stock | 204 | |||
| Net loss attributable to common stockholders | $ (16,176) | $ (11,355) | $ (30,260) | $ (22,363) |
| Net loss per share attributable to common stockholders-basic and diluted | $ (0.86) | $ (0.64) | $ (1.65) | $ (1.57) |
| Weighted average shares outstanding-basic and diluted | 18,852,814 | 17,684,563 | 18,337,030 | 14,272,401 |
Net Loss Per Share Attributab26
| Net Loss Per Share Attributable to Common Stockholders - Schedule of Dilutive Securities Outstanding (Detail) - shares | 3 Months Ended | 6 Months Ended | ||
| Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Options to Purchase Common Stock [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Anti-dilutive securities | 4,194,171 | 2,831,125 | 4,164,904 | 2,159,551 |
| Hercules Warrants [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Anti-dilutive securities | 87,901 | 87,901 | 87,901 | 73,424 |
| Warrants to Purchase Redeemable Convertible Preferred Stock [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Anti-dilutive securities | 25,738 | |||
| Redeemable Convertible Preferred Stock [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Anti-dilutive securities | 2,047,682 | |||
| Unvested Restricted Stock [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Anti-dilutive securities | 72,772 | 109,859 | 78,436 | 87,141 |
Held-to-Maturity Investments -
| Held-to-Maturity Investments - Schedule of Held-to-Maturity Investments (Detail) - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014 |
| Schedule of Held-to-maturity Securities [Line Items] | ||
| Held to Maturity, Amortized Cost, Total | $ 96,133 | $ 72,556 |
| Held-to-maturity investments, Gross Unrealized Gains | 32 | 2 |
| Held-to-maturity investments, Gross Unrealized Losses | (2) | (26) |
| Held-to-maturity investments, Fair Value, Total | 96,163 | 72,532 |
| U.S. Government Treasury and Agency Securities [Member] | ||
| Schedule of Held-to-maturity Securities [Line Items] | ||
| Held to Maturity, Amortized Cost, Total | 96,133 | 72,556 |
| Held-to-maturity investments, Gross Unrealized Gains | 32 | 2 |
| Held-to-maturity investments, Gross Unrealized Losses | (2) | (26) |
| Held-to-maturity investments, Fair Value, Total | $ 96,163 | $ 72,532 |
Held-to-Maturity-Investments -
| Held-to-Maturity-Investments - Amortized Cost and Fair Value of Held-to-Maturity Investments (Detail) - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014 |
| Investments, Debt and Equity Securities [Abstract] | ||
| Held-to-Maturity securities, Maturing in one year or less, Amortized Cost | $ 69,100 | $ 70,055 |
| Maturing after one year through two years, Amortized Cost | 27,033 | 2,501 |
| Held to Maturity, Amortized Cost, Total | 96,133 | 72,556 |
| Held-to-Maturity securities, Maturing in one year or less, Fair Value | 69,111 | |
| Maturing after one year through two years, Fair Value | 27,052 | |
| Held-to-Maturity, Fair Value, Total | $ 96,163 | $ 72,532 |
Long-term Debt - Additional Inf
| Long-term Debt - Additional Information (Detail) - USD ($) | Apr. 07, 2014 | Dec. 15, 2011 | Jun. 28, 2011 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Dec. 31, 2014 | Feb. 11, 2014 | Feb. 04, 2014 | Dec. 31, 2013 | Mar. 26, 2009 |
| Debt Instrument [Line Items] | ||||||||||||
| Estimated fair value of outstanding warrants | $ 765,000 | |||||||||||
| Common stock issued, shares | 20,580,375 | 20,580,375 | 17,786,867 | |||||||||
| Adjustment to preferred stock warrant liability recorded in other income (expense) | $ (2,559,000) | |||||||||||
| Hercules Warrants [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Adjustment to preferred stock warrant liability recorded in other income (expense) | $ 0 | $ 0 | $ 0 | $ (671,000) | ||||||||
| Series A Warrants [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Estimated fair value of outstanding warrants | 0 | 0 | $ 0 | |||||||||
| Series B Warrants [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Estimated fair value of outstanding warrants | $ 0 | $ 0 | $ 0 | |||||||||
| Second Amendment [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Loan drew in advance | $ 5,000,000 | $ 7,000,000 | ||||||||||
| Annual interest rate | 10.15% | |||||||||||
| Principal monthly installments period | April 1, 2012 through January 2, 2015 | |||||||||||
| Hercules Loan [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Loan and security agreement | $ 7,000,000 | |||||||||||
| Repayment of debt | $ 3,590,000 | |||||||||||
| IPO closing date | Feb. 4, 2014 | |||||||||||
| Common stock issued, shares | 12,702 | |||||||||||
| Hercules Loan [Member] | Series A Warrants [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Warrants exercised, number of shares | 21,000 | 21,000 | ||||||||||
| Warrants exercised, exercise price | $ 25 | $ 25 | ||||||||||
| Hercules Loan [Member] | Series B Warrants [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Warrants exercised, number of shares | 26,400 | 26,400 | ||||||||||
| Warrants exercised, exercise price | $ 25 | $ 25 | ||||||||||
| Hercules Loan [Member] | Second Amendment [Member] | ||||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Loan and security agreement | $ 12,000,000 |
Long-term Debt - Summary of Est
| Long-term Debt - Summary of Estimated Fair Values of Outstanding Warrants Using Black-Scholes Option-Pricing Model (Detail) - Feb. 04, 2014 - Hercules Warrants [Member] - $ / shares | Total |
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | |
| Stock price | $ 32.66 |
| Expected option term (in years) | 3 years |
| Expected volatility | 62.00% |
| Risk-free interest rate | 0.69% |
| Expected dividend yield | 0.00% |
Stock-Based Compensation - Addi
| Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended | ||
| Sep. 30, 2013 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Stock-based compensation expense | $ 4,981 | $ 4,617 | |||
| Nonemployee Stock Option [Member] | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Stock option, granted | 132,500 | ||||
| Stock options, granted fair value | $ 337 | ||||
| Stock-based compensation expense | $ 64 | $ 50 | $ 155 | $ 1,661 | |
| Unvested stock options | 35,000 | 35,000 | |||
| Employee Stock Option | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Stock option, granted | 210,500 | 1,810,806 | 849,926 | 1,810,806 | |
| Stock-based compensation expense | $ 2,597 | $ 2,355 | $ 4,826 | $ 2,956 | |
| Fair value of stock options | $ 1,776 | $ 19,622 | $ 9,303 | $ 19,622 | |
Stock-Based Compensation - Sche
| Stock-Based Compensation - Schedule of Valuation Assumptions (Detail) - $ / shares | 3 Months Ended | 6 Months Ended | ||
| Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | |
| Nonemployee Stock Option [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Expected volatility | 73.00% | |||
| Expected dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
| Nonemployee Stock Option [Member] | Minimum [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock price | $ 13.95 | $ 16.16 | $ 13.95 | $ 16.16 |
| Expected option term (in years) | 4 years 9 months 29 days | 6 years 1 month 10 days | 4 years 4 months 13 days | 3 months |
| Expected volatility | 66.00% | 66.00% | 56.00% | |
| Risk-free interest rate | 1.43% | 2.12% | 1.21% | 0.08% |
| Nonemployee Stock Option [Member] | Maximum [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock price | $ 20.07 | $ 22.57 | $ 24.43 | $ 41.12 |
| Expected option term (in years) | 5 years 4 days | 6 years 4 months 24 days | 5 years 3 months 15 days | 6 years 10 months 10 days |
| Expected volatility | 67.00% | 68.00% | 73.00% | |
| Risk-free interest rate | 1.57% | 2.27% | 1.57% | 2.29% |
| Employee Stock Option | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Expected volatility | 67.00% | |||
| Expected dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
| Employee Stock Option | Minimum [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock price | $ 13.87 | $ 16.30 | $ 13.87 | $ 16.30 |
| Expected option term (in years) | 5 years 6 months | 5 years 6 months | 5 years 6 months | 5 years 6 months |
| Expected volatility | 73.00% | 67.00% | 73.00% | |
| Risk-free interest rate | 1.77% | 1.92% | 1.51% | 1.92% |
| Employee Stock Option | Maximum [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock price | $ 13.95 | $ 18.73 | $ 24.03 | $ 18.73 |
| Expected option term (in years) | 6 years 3 months | 6 years 3 months | 6 years 3 months | 6 years 3 months |
| Expected volatility | 74.00% | 69.00% | 74.00% | |
| Risk-free interest rate | 1.81% | 2.00% | 1.81% | 2.00% |
Redeemable Convertible Prefer33
| Redeemable Convertible Preferred Stock - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||||
| Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Dec. 31, 2014 | Feb. 04, 2014 | |
| Conversion of Stock [Line Items] | ||||||
| Issuance of common stock | 20,580,375 | 20,580,375 | 17,786,867 | |||
| Adjustment to preferred stock warrant liability recorded in other income (expense) | $ (2,559) | |||||
| Redeemable Convertible Preferred Stock [Member] | ||||||
| Conversion of Stock [Line Items] | ||||||
| Issuance of common stock | 10,589,434 | |||||
| Series C Preferred Stock [Member] | ||||||
| Conversion of Stock [Line Items] | ||||||
| Fair value of preferred stock warrants | $ 2,323 | |||||
| Adjustment to preferred stock warrant liability recorded in other income (expense) | $ 0 | $ 0 | $ 0 | $ (1,888) | ||
Redeemable Convertible Prefer34
| Redeemable Convertible Preferred Stock - Summary of Estimated Fair Values of Outstanding Warrants Using Black-Scholes Option-Pricing Model (Detail) - Feb. 04, 2014 - Series C Redeemable Convertible Preferred Stock [Member] - $ / shares | Total |
| Temporary Equity [Line Items] | |
| Stock price | $ 32.66 |
| Expected option term (in years) | 4 years 4 months 21 days |
| Expected volatility | 65.00% |
| Risk-free interest rate | 1.52% |
| Expected dividend yield | 0.00% |
Fair Value Measurements - Sched
| Fair Value Measurements - Schedule of Assets Measured or Disclosed at Fair Value (Detail) - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014 |
| Held-to-maturity investments | ||
| U.S. treasury securities and government agency bonds | $ 96,163 | $ 72,532 |
| Assets held in restriction | ||
| Total | 115,124 | 94,337 |
| Money Market Fund [Member] | ||
| Cash equivalents | ||
| Money market fund | 17,845 | 20,425 |
| Assets held in restriction | ||
| Restricted investments, at fair value | 1,116 | |
| Money Market Fund And Certificate Of Deposit [Member] | ||
| Assets held in restriction | ||
| Restricted investments, at fair value | 1,380 | |
| U.S. Government Treasury and Agency Securities [Member] | ||
| Held-to-maturity investments | ||
| U.S. treasury securities and government agency bonds | 96,163 | 72,532 |
| Level 1[Member] | ||
| Assets held in restriction | ||
| Total | 17,845 | 20,425 |
| Level 1[Member] | Money Market Fund [Member] | ||
| Cash equivalents | ||
| Money market fund | 17,845 | 20,425 |
| Level 2 [Member] | ||
| Assets held in restriction | ||
| Total | 97,279 | 73,912 |
| Level 2 [Member] | Money Market Fund [Member] | ||
| Assets held in restriction | ||
| Restricted investments, at fair value | 1,116 | |
| Level 2 [Member] | Money Market Fund And Certificate Of Deposit [Member] | ||
| Assets held in restriction | ||
| Restricted investments, at fair value | 1,380 | |
| Level 2 [Member] | U.S. Government Treasury and Agency Securities [Member] | ||
| Held-to-maturity investments | ||
| U.S. treasury securities and government agency bonds | $ 96,163 | $ 72,532 |
Fair Value Measurements - Addit
| Fair Value Measurements - Additional Information (Detail) - USD ($) | 6 Months Ended | ||
| Jun. 30, 2015 | Dec. 31, 2014 | Jun. 30, 2014 | |
| Debt Instrument Fair Value Carrying Value [Abstract] | |||
| Transfers between Level 1 and Level 2 | $ 0 | $ 0 | |
| Preferred stock conversion date | Feb. 4, 2014 | ||
| Preferred stock, warrants outstanding | 0 | 0 |
Fair Value Measurements - Sch37
| Fair Value Measurements - Schedule of Roll-Forward of Company's Liabilities Measured at Fair Value on Recurring Basis Using Unobservable Inputs (Level 3) (Detail) $ in Thousands | 6 Months Ended |
| Jun. 30, 2014USD ($) | |
| Debt Instrument Fair Value Carrying Value [Abstract] | |
| Balance at the beginning of the period | $ 529 |
| Change in fair value of warrant liability | 2,559 |
| Transfers to Level 2 | $ (3,088) |
Commitments and Contingencies -
| Commitments and Contingencies - Additional Information (Detail) - USD ($) | Jul. 11, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Dec. 01, 2014 |
| Loss Contingencies [Line Items] | ||||||
| Certificate of deposit | $ 264,000 | $ 264,000 | ||||
| Research and development expense | 11,875,000 | $ 6,806,000 | $ 20,567,000 | $ 12,057,000 | ||
| Cambridge Massachusetts , 2014 Operating Lease Agreement [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| Operating lease future minimum payments | $ 9,498,000 | |||||
| Operating lease future minimum payments term | 6 years | |||||
| Letter of credit | $ 1,116,000 | |||||
| Deferred rent obligation | Dec. 1, 2014 | |||||
| City of Hope License Agreement [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| License agreement date | Sep. 30, 2007 | |||||
| Expenses related to license agreement | 0 | 0 | $ 0 | 0 | ||
| Termination of license agreement description | The Company may terminate the license agreement at any time upon 90 days written notice | |||||
| City of Hope License Agreement [Member] | Minimum [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| Expenses related to license agreement | 5,000,000 | |||||
| City of Hope License Agreement [Member] | Maximum [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| Expenses related to license agreement | 10,000,000 | |||||
| Plant Bioscience Limited License Agreement [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| License agreement date | Sep. 30, 2013 | |||||
| Payments on commencement of clinical trial | 100,000 | |||||
| Research and development expense | $ 0 | $ 100,000 | $ 0 | $ 100,000 | ||
| Tekmira Pharmaceuticals Corporation License Agreement [Member] | ||||||
| Loss Contingencies [Line Items] | ||||||
| Expenses related to license agreement | 3,000,000 | |||||
| Aggregate development milestones and royalty | $ 22,000,000 |
Litigation - Additional Informa
| Litigation - Additional Information (Detail) - USD ($) | Jun. 30, 2015 | Dec. 31, 2014 |
| Commitments and Contingencies Disclosure [Abstract] | ||
| Outstanding litigation liabilities | $ 0 | $ 0 |