Intellia Therapeutics (NTLA) 10-Q 2 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 26, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	NTLA
Entity Registrant Name	INTELLIA THERAPEUTICS, INC.
Entity Central Index Key	1,652,130
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		36,028,677

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 257,551	$ 273,064
Accounts receivable	2,443	6,454
Prepaid expenses and other current assets	1,084	1,788
Total current assets	261,078	281,306
Property and equipment, net	11,418	10,628
Other assets	6,767	7,035
Total Assets	279,263	298,969
Current Liabilities:
Accounts payable	1,434	4,652
Accrued expenses	3,559	5,900
Current portion of deferred revenue	19,917	20,178
Total current liabilities	24,910	30,730
Deferred revenue, net of current portion	54,092	58,109
Other long-term liabilities	378	293
Commitments and contingencies
Stockholders' Equity:
Common stock, $0.0001 par value; 120,000,000 shares authorized, 36,025,676 shares and 36,018,540 shares issued and outstanding, respectively	4	4
Additional paid-in capital	266,080	263,403
Accumulated deficit	(66,201)	(53,570)
Total stockholders' equity	199,883	209,837
Total Liabilities and Stockholders' Equity	$ 279,263	$ 298,969

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	36,025,676	36,018,540
Common stock, shares outstanding	36,025,676	36,018,540

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Collaboration revenue	$ 6,215	$ 1,777
Operating expenses:
Research and development	13,431	5,225
General and administrative	5,732	3,246
Total operating expenses	19,163	8,471
Operating loss	(12,948)	(6,694)
Interest income	317	5
Net loss	$ (12,631)	$ (6,689)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.36)	$ (9.89)
Weighted average shares outstanding, basic and diluted	34,723	676

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (12,631)	$ (6,689)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	660	187
Equity-based compensation	2,630	812
Changes in operating assets and liabilities:
Accounts receivable	4,011
Prepaid expenses and other current assets	704	65
Accounts payable	(954)	(87)
Accrued expenses	(1,893)	(134)
Deferred revenue	(4,278)	(778)
Other assets	268	(2,823)
Other long-term liabilities	85	26
Net cash used in operating activities	(11,398)	(9,421)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(4,162)	(1,008)
Net cash used in investing activities	(4,162)	(1,008)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments to acquire in-process research and development		(200)
Payment of preferred unit and preferred stock issuance costs		(100)
Proceeds from options exercised	47
Payment of common stock offering costs		(895)
Net cash provided by (used in) financing activities	47	(1,195)
Net decrease in cash and cash equivalents	(15,513)	(11,624)
Cash and cash equivalents, beginning of period	273,064	75,816
Cash and cash equivalents, end of period	257,551	64,192
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Purchases of property and equipment unpaid at period end	$ 378	918
Acquisition of in-process research and development unpaid at period end		400
Financing costs incurred but unpaid at period end		$ 454

Overview and Basis of Presentat

Overview and Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	1. Overview and Basis of Presentation Intellia Therapeutics, Inc. (collectively referred to with its wholly-owned, controlled subsidiary, Intellia Securities Corp., as “Intellia” or the “Company”) is a genome editing company focused on developing potentially curative therapeutics utilizing a biological tool known as CRISPR/Cas9. The consolidated financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S.”) have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K The unaudited consolidated financial statements include the accounts of Intellia Therapeutics, Inc. and its wholly-owned, controlled subsidiary. All intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, the information furnished reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended March 31, 2017 and 2016 are referred to as the first quarter of 2017 and 2016, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), 2014-09 2014-09. 2014-09, In February 2016, the FASB issued ASU No. 2016-02, Leases 2016-02 Leases 2016-02 2016-02 In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting 2016-09 Compensation – Stock Compensation 2016-09

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company classifies fair value based measurements using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1, quoted market prices in active markets for identical assets or liabilities; Level 2, observable inputs other than quoted market prices included in Level 1, such as quoted market prices for markets that are not active or other inputs that are observable or can be corroborated by observable market data; and Level 3, unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities, including certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The Company’s financial instruments as of March 31, 2017 and December 31, 2016 consisted primarily of cash and cash equivalents, accounts receivable and accounts payable. As of March 31, 2017 and December 31, 2016, the Company’s financial assets recognized at fair value consisted of the following: Fair Value as of March 31, 2017 Total Level 1 Level 2 Level 3 (In thousands) Cash equivalents $ 255,735 $ 255,735 $ — $ — Total $ 255,735 $ 255,735 $ — $ — Fair Value as of December 31, 2016 Total Level 1 Level 2 Level 3 (In thousands) Cash equivalents $ 270,448 $ 270,448 $ — $ — Total $ 270,448 $ 270,448 $ — $ —

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Accrued Expenses	4. Accrued Expenses Accrued expenses consisted of the following: March 31, 2017 December 31, (In thousands) Employee compensation and benefits $ 1,532 $ 2,703 Research and development and professional expenses 2,027 3,197 Accrued expenses $ 3,559 $ 5,900

Collaborations

Collaborations	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborations	5. Collaborations Novartis Institutes for BioMedical Research In December 2014, the Company entered into a strategic collaboration agreement with Novartis Institutes for Biomedical Research, Inc. (“Novartis”) primarily focused on the development of new ex vivo (“CAR-T Agreement Structure Under the terms of the collaboration, the Company and Novartis may research potential therapeutic, prophylactic and palliative ex vivo CAR-T non-exclusive CAR-T CAR-T CAR-T CAR-T CAR-T CAR-T in vivo non-exclusive in vivo in vivo in vivo in vivo The Company received an upfront technology access payment from Novartis of $10.0 million in January 2015 and is entitled to additional technology access fees of $20.0 million and quarterly research payments of $1.0 million, or up to $20.0 million in the aggregate, during the five-year research term. For each product under the collaboration, subject to certain conditions, the Company may be eligible to receive (i) up to $30.3 million in development milestones, including for the filing of an investigational new drug application and for the dosing of the first patient in each of Phase IIa, Phase IIb and Phase III clinical trials, (ii) up to $50.0 million in regulatory milestones for the product’s first indication, including regulatory approvals in the U.S. and European Union (“EU”), (iii) up to $50.0 million in regulatory milestones for the product’s second indication, if any, including U.S. and EU regulatory approvals, (iv) royalties on net sales in the mid-single in vivo Class A-1 Class A-2 Collaboration Revenue Through March 31, 2017, excluding amounts allocated to Novartis’ purchase of the Company’s Class A-1 Class A-2 Regeneron Pharmaceuticals, Inc. In April 2016, the Company entered into a license and collaboration agreement with Regeneron Pharmaceuticals, Inc. (“Regeneron”). The agreement includes a product component to research, develop and commercialize CRISPR/Cas-based Agreement Structure Under the terms of the collaboration, the Company and Regeneron have agreed to a target selection process, whereby Regeneron may obtain exclusive rights for up to 10 targets to be chosen by Regeneron during the collaboration term, subject to various adjustments and limitations set forth in the agreement. Of these 10 total targets, Regeneron may select up to five non-liver co-development co-commercialization The Company retains the exclusive right to solely develop products for certain indications. During the target selection process, the Company has the right to choose additional liver targets for its own development using commercially reasonable efforts. Certain targets that either the Company or Regeneron select may be subject to further co-development co-commercialization non-liver Research activities under the collaboration will be governed by evaluation and research and development plans that will outline the parties’ responsibilities under, anticipated timelines of and budgets for, the various programs. The Company will assist Regeneron with the preliminary evaluation of liver targets, and Regeneron will be responsible for preclinical research and the conduct of clinical development, manufacturing and commercialization of products directed to each of its exclusive targets under the oversight of a joint steering committee. The Company may assist, as requested by Regeneron, with the later discovery and research of product candidates directed to any selected target. For each selected target, Regeneron is required to use commercially reasonable efforts to submit regulatory filings necessary to achieve initial investigational new drug (“IND”) acceptance for at least one product directed to each applicable target, and following IND acceptance for at least one product, to develop and commercialize such product. In connection with this collaboration, Regeneron agreed to purchase $50.0 million of the Company’s common stock in a private placement concurrent with the Company’s initial public offering, and the Company received a nonrefundable upfront payment of $75.0 million. In addition, the Company is eligible to earn, on a per-licensed ex-U.S. per-product co-development co-commercialization The fixed portion of consideration under the collaboration arrangement was determined to be the $75.0 million nonrefundable upfront payment, for which there are no contingent terms. The significant deliverables of this multiple-element revenue arrangement were determined to be licenses to targets, the associated research activities and evaluation plans for these programs and the technology collaboration. The Company further determined that the licenses and associated research activities and evaluation plans did not have standalone value due to the specialized nature of the services to be provided by the Company; therefore, these deliverables are not separable, and, accordingly, the license and services are treated as a single unit of accounting. The Company additionally concluded that the technology collaboration has standalone value from the product development, as shared rights to technological advancements under the technology collaboration could be separately applied by Regeneron to other programs. The Company allocated the $75.0 million in fixed consideration to the two units of accounting based on the estimated relative selling price of each deliverable. The Company estimated the selling price of each deliverable by taking into consideration internal estimates of research and development personnel needed to perform the research and development services, estimates of expected cash outflows to third parties for services and supplies, selling prices of comparable transactions and typical gross profit margins. As a result of this evaluation, the Company allocated $63.8 million to the licenses to targets and the associated research activities and evaluation plans and $11.2 million to the technology collaboration. The $63.8 million allocated to the licenses to targets and the associated research activities and evaluation plans for these programs is being recognized over the six-year Collaboration Revenue Through March 31, 2017, the Company recorded a $75.0 million upfront payment and $1.4 million for research and development services under the Regeneron agreement. Through March 31, 2017, the Company recognized $12.8 million of collaboration revenue, including $4.1 million in the three months ended March 31, 2017, in the consolidated statement of operations. As of March 31, 2017 and December 31, 2016, the Company had deferred revenue of $63.6 million and $66.7 million, respectively, related to this agreement.

Equity-Based Compensation

Equity-Based Compensation	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity-Based Compensation	6. Equity-Based Compensation Equity-based compensation expense is classified in the consolidated statements of operations as follows: Three Months Ended March 31, 2017 2016 (In thousands) Research and development $ 1,503 $ 454 General and administrative 1,127 358 Total $ 2,630 $ 812 Restricted Stock The following table summarizes the Company’s restricted stock activity, including converted Founder Stock, for the three months ended March 31, 2017: Number of Shares Weighted Average Grant Date Fair Value per Share Unvested restricted stock as of January 1, 2017 1,361,855 $ 0.81 Vested (186,917 ) 0.73 Unvested restricted stock as of March 31, 2017 1,174,938 $ 0.82 As of March 31, 2017, there was $2.7 million of unrecognized equity-based compensation expense related to restricted stock that is expected to vest. These costs are expected to be recognized over a weighted average remaining vesting period of 1.8 years. Stock Options The weighted average grant date fair value of options, estimated as of the grant date using the Black-Scholes option pricing model, was $10.38 per option and $4.98 per option for those options granted during the three months ended March 31, 2017 and 2016, respectively. Key assumptions used to apply this pricing model were as follows: Three Months Ended March 31, 2017 Three Months Ended March 31, 2016 Risk-free interest rate 1.9 % 1.3 % Expected life of options 6.0 years 6.0 years Expected volatility of underlying stock 92.6 % 87.7 % Expected dividend yield 0.0 % 0.0 % The following is a summary of stock option activity for the three months ended March 31, 2017: Number of Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (In years) (In thousands) Outstanding at January 1, 2017 3,040,214 $ 8.35 Granted 1,343,428 13.71 Exercised (7,136 ) 6.56 Forfeited (3,284 ) 16.03 Outstanding at March 31, 2017 4,373,222 $ 9.99 9.1 $ 17,929 Exercisable at March 31, 2017 780,588 $ 7.12 8.8 $ 5,440 As of March 31, 2017, there was $25.0 million of unrecognized compensation cost related to stock options that are expected to vest. These costs are expected to be recognized over a weighted average remaining vesting period of 3.2 years.

Loss Per Share

Loss Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Loss Per Share	7. Loss Per Share The Company calculates basic (loss) earnings per share by dividing (loss) income allocable to common stockholders by the weighted average number of common shares outstanding. The Company computes diluted (loss) earnings per share after giving consideration to the dilutive effect of preferred stock, common stock and restricted common stock that are outstanding during the period, except where such non-participating Basic and diluted loss per share attributable to common stockholders was calculated as follows: Three Months Ended March 31, 2017 2016 (In thousands except per share data) Net loss $ (12,631 ) $ (6,689 ) Weighted average shares outstanding, basic and diluted 34,723 676 Net loss per share attributable to common stockholders, basic and diluted $ (0.36 ) $ (9.89 ) In May 2016, the Company issued an additional 6,900,000 shares of common stock in connection with its initial public offering (“IPO”) and 23,481,956 shares of common stock in connection with the automatic conversion of its convertible preferred stock upon the closing of the IPO. In addition, the Company issued a total of 3,055,554 shares of common stock in two separate, concurrent private placements upon the closing of the IPO. The issuance of these shares resulted in a significant increase in the Company’s weighted average shares outstanding and will impact the year-over-year comparability of the Company’s (loss) earnings per share calculations into 2017. The following common stock equivalents were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive: Three Months Ended March 31, 2017 2016 (In thousands) Unvested restricted stock 1,175 1,774 Stock options 4,373 2,618 5,548 4,392

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	8. Related Party Transactions In July 2014, the Company issued Caribou Therapeutics Holdco, LLC, a wholly-owned subsidiary of Caribou Biosciences, Inc. (“Caribou”), 8,110,599 Junior Preferred Units. As a result of this and related transactions, Caribou owned 15.5% of the Company’s voting interests as of March 31, 2017. The Company recognized research and development expense of $0.4 million during the three months ended March 31, 2016 and an insignificant amount during the three months ended March 31, 2017, related to license and service agreements entered into with Caribou. In addition, the Company recognized general and administrative expense of $0.2 million during the three months ended March 31, 2016 and an insignificant amount during the three months ended March 31, 2017, related to the Company’s obligation to pay 30.0% of Caribou’s patent prosecution, filing and maintenance costs under its intellectual property license agreement with Caribou. In connection with its entry into the collaboration and license agreement and related equity transactions with Novartis, the Company issued Novartis 4,761,905 Class A-1 Class A-2 Collaborations The Company recognized collaboration revenue of $2.2 million and $1.8 million in the three months ended March 31, 2017 and 2016, respectively, in the consolidated statements of operations related to this agreement. As of March 31, 2017 and December 31, 2016, the Company had recorded accounts receivable of $1.0 million and $6.0 million and deferred revenue of $10.4 million and $11.6 million, respectively, related to this collaboration.

Summary of Significant Accoun14

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), 2014-09 2014-09. 2014-09, In February 2016, the FASB issued ASU No. 2016-02, Leases 2016-02 Leases 2016-02 2016-02 In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting 2016-09 Compensation – Stock Compensation 2016-09

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Financial Assets Recognized at Fair Value	As of March 31, 2017 and December 31, 2016, the Company’s financial assets recognized at fair value consisted of the following: Fair Value as of March 31, 2017 Total Level 1 Level 2 Level 3 (In thousands) Cash equivalents $ 255,735 $ 255,735 $ — $ — Total $ 255,735 $ 255,735 $ — $ — Fair Value as of December 31, 2016 Total Level 1 Level 2 Level 3 (In thousands) Cash equivalents $ 270,448 $ 270,448 $ — $ — Total $ 270,448 $ 270,448 $ — $ —

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following: March 31, 2017 December 31, (In thousands) Employee compensation and benefits $ 1,532 $ 2,703 Research and development and professional expenses 2,027 3,197 Accrued expenses $ 3,559 $ 5,900

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Equity-Based Compensation Expense	Equity-based compensation expense is classified in the consolidated statements of operations as follows: Three Months Ended March 31, 2017 2016 (In thousands) Research and development $ 1,503 $ 454 General and administrative 1,127 358 Total $ 2,630 $ 812
Summary of Restricted Stock Activity, Including Converted Founder Stock	The following table summarizes the Company’s restricted stock activity, including converted Founder Stock, for the three months ended March 31, 2017: Number of Shares Weighted Average Grant Date Fair Value per Share Unvested restricted stock as of January 1, 2017 1,361,855 $ 0.81 Vested (186,917 ) 0.73 Unvested restricted stock as of March 31, 2017 1,174,938 $ 0.82
Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted	Key assumptions used to apply this pricing model were as follows: Three Months Ended March 31, 2017 Three Months Ended March 31, 2016 Risk-free interest rate 1.9 % 1.3 % Expected life of options 6.0 years 6.0 years Expected volatility of underlying stock 92.6 % 87.7 % Expected dividend yield 0.0 % 0.0 %
Summary of Stock Option Activity	The following is a summary of stock option activity for the three months ended March 31, 2017: Number of Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (In years) (In thousands) Outstanding at January 1, 2017 3,040,214 $ 8.35 Granted 1,343,428 13.71 Exercised (7,136 ) 6.56 Forfeited (3,284 ) 16.03 Outstanding at March 31, 2017 4,373,222 $ 9.99 9.1 $ 17,929 Exercisable at March 31, 2017 780,588 $ 7.12 8.8 $ 5,440

Loss Per Share (Tables)

Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	Basic and diluted loss per share attributable to common stockholders was calculated as follows: Three Months Ended March 31, 2017 2016 (In thousands except per share data) Net loss $ (12,631 ) $ (6,689 ) Weighted average shares outstanding, basic and diluted 34,723 676 Net loss per share attributable to common stockholders, basic and diluted $ (0.36 ) $ (9.89 )
Potential Dilutive Securities Excluded from Computation of Diluted Net Loss Per Common Share	The following common stock equivalents were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive: Three Months Ended March 31, 2017 2016 (In thousands) Unvested restricted stock 1,175 1,774 Stock options 4,373 2,618 5,548 4,392

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Recognized at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 255,735	$ 270,448
Total	255,735	270,448
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	255,735	270,448
Total	$ 255,735	$ 270,448

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Employee compensation and benefits	$ 1,532	$ 2,703
Research and development and professional expenses	2,027	3,197
Accrued expenses	$ 3,559	$ 5,900

Collaborations - Additional Inf

Collaborations - Additional Information (Detail)	1 Months Ended		3 Months Ended		28 Months Ended
	Apr. 30, 2016USD ($)Unit	Jan. 31, 2015USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue			$ 6,215,000	$ 1,777,000
Novartis [Member] | Class A Preferred Units [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from issuance of preferred stock		$ 9,000,000
Estimated fair value of units		11,600,000
Difference between cash proceeds received and estimated fair value of preferred units		2,600,000
Novartis [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development based milestone payments under agreement		30,300,000
Regulatory based milestone payments for first indication		50,000,000
Regulatory based milestone payments for second indication		50,000,000
Sales based milestone payments under agreement		100,000,000
Novartis [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue					$ 26,400,000
Technology access fees		20,000,000
Quarterly research payments		$ 1,000,000
Research term		5 years
Collaboration revenue			2,200,000	$ 1,800,000	16,000,000
Deferred revenue			10,400,000		10,400,000	$ 11,600,000
Accounts receivable			1,000,000		1,000,000	6,000,000
Novartis [Member] | Collaborative Arrangement [Member] | Upfront Technology Access Payment [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		$ 10,000,000
Novartis [Member] | Collaborative Arrangement [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total research funding		$ 20,000,000
Regeneron Pharmaceuticals Inc. [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue			4,100,000		12,800,000
Deferred revenue			$ 63,600,000		63,600,000	$ 66,700,000
Purchase of common stock through private placement	$ 50,000,000
Percentage of obligated fund on research and development costs	50.00%
Number of accounting based units | Unit	2
Amount allocated to licenses to targets and associated research activities and evaluation plans	$ 63,800,000
Licenses to targets and associated research activities and evaluation plans performance period	6 years
Amount allocated to technology collaboration	$ 11,200,000
Revenue Recognition, Multiple-deliverable Arrangements, Allocation to Specific Unit of Accounting			The Company allocated the $75.0 million in fixed consideration to the two units of accounting based on the estimated relative selling price of each deliverable.
Regeneron Pharmaceuticals Inc. [Member] | Collaborative Arrangement [Member] | Upfront Technology Access Payment [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue					75,000,000
Regeneron Pharmaceuticals Inc. [Member] | Collaborative Arrangement [Member] | Research and Development Services [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue					$ 1,400,000
Regeneron Pharmaceuticals Inc. [Member] | Collaborative Arrangement [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development based milestone payments under agreement	25,000,000
Sales based milestone payments under agreement	185,000,000
Regulatory based milestone payments under agreement	$ 110,000,000

Equity-Based Compensation - Sch

Equity-Based Compensation - Schedule of Equity-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 2,630	$ 812
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	1,503	454
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 1,127	$ 358

Equity-Based Compensation - Sum

Equity-Based Compensation - Summary of Restricted Stock Activity, Including Converted Founder Stock (Detail)	3 Months Ended
	Mar. 31, 2017$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Unvested, Beginning balance | shares	1,361,855
Number of Shares, Vested | shares	(186,917)
Number of Shares, Unvested, Ending balance | shares	1,174,938
Weighted Average Grant Date Fair Value per Share, Unvested, Beginning balance | $ / shares	$ 0.81
Weighted Average Grant Date Fair Value per Share, Vested | $ / shares	0.73
Weighted Average Grant Date Fair Value per Share, Unvested, Ending balance | $ / shares	$ 0.82

Equity-Based Compensation - Add

Equity-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized stock-based compensation expense	$ 2.7
Weighted average grant date fair value per share	$ 10.38	$ 4.98
Unrecognized compensation cost related to stock options	$ 25
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of unrecognized compensation costs	1 year 9 months 18 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of unrecognized compensation costs	3 years 2 months 12 days

Equity-Based Compensation - S25

Equity-Based Compensation - Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted (Detail)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	1.90%	1.30%
Expected life of options	6 years	6 years
Expected volatility of underlying stock	92.60%	87.70%
Expected dividend yield	0.00%	0.00%

Equity-Based Compensation - S26

Equity-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options, Outstanding, Beginning Balance | shares	3,040,214
Number of options, Granted | shares	1,343,428
Number of options, Exercised | shares	(7,136)
Number of options, Forfeited | shares	(3,284)
Number of Options, Outstanding, Ending Balance | shares	4,373,222
Number of Options, Exercisable | shares	780,588
Weighted Average Exercise Price per Share, Outstanding, Beginning Balance | $ / shares	$ 8.35
Weighted Average Exercise Price per Share, Granted | $ / shares	13.71
Weighted Average Exercise Price per Share, Exercised | $ / shares	6.56
Weighted Average Exercise Price per Share, Forfeited | $ / shares	16.03
Weighted Average Exercise Price per Share, Outstanding, Ending Balance | $ / shares	9.99
Weighted Average Exercise Price per Share, Exercisable | $ / shares	$ 7.12
Weighted Average Remaining Contractual Term, Outstanding	9 years 1 month 6 days
Weighted Average Remaining Contractual Term, Exercisable	8 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding | $	$ 17,929
Aggregate Intrinsic Value, Exercisable | $	$ 5,440

Loss Per Share - Schedule of Ba

Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (12,631)	$ (6,689)
Weighted average shares outstanding, basic and diluted	34,723	676
Net loss per share attributable to common stockholders, basic and diluted	$ (0.36)	$ (9.89)

Loss Per Share - Additional Inf

Loss Per Share - Additional Information (Detail)	1 Months Ended
	May 31, 2016shares
IPO [Member]
Earnings Loss Per Share [Line Items]
Number of common stock issued upon conversion of shares	6,900,000
Conversion of convertible preferred stock into common stock	23,481,956
Private Placement [Member]
Earnings Loss Per Share [Line Items]
Number of common stock issued upon conversion of shares	3,055,554

Loss Per Share - Potential Dilu

Loss Per Share - Potential Dilutive Securities Excluded from Computation of Diluted Net Loss Per Common Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	5,548	4,392
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	1,175	1,774
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	4,373	2,618

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2015	Jul. 31, 2014
Related Party Transaction [Line Items]
Research and development expense related to license and service agreements with related party		$ 13,431	$ 5,225
General and administrative expenses		5,732	3,246
Collaboration revenue		$ 6,215	1,777
Caribou [Member]
Related Party Transaction [Line Items]
Junior preferred units issued							8,110,599
Percentage of shares owned		15.50%
Research and development expense related to license and service agreements with related party			400
General and administrative expenses			$ 200
Percentage of related party obligation			30.00%
Novartis [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Percentage of shares owned		15.70%
Common stock, shares acquired	277,777
Collaboration revenue		$ 2,200	$ 1,800
Accounts receivable		1,000		$ 6,000
Deferred revenue		$ 10,400		$ 11,600
Novartis [Member] | Class A-1 Preferred Units [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Junior preferred units issued					4,761,905
Novartis [Member] | Class A-2 Preferred Units [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Junior preferred units issued					2,666,666
Novartis [Member] | Series B Preferred Stock [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Preferred stock, shares acquired						761,905