ImmunityBio (IBRX) 10-Q 7 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 01, 2017
Document Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	NK
Entity Registrant Name	NANTKWEST, INC.
Entity Central Index Key	1,326,110
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		79,440,700

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 39,039	$ 8,083
Due from related parties	79	1,089
Prepaid expenses and other current assets	5,973	5,135
Marketable securities	136,466	190,838
Total current assets	181,557	205,145
Marketable securities, noncurrent	47,054	87,571
Property, plant and equipment, net	60,218	18,906
Cost method investment	8,500	0
Intangible assets, net	3,956	5,086
Other assets	335	788
Total assets	301,620	317,496
Current liabilities:
Accounts payable	4,271	4,045
Accrued expenses	14,381	5,864
Due to related parties	2,216	1,753
Financing obligation	14,880	253
Other current liabilities	1,130	638
Total current liabilities	36,878	12,553
Build-to-suit liability, less current portion	5,189	5,651
Financing obligation, less current portion	1,885	2,025
Deferred rent	3,595	2,426
Deferred tax liability	779	996
Other liabilities	370	427
Total liabilities	48,696	24,078
Commitments and contingencies (Note 8)	0	0
Stockholders’ equity
Common stock	8	8
Additional paid-in capital	700,639	680,757
Accumulated other comprehensive loss	(237)	(284)
Accumulated deficit	(447,486)	(387,063)
Total stockholders’ equity	252,924	293,418
Total liabilities and stockholders’ equity	$ 301,620	$ 317,496

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	79,430,700	81,983,937
Common stock, shares outstanding	79,430,700	81,983,937

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenue	$ 14	$ 12	$ 25	$ 18
Operating expenses:
Research and development	9,706	6,389	18,954	11,344
Selling, general and administrative	14,128	28,588	30,355	55,255
Total operating expenses	23,834	34,977	49,309	66,599
Loss from operations	(23,820)	(34,965)	(49,284)	(66,581)
Other income:
Investment income, net	681	739	1,460	1,507
Interest expense	(154)	0	(191)	0
Other income (expense), net	(283)	1	(174)	29
Total other income	244	740	1,095	1,536
Loss before income taxes	(23,576)	(34,225)	(48,189)	(65,045)
Income tax benefit	(124)	(228)	(222)	(371)
Net loss	$ (23,452)	$ (33,997)	$ (47,967)	$ (64,674)
Net loss per share:
Basic and diluted	$ (0.29)	$ (0.41)	$ (0.60)	$ (0.79)
Weighted average number of shares during the period:
Basic and diluted	81,440,816	81,959,248	79,426,402	81,769,964

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (23,452)	$ (33,997)	$ (47,967)	$ (64,674)
Other comprehensive income, net of income taxes:
Net unrealized gain (loss) on available-for-sale securities	(280)	129	(236)	646
Reclassification of net realized gains on available-for-sale securities included in net loss	(1)	(23)	(1)	(30)
Total other comprehensive income (loss)	(281)	106	(237)	616
Comprehensive loss	$ (23,733)	$ (33,891)	$ (48,204)	$ (64,058)

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 6 months ended Jun. 30, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2016	$ 293,418	$ 8	$ 680,757	$ (284)	$ (387,063)
Beginning Balance, Shares at Dec. 31, 2016	81,983,937	81,983,937
Exercise of stock options	$ 1,154	$ 0	1,154	0	0
Exercise of stock options, Shares		614,136
Stock-based compensation expense	19,399	$ 0	19,399	0	0
Vesting of restricted stock units		25,793
Exercise of warrants	38	$ 0	38	0	0
Exercise of warrants, Shares		32,787
Employee payroll taxes withheld related to option exercises and vesting of restricted stock units	(709)	$ 0	(709)	0	0
Employee payroll taxes withheld related to option exercises and vesting of restricted stock units, Shares		(153,744)
Repurchase of common stock	$ (12,456)	$ 0	0	0	(12,456)
Repurchase of common stock, Shares	(3,072,209)	(3,072,209)
Other comprehensive income, net	$ 47	$ 0	0	47	0
Net loss	(47,967)	0	0	0	(47,967)
Ending Balance at Jun. 30, 2017	$ 252,924	$ 8	$ 700,639	$ (237)	$ (447,486)
Ending Balance, Shares at Jun. 30, 2017	79,430,700	79,430,700

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net loss	$ (47,967)	$ (64,674)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,536	998
Stock-based compensation expense	19,399	43,917
Deferred income tax benefit	(217)	(373)
Loss on disposal of assets	0	18
Non-cash interest items, net	470	(516)
Amortization of net premiums on marketable securities	940	943
Loss (gain) on sales of marketable securities	1	(69)
Changes in operating assets and liabilities:
Receivables, net, prepaid expenses and other current assets	(1,306)	(358)
Other assets	452	(162)
Accounts payable	(1,067)	84
Accrued expenses and other liabilities	(1,104)	1,638
Due to related parties	1,429	375
Deferred rent and revenue	1,427	1,022
Net cash used in operating activities	(25,007)	(17,157)
Investing activities:
Purchases of property, plant and equipment	(12,665)	(2,123)
Purchase of cost method investment	(8,500)	0
Purchases of marketable securities	(46,518)	(165,837)
Sales/maturities of marketable securities	140,540	55,897
Net cash provided by (used in) investing activities	72,857	(112,063)
Financing activities:
Principal payments of financing/capital lease obligations	(4,920)	0
Proceeds from exercise of stock options and warrants	1,191	859
Repurchase of common stock with commissions	(12,456)	(9,324)
Net share settlement for RSU vesting and option exercises	(709)	0
Net cash used in financing activities	(16,894)	(8,465)
Net increase (decrease) in cash and cash equivalents	30,956	(137,685)
Cash and cash equivalents, beginning of period	8,083	175,908
Cash and cash equivalents, end of period	39,039	38,223
Cash paid during the period for:
Interest	238	0
Income taxes	3	1
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment purchases acquired under capital lease	19,448	0
Property and equipment purchases included in accounts payable and accrued expenses	13,402	2,059
Unrealized gain on marketable securities	74	962
Cashless exercise of warrants	16	456
Lease Incentive	$ 0	$ 50

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Organization NantKwest, Inc. (the Company) was incorporated in Illinois on October 7, 2002 under the name ZelleRx Corporation. On January 22, 2010, the Company changed its name to Conkwest, Inc., and on July 10, 2015, the Company changed its name to NantKwest, Inc. In March 2014, the Company redomesticated from the State of Illinois to the State of Delaware and the Illinois Company ceased to exist. The Company is a pioneering clinical-stage immunotherapy biotechnology company headquartered in San Diego, California with certain operations in Culver City and El Segundo, California and Woburn, Massachusetts. The Company is focused on harnessing the power of the innate immune system by using the natural killer cell to treat cancer, infectious diseases and inflammatory diseases. A critical aspect of our strategy is to invest significantly in expanding our aNK platform and the development of our product candidates. The Company holds the exclusive right to commercialize activated natural killer (aNK) cells, a commercially viable natural killer cell-line, and a variety of genetically modified derivatives capable of killing cancer and virally infected cells. The Company owns corresponding U.S. and foreign composition and methods-of-use patents and applications covering the clinical use of aNK cells as a therapeutic to treat a spectrum of clinical conditions. In addition, the Company licensed exclusive commercial rights to a portfolio of CD16 bearing aNK cells along with the corresponding U.S. and foreign composition and methods-of-use patents and applications covering the non-clinical use in laboratory testing of monoclonal antibodies, as well as clinical use as a therapeutic to treat cancers in combination with antibody products. The Company has licensed or sub-licensed its CD16 bearing aNK cell lines and intellectual property to numerous pharmaceutical and biotechnology companies for such non-clinical uses. The Company also licensed exclusive commercial rights to a unique HER2-specific receptor bearing aNK cell line along with the corresponding U.S. and foreign composition and methods-of-use patents and applications covering clinical use as a therapeutic to treat cancers. The Company retains exclusive worldwide rights to clinical and research data, intellectual property and know-how developed with the Company’s aNK cells, as well as the only clinical grade master cell bank. Unaudited Interim The accompanying condensed consolidated balance sheet at June 30, 2017, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2017, the condensed consolidated statements of cash flows for the six months ended June 30, 2017, and the condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2017 have been prepared by management of the Company and have not been audited. These financial statements have been prepared on the same basis as the audited consolidated financial statements for the fiscal year ended December 31, 2016 and, in the opinion of management, include all normal recurring adjustments necessary for a fair statement of the Company’s results for the periods presented. These financial statements should be read in conjunction with the financial statements and notes thereto for the fiscal year ended December 31, 2016 included in the Company’s Annual Report on Form 10-K. Interim operating results are not necessarily indicative of operating results for the full year. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (GAAP). Principles of Consolidation The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Inex Bio, Inc., and have been prepared in accordance with GAAP. All intercompany amounts have been eliminated. Liquidity As of June 30, 2017, the Company had an accumulated deficit of approximately $447.5 million. The Company also had negative cash flow from operations of approximately $25.0 million during the six months ended June 30, 2017. The Company expects that it will likely need additional capital to further fund development of, and seek regulatory approvals for, its product candidates, and begin to commercialize any approved products. The Company is currently focused primarily on the development of immunotherapeutic treatments for cancers and debilitating viral infections using targeted cancer killing cell lines, and believes such activities will result in the Company’s continued incurrence of significant research and development and other expenses related to those programs. If the clinical trials for any of the Company’s product candidates fail or produce unsuccessful results and those product candidates do not gain regulatory approval, or if any of the Company’s product candidates, if approved, fails to achieve market acceptance, the Company may never become profitable. Even if the Company achieves profitability in the future, it may not be able to sustain profitability in subsequent periods. The Company intends to cover its future operating expenses through cash and cash equivalents and marketable securities on hand and through a combination of equity offerings, debt financings, government or other third-party funding, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements. Additional financing may not be available to the Company when needed and, if available, financing may not be obtained on terms favorable to the Company or its stockholders. While the Company expects its existing cash and cash equivalents and marketable securities will enable it to fund operations and capital expenditure requirements for at least the next twelve months, it may not have sufficient funds to reach commercialization. Failure to obtain adequate financing when needed may require the Company to delay, reduce, limit or terminate some or all of its development programs or future commercialization efforts or grant rights to develop and market product candidates that the Company might otherwise prefer to develop and market itself which could adversely affect the Company’s ability to operate as a going concern. If the Company raises additional funds from the issuance of equity securities, substantial dilution to existing stockholders may result. If the Company raises additional funds by incurring debt financing, the terms of the debt may involve significant cash payment obligations as well as covenants and specific financial ratios that may restrict the Company’s ability to operate its business.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies With the exception of the policy for cost method investments noted below, there have been no significant changes to the items that the Company disclosed as its summary of significant accounting policies in the Annual Report on Form 10-K for the year ended December 31, 2016. Accounting for The Company owns non-marketable equity securities that are accounted for under the cost method because the preferred stock is not considered in-substance common stock and the preferred stock does not have a readily determinable fair value. All investments are reviewed on a regular basis for possible impairment. If an investment's fair value is determined to be less than its net carrying value and the decline is determined to be other-than-temporary, the investment is written down to its fair value. Such an evaluation is judgmental and dependent on specific facts and circumstances. Factors considered in determining whether an other-than-temporary decline in value has occurred include: market value of the investment based on most recent rounds of financing by the investee, length of time that the market value was below its cost basis, financial condition and business prospects of the investee, the Company’s intent and ability to retain the investment for a sufficient period of time to allow for recovery in market value of the investment, issues that raise concerns about the investee's ability to continue as a going concern, and any other information that the Company may be aware of related to the investment. Use of Estimates The preparation of condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to stock-based compensation, warrants, the valuation allowance for deferred tax assets, preclinical and clinical trial accruals, impairment assessments, and the valuation of build-to-suit lease assets. The Company bases its estimates on historical experience and on various other market-specific and relevant assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates. Basic and Diluted Net Loss per Share of Common Stock Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding for the period. Diluted loss per share is computed similarly to basic loss per share except that the denominator is increased to include the number of additional shares that would have been outstanding if the potential common shares had been issued and if the additional common shares were dilutive. For all periods presented, potentially dilutive securities are excluded from the computation of fully diluted loss per share as their effect is anti-dilutive. The following table details those securities that have been excluded from the computation of potentially dilutive securities: As of June 30, 2017 2016 Outstanding options 5,693,250 7,064,002 Outstanding restricted stock units 979,825 1,424,772 Outstanding warrants 17,735,527 17,794,544 Total 24,408,602 26,283,318 Amounts in the table above reflect the common stock equivalents of the noted instruments. Recent Accounting Pronouncements Application of New or Revised Accounting Standards – Not Yet Adopted In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting. Adoption of ASU 2017-09 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. Adoption of ASU 2016-18 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Adoption of ASU 2016-13 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. Adoption of ASU 2016-01 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In May 2014, the FASB issued guidance codified in ASC Topic 606, ASU 2014-09, Revenue Recognition—Revenue from Contracts with Customers Revenue Recognition doption of ASU 2014-09 is not expected to have a significant impact, the Company is currently evaluating the impact of the adoption on the Company’s consolidated financial statements and disclosures.

Financial Statement Details

Financial Statement Details	6 Months Ended
	Jun. 30, 2017
Financial Statement Details [Abstract]
Financial Statement Details	3. Financial Statement Details Prepaid Expenses and Other Current Assets As of June 30, 2017 and December 31, 2016, prepaid expenses and other current assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Tenant improvement allowance receivable $ 1,524 $ — Prepaid services 1,509 1,191 Interest receivable - marketable securities 1,014 1,484 Equipment deposits 482 482 Prepaid rent 362 360 Prepaid legal fees 350 350 Prepaid license fees 308 462 Prepaid insurance 122 531 Other 302 275 $ 5,973 $ 5,135 Property, Plant and Equipment, Net As of June 30, 2017 and December 31, 2016, property, plant and equipment consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Construction in progress $ 27,256 $ 6,939 Buildings under financing leases 23,796 4,348 Equipment 8,261 5,458 Leasehold improvements 2,424 2,367 Software 879 769 Furniture & fixtures 233 203 62,849 20,084 Accumulated depreciation (2,631 ) (1,178 ) $ 60,218 $ 18,906 Depreciation expense related to property, plant and equipment was $0.8 million and $0.1 million for the three months ended June 30, 2017 and 2016, respectively, and $1.4 million and $0.1 million for the six months ended June 30, 2017 and 2016, respectively. Buildings under financing leases of $23.8 million are comprised of $19.5 million related to a capital lease (See Note 8 – Capital Lease) Financing Lease Obligation) Construction in progress as of June 30, 2017 includes the estimated fair value of $5.1 million for the Company’s build-to-suit lease related to its facility in El Segundo, California, for which the Company is the “deemed owner” for accounting purposes only. See Note 8 – Build-to-suit Lease Intangible Assets, Net As of June 30, 2017 and December 31, 2016, intangible assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Technology license $ 9,042 $ 9,042 Less accumulated amortization (5,086 ) (3,956 ) $ 3,956 $ 5,086 Amortization expense was $0.6 million and $0.5 million for the three months ended June 30, 2017 and 2016, respectively, and $1.1 million and $0.9 million for the six months ended June 30, 2017 and 2016, respectively. Amortization for the Company’s technology license is included in research and development expense in the condensed consolidated statement of operations. Other Assets As of June 30, 2017 and December 31, 2016, other assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Restricted cash $ 179 $ 179 Security deposits 139 137 Equipment not placed in service — 362 Other 17 110 $ 335 $ 788 Accrued Expenses As of June 30, 2017 and December 31, 2016, accrued expenses consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Accrued construction costs $ 10,196 $ 1,053 Accrued bonus 1,237 1,732 Accrued professional and service fees 942 1,008 Accrued compensation 647 898 Accrued preclinical and clinical trial costs 562 662 Accrued laboratory equipment and supplies 469 190 Accrued software license fees 202 121 Other 126 200 $ 14,381 $ 5,864 Financing Obligation As of June 30, 2017 and December 31, 2016, the financing obligation consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Capital lease obligation - current portion $ 14,612 $ — Financing obligation - current portion 268 253 $ 14,880 $ 253 Other Current Liabilities As of June 30, 2017 and December 31, 2016, other current liabilities were made up of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Deferred rent - current portion $ 484 $ 197 Build-to-suit lease liability - current portion 409 281 Other 237 160 $ 1,130 $ 638 Investment Income, Net Net investment income includes interest income from all bank accounts as well as marketable securities, net realized gains or losses on sales of investments and the amortization of the premiums and discounts of the investments and is as follows for the three and six months ended June 30, 2017 and 2016 (in thousands): Three Months Ended June 30, Six Months Ended June 30, (Unaudited) (Unaudited) 2017 2016 2017 2016 Interest income $ 1,049 $ 1,239 $ 2,403 $ 2,431 Investment amortization accretion expense, net (367 ) (516 ) (939 ) (942 ) Net realized gains (losses) on investments (1 ) 16 (4 ) 18 $ 681 $ 739 $ 1,460 $ 1,507 Interest income includes interest from the Company’s bank deposits. The Company did not recognize an impairment loss on any investments for the six months ended June 30, 2017 and 2016.

Cost Method Investment

Cost Method Investment	6 Months Ended
	Jun. 30, 2017
Investments All Other Investments [Abstract]
Cost Method Investment	4. Cost Method Investment In March 2017, the Company participated in a Series B convertible preferred stock financing and invested $8.5 million in Viracta Therapeutics, Inc. (Viracta), a clinical stage drug development company. The Company has an option (but not the obligation) to purchase up to an additional $8.5 million worth of shares of the Series B convertible preferred stock by September 30, 2017. In May 2017, the Company executed an exclusive worldwide license with Viracta to develop and commercialize Viracta’s proprietary histone deacetylase inhibitor drug candidate for use in combination with NK cell therapy and possibly additional therapies. See Note 7 for further information regarding the license. Based on the level of equity investment at risk, Viracta is not a Variable Interest Entity (VIE). The Company is not consolidating Viracta, but is accounting for this investment using the cost method because the preferred stock is not considered in-substance common stock and preferred stock does not have a readily determinable fair value. As of June 30, 2017, the Company did not estimate the fair value of this cost method investment as there were no events or changes in circumstances that may have had a significant adverse effect on the fair value of the investment. The cost of the investment is recorded in cost method investment in the condensed consolidated balance sheet as of June 30, 2017.

Cash Equivalents and Marketable

Cash Equivalents and Marketable Securities	6 Months Ended
	Jun. 30, 2017
Cash Equivalents And Marketable Securities [Abstract]
Cash Equivalents and Marketable Securities	5. Cash Equivalents and Marketable Securities As of June 30, 2017, all of the Company’s marketable securities are classified as available-for-sale and are scheduled to mature within 4.2 years. At June 30, 2017, the detail of the Company’s cash equivalents and marketable securities is as follows (in thousands): June 30, 2017 (unaudited) Amortized Cost Unrealized Unrealized Losses Fair Value Current: Commercial paper $ 9,480 $ — $ — $ 9,480 Corporate debt securities 108,422 35 (87 ) 108,370 Government sponsored securities 27,251 — (40 ) 27,211 Foreign government bonds 5,401 — (9 ) 5,392 Current portion 150,554 35 (136 ) 150,453 Noncurrent: Corporate debt securities 42,385 57 (144 ) 42,298 Government sponsored securities 4,778 — (22 ) 4,756 Noncurrent portion 47,163 57 (166 ) 47,054 Total $ 197,717 $ 92 $ (302 ) $ 197,507 The cash equivalent portion included in the current fair values above is $6.5 million in commercial paper and $7.5 million in corporate debt securities. At December 31, 2016, the detail of the Company’s cash equivalents and marketable securities is as follows (in thousands): December 31, 2016 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Corporate debt securities $ 165,605 $ 40 $ (76 ) $ 165,569 Government sponsored securities 22,252 21 (1 ) 22,272 Foreign government bonds 5,004 — (2 ) 5,002 Current portion 192,861 61 (79 ) 192,843 Noncurrent: Corporate debt securities 69,414 71 (290 ) 69,195 Government sponsored securities 17,018 2 (38 ) 16,982 Foreign government bonds 1,405 — (11 ) 1,394 Noncurrent portion 87,837 73 (339 ) 87,571 Total $ 280,698 $ 134 $ (418 ) $ 280,414 Included in corporate debt securities is $2.0 million of cash equivalents at December 31, 2016. Available-for-sale investments that had been in an unrealized loss position for more and less than 12 months at June 30, 2017 and December 31, 2016 are as follows (in thousands): June 30, 2017 (unaudited) Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Commercial paper $ 2,996 $ — $ — $ — Corporate debt securities 94,709 (219 ) 2,495 (12 ) Government sponsored securities 31,966 (62 ) — — Foreign government bonds 5,392 (9 ) — — Total $ 135,063 $ (290 ) $ 2,495 $ (12 ) December 31, 2016 Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 150,320 $ (366 ) $ — $ — Government sponsored securities 17,204 (39 ) — — Foreign government bonds 6,396 (13 ) — — Total $ 173,920 $ (418 ) $ — $ — The Company evaluated its securities for other-than-temporary impairment and concluded that the decline in value was primarily caused by current economic and market conditions. The Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases. Therefore, the Company did not have any other-than-temporary impairment loss during the six months ended June 30, 2017. At June 30, 2017, 61 of the securities and bonds are in an unrealized loss position. The Company recorded realized gains and losses on sales or maturities of available-for-sale securities as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, (unaudited) (unaudited) 2017 2016 2017 2016 Gross realized gains $ — $ 33 $ 2 $ 92 Gross realized losses (1 ) (17 ) (6 ) (74 ) Net realized (losses) gains $ (1 ) $ 16 $ (4 ) $ 18

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements Recurring Valuations In accordance with the authoritative guidance for financial assets and liabilities measured at fair value on a recurring basis (ASC Topic 820), the Company prioritizes the inputs used to measure fair value from market-based assumptions to entity specific assumptions as follows: • Level 1—Inputs based on quoted market prices for identical assets or liabilities in active markets at the measurement date. • Level 2—Observable inputs other than quoted prices in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. • Level 3—Inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The inputs are unobservable in the market and significant to the instruments valuation. The following tables present the Company’s hierarchy for its assets measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016 (in thousands): Fair Value Measurements at June 30, 2017 (unaudited) Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents* $ 13,987 $ — $ 13,987 $ — Commercial paper 2,996 — 2,996 — Corporate debt securities 100,867 — 100,867 — Government sponsored securities 27,211 — 27,211 — Foreign government bonds 5,392 — 5,392 — Noncurrent: Corporate debt securities 42,298 — 42,298 — Government sponsored securities 4,756 — 4,756 — Total assets measured at fair value $ 197,507 $ — $ 197,507 $ — *This amount excludes $25.1 million in depository institutions that are classified as Level 1 assets. Fair Value Measurements at December 31, 2016 Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents* $ 2,005 $ — $ 2,005 $ — Corporate debt securities 163,564 — 163,564 — Government sponsored securities 22,272 — 22,272 — Foreign government bonds 5,002 — 5,002 — Noncurrent: Corporate debt securities 69,195 — 69,195 — Government sponsored securities 16,982 — 16,982 Foreign government bonds 1,394 — 1,394 — Total assets measured at fair value $ 280,414 $ — $ 280,414 $ — *This amount excludes $6.1 million in depository institutions that are classified as Level 1 assets. Non-recurring Valuation Non-financial assets and liabilities are recognized at fair value subsequent to initial recognition when they are deemed to be other-than-temporarily impaired. There were no material non-financial assets and liabilities deemed to be other-than-temporarily impaired and measured at fair value on a non-recurring basis for the six months ended June 30, 2017. As of June 30, 2017, the Company did not estimate the fair value of the Viracta cost method investment as there were no events or changes in circumstances that may have had a significant adverse effect on the fair value of the investment.

Collaboration and License Agree

Collaboration and License Agreements	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration and License Agreements	7. Collaboration and License Agreements Collaborative Arrangement A collaborative arrangement is a contractual arrangement that involves a joint operating activity. These arrangements involve two or more parties who are (i) active participants in the activity, and (ii) exposed to significant risks and rewards dependent on the commercial success of the activity. Exclusive Co-Development Agreement In August 2016, the Company entered into an exclusive Co-Development Agreement (the Co-Development Agreement) with Altor BioScience Corporation (Altor), a related party (Note 9). Under the Co-Development Agreement, the Company and Altor agreed to exclusively collaborate on the development of therapeutic applications combining the Company’s proprietary natural killer cells with Altor's ALT-801 and/or ALT-803 products with respect to certain technologies and intellectual property rights as may be agreed between the parties for the purpose of jointly developing therapeutic applications of certain effector cell lines. The Company will be the lead developer for each product developed by the parties pursuant to the Co-Development Agreement unless otherwise agreed to under a given project plan. Under the terms of the Co-Development Agreement, both parties grant a co-exclusive, royalty free, fully paid-up, worldwide license, with the right to sublicense (only to a third-party contractor assisting with research and development activities under this Co-Development Agreement and subject to prior consent, not to be unreasonably withheld), under the intellectual property (IP), including the parties interest in the joint IP, solely to conduct any development activities agreed to by the steering committee as set forth in any development plan. Unless otherwise mutually agreed by the parties in the development plan for a project, the Company shall be responsible for all costs and expenses incurred by either party related to conducting clinical trials and other activities under each development program, including costs associated with patient enrollment, materials and supplies, third-party staffing and regulatory filings. Altor will supply free of charge sufficient amounts of Altor products for all pre-clinical requirements and all clinical requirements for up to 400 patients in Phase I and/or Phase II clinical trials, as required under the development plan for a project per the Co-Development agreement. Altor and the Company each will own an undivided interest in and to all rights, title and interest in and to the joint product rights. The Co-Development Agreement expires upon the fifth anniversary of the effective date. During the six months ended June 30, 2017, the Company has dosed several patients with ALT-803 in its Phase II Merkel Cell Carcinoma trial. No charges for supplies or milestones by Altor have been incurred in association with the above trial during the six months ended June 30, 2017. Royalties and In-licensing Agreement License Agreement In May 2017, the Company entered into an agreement with Viracta to grant the Company exclusive world-wide rights to Viracta’s Phase II drug candidate, VRx-3996, for use in combination with the Company’s platform of natural killer cell therapies. In consideration for the license, the Company is obligated to pay to Viracta (i) mid-single digit percentage royalties of net sales of licensed products for therapeutic use; and (ii) milestone payments ranging from $10.0 million to $25.0 million for various regulatory approvals and cumulative net sales levels. The Company may terminate the agreement, in its sole discretion, in whole or on a product by product and/or country by country basis, at any time upon 90 days’ prior written notice. In addition, either party may terminate the agreement in the event of a material breach or for bankruptcy of the other party.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	8. Commitments and Contingencies Contingencies The Company records accruals for loss contingencies to the extent that the Company concludes it is probable that a liability has been incurred and the amount of the related loss can be reasonably estimated. The Company evaluates, on a quarterly basis, developments in legal proceedings and other matters that could cause a change in the potential amount of the liability recorded or of the range of potential losses disclosed. Appeal of USPTO Decision In March 2009, the Company received a final rejection in one of the Company’s original patent applications pertaining to certain limited methods of use claims for NK-92 from the U.S. Patent and Trademark Office (the USPTO), but the USPTO allowed claims on all of the other proposed claims, including other methods of use. The Company appealed this decision with the USPTO Board of Appeals and, in the fall of 2013, the Board of Appeals reversed the Examiner’s rejection of the claim to certain limited methods of use with NK-92, but affirmed the Examiner’s rejection of the remaining patent claims. In December 2013, the Company brought an action in the U.S. District Court for the Eastern District of Virginia to review the decision of the USPTO as the Company disagreed with the decision as to the certain limited non-allowed claims. On September 2, 2015, the U.S. District Court granted the USPTO’s motion for summary judgment. On September 24, 2015, the Company filed a notice of appeal to the United States Court of Appeals for the Federal Circuit. In September 2015, the USPTO filed a Motion for Expenses seeking $0.1 million for attorney’s fees and the USPTO’s expert witness fees. In February 2016, the U.S. District Court denied the USPTO’s Motion for Expenses for attorney’s fees and granted Director’s Motion for Expenses for the USPTO’s expert witness fees. The USPTO filed a notice of appeal on April 5, 2016. In May 2017, the Federal Circuit affirmed the U.S. District Court’s summary judgement ruling. The formal mandate was issued on June 26, 2017. In June 2017, the Federal Circuit reversed the U.S. District Court and remanded the case for the U.S. District Court to enter an award of $0.1 million in favor of the USPTO. Based on the information available at present, the Company cannot reasonably estimate a range of loss for this action beyond the attorney and expert witness fees. Accordingly, the fees have been accrued, but no liability associated with this action beyond the fees has been accrued. The Company is expensing legal costs associated with defending this litigation as the costs are incurred. Securities Litigation In March 2016, a putative securities class action complaint captioned Sudunagunta v. NantKwest, Inc., et al. On September 6, 2016, a shareholder derivative complaint captioned Bushansky v. Soon-Shiong, et al. Contractual Obligations - Leases The Company leases: (i) office space in Cardiff-by-the-Sea, California; (ii) a research facility in Woburn, Massachusetts; (iii) office space in Cary, North Carolina; (iv) a research facility in San Diego, California; (v) research and manufacturing space in Culver City, California, from a related party (Note 9); (vi) a research and manufacturing facility in El Segundo, California, also from a related party (Note 9); and (vii) a warehouse and distribution facility in El Segundo, California. The Company recognizes rent expense under its operating leases on a straight-line basis. Rent expense for the three months ended June 30, 2017 and 2016 was $0.7 million and $0.7 million, respectively, and $1.4 million and $1.4 million for the six months ended June 30, 2017 and 2016, respectively. Capital Lease In April 2017, the Company entered into an agreement to purchase a commercial building with approximately 36,000 square feet, located in El Segundo, California. The Company intends to use this facility as a warehouse and distribution facility as it is adjacent to the El Segundo, California, research and manufacturing facility. The agreement contemplates the purchase of the building by January 31, 2018 or earlier dependent on the close of escrow. The Company made a deposit of $5.0 million to the escrow holder upon execution of the purchase agreement. The balance of the purchase price, or $15.2 million, is due upon close of escrow. The closing of the transaction is contingent upon certain seller and buyer performance conditions. The deposit is refundable in the event of the seller’s default under the purchase agreement subject to termination fees of up to $38,000. The Company further entered into a lease agreement related to this facility which commenced on May 1, 2017 and terminates on the earlier of close of escrow or termination of the purchase agreement. There is no monthly base rent under the lease. The Company effectively has a bargain purchase option to purchase the building upon termination of the escrow period and, therefore, accounted for the lease as a capital lease. Upon lease commencement, the Company recorded a capital lease asset and a corresponding capital lease obligation equal to the present value of all payments required under the purchase agreement. The capital lease asset is amortized in accordance with the Company’s depreciation policy and the capital lease obligation, reduced by the deposit made, will be accreted over the lease term. Build-to-suit Lease In September 2016, the Company entered into a lease agreement with 605 Doug St, LLC, a related party (Note 9), for approximately 24,250 square feet in El Segundo, California, which is to be converted to a research and development laboratory and a Good Manufacturing Practices (GMP) laboratory. The lease runs from July 2016 through July 2023. The Company has the option to extend the lease for an additional three year term through July 2026. The monthly rent is $0.1 million with annual increases of 3% beginning in July 2017. During the construction period, the Company records the rent payments as (1) a reduction of the build-to-suit lease liability; (2) deferred rent; and (3) rent expense on the imputed cost to lease the underlying land of the facility, which is considered an operating lease. For the three and six months ended June 30, 2017, the Company recorded $0.1 million and $0.1 million in rent expense, respectively, which is recorded in research and development expense in the condensed consolidated statement of operations. The Company is responsible for costs to build out the laboratory and has incurred costs of approximately $20.2 million as of June 30, 2017, which is reflected in construction in progress in the condensed consolidated balance sheet. Additionally, in order for the facility to meet the Company's research and development and GMP laboratory specifications, the Company started to make certain structural changes to the facility as part of the conversion to laboratory space. As a result of these changes, the Company concluded that it is the “deemed owner” of the building (for accounting purposes only) during the construction period. Accordingly, the Company recorded a non-cash build-to-suit lease asset of $5.1 million, representing its estimate of the fair market value of the building, and a corresponding construction build-to-suit lease liability, recorded as a component of other current and non-current liabilities in the condensed consolidated balance sheet as of June 30, 2017. Upon completion of construction of this facility, the Company evaluates the de-recognition of the asset and liability under the provisions of ASC 840-40 Leases - Sale-Leaseback Transactions Financing Lease Obligation In November 2015, the Company entered into a facility license agreement with NantWorks LLC (NantWorks) (Note 9) for approximately 9,500 square feet of office space in Culver City, California, which has been converted to a research and development laboratory and a GMP laboratory. The license was effective in May 2015 and extends through December 2020. The Company has the option to extend the license through December 2023. The monthly license fee is $47,000 with annual increases of 3% beginning in January 2017. The Company records the rent payments as (1) a reduction of the financing obligation; (2) imputed interest expense; and (3) rent expense on the imputed cost to lease the underlying land of the facility, which is considered an operating lease. For the three months ended June 30, 2017 and 2016, the Company recorded $47,000 and $0.1 million, respectively, and $0.1 million and $0.2 million for the six months ended June 30, 2017 and 2016, respectively, in rent expense, which is reflected in research and development expense in the condensed consolidated statement of operations. Under the facility license agreement, the Company was responsible for costs to build out the laboratory and incurred costs of approximately $3.5 million. The Company concluded that it was the “deemed owner” of the building (for accounting purposes only) during the construction period. The Company recorded the build out costs as an asset with a corresponding build-to-suit liability, which was recorded as a component of other current and non-current liabilities in the condensed consolidated balance sheet while the building was under construction. Upon completion of construction of this building in August 2016, the Company evaluated the de-recognition of the asset and liability under the provisions of ASC 840-40, Leases – Sale-Leaseback Transactions. Commitments The Company did not enter into any significant contracts during the six months ended June 30, 2017 other than those disclosed in this document .

Related Party Agreements

Related Party Agreements	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
Related Party Agreements	9. Related Party Agreements The Company’s Chairman and CEO founded and has a controlling interest in NantWorks, which is a collection of multiple companies in the healthcare and technology space. As described below, the Company has entered into arrangements with NantWorks and certain affiliates of NantWorks to facilitate the development of new genetically modified NK cells for the Company’s product pipeline. Tensorcom, Inc. In April 2017, the Company entered into a sublease agreement with Tensorcom, Inc. (Tensorcom) related to its San Diego, California, research and development laboratory and office space, with an initial lease from May 1, 2017 through April 30, 2018. The Company’s Chairman and CEO indirectly owns all of the outstanding equity of Tensorcom. The sublease agreement converts to a month-to-month lease after the initial lease term, not to exceed the expiration of the lease agreement between the Company and the third party landlord. After the initial term, the sublease agreement can be terminated by either party by providing a thirty day written notice. The sublease includes a portion of the premises consisting of approximately 6,557 rentable square feet of space. The monthly base rent is $25,000 per month, with an annual 3% increase. For the three months ended June 30, 2017, the Company recognized $15,000 in other income in the condensed consolidated statement of operations under the sublease agreement. At June 30, 2017, there was no balance due between the parties. VivaBioCell S.p.A. In February 2017, the Company entered into a research grant agreement with VivaBioCell S.p.A. (VBC), an affiliated company of NantWorks, under which VBC will conduct research and development activities related to the Company’s NK cell lines using VBC’s proprietary technology. The Company paid $0.6 million to VBC, which is recognized in prepaid expenses and other current assets in the condensed consolidated balance sheet, and expects to benefit from the research and development activities over a one year timeframe. For the three and six months ended June 30, 2017, $0.1 million and $0.2 million, respectively, has been recognized in research and development expense in the condensed consolidated statement of operations and prepaid expenses and other current assets in the condensed consolidated balance sheet has been reduced by that amount. 605 Doug St. LLC In September 2016, the Company entered into a lease agreement with 605 Doug St. LLC, an entity owned by the Company’s Chairman and CEO, for approximately 24,250 square feet in El Segundo, California, which is to be converted to a research and development laboratory and a GMP laboratory. The lease runs from July 2016 through July 2023. The Company has the option to extend the lease for an additional three year term through July 2026. The monthly rent is $0.1 million with annual increases of 3% beginning in July 2017. See Note 8 – Build-to-suit Lease Altor In August 2016, the Company entered into a Co-Development Agreement with Altor as described in Note 7. The Company’s Chairman and CEO is also the Chairman of Altor. Altor is a wholly owned subsidiary of NantCell Inc. (NantCell), and the Company’s Chairman and CEO is also the Chairman and CEO of NantCell and holds a greater than 20% ownership interest in NantCell. No charges for supplies or milestones by Altor have been incurred in association with the above trial during the three and six months ended June 30, 2017. NantBioScience, Inc. In March 2016, NantBioScience, Inc. (NantBioScience), a NantWorks company, and the National Cancer Institute entered into a cooperative research and development agreement. The agreement covers NantBioScience and its affiliates, including the Company. Under the agreement, the parties will collaborate on the preclinical and clinical development of proprietary recombinant NK cells and monoclonal antibodies in monotherapy and in combination immunotherapies. The Company expects to benefit from the preclinical and clinical research conducted during the first and second year under this agreement and is providing the first and second year funding under the five-year agreement. In both April 2016 and April 2017, the Company paid $0.6 million to the National Cancer Institute as a prepayment for the first and second year of funding. The Company recognizes research and development expense ratably over a 12-month period for each funding year and recorded $0.2 million and $0.2 million of expense for the three months ended June 30, 2017 and 2016, respectively, and $0.3 million and $0.2 million for the six months ended June 30, 2017 and 2016, respectively. NantWorks Under the NantWorks shared services agreement executed in November 2015, but effective August 2015, NantWorks provides corporate, general and administrative, manufacturing strategy, research and development, regulatory and clinical trial strategy and other support services, and the Company is charged for the services at cost plus reasonable allocations for indirect costs that relate to the employees providing the services. For the three months ended June 30, 2017 and 2016, the Company recorded $0.6 million and $0.7 million, respectively, and $1.3 million and $1.5 million for the six months ended June 30, 2017 and 2016, respectively, to selling, general and administrative expense. For the three months ended June 30, 2017 and 2016, the Company recorded $0.7 million and $0.5 million, respectively, and $1.5 million and $0.8 million for the six months ended June 30, 2017 and 2016, respectively, in research and development expense under this arrangement in the condensed consolidated statement of operations. In June 2016, the Company amended the existing shared services agreement with NantWorks whereby the Company can provide such support services to NantWorks and/or any of its affiliates. For the three months ended June 30, 2017 and 2016, the Company recorded expense reimbursements of $0.1 million and $42,000, respectively, and $0.2 million and $42,000 for the six months ended June 30, 2017 and 2016, respectively, to selling, general and administrative expense. For the three months ended June 30, 2017 and 2016, the Company recorded expense reimbursements of 0.1 million and $9,000, respectively, and $0.3 million and $9,000 for the six months ended June 30, 2017 and 2016, respectively, to research and development expense. The Company owed NantWorks a net amount of $2.1 million for all agreements between the two affiliates at June 30, 2017, which is included in due to related parties in the condensed consolidated balance sheet. In November 2015, the Company entered into a facility license agreement with NantWorks, which became effective May 2015, for approximately 9,500 square feet in Culver City, California, which has been converted to a research and development laboratory and a GMP laboratory. See Note 8 - Financing Lease Obligation NantOmics, LLC In June 2015, the Company entered into an agreement with NantOmics, LLC (NantOmics) to obtain genomic sequencing and proteomic analysis services, as well as related data management and bioinformatics services, exclusively from NantOmics. The Company is obligated to pay NantOmics a fixed, per sample fee, determined based on the type of services being provided. The agreement has an initial term of five years and renews automatically for successive one year periods, unless terminated earlier. For the three months ended June 30, 2017 and 2016, the Company recorded operating expense of $13,000 and $0, respectively, and $13,000 and $0.1 million for the six months ended June 30, 2017 and 2016, respectively, under the agreement to research and development expense in the condensed consolidated statement of operations. The Company owed NantOmics $13,000 at June 30, 2017. NantCell In June 2015, the Company also entered into a supply agreement with NantCell pursuant to which the Company has the right to purchase NantCell’s proprietary bioreactors, made according to specifications mutually agreed to with NantCell. The Company also has the right to purchase reagents and consumables associated with such equipment from NantCell. In September 2015, the Company made a $0.5 million nonrefundable, upfront payment to NantCell as required by the agreement, which upfront payment is creditable against the Company’s future development activities and equipment purchases under the agreement. The agreement has an initial term of five years and renews automatically for successive one year periods unless terminated earlier. The upfront payment was included in prepaid expenses in the condensed consolidated balance sheets. During the three and six months ended June 30, 2017, the Company recorded research and development expense of $33,000 and $0.3 million, respectively, in the condensed consolidated statement of operations, which consumed the remaining $0.3 million of the $0.5 million prepayment. At June 30, 2017, there is no balance due between the parties.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity Stock Repurchase— In November 2015, the board of directors approved a share repurchase program (2015 Share Repurchase Program) allowing the CEO or CFO, on behalf of the Company, to repurchase from time to time, in the open market or in privately negotiated transactions, up to $50.0 million of the Company’s outstanding shares of common stock, exclusive of any commissions, markups or expenses. The timing and amounts of any purchases will be based on market conditions and other factors, including price, regulatory requirements and other corporate considerations. The 2015 Share Repurchase Program does not require the purchase of any minimum number of shares and may be suspended, modified or discontinued at any time without prior notice. The Company expects to finance the purchases with existing cash balances. During the three and six months ended June 30, 2017, the Company repurchased 2,772,209 and 3,072,209 shares of its common stock, respectively, at prices ranging between $3.10 and $4.75 per share for a total of $12.4 million. The Company incurred approximately $0.1 million of broker commissions on the repurchases. During the year ended December 31, 2016, the Company repurchased 2,157,944 shares of common stock for a total of $15.8 million. The shares are formally retired through board approval upon repurchase. The Company accounted for the repurchases under the constructive retirement method and allocated the excess of the repurchase price over par value to accumulated deficit. At June 30, 2017, $21.8 million remained authorized for repurchase under the Company’s 2015 Share Repurchase Program. A summary of common stock repurchases for the six months ended June 30, 2017 is as follows: Total number of shares purchased Average price paid per share Total number of shares purchased as part of publicly announced plans or programs Maximum approximate dollar value of shares that may yet be purchased under the plans or programs March 300,000 $ 3.50 300,000 $33.1 million May 1,028,200 $ 3.92 1,328,200 $29.1 million June 1,744,009 $ 4.18 3,072,209 $21.8 million Total 3,072,209 $ 4.03

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation The following table presents stock-based compensation expense included in the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, (unaudited) (unaudited) 2017 2016 2017 2016 Stock-based compensation expense: Warrants for common stock to an officer $ 7,827 $ 15,182 $ 16,313 $ 27,272 Employee stock options 952 4,858 2,303 9,751 Employee restricted stock units (93 ) 3,148 225 6,530 Non-employee restricted stock units 695 167 558 364 $ 9,381 $ 23,355 $ 19,399 $ 43,917 Stock-based compensation expense in operating expenses: Research and development $ (49 ) $ 291 $ 43 $ 564 Selling, general and administrative 9,430 23,064 19,356 43,353 $ 9,381 $ 23,355 $ 19,399 $ 43,917 In the second quarter of 2016, the Company adopted ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ASU 2016-09 also requires the recognition of the income tax effects of awards in the condensed consolidated statement of operations when the awards vest or are settled, thus eliminating addition paid-in capital pools. The Company elected to adopt the amendments related to the presentation of excess tax benefits in the condensed consolidated statement of cash flows using a prospective transition method. Stock Options The following table summarizes stock option activity for the six months ended June 30, 2017 (in thousands, except for share and year amounts): Number of Shares Weighted- Average Exercise Price Aggregate Intrinsic Value Weighted- Average Remaining Contractual Life (in years) Outstanding at December 31, 2016 6,307,386 $ 7.14 $ 19,100 6.4 Options exercised (614,136 ) $ 1.88 Outstanding at June 30, 2017 5,693,250 $ 7.71 $ 24,666 5.8 Vested and Exercisable at June 30, 2017 4,883,219 $ 8.62 $ 20,299 6.4 The aggregate intrinsic value of stock options exercised during the six months ended June 30, 2017 was $1.7 million. The total unrecognized stock-based compensation expense related to non-vested stock options as of June 30, 2017 is $6.7 million, which is expected to be recognized over a weighted-average period of 1.8 years. Restricted Stock Units The following table summarizes the activity for restricted stock units: Number of Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2016 814,456 $ 13.98 Granted 393,262 $ 3.93 Vested (25,793 ) $ 9.87 Forfeited (202,100 ) $ 11.77 Unvested balance at June 30, 2017 979,825 $ 10.51 During the six months ended June 30, 2017, the Company granted 316,012 shares of restricted stock units to employees and 77,250 shares to non-employees. Of the 77,250 shares granted to non-employees, 27,250 shares were granted to employees of related companies under the Company’s shared services agreement with NantWorks (Note 9). As of June 30, 2017, there was $5.1 million of unrecognized stock-based compensation expense related to restricted stock units that is expected to be recognized over a weighted-average period of 2.8 years. Of that amount, $3.0 million of unrecognized expense is related to employee grants with a weighted-average period of 2.8 years and $2.1 million of unrecognized expense is related to non-employee grants with a weighted-average period of 2.8 years that is impacted by periodic mark-to-market adjustments. Warrants The following table summarizes the warrant activity for the six months ended June 30, 2017: Outstanding at December 31, 2016 17,768,314 Warrants exercised (32,787 ) Outstanding at June 30, 2017 17,735,527 Vested and exercisable at June 30, 2017 15,328,577 The total unrecognized stock-based compensation expense related to non-vested warrants as of June 30, 2017 is $33.1 million, which is expected to be recognized over a weighted-average period of 1.1 years.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The difference between the federal statutory tax rate of 34% and the Company’s 0% tax rate is due to losses in jurisdictions from which the Company cannot benefit. Intraperiod tax allocation rules require the Company to allocate the provision for income taxes between continuing operations and other categories of earnings, such as other comprehensive income. In periods in which the Company has a year-to-date pre-tax loss from continuing operations and pre-tax income in other categories of earnings, such as other comprehensive income, the Company must allocate the tax provision to the other categories of earnings. The Company then records a related tax benefit in continuing operations. During the six months ended June 30, 2017, the Company recorded unrealized gains on its marketable securities in other comprehensive income, net of taxes. As a result, the Company recorded a tax benefit of $4,000 and $0.1 million for the three months ended June 30, 2017 and 2016, respectively and $10,000 and $0.2 million for the six months ended June 30, 2017 and 2016, respectively, in the condensed consolidated statement of operations. The Company also recorded other comprehensive income of $2,000 and $0.1 million for the three months ended June 30, 2017 and 2016, respectively, and $28,000 and $0.4 million for the six months ended June 30, 2017 and 2016, respectively, in the condensed consolidated balance sheet. The Company is operating in Korea. During the three months ended June 30, 2017 and 2016, the tax benefit related to Korea is $0.1 million for each period. During the six months ended June 30, 2017 and 2016, the tax benefit related to Korea is $0.2 million for each period. The Company currently files federal and state income tax returns in the United States and in Korea. Income tax expense consists of U.S. federal, state, and Korean income taxes. To date, the Company has not been required to pay U.S. federal income taxes because of current and accumulated net operating losses.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events Related Party Agreement In July 2017, the Company entered into a clinical trial agreement with John Lee, M.D. and Leonard Sender, M.D., Inc., a professional medical corporation, dba Chan Soon-Shiong Institutes for Medicine (CSSIM), in El Segundo, California. CSSIM is a related party as it is owned by two officers of the Company and NantWorks provides administrative services to CSSIM. One of the Company’s officers will be the principal investigator for the trial on behalf of CSSIM. The clinical trial is an open-label, Phase I study of haNK for infusion in subjects with metastatic or locally advanced solid tumors. The cost under this agreement is estimated at $0.5 million.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Inex Bio, Inc., and have been prepared in accordance with GAAP. All intercompany amounts have been eliminated.
Liquidity	Liquidity As of June 30, 2017, the Company had an accumulated deficit of approximately $447.5 million. The Company also had negative cash flow from operations of approximately $25.0 million during the six months ended June 30, 2017. The Company expects that it will likely need additional capital to further fund development of, and seek regulatory approvals for, its product candidates, and begin to commercialize any approved products. The Company is currently focused primarily on the development of immunotherapeutic treatments for cancers and debilitating viral infections using targeted cancer killing cell lines, and believes such activities will result in the Company’s continued incurrence of significant research and development and other expenses related to those programs. If the clinical trials for any of the Company’s product candidates fail or produce unsuccessful results and those product candidates do not gain regulatory approval, or if any of the Company’s product candidates, if approved, fails to achieve market acceptance, the Company may never become profitable. Even if the Company achieves profitability in the future, it may not be able to sustain profitability in subsequent periods. The Company intends to cover its future operating expenses through cash and cash equivalents and marketable securities on hand and through a combination of equity offerings, debt financings, government or other third-party funding, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements. Additional financing may not be available to the Company when needed and, if available, financing may not be obtained on terms favorable to the Company or its stockholders. While the Company expects its existing cash and cash equivalents and marketable securities will enable it to fund operations and capital expenditure requirements for at least the next twelve months, it may not have sufficient funds to reach commercialization. Failure to obtain adequate financing when needed may require the Company to delay, reduce, limit or terminate some or all of its development programs or future commercialization efforts or grant rights to develop and market product candidates that the Company might otherwise prefer to develop and market itself which could adversely affect the Company’s ability to operate as a going concern. If the Company raises additional funds from the issuance of equity securities, substantial dilution to existing stockholders may result. If the Company raises additional funds by incurring debt financing, the terms of the debt may involve significant cash payment obligations as well as covenants and specific financial ratios that may restrict the Company’s ability to operate its business.
Accounting for Cost Method Investments	Accounting for The Company owns non-marketable equity securities that are accounted for under the cost method because the preferred stock is not considered in-substance common stock and the preferred stock does not have a readily determinable fair value. All investments are reviewed on a regular basis for possible impairment. If an investment's fair value is determined to be less than its net carrying value and the decline is determined to be other-than-temporary, the investment is written down to its fair value. Such an evaluation is judgmental and dependent on specific facts and circumstances. Factors considered in determining whether an other-than-temporary decline in value has occurred include: market value of the investment based on most recent rounds of financing by the investee, length of time that the market value was below its cost basis, financial condition and business prospects of the investee, the Company’s intent and ability to retain the investment for a sufficient period of time to allow for recovery in market value of the investment, issues that raise concerns about the investee's ability to continue as a going concern, and any other information that the Company may be aware of related to the investment.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to stock-based compensation, warrants, the valuation allowance for deferred tax assets, preclinical and clinical trial accruals, impairment assessments, and the valuation of build-to-suit lease assets. The Company bases its estimates on historical experience and on various other market-specific and relevant assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Basic and Diluted Net Loss Per Share of Common Stock	Basic and Diluted Net Loss per Share of Common Stock Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding for the period. Diluted loss per share is computed similarly to basic loss per share except that the denominator is increased to include the number of additional shares that would have been outstanding if the potential common shares had been issued and if the additional common shares were dilutive. For all periods presented, potentially dilutive securities are excluded from the computation of fully diluted loss per share as their effect is anti-dilutive. The following table details those securities that have been excluded from the computation of potentially dilutive securities: As of June 30, 2017 2016 Outstanding options 5,693,250 7,064,002 Outstanding restricted stock units 979,825 1,424,772 Outstanding warrants 17,735,527 17,794,544 Total 24,408,602 26,283,318 Amounts in the table above reflect the common stock equivalents of the noted instruments.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Application of New or Revised Accounting Standards – Not Yet Adopted In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting. Adoption of ASU 2017-09 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. Adoption of ASU 2016-18 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Adoption of ASU 2016-13 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. Adoption of ASU 2016-01 is not expected to have a significant impact in the Company’s consolidated financial statements and disclosures. In May 2014, the FASB issued guidance codified in ASC Topic 606, ASU 2014-09, Revenue Recognition—Revenue from Contracts with Customers Revenue Recognition doption of ASU 2014-09 is not expected to have a significant impact, the Company is currently evaluating the impact of the adoption on the Company’s consolidated financial statements and disclosures.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Securities Excluded from the Computation of Potentially Dilutive Securities	The following table details those securities that have been excluded from the computation of potentially dilutive securities: As of June 30, 2017 2016 Outstanding options 5,693,250 7,064,002 Outstanding restricted stock units 979,825 1,424,772 Outstanding warrants 17,735,527 17,794,544 Total 24,408,602 26,283,318 Amounts in the table above reflect the common stock equivalents of the noted instruments.

Financial Statement Details (Ta

Financial Statement Details (Tables)	6 Months Ended
	Jun. 30, 2017
Financial Statement Details [Abstract]
Prepaid Expenses and Other Current Assets	As of June 30, 2017 and December 31, 2016, prepaid expenses and other current assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Tenant improvement allowance receivable $ 1,524 $ — Prepaid services 1,509 1,191 Interest receivable - marketable securities 1,014 1,484 Equipment deposits 482 482 Prepaid rent 362 360 Prepaid legal fees 350 350 Prepaid license fees 308 462 Prepaid insurance 122 531 Other 302 275 $ 5,973 $ 5,135
Property, Plant and Equipment, Net	As of June 30, 2017 and December 31, 2016, property, plant and equipment consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Construction in progress $ 27,256 $ 6,939 Buildings under financing leases 23,796 4,348 Equipment 8,261 5,458 Leasehold improvements 2,424 2,367 Software 879 769 Furniture & fixtures 233 203 62,849 20,084 Accumulated depreciation (2,631 ) (1,178 ) $ 60,218 $ 18,906
Intangible Assets, Net	As of June 30, 2017 and December 31, 2016, intangible assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Technology license $ 9,042 $ 9,042 Less accumulated amortization (5,086 ) (3,956 ) $ 3,956 $ 5,086
Other Assets	As of June 30, 2017 and December 31, 2016, other assets consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Restricted cash $ 179 $ 179 Security deposits 139 137 Equipment not placed in service — 362 Other 17 110 $ 335 $ 788
Accrued Expenses	As of June 30, 2017 and December 31, 2016, accrued expenses consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Accrued construction costs $ 10,196 $ 1,053 Accrued bonus 1,237 1,732 Accrued professional and service fees 942 1,008 Accrued compensation 647 898 Accrued preclinical and clinical trial costs 562 662 Accrued laboratory equipment and supplies 469 190 Accrued software license fees 202 121 Other 126 200 $ 14,381 $ 5,864
Financing Obligation	As of June 30, 2017 and December 31, 2016, the financing obligation consisted of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Capital lease obligation - current portion $ 14,612 $ — Financing obligation - current portion 268 253 $ 14,880 $ 253
Other Current Liabilities	As of June 30, 2017 and December 31, 2016, other current liabilities were made up of (in thousands): June 30, 2017 December 31, 2016 (Unaudited) Deferred rent - current portion $ 484 $ 197 Build-to-suit lease liability - current portion 409 281 Other 237 160 $ 1,130 $ 638
Investment Income, Net	Net investment income includes interest income from all bank accounts as well as marketable securities, net realized gains or losses on sales of investments and the amortization of the premiums and discounts of the investments and is as follows for the three and six months ended June 30, 2017 and 2016 (in thousands): Three Months Ended June 30, Six Months Ended June 30, (Unaudited) (Unaudited) 2017 2016 2017 2016 Interest income $ 1,049 $ 1,239 $ 2,403 $ 2,431 Investment amortization accretion expense, net (367 ) (516 ) (939 ) (942 ) Net realized gains (losses) on investments (1 ) 16 (4 ) 18 $ 681 $ 739 $ 1,460 $ 1,507

Cash Equivalents and Marketab24

Cash Equivalents and Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2017
Cash Equivalents And Marketable Securities [Abstract]
Schedule of Cash Equivalents and Marketable Securities Available-for-Sale	At June 30, 2017, the detail of the Company’s cash equivalents and marketable securities is as follows (in thousands): June 30, 2017 (unaudited) Amortized Cost Unrealized Unrealized Losses Fair Value Current: Commercial paper $ 9,480 $ — $ — $ 9,480 Corporate debt securities 108,422 35 (87 ) 108,370 Government sponsored securities 27,251 — (40 ) 27,211 Foreign government bonds 5,401 — (9 ) 5,392 Current portion 150,554 35 (136 ) 150,453 Noncurrent: Corporate debt securities 42,385 57 (144 ) 42,298 Government sponsored securities 4,778 — (22 ) 4,756 Noncurrent portion 47,163 57 (166 ) 47,054 Total $ 197,717 $ 92 $ (302 ) $ 197,507 At December 31, 2016, the detail of the Company’s cash equivalents and marketable securities is as follows (in thousands): December 31, 2016 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Corporate debt securities $ 165,605 $ 40 $ (76 ) $ 165,569 Government sponsored securities 22,252 21 (1 ) 22,272 Foreign government bonds 5,004 — (2 ) 5,002 Current portion 192,861 61 (79 ) 192,843 Noncurrent: Corporate debt securities 69,414 71 (290 ) 69,195 Government sponsored securities 17,018 2 (38 ) 16,982 Foreign government bonds 1,405 — (11 ) 1,394 Noncurrent portion 87,837 73 (339 ) 87,571 Total $ 280,698 $ 134 $ (418 ) $ 280,414
Available-for-Sale Investments in Unrealized Loss Position	Available-for-sale investments that had been in an unrealized loss position for more and less than 12 months at June 30, 2017 and December 31, 2016 are as follows (in thousands): June 30, 2017 (unaudited) Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Commercial paper $ 2,996 $ — $ — $ — Corporate debt securities 94,709 (219 ) 2,495 (12 ) Government sponsored securities 31,966 (62 ) — — Foreign government bonds 5,392 (9 ) — — Total $ 135,063 $ (290 ) $ 2,495 $ (12 ) December 31, 2016 Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 150,320 $ (366 ) $ — $ — Government sponsored securities 17,204 (39 ) — — Foreign government bonds 6,396 (13 ) — — Total $ 173,920 $ (418 ) $ — $ —
Schedule of Realized Gains and Losses on Sales or Maturities of Available-for-Sale Securities	The Company recorded realized gains and losses on sales or maturities of available-for-sale securities as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, (unaudited) (unaudited) 2017 2016 2017 2016 Gross realized gains $ — $ 33 $ 2 $ 92 Gross realized losses (1 ) (17 ) (6 ) (74 ) Net realized (losses) gains $ (1 ) $ 16 $ (4 ) $ 18

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on Recurring Basis	The following tables present the Company’s hierarchy for its assets measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016 (in thousands): Fair Value Measurements at June 30, 2017 (unaudited) Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents* $ 13,987 $ — $ 13,987 $ — Commercial paper 2,996 — 2,996 — Corporate debt securities 100,867 — 100,867 — Government sponsored securities 27,211 — 27,211 — Foreign government bonds 5,392 — 5,392 — Noncurrent: Corporate debt securities 42,298 — 42,298 — Government sponsored securities 4,756 — 4,756 — Total assets measured at fair value $ 197,507 $ — $ 197,507 $ — *This amount excludes $25.1 million in depository institutions that are classified as Level 1 assets. Fair Value Measurements at December 31, 2016 Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents* $ 2,005 $ — $ 2,005 $ — Corporate debt securities 163,564 — 163,564 — Government sponsored securities 22,272 — 22,272 — Foreign government bonds 5,002 — 5,002 — Noncurrent: Corporate debt securities 69,195 — 69,195 — Government sponsored securities 16,982 — 16,982 Foreign government bonds 1,394 — 1,394 — Total assets measured at fair value $ 280,414 $ — $ 280,414 $ — *This amount excludes $6.1 million in depository institutions that are classified as Level 1 assets.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Summary of Common Stock Repurchases	A summary of common stock repurchases for the six months ended June 30, 2017 is as follows: Total number of shares purchased Average price paid per share Total number of shares purchased as part of publicly announced plans or programs Maximum approximate dollar value of shares that may yet be purchased under the plans or programs March 300,000 $ 3.50 300,000 $33.1 million May 1,028,200 $ 3.92 1,328,200 $29.1 million June 1,744,009 $ 4.18 3,072,209 $21.8 million Total 3,072,209 $ 4.03

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation Expense Included in Operations Statement	The following table presents stock-based compensation expense included in the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, (unaudited) (unaudited) 2017 2016 2017 2016 Stock-based compensation expense: Warrants for common stock to an officer $ 7,827 $ 15,182 $ 16,313 $ 27,272 Employee stock options 952 4,858 2,303 9,751 Employee restricted stock units (93 ) 3,148 225 6,530 Non-employee restricted stock units 695 167 558 364 $ 9,381 $ 23,355 $ 19,399 $ 43,917 Stock-based compensation expense in operating expenses: Research and development $ (49 ) $ 291 $ 43 $ 564 Selling, general and administrative 9,430 23,064 19,356 43,353 $ 9,381 $ 23,355 $ 19,399 $ 43,917
Summarizes Stock Option Activity	The following table summarizes stock option activity for the six months ended June 30, 2017 (in thousands, except for share and year amounts): Number of Shares Weighted- Average Exercise Price Aggregate Intrinsic Value Weighted- Average Remaining Contractual Life (in years) Outstanding at December 31, 2016 6,307,386 $ 7.14 $ 19,100 6.4 Options exercised (614,136 ) $ 1.88 Outstanding at June 30, 2017 5,693,250 $ 7.71 $ 24,666 5.8 Vested and Exercisable at June 30, 2017 4,883,219 $ 8.62 $ 20,299 6.4
Restricted Stock Units Activity	The following table summarizes the activity for restricted stock units: Number of Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2016 814,456 $ 13.98 Granted 393,262 $ 3.93 Vested (25,793 ) $ 9.87 Forfeited (202,100 ) $ 11.77 Unvested balance at June 30, 2017 979,825 $ 10.51
Summary of Warrant Activity	The following table summarizes the warrant activity for the six months ended June 30, 2017: Outstanding at December 31, 2016 17,768,314 Warrants exercised (32,787 ) Outstanding at June 30, 2017 17,735,527 Vested and exercisable at June 30, 2017 15,328,577

Description of Business and B28

Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Jan. 01, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (447,486)		$ (387,063)	$ 31,000
Net cash used in operating activities	$ (25,007)	$ (17,157)

Summary of Significant Accoun29

Summary of Significant Accounting Policies - Securities Excluded from the Computation of Potentially Dilutive Securities (Detail) - shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	24,408,602	26,283,318
Employee Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	5,693,250	7,064,002
Outstanding Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	979,825	1,424,772
Outstanding Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	17,735,527	17,794,544

Financial Statement Details - P

Financial Statement Details - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial Statement Details [Abstract]
Tenant improvement allowance receivable	$ 1,524	$ 0
Prepaid services	1,509	1,191
Interest receivable - marketable securities	1,014	1,484
Equipment deposits	482	482
Prepaid rent	362	360
Prepaid legal fees	350	350
Prepaid license fees	308	462
Prepaid insurance	122	531
Other	302	275
Total prepaid expenses and other current assets	$ 5,973	$ 5,135

Financial Statement Details -31

Financial Statement Details - Property, Plant and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 62,849	$ 20,084
Accumulated depreciation	(2,631)	(1,178)
Property, plant and equipment, net	60,218	18,906
Construction in Progress
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	27,256	6,939
Building Under Financing Lease
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	23,796	4,348
Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	8,261	5,458
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	2,424	2,367
Software
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	879	769
Furniture And Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 233	$ 203

Financial Statement Details - A

Financial Statement Details - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financial Statement Details [Line Items]
Depreciation expense related to property, plant and equipment	$ 800,000	$ 100,000	$ 1,400,000	$ 100,000
Property, plant and equipment, gross	62,849,000		62,849,000		$ 20,084,000
Amortization expense	600,000	$ 500,000	1,100,000	900,000
Impairment loss on recognized investments			0	$ 0
El Segundo California
Financial Statement Details [Line Items]
Non cash build to suit lease asset	5,100,000		5,100,000
Building Under Financing Lease
Financial Statement Details [Line Items]
Property, plant and equipment, gross	23,796,000		23,796,000		$ 4,348,000
Capital Lease
Financial Statement Details [Line Items]
Property, plant and equipment, gross	19,500,000		19,500,000
Financing Lease
Financial Statement Details [Line Items]
Property, plant and equipment, gross	$ 4,300,000		$ 4,300,000

Financial Statement Details - I

Financial Statement Details - Intangible Assets, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Intangible assets, net	$ 3,956	$ 5,086
Technology License
Finite Lived Intangible Assets [Line Items]
Total intangible assets	9,042	9,042
Less accumulated amortization	(5,086)	(3,956)
Intangible assets, net	$ 3,956	$ 5,086

Financial Statement Details - O

Financial Statement Details - Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial Statement Details [Abstract]
Restricted cash	$ 179	$ 179
Security deposits	139	137
Equipment not placed in service	0	362
Other	17	110
Other Assets Noncurrent	$ 335	$ 788

Financial Statement Details -35

Financial Statement Details - Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial Statement Details [Abstract]
Accrued construction costs	$ 10,196	$ 1,053
Accrued bonus	1,237	1,732
Accrued professional and service fees	942	1,008
Accrued compensation	647	898
Accrued preclinical and clinical trial costs	562	662
Accrued laboratory equipment and supplies	469	190
Accrued software license fees	202	121
Other	126	200
Accrued Liabilities Current	$ 14,381	$ 5,864

Financial Statement Details - F

Financial Statement Details - Financing Obligation (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial Statement Details [Abstract]
Capital lease obligation - current portion	$ 14,612	$ 0
Financing obligation - current portion	268	253
Financing obligation	$ 14,880	$ 253

Financial Statement Details -37

Financial Statement Details - Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial Statement Details [Abstract]
Deferred rent - current portion	$ 484	$ 197
Build-to-suit lease liability - current portion	409	281
Other	237	160
Other current liabilities	$ 1,130	$ 638

Financial Statement Details -38

Financial Statement Details - Investment Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financial Statement Details [Abstract]
Interest income	$ 1,049	$ 1,239	$ 2,403	$ 2,431
Investment amortization accretion expense, net	(367)	(516)	(939)	(942)
Net realized gains (losses) on investments	(1)	16	(4)	18
Investment income, net	$ 681	$ 739	$ 1,460	$ 1,507

Cost Method Investment - Additi

Cost Method Investment - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Schedule Of Cost Method Investments [Line Items]
Cost method investment		$ 8,500,000		$ 0
Viracta Therapeutics, Inc. | Series B Convertible Preferred Stock
Schedule Of Cost Method Investments [Line Items]
Cost method investment			$ 8,500,000
Viracta Therapeutics, Inc. | Series B Convertible Preferred Stock | Scenario, Forecast | Maximum
Schedule Of Cost Method Investments [Line Items]
Option to purchase additional shares under cost method investment	$ 8,500,000

Cash Equivalents and Marketab40

Cash Equivalents and Marketable Securities - Additional Information (Detail) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)Security	Dec. 31, 2016USD ($)
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities maturity period	4 years 2 months 12 days
Maximum
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, period of unrealized loss positions	12 months	12 months
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Cash equivalent portions included in current fair values	$ 7.5	$ 2
Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Number of available-for-sale securities in unrealized loss positions | Security	61
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Cash equivalent portions included in current fair values	$ 6.5

Cash Equivalents and Marketab41

Cash Equivalents and Marketable Securities - Schedule of Cash Equivalents and Marketable Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 197,717	$ 280,698
Unrealized Gains	92	134
Unrealized Losses	(302)	(418)
Fair Value	197,507	280,414
Current Assets
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	150,554	192,861
Unrealized Gains	35	61
Unrealized Losses	(136)	(79)
Fair Value	150,453	192,843
Current Assets | Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	27,251	22,252
Unrealized Gains	0	21
Unrealized Losses	(40)	(1)
Fair Value	27,211	22,272
Current Assets | Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	108,422	165,605
Unrealized Gains	35	40
Unrealized Losses	(87)	(76)
Fair Value	108,370	165,569
Current Assets | Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	9,480
Unrealized Gains	0
Unrealized Losses	0
Fair Value	9,480
Current Assets | Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	5,401	5,004
Unrealized Gains	0	0
Unrealized Losses	(9)	(2)
Fair Value	5,392	5,002
Noncurrent Assets
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	47,163	87,837
Unrealized Gains	57	73
Unrealized Losses	(166)	(339)
Fair Value	47,054	87,571
Noncurrent Assets | Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	4,778	17,018
Unrealized Gains	0	2
Unrealized Losses	(22)	(38)
Fair Value	4,756	16,982
Noncurrent Assets | Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	42,385	69,414
Unrealized Gains	57	71
Unrealized Losses	(144)	(290)
Fair Value	$ 42,298	69,195
Noncurrent Assets | Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		1,405
Unrealized Gains		0
Unrealized Losses		(11)
Fair Value		$ 1,394

Cash Equivalents and Marketab42

Cash Equivalents and Marketable Securities - Available-for-Sale Investments in Unrealized Loss Position (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	$ 135,063	$ 173,920
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(290)	(418)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	2,495	0
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	(12)	0
Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	31,966	17,204
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(62)	(39)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	0	0
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	0	0
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	94,709	150,320
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(219)	(366)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	2,495	0
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	(12)	0
Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	5,392	6,396
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(9)	(13)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	0	0
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	0	$ 0
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	2,996
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	0
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	0
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	$ 0

Cash Equivalents and Marketab43

Cash Equivalents and Marketable Securities -Schedule of Realized Gains and Losses on Sales or Maturities of Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Cash Equivalents And Marketable Securities [Abstract]
Available-for-sale Securities, Gross Realized Gains	$ 0	$ 33	$ 2	$ 92
Available-for-sale Securities, Gross Realized Losses	(1)	(17)	(6)	(74)
Available-for-sale Securities, Net Realized Gains	$ (1)	$ 16	$ (4)	$ 18

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 197,507	$ 280,414
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	197,507	280,414
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,392	5,002
Current Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	27,211	22,272
Current Assets | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	13,987	2,005
Current Assets | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,996
Current Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	100,867	163,564
Current Assets | Level 1 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 1 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 1 | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 1 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0
Current Assets | Level 1 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 2 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,392	5,002
Current Assets | Level 2 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	27,211	22,272
Current Assets | Level 2 | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	13,987	2,005
Current Assets | Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,996
Current Assets | Level 2 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	100,867	163,564
Current Assets | Level 3 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 3 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 3 | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Current Assets | Level 3 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0
Current Assets | Level 3 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Noncurrent Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value		1,394
Noncurrent Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	4,756	16,982
Noncurrent Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	42,298	69,195
Noncurrent Assets | Level 1 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value		0
Noncurrent Assets | Level 1 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Noncurrent Assets | Level 1 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Noncurrent Assets | Level 2 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value		1,394
Noncurrent Assets | Level 2 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	4,756	16,982
Noncurrent Assets | Level 2 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	42,298	69,195
Noncurrent Assets | Level 3 | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value		0
Noncurrent Assets | Level 3 | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Noncurrent Assets | Level 3 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 0	$ 0

Fair Value Measurements - Sum45

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash in depository institutions	$ 25.1	$ 6.1

Collaboration and License Agr46

Collaboration and License Agreements - Additional Information (Detail)	1 Months Ended	6 Months Ended
	May 31, 2017USD ($)	Jun. 30, 2017USD ($)Patient
Viracta Therapeutics, Inc.
Licensing Agreement [Line Items]
License agreement termination notice period	90 days
Viracta Therapeutics, Inc. | Minimum
Licensing Agreement [Line Items]
Milestone Payment Amount	$ 10,000,000
Viracta Therapeutics, Inc. | Maximum
Licensing Agreement [Line Items]
Milestone Payment Amount	$ 25,000,000
Altor
Licensing Agreement [Line Items]
Maximum number of patients in phase 1 and 2 for clinical trials | Patient		400
Supplies and milestone charges for conducting clinical trials		$ 0

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Detail)	1 Months Ended		3 Months Ended		6 Months Ended
	Apr. 30, 2017USD ($)ft²	Sep. 30, 2015USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)ft²	Nov. 30, 2015ft²	May 31, 2015ft²
Commitments And Contingencies [Line Items]
Rent expense			$ 700,000	$ 700,000	$ 1,400,000	$ 1,400,000
Property, plant and equipment, gross			62,849,000		62,849,000		$ 20,084,000
Building Under Financing Lease
Commitments And Contingencies [Line Items]
Property, plant and equipment, gross			23,796,000		23,796,000		$ 4,348,000
Doug St, LLC
Commitments And Contingencies [Line Items]
Base rent - monthly					$ 100,000
Period of agreement					The lease runs from July 2016 through July 2023. The Company has the option to extend the lease for an additional three year term through July 2026. The monthly rent is $0.1 million with annual increases of 3% beginning in July 2017.
Optional extended lease term					3 years
Percentage of annual increase of base rent					3.00%
Annual percentage increases to base rent commencement date					Jul. 31, 2017
Costs incurred			20,200,000		$ 20,200,000
Non cash build to suit lease asset			5,100,000		$ 5,100,000
Property and equipment estimated useful lives					39 years
Doug St, LLC | Research and Development
Commitments And Contingencies [Line Items]
Rent expense			100,000		$ 100,000
NantWorks
Commitments And Contingencies [Line Items]
Base rent - monthly					$ 47,000
Number of square foot of facility leased | ft²									9,500	9,500
Period of agreement					The license was effective in May 2015 and extends through December 2020. The Company has the option to extend the license through December 2023. The monthly license fee is $47,000 with annual increases of 3% beginning in January 2017.
Percentage of annual increase of base rent					3.00%
Annual percentage increases to base rent commencement date					Jan. 31, 2017
Costs incurred								$ 3,500,000
Property and equipment estimated useful lives					39 years
NantWorks | Building Under Financing Lease
Commitments And Contingencies [Line Items]
Property, plant and equipment, gross			4,300,000		$ 4,300,000
NantWorks | Research and Development
Commitments And Contingencies [Line Items]
Rent expense			47,000	$ 100,000	100,000	$ 200,000
El Segundo California
Commitments And Contingencies [Line Items]
Non cash build to suit lease asset			$ 5,100,000		$ 5,100,000
El Segundo California | Doug St, LLC
Commitments And Contingencies [Line Items]
Number of square foot of facility leased | ft²								24,250
El Segundo California | Agreement to Purchase Commercial Building
Commitments And Contingencies [Line Items]
Area of Land | ft²	36,000
Escrow deposit	$ 5,000,000
Balance of purchase price	15,200,000
Purchase agreement, termination fees	38,000
Base rent - monthly	$ 0
USPTO
Commitments And Contingencies [Line Items]
Attorney's fees and expert witness fees		$ 100,000

Related Party Agreements - Addi

Related Party Agreements - Additional Information (Detail)	1 Months Ended			3 Months Ended		6 Months Ended
	Apr. 30, 2017USD ($)ft²	Apr. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Feb. 28, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016ft²	Aug. 31, 2016	Nov. 30, 2015ft²	May 31, 2015ft²
Related Party Transaction [Line Items]
Prepaid expenses and other current assets				$ 5,973,000		$ 5,973,000			$ 5,135,000
Research and development				9,706,000	$ 6,389,000	18,954,000	$ 11,344,000
Due to related parties				2,216,000		2,216,000			$ 1,753,000
Selling, general and administrative				14,128,000	28,588,000	30,355,000	55,255,000
VivaBioCell S.p.A.
Related Party Transaction [Line Items]
Prepaid expenses and other current assets								$ 600,000
Research and development				100,000		$ 200,000
Doug St, LLC
Related Party Transaction [Line Items]
Period of agreement						The lease runs from July 2016 through July 2023. The Company has the option to extend the lease for an additional three year term through July 2026. The monthly rent is $0.1 million with annual increases of 3% beginning in July 2017.
Base rent - monthly						$ 100,000
Percentage of annual increase of base rent						3.00%
Annual percentage increases to base rent commencement date						Jul. 31, 2017
Due to related parties				0		$ 0
Doug St, LLC | Research and Development
Related Party Transaction [Line Items]
Rent expense				100,000		100,000
Altor
Related Party Transaction [Line Items]
Research and development charges incurred for supplies or milestone				0		0
Altor | Minimum
Related Party Transaction [Line Items]
Percentage of ownership interest owned by CEO											20.00%
NantBioScience
Related Party Transaction [Line Items]
Research and development	$ 600,000	$ 600,000		$ 200,000	$ 200,000	$ 300,000	$ 200,000
Initial term of agreement entered into with the related party by the entity						5 years
Research and development expense, ratable payment period				12 months	12 months	12 months	12 months
NantWorks
Related Party Transaction [Line Items]
Number of square foot of facility leased | ft²												9,500	9,500
Base rent - monthly						$ 47,000
Percentage of annual increase of base rent						3.00%
Annual percentage increases to base rent commencement date						Jan. 31, 2017
Due to related parties				$ 2,100,000		$ 2,100,000
NantWorks | Shared Services Agreement
Related Party Transaction [Line Items]
Research and development				700,000	$ 500,000	1,500,000	$ 800,000
Selling, general and administrative				600,000	700,000	1,300,000	1,500,000
NantWorks | Reimbursements | Shared Services Agreement
Related Party Transaction [Line Items]
Research and development				100,000	9,000	300,000	9,000
Selling, general and administrative				100,000	42,000	200,000	42,000
NantWorks | Research and Development
Related Party Transaction [Line Items]
Rent expense				47,000	100,000	100,000	200,000
NantOmnics
Related Party Transaction [Line Items]
Research and development				13,000	$ 0	13,000	$ 100,000
Due to related parties				13,000		$ 13,000
Initial term of agreement entered into with the related party by the entity						5 years
Related party, agreement renewal term						1 year
NantCell
Related Party Transaction [Line Items]
Due between parties				0		$ 0
Research and development				33,000		$ 300,000
Initial term of agreement entered into with the related party by the entity						5 years
Related party, agreement renewal term						1 year
Non refundable upfront payment			$ 500,000
San Diego California | Tensorcom, Inc
Related Party Transaction [Line Items]
Period of agreement						Initial lease from May 1, 2017 through April 30, 2018
Sublease termination notice period	30 days
Number of square foot of facility leased | ft²	6,557
Base rent - monthly	$ 25,000
Percentage of annual increase of base rent	3.00%
Due between parties				0		$ 0
San Diego California | Tensorcom, Inc | Other Income
Related Party Transaction [Line Items]
Sublease revenue recognized				$ 15,000
El Segundo California | Doug St, LLC
Related Party Transaction [Line Items]
Number of square foot of facility leased | ft²										24,250

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2017	May 31, 2017	Mar. 31, 2017	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Nov. 30, 2015
Class Of Stock [Line Items]
Total amount authorized for repurchase							$ 50,000,000
Repurchase of common stock, shares	1,744,009	1,028,200	300,000	2,772,209	3,072,209	2,157,944
Repurchase of common stock, par value	$ 4.18	$ 3.92	$ 3.50		$ 4.03
Repurchase of common stock before commissions, value					$ 12,400,000	$ 15,800,000
Broker commissions on the repurchases					100,000
Remained authorized shares for repurchase	$ 21,800,000	$ 29,100,000	$ 33,100,000	$ 21,800,000	$ 21,800,000
Minimum
Class Of Stock [Line Items]
Repurchase of common stock, par value					$ 3.10
Maximum
Class Of Stock [Line Items]
Repurchase of common stock, par value					$ 4.75

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Common Stock Repurchases (Detail) - USD ($)	1 Months Ended			3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2017	May 31, 2017	Mar. 31, 2017	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Equity [Abstract]
Total number of shares purchased	1,744,009	1,028,200	300,000	2,772,209	3,072,209	2,157,944
Average price paid per share	$ 4.18	$ 3.92	$ 3.50		$ 4.03
Total number of shares purchased as part of publicly announced plans or programs	3,072,209	1,328,200	300,000
Maximum approximate dollar value of shares that may yet be purchased under the plans or programs	$ 21,800,000	$ 29,100,000	$ 33,100,000	$ 21,800,000	$ 21,800,000

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Based Compensation Expenses Related to Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 9,381	$ 23,355	$ 19,399	$ 43,917
Warrants For Common Stock | Officer
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	7,827	15,182	16,313	27,272
Employee Stock Option
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	952	4,858	2,303	9,751
Employee Restricted Stock Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	(93)	3,148	225	6,530
Non Employee Restricted Stock Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	695	167	558	364
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	(49)	291	43	564
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 9,430	$ 23,064	$ 19,356	$ 43,353

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2016	Jun. 30, 2017	Dec. 31, 2016	Jan. 01, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accumulated deficit		$ (447,486)	$ (387,063)	$ 31,000
Additional stock compensation expense	$ 27,000
Outstanding Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to non-vested stock options		$ 33,100
Weighted-average period for recognition		1 year 1 month 6 days
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate intrinsic value of stock options exercised		$ 1,700
Unrecognized stock-based compensation expense related to non-vested stock options		$ 6,700
Weighted-average period for recognition		1 year 9 months 18 days
Employee Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period for recognition		2 years 9 months 18 days
Number of Shares, Granted		316,012
Unrecognized compensation cost related to non-vested stock options		$ 3,000
Non Employee Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period for recognition		2 years 9 months 18 days
Number of Shares, Granted		77,250
Unrecognized compensation cost related to non-vested stock options		$ 2,100
Employee Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period for recognition		2 years 9 months 18 days
Number of Shares, Granted		393,262
Unrecognized compensation cost related to non-vested stock options		$ 5,100
Employee Restricted Stock Units | Employees Of Related Company
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted		27,250

Stock-Based Compensation - St53

Stock-Based Compensation - Stock Option Activity (Detail) - Employee Stock Option - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Number of Shares
Stock Options, Beginning Balance	6,307,386
Stock Options, Options exercised	(614,136)
Stock Options, Ending Balance	5,693,250	6,307,386
Stock Options, Vested and Exercisable	4,883,219
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding Beginning balance	$ 7.14
Weighted Average Exercise Price, Options exercised	1.88
Weighted Average Exercise Price, Outstanding Ending balance	7.71	$ 7.14
Weighted Average Exercise Price, Vested and Exercisable	$ 8.62
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding	$ 24,666	$ 19,100
Aggregate Intrinsic Value, Vested and Exercisable	$ 20,299
Weighted Average Remaining Contractual Life
Weighted Average Remaining Contractual Life, Outstanding	5 years 9 months 18 days	6 years 4 months 24 days
Weighted Average Remaining Contractual Life, Vested and Exercisable	6 years 4 months 24 days

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units Activity (Detail) - Outstanding Restricted Stock Units	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Unvested, Beginning balance | shares	814,456
Number of Shares, Granted | shares	393,262
Number of Shares, Vested | shares	(25,793)
Number of Shares, Forfeited | shares	(202,100)
Number of Shares, Unvested, Ending balance | shares	979,825
Weighted-Average Grant Date Fair Value, Unvested, beginning balance | $ / shares	$ 13.98
Weighted-Average Grant Date Fair Value, Granted | $ / shares	3.93
Weighted-Average Grant Date Fair Value, Vested | $ / shares	9.87
Weighted-Average Grant Date Fair Value, Forfeited | $ / shares	11.77
Weighted-Average Grant Date Fair Value, Unvested, ending balance | $ / shares	$ 10.51

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Warrant Activity (Detail) - Outstanding Warrants	6 Months Ended
	Jun. 30, 2017shares
Warrant [Line Items]
Warrants, Beginning Balance	17,768,314
Warrants exercised	(32,787)
Warrants, Ending Balance	17,735,527
Warrants, Vested and exercisable Ending Balance	15,328,577

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax [Line Items]
Federal statutory tax rate			34.00%
Company's effective tax rate			0.00%
Tax benefit	$ 4,000	$ 100,000	$ 10,000	$ 200,000
Tax benefit in other comprehensive income	2,000	100,000	28,000	400,000
Korea
Income Tax [Line Items]
Tax benefit	$ 100,000	$ 100,000	$ 200,000	$ 200,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Chan Soon-Shiong Institutes for Medicine (CSSIM) - CALIFORNIA $ in Millions	1 Months Ended
	Jul. 31, 2017USD ($)Officer
Subsequent Event [Line Items]
Number of officers | Officer	2
Estimated cost of clinical trial agreement | $	$ 0.5