ImmunityBio (IBRX) 10-Q 6 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 02, 2018
Document Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
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		79,207,876

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 16,122	$ 23,872
Due from related parties	54	154
Prepaid expenses and other current assets	4,734	4,152
Marketable debt securities, available-for-sale	88,822	104,280
Note receivable, held-to-maturity	361	0
Total current assets	110,093	132,458
Marketable debt securities, noncurrent	12,580	29,600
Property, plant and equipment, net	78,211	76,726
Equity investment	8,500	8,500
Intangible assets, net	1,695	2,826
Other assets	354	330
Total assets	211,433	250,440
Current liabilities:
Accounts payable	5,502	5,865
Accrued expenses	11,517	11,267
Due to related parties	1,806	2,363
Other current liabilities	1,367	1,373
Total current liabilities	20,192	20,868
Build-to-suit liability, less current portion	0	4,909
Financing obligation, less current portion	6,267	1,741
Deferred rent	3,049	3,325
Deferred tax liability	250	498
Other liabilities	44	255
Total liabilities	29,802	31,596
Commitments and contingencies (Note 8)	0	0
Stockholders’ equity
Common stock, $0.0001 par value; 500,000,000 shares authorized; 79,165,819 and 79,021,878 issued and outstanding as of June 30, 2018 and December 31, 2017	8	8
Additional paid-in capital	735,849	717,930
Accumulated other comprehensive loss	(448)	(381)
Accumulated deficit	(553,778)	(498,713)
Total stockholders’ equity	181,631	218,844
Total liabilities and stockholders’ equity	$ 211,433	$ 250,440

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
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	79,165,819	79,021,878
Common stock, shares outstanding	79,165,819	79,021,878

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenue	$ 4	$ 14	$ 9	$ 25
Operating expenses:
Research and development (including amounts to related parties)	14,688	9,706	28,679	18,954
Selling, general and administrative (including amounts to related parties)	13,594	14,128	27,892	30,355
Total operating expenses	28,282	23,834	56,571	49,309
Loss from operations	(28,278)	(23,820)	(56,562)	(49,284)
Other income:
Investment income, net	490	681	995	1,460
Interest expense (including amounts to related parties)	(106)	(154)	(139)	(191)
Other income (expense), net (including amounts to related parties)	39	(283)	208	(174)
Total other income	423	244	1,064	1,095
Loss before income taxes	(27,855)	(23,576)	(55,498)	(48,189)
Income tax benefit	123	124	247	222
Net loss	$ (27,732)	$ (23,452)	$ (55,251)	$ (47,967)
Net loss per share:
Basic and diluted	$ (0.35)	$ (0.29)	$ (0.70)	$ (0.60)
Weighted-average number of shares during the period:
Basic and diluted	79,107,208	81,440,816	79,071,824	79,426,402

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (27,732)	$ (23,452)	$ (55,251)	$ (47,967)
Other comprehensive income, net of income taxes:
Net unrealized gain (loss) on available-for-sale securities	107	(280)	(67)	(236)
Reclassification of net realized gains on available-for-sale securities included in net loss	0	(1)	0	(1)
Total other comprehensive income (loss)	107	(281)	(67)	(237)
Comprehensive loss	$ (27,625)	$ (23,733)	$ (55,318)	$ (48,204)

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2017	$ 218,844	$ 8	$ 717,930	$ (381)	$ (498,713)
Beginning Balance, Shares at Dec. 31, 2017	79,021,878	79,021,878
Stock-based compensation expense	$ 18,007	$ 0	18,007	0	0
Vesting of restricted stock units	0	$ 0	0	0	0
Vesting of restricted stock units, Shares		154,123
Exercise of warrants	35	$ 0	35	0	0
Exercise of warrants, Shares		21,675
Employee payroll taxes withheld related to vesting of restricted stock units	(123)	$ 0	(123)	0	0
Employee payroll taxes withheld related to vesting of restricted stock units, Shares		(31,857)
Cumulative effect of the adoption of the new revenue standard	186	$ 0	0	0	186
Other comprehensive loss, net	(67)	0	0	(67)	0
Net loss	(55,251)	0	0	0	(55,251)
Ending Balance at Jun. 30, 2018	$ 181,631	$ 8	$ 735,849	$ (448)	$ (553,778)
Ending Balance, Shares at Jun. 30, 2018	79,165,819	79,165,819

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net loss	$ (55,251)	$ (47,967)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,992	2,536
Stock-based compensation expense	18,007	19,399
Deferred income tax benefit	(248)	(217)
Loss on disposal of assets	90	0
Non-cash interest items, net	91	470
Amortization of net premiums on marketable debt securities	343	940
Loss on sales of marketable debt securities	0	1
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(544)	(1,306)
Other assets	12	452
Accounts payable	1,875	(1,067)
Accrued expenses and other liabilities	603	(1,104)
Due to related parties	(508)	1,429
Deferred rent and revenue	(239)	1,427
Net cash used in operating activities	(31,777)	(25,007)
Investing activities:
Purchases of property, plant and equipment	(7,394)	(12,665)
Purchase of equity investment	0	(8,500)
Purchase of debt securities, held-to-maturity	(361)	0
Purchases of marketable debt securities, available-for-sale	(53,503)	(46,518)
Sales/maturities of marketable debt securities	85,571	140,540
Net cash provided by investing activities	24,313	72,857
Financing activities:
Principal payments of financing/capital lease obligations	(198)	(4,920)
Proceeds from exercise of stock options and warrants	35	1,191
Repurchase of common stock with commissions	0	(12,456)
Net share settlement for RSU vesting and option exercises	(123)	(709)
Net cash used in financing activities	(286)	(16,894)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(7,750)	30,956
Cash, cash equivalents and restricted cash, beginning of period	24,051	8,262
Cash, cash equivalents, and restricted cash, end of period	16,301	39,218
Reconciliation of cash, cash equivalents, and restricted cash at end of period:
Cash and cash equivalents	16,122	39,039
Restricted cash included in other assets	179	179
Cash, cash equivalents, and restricted cash, end of period	16,301	39,218
Supplemental disclosure of cash flow information:
Interest	179	238
Income taxes	4	3
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment purchases acquired under capital lease expenses	0	19,448
Property and equipment purchases included in accounts payable, accrued expenses, and other liabilities	6,704	13,402
Unrealized gain (loss) on marketable debt securities	(67)	74
Cashless exercise of warrants	$ 1	$ 16

Description of Business

Description of Business	6 Months Ended
	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of Business 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 the Company’s strategy is to invest significantly in expanding the activated natural killer (aNK) platform and the development of the Company’s product candidates. The Company holds the exclusive right to commercialize 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. The Company also 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. Liquidity As of June 30, 2018, the Company had an accumulated deficit of approximately $553.8 million. The Company also had negative cash flow from operations of approximately $31.8 million during the six months ended June 30, 2018. 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, fail 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 debt 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 debt 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, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies There have been no material changes in the Company’s significant accounting policies other than the adoption of accounting pronouncements below, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Basis of Presentation The accompanying condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP). The unaudited condensed consolidated financial statements reflect all adjustments which are, in the opinion of management, necessary to present fairly the results for the interim periods presented and have been prepared on the same basis as the audited consolidated financial statements for the fiscal year ended December 31, 2017. The unaudited condensed consolidated financial statements do not include all information and notes necessary for a complete presentation of results of income, comprehensive income, financial position, and cash flows in conformity with GAAP. Accordingly, these financial statements should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2017 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 consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP 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, 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. Principles of Consolidation and Equity Investments The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Inex Bio, Inc. and 557 Doug St, LLC, and have been prepared in accordance with GAAP. All intercompany amounts have been eliminated. The Company applies the variable interest model under Accounting Standards Codification (ASC) Topic 810, Consolidation For entities the Company holds an equity investment in and are not consolidated under the VIE Model, the Company considers whether its investment constitutes ownership of a majority of the voting interests in the entity and therefore should be considered for consolidation under the voting interest model. Unconsolidated equity investments in the common stock or in-substance common stock of an entity under which the Company is able to exercise significant influence, but not control, are accounted for using the equity method. The Company’s ability to exercise significant influence is generally indicated by ownership of 20 to 50 percent interest in the voting securities of the entity. All other unconsolidated equity investments on which the Company is not able to exercise significant influence will be subsequently measured at fair value with unrealized The Company owns non-marketable equity securities that are accounted for as an equity investment at cost minus impairment and plus or minus changes resulting from observable price changes because the preferred stock held by the Company is not considered in-substance common stock and such 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, 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 impairment indicator is present include: the investees’ earning performance and clinical trial performance, change in the investees’ industry and geographic area in which it operates, offers to purchase or sell the security for a price less than the cost 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. Factors considered in determining whether an observable price change has occurred include: the price at which the investee issues equity instruments similar to those of the Company’s investment and the rights and preferences of those equity instruments compared to the Company’s. Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash and cash equivalents and marketable debt securities. The Company’s cash and cash equivalents are with one major financial institution in the United States and one in Korea. Drug candidates developed by the Company will require approvals or clearances from the U.S. Food and Drug Administration (“FDA”) or international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s drug candidates will receive any of the required approvals or clearances. If the Company were to be denied approval or clearance or any such approval or clearance were to be delayed, it would have a material adverse impact on the Company. 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, 2018 2017 Outstanding options 5,693,250 5,693,250 Outstanding restricted stock units 890,512 979,825 Outstanding warrants 17,699,413 17,735,527 Total 24,283,175 24,408,602 Amounts in the table above reflect the common stock equivalents of the noted instruments. Recently Adopted Accounting Policies Financial Assets and Financial Liabilities Effective January 1, 2018, the Company adopted Accounting Standard Update (ASU) 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities Revenue Recognition Beginning January 1, 2018, the Company follows the provisions of Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers The Company derives substantially all of its revenue from non-exclusive license agreements with a limited number of pharmaceutical and biotechnology companies granting them the right to use the Company’s cell lines and intellectual property for non-clinical use. These agreements generally include upfront fees and annual research license fees for such use, as well as commercial license fees for sales of the Company’s licensee’s products developed or manufactured using the Company’s intellectual property and cell lines. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC Topic 606. A contract’s transaction price is allocated to each distinct performance obligation based on relative standalone selling price and recognized as revenue when, or as, the performance obligation is satisfied. Under the Company’s license agreements with customers, the Company typically promises to provide a license to use certain cell lines and related patents, the related know-how, and future research and development data that affects the license. The Company concluded that these promises represent one performance obligation due to the highly interrelated nature of the promises. The Company provides the cell lines and know-how immediately upon entering into the contracts. The research and development data is provided throughout the term of the contract when and if available. The Company’s license agreement with Intrexon included a nonrefundable upfront payment of $0.4 million, received when the Company entered into the contract in 2010. In this instance, the Company determined that under ASC 606 it would be appropriate to recognize the initial milestone payment at a point in time, when it transferred the license. In this case, the intellectual property provided under the contract is functional intellectual property under ASC 606 and was determined to be a distinct performance obligation in the context of the arrangement. Prior to adoption, the upfront payment had been initially recorded as deferred revenue and was being recognized into revenue on a straight-line basis. As a result, upon adoption of ASC 606, the Company adjusted its opening retained deficit for the effects of recognizing revenue upfront for the initial milestone. The adjustment to opening retained deficit upon adoption was not material. The license agreements may include nonrefundable upfront payments, event-based milestone payments, sales-based royalty payments, or some combination of these. The event-based milestone payments represent variable consideration and the Company uses the most likely amount method to estimate this variable consideration. Given the high degree of uncertainly around achievement of these milestones, the Company does not recognize revenue from these milestone payments until the uncertainty associated with these payments is resolved. The Company currently estimates variable consideration related to milestone payments to be zero and, as such, no revenue has been recognized for milestone payments. The Company will recognize revenue from sales-based royalty payments when or as the sales occur. On a quarterly basis, the Company will re-evaluate its estimate of milestone variable consideration to determine whether any amount should be included in the transaction price and recorded in revenue prospectively. Upon adoption, the Company changed its accounting policy from accounting for milestones payments under the milestone method to accounting for variable consideration as discussed above. The change in accounting policy did not change any amounts in the financial statements because of the significant uncertainty surrounding the estimate of variable consideration for milestone payments. The Company’s revenue from non-clinical license agreements is nominal. In the future, the Company may generate revenue from license agreements entered into for therapeutic uses. To date, the Company has not generated any revenue from product sales. If the Company fails to complete the development of its product candidates in a timely manner or fails to obtain regulatory approval for them, the Company may never be able to generate substantial future revenue. Statement of Cash Flows Effective January 1, 2018, the Company adopted ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments Statement of Cash Flows: Restricted Cash, a consensus of the FASB’s Emerging Issues Task Force Recently Issued Accounting Pronouncements – Not Yet Adopted In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. Adoption of ASU 2018-02 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 on the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases

Financial Statement Details

Financial Statement Details	6 Months Ended
	Jun. 30, 2018
Financial Statement Details [Abstract]
Financial Statement Details	3. Financial Statement Details Prepaid Expenses and Other Current Assets As of June 30, 2018 and December 31, 2017, prepaid expenses and other current assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Insurance claim receivable $ 1,932 $ 340 Interest receivable - marketable debt securities 674 764 Prepaid license fees 598 597 Prepaid services 460 416 Prepaid rent 375 373 Prepaid supplies 309 210 Prepaid insurance 123 572 Equipment deposits — 482 Other 263 398 $ 4,734 $ 4,152 Property, Plant and Equipment, Net As of June 30, 2018 and December 31, 2017, property, plant and equipment, net consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Construction in progress $ 700 $ 42,281 Buildings 59,356 23,811 Equipment 19,619 9,625 Leasehold improvements 4,019 3,918 Software 1,224 1,092 Furniture & fixtures 479 302 85,397 81,029 Accumulated depreciation (7,186 ) (4,303 ) $ 78,211 $ 76,726 Depreciation expense related to property, plant and equipment was $1.8 million and $0.8 million for the three months ended June 30, 2018 and 2017, respectively, and $2.9 million and $1.4 million for the six months ended June 30, 2018 and 2017, respectively. Buildings of $59.4 million include buildings under build-to-suit leases of $39.9 million and $19.5 million related to the Company’s purchased warehouse and distribution facility. Building value under build-to-suit leases represents the estimated fair market value of the buildings and capitalized construction costs where the Company is the “deemed owner” of the assets, for accounting purposes only. See Note 8 – Financing Lease Obligation Intangible Assets, Net As of June 30, 2018 and December 31, 2017, intangible assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Technology license $ 9,042 $ 9,042 Less accumulated amortization (7,347 ) (6,216 ) $ 1,695 $ 2,826 Amortization expense related to intangible assets was $0.6 million and $0.6 million for the three months ended June 30, 2018 and 2017, respectively, and $1.1 million and $1.1 million for the six months ended June 30, 2018 and 2017, respectively. Amortization for the Company’s technology license is included in research and development expense on the condensed consolidated statements of operations. Other Assets As of June 30, 2018 and December 31, 2017, other assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Restricted cash $ 179 $ 179 Security deposits 113 127 Other 62 24 $ 354 $ 330 Restricted cash is a certificate of deposit that is collateral for the letter of credit required as a security deposit for the Company’s San Diego, California, facility by the Company’s landlord. Accrued Expenses As of June 30, 2018 and December 31, 2017, accrued expenses consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Accrued construction costs $ 5,214 $ 6,212 Accrued bonus 1,600 1,930 Accrued professional and service fees 1,387 1,048 Accrued preclinical and clinical trial costs 1,264 521 Accrued compensation 1,021 944 Accrued laboratory equipment and supplies 839 — Other 192 612 $ 11,517 $ 11,267 Other Current Liabilities As of June 30, 2018 and December 31, 2017, other current liabilities were made up of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Financing obligation - current portion $ 585 $ 284 Deferred rent - current portion 558 520 Build-to-suit lease liability - current portion — 334 Other 224 235 $ 1,367 $ 1,373 Investment Income, Net Net investment income includes interest income from all bank accounts as well as marketable debt 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, 2018 and 2017 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 (Unaudited) (Unaudited) Interest income $ 632 $ 1,049 $ 1,336 $ 2,403 Investment amortization accretion expense, net (142 ) (367 ) (343 ) (939 ) Net realized gains (losses) on investments — (1 ) 2 (4 ) $ 490 $ 681 $ 995 $ 1,460 Interest income includes interest from the Company’s bank deposits. The Company did not recognize an impairment loss on any investments for the three and six months ended June 30, 2018 and 2017.

Equity Investment

Equity Investment	6 Months Ended
	Jun. 30, 2018
Investments All Other Investments [Abstract]
Equity Investment	4. Equity 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 did not exercise its option to purchase up to an additional $8.5 million worth of shares of the Series B convertible preferred stock by the expiration date of 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. Based on the level of equity investment at risk, Viracta is not a Variable Interest Entity (VIE) and therefore is not consolidated under the VIE Model. Also, the Company does not hold a controlling financial interest in Viracta and therefore is not consolidating Viracta under the voting interest model. As the preferred stock is not considered in-substance common stock, the investment is not within the scope of accounting for the investment under the equity method. As the preferred stock does not have a readily determinable fair value, the Company has elected to apply the practicability exception noted under ASC 825 and estimates the fair value at its $8.5 million cost minus impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. As of June 30, 2018, the Company’s qualitative impairment assessment did not indicate there were events or changes in circumstances that may have had a significant adverse effect on the fair value of the investment. The Company has not recorded any impairments as of June 30, 2018 or on a cumulative basis. Further, the Company has not identified any downward or upward adjustments due to observable price changes in the investment as of June 30, 2018 or on a cumulative basis. The $8.5 million cost of the investment is recorded in equity investment on the condensed consolidated balance sheet as of June 30, 2018. In addition, in June 2018, Viracta executed a 2018 Note and Warrant Purchase Agreement with existing and new investors, including the Company. The initial closing under the Purchase Agreement occurred in June 2018, at which point the Company purchased a convertible note, for $0.4 million, which under certain circumstances is convertible into Series B Preferred Stock, and a warrant to purchase Viracta’s common shares. The convertible note accrues interest at 8% and has a one year maturity date. The Company classified the convertible note as a held-to-maturity marketable security on the condensed consolidated balance sheets.

Cash Equivalents and Marketable

Cash Equivalents and Marketable Debt Securities	6 Months Ended
	Jun. 30, 2018
Cash Equivalents And Marketable Securities [Abstract]
Cash Equivalents and Marketable Debt Securities	5. Cash Equivalents and Marketable Debt Securities As of June 30, 2018, all of the Company’s marketable debt securities are classified as available-for-sale or held-to-maturity and are scheduled to mature within 3.2 years. At June 30, 2018, the detail of the Company’s cash equivalents and marketable debt securities is as follows (in thousands): June 30, 2018 (unaudited) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Available-for-sale Corporate debt securities $ 74,516 $ — $ (154 ) $ 74,362 Government sponsored securities 5,991 1 (3 ) 5,989 Foreign government bonds 2,997 — — 2,997 Commercial paper 5,473 1 — 5,474 Total available-for-sale 88,977 2 (157 ) 88,822 Held-to-maturity, note receivable 361 — — 361 Current portion 89,338 2 (157 ) 89,183 Noncurrent: Corporate debt securities 10,114 — (228 ) 9,886 Government sponsored securities 2,758 — (64 ) 2,694 Noncurrent portion 12,872 - (292 ) 12,580 Total $ 102,210 $ 2 $ (449 ) $ 101,763 At December 31, 2017, the detail of the Company’s cash equivalents and marketable debt securities is as follows (in thousands): December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Corporate debt securities $ 82,188 $ 5 $ (84 ) $ 82,109 Government sponsored securities 19,261 — (28 ) 19,233 Foreign government bonds 6,441 — (5 ) 6,436 Current portion 107,890 5 (117 ) 107,778 Noncurrent: Corporate debt securities 27,109 — (226 ) 26,883 Government sponsored securities 2,760 — (43 ) 2,717 Noncurrent portion 29,869 — (269 ) 29,600 Total $ 137,759 $ 5 $ (386 ) $ 137,378 Included in foreign government bonds is $3.5 million of cash equivalents at December 31, 2017. Available-for-sale investments that had been in an unrealized loss position for more and less than 12 months at June 30, 2018 and December 31, 2017 are as follows (in thousands): June 30, 2018 (unaudited) Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 62,011 $ (213 ) $ 17,733 $ (169 ) Government sponsored securities 2,694 (64 ) 2,000 (3 ) Foreign government bonds 2,997 — — — Total $ 67,702 $ (277 ) $ 19,733 $ (172 ) December 31, 2017 Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 67,522 $ (104 ) $ 35,918 $ (206 ) Government sponsored securities 9,744 (20 ) 12,205 (51 ) Foreign government bonds 1,542 — 1,396 (5 ) Total $ 78,808 $ (124 ) $ 49,519 $ (262 ) 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, 2018. At June 30, 2018, 48 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, 2018 2017 2018 2017 (Unaudited) (Unaudited) Gross realized gains $ — $ — $ 2 $ 2 Gross realized losses — (1 ) — (6 ) Net realized gains $ — $ (1 ) $ 2 $ (4 )

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements Fair value is defined as an exit price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. 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, 2018 and December 31, 2017 (in thousands): Fair Value Measurements at June 30, 2018 (unaudited) Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents $ 16,122 $ 16,122 $ — $ — Corporate debt securities 74,362 — 74,362 — Government sponsored securities 5,989 — 5,989 — Foreign government bonds 2,997 — 2,997 — Commercial paper 5,474 — 5,474 — Noncurrent: Corporate debt securities 9,886 — 9,886 — Government sponsored securities 2,694 — 2,694 — Total assets measured at fair value $ 117,524 $ 16,122 $ 101,402 $ — Fair Value Measurements at December 31, 2017 Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents $ 23,872 $ 20,374 $ 3,498 $ — Corporate debt securities 82,109 — 82,109 — Government sponsored securities 19,233 — 19,233 — Foreign government bonds 2,938 — 2,938 — Noncurrent: Corporate debt securities 26,883 — 26,883 — Government sponsored securities 2,717 — 2,717 Total assets measured at fair value $ 157,752 $ 20,374 $ 137,378 $ — 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 three months ended June 30, 2018.

Collaboration and License Agree

Collaboration and License Agreements	6 Months Ended
	Jun. 30, 2018
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. There were no new collaborative agreements during the three months ended June 30, 2018 . License Agreement Chemotherapeutisches Forschungsinstitut Georg-Speyer-Haus (GSH) and DRK-Blutspendedienst Baden-Wurttenberg-Hessen gGmbH (BSD) License Agreement In August 2015, the Company entered into a license agreement with GSH and BSD under which the Company was granted an exclusive license to certain GSH-BSD patents, materials, and know-how that specifically targets ErbB2 expressing cancers. In addition, GSH granted the Company an exclusive license to certain GSH only technology and materials. In consideration for the licenses, the Company agreed to pay initial and annual licensing fees, regulatory and commercial milestones, and low single-digit percentage royalties on net sales of licensed products. The royalty term shall continue in a particular country until the later of (i) the expiration of the valid patent claims in such country or (ii) a specified period of time after the first commercial sale of licensed product in such country. The license agreement shall continue until no further payments are due at which time the licenses and rights will continue on a non-exclusive, royalty-free basis. The license agreement can be terminated earlier: (i) for material breach by either party after 60 days cure period, (ii) if the Company declares bankruptcy or insolvency or (iii) by the Company in its sole discretion upon 60 days prior written notice. In January 2018, the Company began expensing the first annual license fee of $0.5 million. The license fee is currently in prepaid expenses and other current assets on the condensed consolidated balance sheet. The Company is amortizing the license over the twelve month period and recorded $0.1 million and $0.2 million of expense in research and development on the condensed consolidated statements of operations for the three and six months ended June 30, 2018.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2018
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. Additionally, the Company records receivables from third-party insurers when recovery has been determined to be probable. This includes instances when the Company’s third-party insurers have agreed to reimburse certain legal defense costs incurred with the applicable law firms by the Company. 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 judgment ruling. The formal mandate was issued on June 26, 2017. In June 2017, the Federal Circuit reversed the U.S. District Court’s fees ruling and remanded the case for the U.S. District Court to enter an award of $0.1 million in favor of the USPTO. On August 31, 2017, a majority of active Federal Circuit judges voted to vacate the June 2017 decision and hear the case en banc sua sponte. On July 27, 2018, the Federal Circuit sitting en banc affirmed the U.S. District Court. The USPTO may seek rehearing or Supreme Court review. 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. 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. The actions originally filed in state court were removed to federal court, and the various related actions have been consolidated. Plaintiffs assert causes of action for alleged Plaintiffs during various time periods from In September 2017, the court denied defendants' motion to dismiss the third amended consolidated complaint. On September 6, 2016, a putative Bushansky v. Soon-Shiong, et al. The Company is named solely as a nominal defendant. On May 25, 2018, the California court of appeal affirmed the dismissal. On July 3, 2018, plaintiffs filed a petition for review with the California Supreme Court. On July 26, 2018, the Company filed an answer to the petition for review with the California Supreme Court. In October 2017, the first of two putative stockholder derivative complaints was filed in the Delaware Court of Chancery. The Delaware actions have been consolidated as In re NantKwest, Inc. Derivative Litigation, Cons. C.A. No. 2017-0774-VCL. A consolidated complaint was filed asserting that various of the Company's current and former directors and officers breached their fiduciary duties to the Company based on factual allegations similar to those in the Sudunagunta Bushansky On February 5, 2018, the defendants filed a motion to dismiss the consolidated complaint. On May 18, 2018, the Court granted the motion and dismissed the action. No appeal has been filed, and the deadline for appeal has passed. Insurance Recoveries The Company has reflected its right to insurance recoveries, limited to the extent of incurred or probable losses, as a receivable when such recoveries have been agreed to with its third-party insurers and receipt is deemed probable. This includes instances where the Company’s third-party insurers have agreed to reimburse certain legal defense costs incurred with applicable law firms by the Company. The amount of such receivable recorded at June 30, 2018 was $1.9 million and is included in prepaid expenses and other current assets on the Company’s condensed consolidated balance sheets. Contractual Obligations - Leases The Company leases: (i) office space in Cardiff-by-the-Sea, California; (ii) a research facility in Woburn, Massachusetts; (iii) a research facility and office space in San Diego, California; (iv) research and manufacturing space in Culver City, California, from a related party; and (v) a research and manufacturing facility in El Segundo, California, also from a related party. See Note 9 – Related Party Agreements The Company recognizes rent expense under its operating leases on a straight-line basis. Rent expense for the three months ended June 30, 2018 and 2017 was $0.7 million and $0.7 million, respectively, and $1.4 million and $1.4 million for the six months ended June 30, 2018 and 2017, respectively. Financing Lease Obligation – El Segundo 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 has been converted to a research and development laboratory and a current Good Manufacturing Practices (cGMP) manufacturing facility. 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. 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. Rent expense for this facility is recorded in research and development expense in the condensed consolidated statements of operations and was $0.1 million and $0.1 million for the three months ended June 30, 2018 and 2017, respectively, and was $0.1 million and $0.1 million, for the six months ended June 30, 2018 and 2017, respectively. The Company was responsible for costs to build out the facility and has incurred costs of approximately $30.4 million. Additionally, in order for the facility to meet the Company's research and development laboratory and cGMP specifications, the Company made certain structural changes to the facility as part of the conversion. 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. 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 May 2018, the Company evaluated the derecognition of the asset and liability under the provisions of ASC 840-40, Leases – Sale-Leaseback Transactions. Financing Lease Obligation – Culver City 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 cGMP manufacturing facility. 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. Rent expense for this facility is recorded in research and development expense in the consolidated statements of operations and was $47,000 and $47,000 for the three months ended June 30, 2018 and 2017, respectively, and was $0.1 million and $0.1 million, for the six months ended June 30, 2018 and 2017, respectively. Under the facility license agreement, the Company was responsible for costs to build out the laboratory and manufacturing facility space 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 derecognition 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, 2018 other than those disclosed in this document .

Related Party Agreements

Related Party Agreements	6 Months Ended
	Jun. 30, 2018
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. Liquid Genomics, Inc. In March 2018, the Company entered into an agreement with Liquid Genomics, Inc. (Liquid Genomics) to obtain blood-based tumor profiling services. Liquid Genomics is a related party of the Company as it is a wholly owned subsidiary of NantHealth, Inc., a majority owned subsidiary of NantWorks. The Company is obligated to pay Liquid Genomics fixed, per-patient fees. The agreement has an initial term of five years and renews automatically for successive one year periods, unless terminated earlier. During the three and six months ended June 30, 2018, $0.1 million has been recognized in research and development expense on the condensed consolidated statements of operations. As of June 30, 2018, the Company owes Liquid Genomics $0.1 million, which is included in due to related parties on the condensed consolidated balance sheets. John Lee, M.D. and Leonard Sender, M.D., Inc., a professional medical corporation, dba In 2017 and 2018, the Company entered into multiple agreements 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, to conduct various clinical trials. 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 is an investigator for the trials on behalf of CSSIM. During the three and six months ended June 30, 2018, $0.7 million and $1.4 million, respectively, has been recognized in research and development expense on the condensed consolidated statements of operations. As of June 30, 2018, the Company owes CSSIM $0.7 million, which is included in due to related parties on the condensed consolidated balance sheet. Tensorcom, Inc. In April 2017, the Company entered into a sublease agreement with Tensorcom, Inc. (Tensorcom) for a portion of its San Diego, California, research and development laboratory and office space, with a lease from May 1, 2017 through its expiration in April 30, 2018. The Company’s Chairman and CEO indirectly owns all of the outstanding equity of Tensorcom. Rent income from this sublease is recorded in other income on the condensed consolidated statements of operations and was $32,000 and $15,000 for the three months ended June 30, 2018 and 2017, respectively, and was $0.1 million and $15,000, for the six months ended June 30, 2018 and 2017, respectively. At June 30, 2018, the Company owed Tensorcom $33,000, which is included in due to related parties on the condensed consolidated balance sheet. VivaBioCell S.p.A. In February 2017, the Company entered into a research grant agreement with VivaBioCell S.p.A. (VBC), a subsidiary of NantCell, Inc. NantCell is an affiliate of NantWorks. Pursuant to this research grant agreement, VBC conducted 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 was recorded in prepaid expenses and other current assets on the condensed consolidated balance sheet and benefited from the research and development activities over a one year timeframe. The Company recognized research and development expense of $0 and $0.1 million in the condensed consolidated statements of operations for the three months ended June 30, 2018 and 2017 and $0.1 million and $0.2 million for the six months ended June 30, 2018 and 2017. Prepaid expenses and other current assets on the condensed consolidated balance sheet has been reduced by the expense recognized. 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 has been converted to a research and development laboratory and a cGMP manufacturing facility. 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 – Financing Lease Obligation – El Segundo Altor BioScience, LLC In August 2016, the Company entered into an exclusive Co-Development Agreement (the Co-Development Agreement) with Altor BioScience, LLC, formerly known as Altor BioScience Corporation (Altor). Altor is a related party of the Company as it is a wholly owned subsidiary of NantCell, Inc. (NantCell). NantCell is an affiliate of NantWorks. 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 granted 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 is 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 is required to 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. T he Company has dosed several patients with ALT-803 in several phase Ib/II and II trials. 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, 2018 and 2017. NantBio, Inc. In January 2018, the Company entered into a laboratory services agreement with NantBio, Inc. (NantBio) a NantWorks company. The agreement, effective December 2017, includes a sublease of approximately 1,965 square feet of laboratory and office space at the Company’s San Diego, California, research facility. The term of the sublease is 24 months, but can be terminated by either party with 30 days prior written notice. The sublease agreement converts to a month-to-month lease after the initial term, not to exceed the expiration of the lease agreement between the Company and the landlord. The monthly sublease and service fee of $10,000 is subject to an annual 3% increase on the agreement anniversary date. Rent income from this sublease is recorded in other income on the condensed consolidated statements of operations and was $31,000 and $0.1 million for the three and six months ended June 30, 2018, respectively. At June 30, 2018, NantBio owes the Company $17,000, which is included in due from related parties on the condensed consolidated balance sheet. In March 2016, NantBio and the National Cancer Institute entered into a cooperative research and development agreement. The agreement covers NantBio and its affiliates, including the Company. Under the agreement, the parties are collaborating on the preclinical and clinical development of proprietary recombinant NK cells and monoclonal antibodies in monotherapy and in combination immunotherapies. The Company benefited from the preclinical and clinical research conducted during the first and second year under this agreement and provided 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 recognized research and development expense relating to this agreement 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, 2018 and 2017, respectively, and $0.3 million and $0.3 million of expense for the six months ended June 30, 2018 and 2017, respectively. The Company has accrued $0.2 million in anticipation of funding in 2018. 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. 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, 2018 and 2017, the Company recorded selling, general and administrative expense of $0.8 million and $0.9 million, respectively. For the six months ended June 30, 2018 and 2017, the Company recorded selling, general and administrative expense of $1.5 million and $2.0 million, respectively. For the three months ended June 30, 2018 and 2017, the Company recorded research and development expense of $0.9 million and $0.7 million, respectively. For the six months ended June 30, 2018 and 2017, the Company recorded research and development expense of $1.8 million and $1.5 million, respectively. These amounts exclude certain general and administrative expenses provided by third party vendors directly for the Company’s benefit, which have been reimbursed to NantWorks based on those vendors’ invoiced amounts without markup by NantWorks. 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, 2018 and 2017, the Company recorded selling, general and administrative expense reimbursements of $0.2 million and $0.1 million, respectively. For the six months ended June 30, 2018 and 2017, the Company recorded selling, general and administrative expense reimbursements of $0.3 million and $0.2 million, respectively. For the three months ended June 30, 2018 and 2017, the Company recorded research and development expense reimbursements of $0.7 million and $0.1 million, respectively. For the six months ended June 30, 2018 and 2017, the Company recorded research and development expense reimbursements of $1.3 million and $0.3 million, respectively. 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 cGMP manufacturing facility. See Note 8 – Financing Lease Obligation – Culver City In May 2018, the Company entered into an assignment agreement with NantWorks and a third-party construction firm. In conjunction with the agreement, the Company assigned its deposit of $0.4 million with the third-party firm to NantWorks, for which NantWorks will reimburse the Company. This assignment represents unutilized deposits that NantKwest had previously made with the construction company, for which NantWorks can now utilize in applying such funds to future planned construction projects. The Company owed NantWorks a net amount of $0.9 million for all agreements between the two affiliates at June 30, 2018, which is included in due to related parties on the condensed consolidated balance sheet. NantOmics, LLC In June 2015, the Company entered into an agreement, as amended in May 2018, with NantOmics, LLC (NantOmics), an affiliate of NantWorks, to obtain genomic sequencing and proteomic analysis services, as well as related data management and bioinformatics services, exclusively from NantOmics. The Company will have rights to use the data and results generated from NantOmics’ services in connection with the performance of the particular oncology trial with respect to which the services were performed, but NantOmics will own the data and results, as well as any other intellectual property it creates in performing these services on the Company’s behalf. 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, 2018 and 2017, the Company recorded operating expense of $0.1 million and $13,000, respectively, and for the six months ended June 30, 2018 and 2017, the Company recorded operating expense of $0.1 million and $13,000, respectively, under the agreement to research and development expense on the condensed consolidated statements of operations. At June 30, 2018, the Company owes NantOmics $0.1 million, which is included in due to related parties on the condensed consolidated balance sheet. NantCell In June 2015, the Company also entered into a supply agreement with NantCell, an affiliate of NantWorks, 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. The agreement has an initial term of five years and renews automatically for successive one year periods unless terminated earlier. During the three months ended June 30, 2018 and 2017, the Company recorded operating expense of $0 and $33,000, respectively, and during the six months ended June 30, 2018 and 2017, the Company recorded operating expense of $0 and $0.3 million, respectively, in research and development expense on the condensed consolidated statement of operations. At June 30, 2018, the Company has balances of $0.7 million and $0.2 million included in property, plant, and equipment, net, and prepaid expenses and other current assets, respectively, related to purchases from NantCell, on the condensed consolidated balance sheet.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2018
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. At June 30, 2018, $19.1 million remained authorized for repurchase under the Company’s 2015 Share Repurchase Program and no shares were repurchased during the three months ended June 30, 2018.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation The following table presents stock-based compensation expense included on the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 (Unaudited) (Unaudited) Stock-based compensation expense: Warrants for common stock to an officer $ 7,636 $ 7,827 $ 15,272 $ 16,313 Employee stock options 970 952 1,948 2,303 Employee restricted stock units 294 (93 ) 686 225 Non-employee restricted stock units 34 695 101 558 $ 8,934 $ 9,381 $ 18,007 $ 19,399 Stock-based compensation expense in operating expenses: Research and development $ 142 $ (49 ) $ 281 $ 43 Selling, general and administrative 8,792 9,430 17,726 19,356 $ 8,934 $ 9,381 $ 18,007 $ 19,399 Stock Options The following table summarizes stock option activity for the six months ended June 30, 2018 (in thousands, except for share and year amounts): Number of Shares Weighted- Average Exercise Aggregate Intrinsic Value Weighted- Average Remaining Contractual (in years) Outstanding at December 31, 2017 5,693,250 $ 7.71 Options granted/exercised/forfeited — $ — Outstanding at June 30, 2018 5,693,250 $ 7.71 $ 5,466 4.8 Vested and Exercisable at June 30, 2018 5,346,093 $ 8.07 $ 5,167 5.0 The total unrecognized stock-based compensation expense related to non-vested stock options as of June 30, 2018 is $2.9 million, which is expected to be recognized over a weighted-average remaining amortization period of 0.7 years. Restricted Stock Units The following table summarizes the activity for restricted stock units: Number of Shares Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2017 888,189 $ 8.14 Granted 302,466 $ 3.74 Vested (154,123 ) $ 6.19 Forfeited (146,020 ) $ 7.35 Unvested balance at June 30, 2018 890,512 $ 7.11 The Company may grant shares of restricted stock units to both employees and directors of the Company and to employees of related parties that provide shared services to the Company under the Company’s shared services agreement with NantWorks (Note 9). During the six months ended June 30, 2018, the Company granted 302,466 shares of restricted stock units to employees and directors, with no grants to shared services employees. As of June 30, 2018, there was $3.5 million of unrecognized stock-based compensation expense related to restricted stock units that is expected to be recognized over a weighted-average remaining amortization period of 2.3 years. Of that amount, $3.1 million of unrecognized expense is related to employee grants with a weighted-average remaining amortization period of 2.7 years and $0.4 million of unrecognized expense, which is impacted by periodic mark-to-market adjustments, and is related to non-employee grants with a weighted-average remaining amortization period of 0.7 years. Warrants The following table summarizes the warrant activity for the six months ended June 30, 2018: Number of Shares Outstanding at December 31, 2017 17,721,088 Warrants exercised (21,675 ) Outstanding at June 30, 2018 17,699,413 Vested and exercisable at June 30, 2018 17,514,263 The total unrecognized stock-based compensation expense related to non-vested warrants as of June 30, 2018 is $2.5 million, which is expected to be recognized over a weighted-average remaining amortization period of 0.1 years.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The difference between the federal statutory tax rate of 21% 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. The Company did not record any unrealized gains in other comprehensive income during the three and six months ended June 30, 2018. The Company did record unrealized gains on its marketable debt securities in other comprehensive income, net of taxes, during the three and six months ended June 30, 2017. As a result, the Company recorded a tax benefit of $0 and $4,000 for the three months ended June 30, 2018 and 2017, respectively, and $0 and $10,000 for the six months ended June 30, 2018 and 2017 on the condensed consolidated statements of operations. The Company also recorded other comprehensive income of $0 and $2,000, for the three months ended June 30, 2018 and 2017, respectively, and $0 and $28,000, for the six months ended June 30, 2018 and 2017, respectively, in the condensed consolidated balance sheet. The Company is operating in Korea. During the three months ended June 30, 2018 and 2017, the tax benefit related to Korea was $0.1 million for each period . During the six months ended June 30, 2018 and 2017, the tax benefit related to Korea was $0.3 million and $0.2 million, respectively. 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. The Tax Cuts and Jobs Act In March 2018, the FASB issued ASU 2018-05, Income Taxes – Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events Related Party Agreement In July 2018, 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. The clinical trial is a phase Ib study that is part of the Company’s Nant Cancer Vaccine, or NCV, program for treatment of subjects with pancreatic cancer who have progressed on or after standard-of-care therapy. The cost under this agreement is estimated at $2.2 million.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Liquidity	Liquidity As of June 30, 2018, the Company had an accumulated deficit of approximately $553.8 million. The Company also had negative cash flow from operations of approximately $31.8 million during the six months ended June 30, 2018. 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, fail 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 debt 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 debt 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.
Basis of Presentation	Basis of Presentation The accompanying condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP). The unaudited condensed consolidated financial statements reflect all adjustments which are, in the opinion of management, necessary to present fairly the results for the interim periods presented and have been prepared on the same basis as the audited consolidated financial statements for the fiscal year ended December 31, 2017. The unaudited condensed consolidated financial statements do not include all information and notes necessary for a complete presentation of results of income, comprehensive income, financial position, and cash flows in conformity with GAAP. Accordingly, these financial statements should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2017 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 consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP 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, 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.
Principles of Consolidation and Equity Investments	Principles of Consolidation and Equity Investments The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Inex Bio, Inc. and 557 Doug St, LLC, and have been prepared in accordance with GAAP. All intercompany amounts have been eliminated. The Company applies the variable interest model under Accounting Standards Codification (ASC) Topic 810, Consolidation For entities the Company holds an equity investment in and are not consolidated under the VIE Model, the Company considers whether its investment constitutes ownership of a majority of the voting interests in the entity and therefore should be considered for consolidation under the voting interest model. Unconsolidated equity investments in the common stock or in-substance common stock of an entity under which the Company is able to exercise significant influence, but not control, are accounted for using the equity method. The Company’s ability to exercise significant influence is generally indicated by ownership of 20 to 50 percent interest in the voting securities of the entity. All other unconsolidated equity investments on which the Company is not able to exercise significant influence will be subsequently measured at fair value with unrealized The Company owns non-marketable equity securities that are accounted for as an equity investment at cost minus impairment and plus or minus changes resulting from observable price changes because the preferred stock held by the Company is not considered in-substance common stock and such 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, 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 impairment indicator is present include: the investees’ earning performance and clinical trial performance, change in the investees’ industry and geographic area in which it operates, offers to purchase or sell the security for a price less than the cost 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. Factors considered in determining whether an observable price change has occurred include: the price at which the investee issues equity instruments similar to those of the Company’s investment and the rights and preferences of those equity instruments compared to the Company’s.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash and cash equivalents and marketable debt securities. The Company’s cash and cash equivalents are with one major financial institution in the United States and one in Korea. Drug candidates developed by the Company will require approvals or clearances from the U.S. Food and Drug Administration (“FDA”) or international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s drug candidates will receive any of the required approvals or clearances. If the Company were to be denied approval or clearance or any such approval or clearance were to be delayed, it would have a material adverse impact on the Company.
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, 2018 2017 Outstanding options 5,693,250 5,693,250 Outstanding restricted stock units 890,512 979,825 Outstanding warrants 17,699,413 17,735,527 Total 24,283,175 24,408,602 Amounts in the table above reflect the common stock equivalents of the noted instruments.
Recently Adopted Accounting Policies	Recently Adopted Accounting Policies Financial Assets and Financial Liabilities Effective January 1, 2018, the Company adopted Accounting Standard Update (ASU) 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities Revenue Recognition Beginning January 1, 2018, the Company follows the provisions of Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers The Company derives substantially all of its revenue from non-exclusive license agreements with a limited number of pharmaceutical and biotechnology companies granting them the right to use the Company’s cell lines and intellectual property for non-clinical use. These agreements generally include upfront fees and annual research license fees for such use, as well as commercial license fees for sales of the Company’s licensee’s products developed or manufactured using the Company’s intellectual property and cell lines. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC Topic 606. A contract’s transaction price is allocated to each distinct performance obligation based on relative standalone selling price and recognized as revenue when, or as, the performance obligation is satisfied. Under the Company’s license agreements with customers, the Company typically promises to provide a license to use certain cell lines and related patents, the related know-how, and future research and development data that affects the license. The Company concluded that these promises represent one performance obligation due to the highly interrelated nature of the promises. The Company provides the cell lines and know-how immediately upon entering into the contracts. The research and development data is provided throughout the term of the contract when and if available. The Company’s license agreement with Intrexon included a nonrefundable upfront payment of $0.4 million, received when the Company entered into the contract in 2010. In this instance, the Company determined that under ASC 606 it would be appropriate to recognize the initial milestone payment at a point in time, when it transferred the license. In this case, the intellectual property provided under the contract is functional intellectual property under ASC 606 and was determined to be a distinct performance obligation in the context of the arrangement. Prior to adoption, the upfront payment had been initially recorded as deferred revenue and was being recognized into revenue on a straight-line basis. As a result, upon adoption of ASC 606, the Company adjusted its opening retained deficit for the effects of recognizing revenue upfront for the initial milestone. The adjustment to opening retained deficit upon adoption was not material. The license agreements may include nonrefundable upfront payments, event-based milestone payments, sales-based royalty payments, or some combination of these. The event-based milestone payments represent variable consideration and the Company uses the most likely amount method to estimate this variable consideration. Given the high degree of uncertainly around achievement of these milestones, the Company does not recognize revenue from these milestone payments until the uncertainty associated with these payments is resolved. The Company currently estimates variable consideration related to milestone payments to be zero and, as such, no revenue has been recognized for milestone payments. The Company will recognize revenue from sales-based royalty payments when or as the sales occur. On a quarterly basis, the Company will re-evaluate its estimate of milestone variable consideration to determine whether any amount should be included in the transaction price and recorded in revenue prospectively. Upon adoption, the Company changed its accounting policy from accounting for milestones payments under the milestone method to accounting for variable consideration as discussed above. The change in accounting policy did not change any amounts in the financial statements because of the significant uncertainty surrounding the estimate of variable consideration for milestone payments. The Company’s revenue from non-clinical license agreements is nominal. In the future, the Company may generate revenue from license agreements entered into for therapeutic uses. To date, the Company has not generated any revenue from product sales. If the Company fails to complete the development of its product candidates in a timely manner or fails to obtain regulatory approval for them, the Company may never be able to generate substantial future revenue. Statement of Cash Flows Effective January 1, 2018, the Company adopted ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments Statement of Cash Flows: Restricted Cash, a consensus of the FASB’s Emerging Issues Task Force
Recent Accounting Pronouncements - Not Yet Adopted	Recently Issued Accounting Pronouncements – Not Yet Adopted In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. Adoption of ASU 2018-02 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 on the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2018
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, 2018 2017 Outstanding options 5,693,250 5,693,250 Outstanding restricted stock units 890,512 979,825 Outstanding warrants 17,699,413 17,735,527 Total 24,283,175 24,408,602 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, 2018
Financial Statement Details [Abstract]
Prepaid Expenses and Other Current Assets	As of June 30, 2018 and December 31, 2017, prepaid expenses and other current assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Insurance claim receivable $ 1,932 $ 340 Interest receivable - marketable debt securities 674 764 Prepaid license fees 598 597 Prepaid services 460 416 Prepaid rent 375 373 Prepaid supplies 309 210 Prepaid insurance 123 572 Equipment deposits — 482 Other 263 398 $ 4,734 $ 4,152
Property, Plant and Equipment, Net	As of June 30, 2018 and December 31, 2017, property, plant and equipment, net consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Construction in progress $ 700 $ 42,281 Buildings 59,356 23,811 Equipment 19,619 9,625 Leasehold improvements 4,019 3,918 Software 1,224 1,092 Furniture & fixtures 479 302 85,397 81,029 Accumulated depreciation (7,186 ) (4,303 ) $ 78,211 $ 76,726
Intangible Assets, Net	As of June 30, 2018 and December 31, 2017, intangible assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Technology license $ 9,042 $ 9,042 Less accumulated amortization (7,347 ) (6,216 ) $ 1,695 $ 2,826
Other Assets	As of June 30, 2018 and December 31, 2017, other assets consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Restricted cash $ 179 $ 179 Security deposits 113 127 Other 62 24 $ 354 $ 330 Restricted cash is a certificate of deposit that is collateral for the letter of credit required as a security deposit for the Company’s San Diego, California, facility by the Company’s landlord.
Accrued Expenses	As of June 30, 2018 and December 31, 2017, accrued expenses consisted of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Accrued construction costs $ 5,214 $ 6,212 Accrued bonus 1,600 1,930 Accrued professional and service fees 1,387 1,048 Accrued preclinical and clinical trial costs 1,264 521 Accrued compensation 1,021 944 Accrued laboratory equipment and supplies 839 — Other 192 612 $ 11,517 $ 11,267
Other Current Liabilities	As of June 30, 2018 and December 31, 2017, other current liabilities were made up of (in thousands): June 30, 2018 December 31, 2017 (Unaudited) Financing obligation - current portion $ 585 $ 284 Deferred rent - current portion 558 520 Build-to-suit lease liability - current portion — 334 Other 224 235 $ 1,367 $ 1,373
Investment Income, Net	Net investment income includes interest income from all bank accounts as well as marketable debt 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, 2018 and 2017 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 (Unaudited) (Unaudited) Interest income $ 632 $ 1,049 $ 1,336 $ 2,403 Investment amortization accretion expense, net (142 ) (367 ) (343 ) (939 ) Net realized gains (losses) on investments — (1 ) 2 (4 ) $ 490 $ 681 $ 995 $ 1,460

Cash Equivalents and Marketab24

Cash Equivalents and Marketable Debt Securities (Tables)	6 Months Ended
	Jun. 30, 2018
Cash Equivalents And Marketable Securities [Abstract]
Schedule of Cash Equivalents and Marketable Debt Securities Available-for-Sale or Held-to-Maturity	As of June 30, 2018, all of the Company’s marketable debt securities are classified as available-for-sale or held-to-maturity and are scheduled to mature within 3.2 years. At June 30, 2018, the detail of the Company’s cash equivalents and marketable debt securities is as follows (in thousands): June 30, 2018 (unaudited) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Available-for-sale Corporate debt securities $ 74,516 $ — $ (154 ) $ 74,362 Government sponsored securities 5,991 1 (3 ) 5,989 Foreign government bonds 2,997 — — 2,997 Commercial paper 5,473 1 — 5,474 Total available-for-sale 88,977 2 (157 ) 88,822 Held-to-maturity, note receivable 361 — — 361 Current portion 89,338 2 (157 ) 89,183 Noncurrent: Corporate debt securities 10,114 — (228 ) 9,886 Government sponsored securities 2,758 — (64 ) 2,694 Noncurrent portion 12,872 - (292 ) 12,580 Total $ 102,210 $ 2 $ (449 ) $ 101,763 At December 31, 2017, the detail of the Company’s cash equivalents and marketable debt securities is as follows (in thousands): December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Current: Corporate debt securities $ 82,188 $ 5 $ (84 ) $ 82,109 Government sponsored securities 19,261 — (28 ) 19,233 Foreign government bonds 6,441 — (5 ) 6,436 Current portion 107,890 5 (117 ) 107,778 Noncurrent: Corporate debt securities 27,109 — (226 ) 26,883 Government sponsored securities 2,760 — (43 ) 2,717 Noncurrent portion 29,869 — (269 ) 29,600 Total $ 137,759 $ 5 $ (386 ) $ 137,378
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, 2018 and December 31, 2017 are as follows (in thousands): June 30, 2018 (unaudited) Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 62,011 $ (213 ) $ 17,733 $ (169 ) Government sponsored securities 2,694 (64 ) 2,000 (3 ) Foreign government bonds 2,997 — — — Total $ 67,702 $ (277 ) $ 19,733 $ (172 ) December 31, 2017 Less than 12 months More than 12 months Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Corporate debt securities $ 67,522 $ (104 ) $ 35,918 $ (206 ) Government sponsored securities 9,744 (20 ) 12,205 (51 ) Foreign government bonds 1,542 — 1,396 (5 ) Total $ 78,808 $ (124 ) $ 49,519 $ (262 )
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, 2018 2017 2018 2017 (Unaudited) (Unaudited) Gross realized gains $ — $ — $ 2 $ 2 Gross realized losses — (1 ) — (6 ) Net realized gains $ — $ (1 ) $ 2 $ (4 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
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, 2018 and December 31, 2017 (in thousands): Fair Value Measurements at June 30, 2018 (unaudited) Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents $ 16,122 $ 16,122 $ — $ — Corporate debt securities 74,362 — 74,362 — Government sponsored securities 5,989 — 5,989 — Foreign government bonds 2,997 — 2,997 — Commercial paper 5,474 — 5,474 — Noncurrent: Corporate debt securities 9,886 — 9,886 — Government sponsored securities 2,694 — 2,694 — Total assets measured at fair value $ 117,524 $ 16,122 $ 101,402 $ — Fair Value Measurements at December 31, 2017 Total Level 1 Level 2 Level 3 Assets: Current: Cash and cash equivalents $ 23,872 $ 20,374 $ 3,498 $ — Corporate debt securities 82,109 — 82,109 — Government sponsored securities 19,233 — 19,233 — Foreign government bonds 2,938 — 2,938 — Noncurrent: Corporate debt securities 26,883 — 26,883 — Government sponsored securities 2,717 — 2,717 Total assets measured at fair value $ 157,752 $ 20,374 $ 137,378 $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2018
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 on the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 (Unaudited) (Unaudited) Stock-based compensation expense: Warrants for common stock to an officer $ 7,636 $ 7,827 $ 15,272 $ 16,313 Employee stock options 970 952 1,948 2,303 Employee restricted stock units 294 (93 ) 686 225 Non-employee restricted stock units 34 695 101 558 $ 8,934 $ 9,381 $ 18,007 $ 19,399 Stock-based compensation expense in operating expenses: Research and development $ 142 $ (49 ) $ 281 $ 43 Selling, general and administrative 8,792 9,430 17,726 19,356 $ 8,934 $ 9,381 $ 18,007 $ 19,399
Summary of Stock Option Activity	The following table summarizes stock option activity for the six months ended June 30, 2018 (in thousands, except for share and year amounts): Number of Shares Weighted- Average Exercise Aggregate Intrinsic Value Weighted- Average Remaining Contractual (in years) Outstanding at December 31, 2017 5,693,250 $ 7.71 Options granted/exercised/forfeited — $ — Outstanding at June 30, 2018 5,693,250 $ 7.71 $ 5,466 4.8 Vested and Exercisable at June 30, 2018 5,346,093 $ 8.07 $ 5,167 5.0
Restricted Stock Units Activity	The following table summarizes the activity for restricted stock units: Number of Shares Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2017 888,189 $ 8.14 Granted 302,466 $ 3.74 Vested (154,123 ) $ 6.19 Forfeited (146,020 ) $ 7.35 Unvested balance at June 30, 2018 890,512 $ 7.11
Summary of Warrant Activity	The following table summarizes the warrant activity for the six months ended June 30, 2018: Number of Shares Outstanding at December 31, 2017 17,721,088 Warrants exercised (21,675 ) Outstanding at June 30, 2018 17,699,413 Vested and exercisable at June 30, 2018 17,514,263

Description of Business - Addit

Description of Business - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (553,778)		$ (498,713)
Net cash used in operating activities	$ (31,777)	$ (25,007)

Summary of Significant Accoun28

Summary of Significant Accounting Policies - Securities Excluded from the Computation of Potentially Dilutive Securities (Detail) - shares	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	24,283,175	24,408,602
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	5,693,250
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	890,512	979,825
Outstanding Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	17,699,413	17,735,527

Summary of Significant Accoun29

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Feb. 28, 2010	Jun. 30, 2018
Accounting Policies [Line Items]
Variable consideration related to milestone payment		$ 0
Revenue recognized for milestone payment		$ 0
Intrexon Corporation
Accounting Policies [Line Items]
Nonrefundable upfront payment	$ 400

Financial Statement Details - P

Financial Statement Details - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial Statement Details [Abstract]
Insurance claim receivable	$ 1,932	$ 340
Interest receivable - marketable debt securities	674	764
Prepaid license fees	598	597
Prepaid services	460	416
Prepaid rent	375	373
Prepaid supplies	309	210
Prepaid insurance	123	572
Equipment deposits	0	482
Other	263	398
Total prepaid expenses and other current assets	$ 4,734	$ 4,152

Financial Statement Details -31

Financial Statement Details - Property, Plant and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 85,397	$ 81,029
Accumulated depreciation	(7,186)	(4,303)
Property, plant and equipment, net	78,211	76,726
Construction in Progress
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	700	42,281
Buildings
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	59,356	23,811
Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	19,619	9,625
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	4,019	3,918
Software
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	1,224	1,092
Furniture And Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 479	$ 302

Financial Statement Details - A

Financial Statement Details - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financial Statement Details [Line Items]
Depreciation expense related to property, plant and equipment	$ 1,800,000	$ 800,000	$ 2,900,000	$ 1,400,000
Property, plant and equipment, gross	85,397,000		85,397,000		$ 81,029,000
Amortization expense	600,000	600,000	1,100,000	1,100,000
Impairment loss on recognized investments	0	$ 0	0	$ 0
Buildings
Financial Statement Details [Line Items]
Property, plant and equipment, gross	59,356,000		59,356,000		$ 23,811,000
Warehouse Distribution Facility
Financial Statement Details [Line Items]
Property, plant and equipment, gross	19,500,000		19,500,000
Build to Suit Lease
Financial Statement Details [Line Items]
Property, plant and equipment, gross	$ 39,900,000		$ 39,900,000

Financial Statement Details - I

Financial Statement Details - Intangible Assets, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Intangible assets, net	$ 1,695	$ 2,826
Technology License
Finite Lived Intangible Assets [Line Items]
Total intangible assets	9,042	9,042
Less accumulated amortization	(7,347)	(6,216)
Intangible assets, net	$ 1,695	$ 2,826

Financial Statement Details - O

Financial Statement Details - Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Financial Statement Details [Abstract]
Restricted cash	$ 179	$ 179	$ 179
Security deposits	113	127
Other	62	24
Other Assets Noncurrent	$ 354	$ 330

Financial Statement Details -35

Financial Statement Details - Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial Statement Details [Abstract]
Accrued construction costs	$ 5,214	$ 6,212
Accrued bonus	1,600	1,930
Accrued professional and service fees	1,387	1,048
Accrued preclinical and clinical trial costs	1,264	521
Accrued compensation	1,021	944
Accrued laboratory equipment and supplies	839	0
Other	192	612
Accrued Liabilities Current	$ 11,517	$ 11,267

Financial Statement Details -36

Financial Statement Details - Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial Statement Details [Abstract]
Financing obligation - current portion	$ 585	$ 284
Deferred rent - current portion	558	520
Build-to-suit lease liability - current portion	0	334
Other	224	235
Other current liabilities	$ 1,367	$ 1,373

Financial Statement Details -37

Financial Statement Details - Investment Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financial Statement Details [Abstract]
Interest income	$ 632	$ 1,049	$ 1,336	$ 2,403
Investment amortization accretion expense, net	(142)	(367)	(343)	(939)
Net realized gains (losses) on investments	0	(1)	2	(4)
Investment income, net	$ 490	$ 681	$ 995	$ 1,460

Equity Investment - Additional

Equity Investment - Additional Information (Detail) - USD ($)	1 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017
Schedule Of Investments [Line Items]
Equity investment	$ 8,500,000	$ 8,500,000	$ 8,500,000		$ 8,500,000
Equity investment, description		As the preferred stock is not considered in-substance common stock, the investment is not within the scope of accounting for the investment under the equity method. As the preferred stock does not have a readily determinable fair value, the Company has elected to apply the practicability exception noted under ASC 825 and estimates the fair value at its $8.5 million cost minus impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer.
2018 Note and Warrant Purchase Agreement
Schedule Of Investments [Line Items]
Convertible note accrues interest rate	8.00%	8.00%
Convertible note maturity period	1 year
2018 Note and Warrant Purchase Agreement | Series B Preferred Stock
Schedule Of Investments [Line Items]
Purchase of convertible note	$ 400,000
Maximum
Schedule Of Investments [Line Items]
Option to purchase additional shares under equity investment				$ 8,500,000

Cash Equivalents and Marketab39

Cash Equivalents and Marketable Debt Securities - Additional Information (Detail) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018Security	Dec. 31, 2017USD ($)
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities or held-to-maturity period	3 years 2 months 12 days
Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Number of available-for-sale securities in unrealized loss positions | Security	48
Maximum
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, period of unrealized loss positions	12 months	12 months
Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalent portions included in current fair values | $		$ 3.5

Cash Equivalents and Marketab40

Cash Equivalents and Marketable Debt Securities - Schedule of Cash Equivalents and Marketable Debt Securities Available-for-Sale or Held-to-Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 102,210	$ 137,759
Available-for-sale, Unrealized Gains	2	5
Available-for-sale, Unrealized Losses	(449)	(386)
Available-for-sale, Fair Value	101,763	137,378
Current Assets
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	88,977	107,890
Available-for-sale, Unrealized Gains	2	5
Available-for-sale, Unrealized Losses	(157)	(117)
Available-for-sale, Fair Value	88,822	107,778
Available-for-sale and held-to-maturity, Amortized Cost	89,338
Available-for-sale and held-to-maturity, Unrealized Gains	2
Available-for-sale and held-to-maturity, Unrealized Losses	(157)
Available-for-sale and held-to-maturity, Fair Value	89,183
Current Assets | Note Receivable
Schedule Of Available For Sale Securities [Line Items]
Held-to-maturity, Amortized Cost	361
Held-to-maturity, Unrealized Gains	0
Held-to-maturity, Unrealized Losses	0
Held-to-maturity, Fair Value	361
Current Assets | Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	5,991	19,261
Available-for-sale, Unrealized Gains	1	0
Available-for-sale, Unrealized Losses	(3)	(28)
Available-for-sale, Fair Value	5,989	19,233
Current Assets | Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	5,473
Available-for-sale, Unrealized Gains	1
Available-for-sale, Unrealized Losses	0
Available-for-sale, Fair Value	5,474
Current Assets | Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	2,997	6,441
Available-for-sale, Unrealized Gains	0	0
Available-for-sale, Unrealized Losses	0	(5)
Available-for-sale, Fair Value	2,997	6,436
Current Assets | Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	74,516	82,188
Available-for-sale, Unrealized Gains	0	5
Available-for-sale, Unrealized Losses	(154)	(84)
Available-for-sale, Fair Value	74,362	82,109
Noncurrent Assets
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	12,872	29,869
Available-for-sale, Unrealized Gains	0	0
Available-for-sale, Unrealized Losses	(292)	(269)
Available-for-sale, Fair Value	12,580	29,600
Noncurrent Assets | Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	2,758	2,760
Available-for-sale, Unrealized Gains	0	0
Available-for-sale, Unrealized Losses	(64)	(43)
Available-for-sale, Fair Value	2,694	2,717
Noncurrent Assets | Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	10,114	27,109
Available-for-sale, Unrealized Gains	0	0
Available-for-sale, Unrealized Losses	(228)	(226)
Available-for-sale, Fair Value	$ 9,886	$ 26,883

Cash Equivalents and Marketab41

Cash Equivalents and Marketable Debt Securities - Available-for-Sale Investments in Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	$ 67,702	$ 78,808
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(277)	(124)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	19,733	49,519
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	(172)	(262)
Government Sponsored Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	2,694	9,744
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(64)	(20)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	2,000	12,205
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	(3)	(51)
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	62,011	67,522
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	(213)	(104)
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	17,733	35,918
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	(169)	(206)
Foreign Government Bonds
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Investments, Less than 12 months, Estimated Fair Value	2,997	1,542
Available-for-Sale Investments, Less than 12 months, Gross Unrealized Losses	0	0
Available-for-Sale Investments, More than 12 months, Estimated Fair Value	0	1,396
Available-for-Sale Investments, More than 12 months, Gross Unrealized Losses	$ 0	$ (5)

Cash Equivalents and Marketab42

Cash Equivalents and Marketable Debt 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, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Cash Equivalents And Marketable Securities [Abstract]
Available-for-sale Securities, Gross Realized Gains	$ 0	$ 0	$ 2	$ 2
Available-for-sale Securities, Gross Realized Losses	0	(1)	0	(6)
Available-for-sale Securities, Net Realized Gains	$ 0	$ (1)	$ 2	$ (4)

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 117,524	$ 157,752
Current Assets | Cash and cash equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	16,122	23,872
Current Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	74,362	82,109
Current Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,989	19,233
Current Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,997	2,938
Current Assets | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,474
Noncurrent Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	9,886	26,883
Noncurrent Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,694	2,717
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	16,122	20,374
Level 1 | Current Assets | Cash and cash equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	16,122	20,374
Level 1 | Current Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 1 | Current Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 1 | Current Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 1 | Current Assets | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0
Level 1 | Noncurrent Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 1 | Noncurrent Assets | Government Sponsored Securities
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	101,402	137,378
Level 2 | Current Assets | Cash and cash equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	3,498
Level 2 | Current Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	74,362	82,109
Level 2 | Current Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,989	19,233
Level 2 | Current Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,997	2,938
Level 2 | Current Assets | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	5,474
Level 2 | Noncurrent Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	9,886	26,883
Level 2 | Noncurrent Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	2,694	2,717
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Current Assets | Cash and cash equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Current Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Current Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Current Assets | Foreign Government Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Current Assets | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0
Level 3 | Noncurrent Assets | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Level 3 | Noncurrent Assets | Government Sponsored Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 0	$ 0

Collaboration and License Agr44

Collaboration and License Agreements - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2018
Licensing Agreement [Line Items]
Annual license fee	$ 0.5
License fee amortization period			12 months
Research and Development
Licensing Agreement [Line Items]
Amortization of license expense		$ 0.1		$ 0.2

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Detail)	1 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)	Sep. 30, 2016USD ($)ft²	Nov. 30, 2015USD ($)ft²	Sep. 30, 2015USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Aug. 31, 2016USD ($)
Commitments And Contingencies [Line Items]
Rent expense					$ 700,000	$ 700,000	$ 1,400,000	$ 1,400,000
Doug St, LLC
Commitments And Contingencies [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.
Optional extended lease term		3 years
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
Costs incurred					30,400,000		$ 30,400,000
Underlying assets					35,600,000		35,600,000
Doug St, LLC | El Segundo California
Commitments And Contingencies [Line Items]
Number of square foot of facility leased | ft²		24,250
Doug St, LLC | Research and Development
Commitments And Contingencies [Line Items]
Rent expense					100,000	100,000	$ 100,000	100,000
NantWorks
Commitments And Contingencies [Line Items]
Number of square foot of facility leased | ft²			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.
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
Costs incurred									$ 3,500,000
Underlying assets					4,300,000		$ 4,300,000
NantWorks | Research and Development
Commitments And Contingencies [Line Items]
Rent expense					47,000	$ 47,000	0.1	$ 0.1
Prepaid Expenses and Current Assets
Commitments And Contingencies [Line Items]
Insurance claim receivable					$ 1,900,000		$ 1,900,000
USPTO
Commitments And Contingencies [Line Items]
Attorney's fees and expert witness fees				$ 100,000
Award amount in favour to other party	$ 100,000

Related Party Agreements - Addi

Related Party Agreements - Additional Information (Detail)	Dec. 01, 2017USD ($)ft²	May 31, 2018USD ($)	Mar. 31, 2018	Apr. 30, 2017USD ($)	Sep. 30, 2016USD ($)ft²	Apr. 30, 2016USD ($)	Mar. 31, 2016	Nov. 30, 2015USD ($)ft²	Jun. 30, 2015	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)Patient	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Feb. 28, 2017USD ($)
Related Party Transaction [Line Items]
Research and development										$ 14,688,000	$ 9,706,000	$ 28,679,000	$ 18,954,000
Due to related parties										1,806,000		1,806,000		$ 2,363,000
Prepaid expenses and other current assets										4,734,000		4,734,000		4,152,000
Selling, general and administrative expense										13,594,000	14,128,000	27,892,000	30,355,000
Property, plant and equipment, net										78,211,000		78,211,000		$ 76,726,000
Liquid Genomics, Inc.
Related Party Transaction [Line Items]
Initial term of agreement entered into with the related party by the entity			5 years
Related party, agreement renewal term			1 year
Research and development										100,000		100,000
Due to related parties										100,000		100,000
Chan Soon-Shiong Institutes for Medicine (CSSIM) | California
Related Party Transaction [Line Items]
Research and development										700,000		1,400,000
Due to related parties										$ 700,000		700,000
Tensorcom, Inc | San Diego California
Related Party Transaction [Line Items]
Period of agreement										Lease from May 1, 2017 through April 30, 2018
Due between parties										$ 33,000		33,000
Tensorcom, Inc | San Diego California | Other Income
Related Party Transaction [Line Items]
Sublease revenue recognized										32,000	15,000	100,000	15,000
VivaBioCell S.p.A.
Related Party Transaction [Line Items]
Research and development										0	100,000	$ 100,000	200,000
Prepaid expenses and other current assets															$ 600,000
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.
Due between parties										0		$ 0
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
Doug St, LLC | Research and Development
Related Party Transaction [Line Items]
Rent expense										100,000	100,000	$ 100,000	100,000
Doug St, LLC | El Segundo California
Related Party Transaction [Line Items]
Number of square foot of facility leased | ft²					24,250
Altor
Related Party Transaction [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	0	$ 0	0
NantBioScience
Related Party Transaction [Line Items]
Initial term of agreement entered into with the related party by the entity							5 years
Research and development										200,000	200,000	$ 300,000	$ 300,000
Number of square foot of facility leased | ft²	1,965
Base rent - monthly	$ 10,000
Percentage of annual increase of base rent	3.00%
Sublease term	24 months
Sublease termination notice period	30 days
Prepayment of funding amount				$ 600,000		$ 600,000
Research and development expense, ratable payment period												12 months	12 months
Accrued anticipation of funding in 2018										200,000		$ 200,000
NantBioScience | Prepaid Expenses and Current Assets
Related Party Transaction [Line Items]
Due between parties										17,000		17,000
NantBioScience | Other Income
Related Party Transaction [Line Items]
Sublease revenue recognized										31,000		0.1
NantWorks
Related Party Transaction [Line Items]
Due to related parties										900,000		900,000
Number of square foot of facility leased | ft²								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
Transfer of deposit amount to third party		$ 400,000
NantWorks | Shared Services Agreement
Related Party Transaction [Line Items]
Research and development										900,000	700,000	1,800,000	$ 1,500,000
Selling, general and administrative expense										800,000	900,000	1,500,000	2,000,000
NantWorks | Reimbursements | Shared Services Agreement
Related Party Transaction [Line Items]
Research and development										700,000	100,000	1,300,000	300,000
Selling, general and administrative expense										200,000	100,000	300,000	200,000
NantWorks | Research and Development
Related Party Transaction [Line Items]
Rent expense										47,000	47,000	0.1	0.1
NantOmics
Related Party Transaction [Line Items]
Initial term of agreement entered into with the related party by the entity									5 years
Related party, agreement renewal term									1 year
Research and development										0.1	13,000	0.1	13,000
Due to related parties										100,000		100,000
NantCell Inc
Related Party Transaction [Line Items]
Initial term of agreement entered into with the related party by the entity									5 years
Related party, agreement renewal term									1 year
Research and development										0	$ 33,000	0	$ 300,000
Prepaid expenses and other current assets										200,000		200,000
Property, plant and equipment, net										$ 700,000		$ 700,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended
	Jun. 30, 2018	Nov. 30, 2015
Equity [Abstract]
Total amount authorized for repurchase		$ 50,000,000
Repurchase of common stock, shares	0
Remaining authorized repurchase amount	$ 19,100,000

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, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,934	$ 9,381	$ 18,007	$ 19,399
Warrants For Common Stock | Officer
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	7,636	7,827	15,272	16,313
Employee Stock Option
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	970	952	1,948	2,303
Employee Restricted Stock Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	294	(93)	686	225
Non Employee Restricted Stock Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	34	695	101	558
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	142	(49)	281	43
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,792	$ 9,430	$ 17,726	$ 19,356

Stock-Based Compensation - St49

Stock-Based Compensation - Stock Option Activity (Detail) - Employee Stock Option $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)$ / sharesshares
Number of Shares
Stock Options, Beginning Balance | shares	5,693,250
Stock Options, Options granted/exercised/forfeited | shares	0
Stock Options, Ending Balance | shares	5,693,250
Stock Options, Vested and Exercisable | shares	5,346,093
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding Beginning balance | $ / shares	$ 7.71
Weighted Average Exercise Price, Options granted/exercised/forfeited | $ / shares	0
Weighted Average Exercise Price, Outstanding Ending balance | $ / shares	7.71
Weighted Average Exercise Price, Vested and Exercisable | $ / shares	$ 8.07
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding, Beginning balance | $	$ 5,466
Aggregate Intrinsic Value, Vested and Exercisable | $	$ 5,167
Weighted Average Remaining Contractual Life
Weighted Average Remaining Contractual Life, Outstanding	4 years 9 months 18 days
Weighted Average Remaining Contractual Life, Vested and Exercisable	5 years

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)shares
Outstanding Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to non-vested stock options	$ 2.5
Weighted Average Remaining Contractual Life, Outstanding	1 month 6 days
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to non-vested stock options	$ 2.9
Weighted-average period for recognition remaining amortization	8 months 12 days
Weighted Average Remaining Contractual Life, Outstanding	4 years 9 months 18 days
Employee Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period for recognition remaining amortization	2 years 8 months 12 days
Number of shares granted | shares	302,466
Unrecognized compensation cost related to non-vested stock options	$ 3.1
Outstanding Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted | shares	302,466
Unrecognized compensation cost related to non-vested stock options	$ 3.5
Weighted-average remaining amortization period for recognition	2 years 3 months 18 days
Non Employee Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period for recognition remaining amortization	8 months 12 days
Unrecognized compensation cost related to non-vested stock options	$ 0.4

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units Activity (Detail) - Outstanding Restricted Stock Units	6 Months Ended
	Jun. 30, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Unvested, Beginning balance | shares	888,189
Number of Shares, Granted | shares	302,466
Number of Shares, Vested | shares	(154,123)
Number of Shares, Forfeited | shares	(146,020)
Number of Shares, Unvested, Ending balance | shares	890,512
Weighted-Average Grant Date Fair Value, Unvested, beginning balance | $ / shares	$ 8.14
Weighted-Average Grant Date Fair Value, Granted | $ / shares	3.74
Weighted-Average Grant Date Fair Value, Vested | $ / shares	6.19
Weighted-Average Grant Date Fair Value, Forfeited | $ / shares	7.35
Weighted-Average Grant Date Fair Value, Unvested, ending balance | $ / shares	$ 7.11

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Warrant Activity (Detail) - Outstanding Warrants	6 Months Ended
	Jun. 30, 2018shares
Warrant [Line Items]
Number of shares Warrants, Beginning Balance	17,721,088
Number of shares Warrants exercised	(21,675)
Number of shares Warrants, Ending Balance	17,699,413
Number of shares Warrants, Vested and exercisable Ending Balance	17,514,263

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax [Line Items]
Federal statutory tax rate			21.00%		35.00%
Company's effective tax rate			0.00%
Unrealized gains in other comprehensive income	$ 0		$ 0
Tax benefit	0	$ 4,000	0	$ 10,000
Tax benefit in other comprehensive income	0	2,000	0	28,000
Korea
Income Tax [Line Items]
Tax benefit	$ 100,000	$ 100,000	$ 300,000	$ 200,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) $ in Millions	1 Months Ended
	Jul. 31, 2018USD ($)
Chan Soon-Shiong Institutes for Medicine (CSSIM) | California | Subsequent Event
Subsequent Event [Line Items]
Estimated cost of clinical trial agreement	$ 2.2