Alaunos Therapeutics (TCRT) 10-K 5 Mar 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 21, 2019	Jun. 29, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	ZIOP
Entity Registrant Name	ZIOPHARM ONCOLOGY INC
Entity Central Index Key	1,107,421
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 339,372,440
Entity Common Stock, Shares Outstanding		162,294,494
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	true

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 61,729	$ 70,946
Receivables	1,864	19
Prepaid expenses and other current assets	20,692	19,818
Total current assets	84,285	90,783
Property and equipment, net	1,097	1,211
Deposits	128	128
Other non-current assets	9,541	13,484
Total assets	95,051	105,606
Current liabilities:
Accounts payable	707	4,417
Accrued expenses	8,763	9,909
Deferred revenue - current portion		6,389
Deferred rent - current portion	13	141
Total current liabilities	9,483	20,856
Deferred revenue, net of current portion		35,139
Deferred rent, net of current portion	4	1
Derivative liabilities		2,424
Total liabilities	9,487	58,420
Commitments and contingencies (Note 8)
Preferred stock, $0.001 par value, 30,000,000 shares authorized
Stockholders' deficit:
Common stock, $0.001 par value; 250,000,000 shares authorized; 161,066,136 and 142,658,037 shares issued and outstanding at December 31, 2018 and 2017, respectively	161	143
Additional paid-in capital	651,732	615,493
Accumulated deficit	(566,329)	(712,442)
Total stockholders' equity (deficit)	85,564	(96,806)
Total liabilities and stockholders' equity (deficit)	$ 95,051	105,606
Series 1 Preferred Stock
Current liabilities:
Series 1 preferred stock, $1,200 stated value; 250,000 designated; 0 and 119,644 shares issued and outstanding at December 31, 2018 and 2017 respectively; liquidation value of $0 million and $143.6 at December 31, 2018 and 2017, respectively		$ 143,992

BALANCE SHEETS (Parenthetical)

BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	30,000,000	30,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	161,066,136	142,658,037
Common stock, shares outstanding	161,066,136	142,658,037
Series 1 Preferred Stock
Preferred stock, stated value	$ 1,200	$ 1,200
Preferred stock, shares authorized	250,000	250,000
Preferred stock, shares issued	0	119,644
Preferred stock, shares outstanding	0	119,644
Preferred stock, liquidation preference	$ 0	$ 143.6

STATEMENTS OF OPERATIONS

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Collaboration revenue	$ 146	$ 6,389	$ 6,861
Operating expenses:
Research and development	34,134	45,084	157,791
General and administrative	19,918	14,798	14,377
Total operating expenses	54,052	59,882	172,168
Loss from operations	(53,906)	(53,493)	(165,307)
Other income (expense), net	631	465	134
Change in fair value of derivative liabilities	158	(1,295)	(124)
Net loss	(53,117)	(54,323)	(165,297)
Preferred stock dividends	(16,998)	(18,938)	(7,123)
Settlement of a related party relationship	207,361
Net income (loss) applicable to common stockholders	$ 137,246	$ (73,261)	$ (172,420)
Net income (loss) per share - basic	$ 0.96	$ (0.53)	$ (1.32)
Net income (loss) per share - diluted	$ 0.96	$ (0.53)	$ (1.32)
Weighted average common shares outstanding used to compute basic net income (loss) per share	143,508,674	136,938,264	130,391,463
Weighted average common shares outstanding used to compute diluted net income (loss) per share	143,710,160	136,938,264	130,391,463

STATEMENTS OF CHANGES IN PREFER

STATEMENTS OF CHANGES IN PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid In Capital Common Stock	Accumulated Deficit	Series 1 Preferred Stock - Mezzanine
Balance at Dec. 31, 2015	$ 87,371	$ 132	$ 579,939	$ (492,700)
Balance (in shares) at Dec. 31, 2015		131,718,579
Exercise of employee stock options	$ 714	$ 2	712
Exercise of employee stock options (in shares)	234,833	189,696
Stock-based compensation	$ 8,452		8,452
Issuance of restricted common stock		$ 712	(712)
Issuance of restricted common stock (in shares)		711,770
Issuance of common stock in a license agreement	87		87		$ 118,242
Issuance of common stock in a license agreement (in shares)					100,000
Repurchase of restricted common stock	(1,500)	$ (2)	(1,498)
Repurchase of restricted common stock (in shares)		(243,207)
Stock buy-back	(2)		(2)
Stock buy-back (Shares)		(168)
Preferred stock dividends					$ 7,079
Preferred stock dividends	(7,123)		(7,123)
Preferred stock dividends (in shares)					6,184
Net loss	(165,297)			(165,297)
Balance at Dec. 31, 2016	(77,298)	$ 132	580,567	(657,997)	$ 125,321
Balance (in shares) at Dec. 31, 2016		132,376,670			106,184
Exercise of employee stock options	$ 88	$ 1	87
Exercise of employee stock options (in shares)	180,000	59,864
Stock-based compensation	$ 8,454		8,454
Issuance of restricted common stock		$ 1	(1)
Issuance of restricted common stock (in shares)		907,032
Repurchase of restricted common stock	(2,059)	$ (1)	(2,058)
Repurchase of restricted common stock (in shares)		(394,267)
Issuance of common stock, net of commissions and expenses	47,270	$ 10	47,260
Issuance of common stock, net of commissions and expenses (in shares)		9,708,738
Preferred stock dividends					$ 18,672
Preferred stock dividends	(18,938)		(18,938)
Preferred stock dividends (in shares)					13,460
Net loss	(54,323)			(54,323)
Balance at Dec. 31, 2017	(96,806)	$ 143	615,493	(712,442)	$ 143,993
Balance (in shares) at Dec. 31, 2017		142,658,037			119,644
Cumulative effect adjustment ASU No. 2016-09			122	(122)
Exercise of employee stock options	$ 242	$ 2	240
Exercise of employee stock options (in shares)	104,167	104,166
Adjustment for implementation of ASU No. 2014-09, Revenue from Contracts with Customers	$ (8,131)			(8,131)
Stock-based compensation	7,534		7,534
Issuance of restricted common stock	1	$ 2	(1)
Issuance of restricted common stock (in shares)		150,321
Cancelled restricted common stock	1	$ (2)	3
Cancelled restricted common stock (Shares)		(271,433)
Repurchase of restricted common stock	(1,624)	$ (3)	(1,621)
Repurchase of restricted common stock (in shares)		(514,349)
Issuance of common stock, net of commissions and expenses	47,101	$ 19	47,082
Issuance of common stock, net of commissions and expenses (in shares)		18,939,394
Preferred stock dividends					$ 16,775
Preferred stock dividends	(16,998)		(16,998)
Preferred stock dividends (in shares)					11,415
Settlement of a related party relationship (Note 7)	207,361			207,361	$ (160,767)
Settlement of a related party relationship (Note 7) (Shares)					(131,059)
Net loss	(53,117)			(53,117)
Balance at Dec. 31, 2018	$ 85,564	$ 161	$ 651,732	$ (566,329)
Balance (in shares) at Dec. 31, 2018		161,066,136

STATEMENTS OF CHANGES IN PREF_2

STATEMENTS OF CHANGES IN PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Issuance of common stock, commissions and expenses	$ 2,898	$ 2,700	$ 109

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (53,117)	$ (54,323)	$ (165,297)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	575	369	290
Stock-based compensation	7,534	8,454	8,452
Preferred stock issued in exchange for 2016 ECP amendment			118,936
Change in fair value of derivative liabilities	(158)	1,295	124
Issuance of common stock in a license agreement			87
(Increase) decrease in:
Receivables	(1,845)	2	425
Prepaid expenses and other current assets	(1,263)	3,992	(12,452)
Other noncurrent assets	3,942	(12,991)
Increase (decrease) in:
Accounts payable	(3,709)	4,261	(1,852)
Accrued expenses	(1,145)	800	203
Deferred revenue	(146)	(6,389)	(6,861)
Deferred rent	(125)	(139)	(380)
Net cash used in operating activities	(49,457)	(54,669)	(58,325)
Cash flows from investing activities:
Purchases of property and equipment	(459)	(737)	(551)
Net cash used in investing activities	(459)	(737)	(551)
Cash flows from financing activities:
Proceeds from exercise of stock options	240	88	714
Issuance of restricted common stock		(2,059)	(1,500)
Repurchase of common stock	(1,622)		(2)
Proceeds from issuance of common stock, net		47,270
Proceeds from underwritten financing	47,101
Cash paid for settlement of related party relationship	(5,408)
Net cash provided by (used in) financing activities	40,311	45,299	(788)
Net decrease in cash and cash equivalents, and restricted cash	(9,605)	(10,107)	(59,664)
Cash and cash equivalents, and restricted cash, beginning of period	71,334	81,441	140,717
Cash and cash equivalents, and restricted cash, end of period	61,729	71,334	81,441
Supplementary disclosure of cash flow information:
Cash paid for interest	0	0	0
Cash paid for income taxes	0	0	0
Supplementary disclosure of noncash investing and financing activities:
Noncash portion of related party relationship settlement	212,769
Series 1 Preferred Stock
Supplementary disclosure of noncash investing and financing activities:
Payment of dividends in preferred stock	$ 16,998	$ 18,938	7,123
Series 1 preferred stock issued as consideration for a license agreement			$ 119,045

Organization

Organization	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Organization	1. Organization ZIOPHARM Oncology, Inc., which is referred to herein as “ZIOPHARM,” or the “Company,” is a biopharmaceutical company seeking to develop, acquire, and commercialize, on its own or with partners, a diverse portfolio of immuno-oncology therapies. The Company’s operations to date have consisted primarily of raising capital and conducting research and development. The Company’s fiscal year ends on December 31. The Company has operated at a loss since its inception in 2003 and has revenues . The Company anticipates that losses will continue for the foreseeable future. December 31, 2018, the Company’s accumulated deficit was approximately $566.3 million.

Financings

Financings	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Financings	2. Financings On November 11 , 2018 , the Company entered into a securities purchase agreement with certain institutional and accredited investors pursuant to which the Company agreed to issue and sell to the Investors an aggregate of 18 ,939,394 immediately separable units with each Unit being comprised of (i) one share of the Company’s common stock, par value $ 0.001 per share and (ii) a warrant to purchase one share of common stock at a price per unit of $ 2.64 , for net proceeds of approximately $ 47.1 million. On May 11, 2017, the Company sold in an underwritten offering an aggregate of 9,708,738 shares of its common stock to a single investor. The price to the investor in the offering was $5.15 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $ 4.893

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America or U.S. GAAP. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The Company’s most significant estimates and judgments used in the preparation of the financial statements are: • Clinical trial expenses; • Collaboration agreements; • Fair value measurements of stock-based compensation and Series 1 preferred stock (and related dividends); and • Income taxes. Subsequent Events The Company evaluated all events and transactions that occurred after the balance sheet date through the date of this filing. Except as disclosed below, the Company did not have any material subsequent events that impacted its financial statements or disclosures. On December 18, 2018, Ziopharm and TriArm Therapeutics, Ltd. (“TriArm”) announced that the companies plan to launch Eden BioCell, Ltd. (“Eden BioCell”) to lead clinical development and commercialization of Sleeping Beauty For the territory of China, Taiwan and Korea, Ziopharm will license the rights to Eden BioCell for third-generation Sleeping Beauty Sleeping Beauty In February 2019, the Company extended its CRADA with the NCI for the development of adoptive cell transfer, or ACT,-based immunotherapies genetically modified using the Sleeping Beauty Cash and Cash Equivalents Cash equivalents consist primarily of demand deposit accounts and deposits in short-term U.S. treasury money market mutual funds. Cash equivalents are stated at cost, which approximates fair market value. Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company maintains cash accounts in commercial banks, which may, at times, exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents. Property and Equipment Property and equipment are recorded at cost. Expenditures for maintenance and repairs are charged to expense while the costs of significant improvements are capitalized. Depreciation is provided using the straight-line method over the following estimated useful lives of the related assets, which is between three and five years. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheets and related gains or losses are reflected in the statements of operations. Restricted Cash Restricted cash consists of $105 thousand, which is restricted as collateral for a line of credit and is included in other assets. Long-Lived Assets The Company reviews the carrying values of its long-lived assets for possible impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable. Any long-lived assets held for disposal are reported at the lower of their carrying amounts or fair values less costs to sell. Operating Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Company’s Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment and does not track expenses on a program-by-program basis. Warrants The Company assesses whether an equity issued financial instrument is indexed to an entity’s own stock for purposes of determining whether a financial instrument should be treated as a derivative. In applying the methodology, the Company concluded that warrants issued by the Company have terms that meet the criteria to be considered indexed to the Company’s own stock and therefore are classified as equity on the Company’s balance sheet. Fair Value Measurements The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 24,437 $ 24,437 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 66,156 $ 66,156 $ — $ — Derivative liabilities $ (2,424 ) $ — $ — $ (2,424 ) The cash equivalents represent deposits in a short-term United States treasury money market mutual fund quoted in an active market and classified as a Level 1 asset. As discussed further in Notes 6, 8, and 11, the Company issued Intrexon Corporation, or Intrexon, 100,000 shares of the Company’s Series 1 preferred stock, a class of preferred stock authorized by the Company’s board of directors, in consideration of the parties entering into a Third Amendment to Exclusive Channel Partner Agreement, or the 2016 ECP Amendment, amending the existing Exclusive Channel Partner Agreement, effective January 6, 2011 and as amended to date, which the Company refers to as the Channel Agreement, and an Amendment to Exclusive Channel Collaboration Agreement, or the 2016 GvHD Amendment, amending the existing Exclusive Channel Collaboration Agreement, effective September 28, 2015, which the Company refers to as the GvHD Agreement. The Series 1 preferred stock were financial liabilities that consist of a conversion option and a redemption feature and were classified as a Level 3 asset. There were no transfers between asset classes during the year ended December 31, 2018. At June 30, 2016, the Company’s Series 1 preferred stock was valued using a probability-weighted approach and a Monte Carlo simulation model. Additionally, the monthly dividends issued on the outstanding Series 1 preferred stock were valued using the same probability-weighted approach and a Monte Carlo simulation model. However, there is no adjustment or further revaluation after the initial valuation on the Series 1 preferred stock other than required periodic dividends. The Company’s Level 3 financial liabilities consisted of a conversion option and a redemption feature associated with the Company’s Series 1 preferred stock issued to Intrexon that had been bifurcated from the Series 1 preferred stock and were accounted for as derivative liabilities at fair value. The preferred stock derivative liabilities were valued using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and then without derivatives subject to the valuation analysis (“without” scenario). The fair value of the derivatives was then estimated as the difference between the fair value of the preferred stock in the “with” scenario and the preferred stock in the “without” scenario. See Note 8 for additional disclosures on the 2016 ECP Amendment and 2016 GvHD Amendments and Note 11 for additional disclosure on the rights and preferences of the Series 1 preferred stock and valuation methodology. All shares of the Series 1 preferred stock were forfeited by Intrexon on October 5, 2018 in conjunction with the Company’s entry into an Exclusive License Agreement with Precigen, Inc., a wholly owned subsidiary of Intrexon (“Precigen”). Revenue Recognition from Collaboration Agreements The Company adopted Accounting Standards Codification, or ASC Topic 606, Revenue from Contracts with Customers, The Company primarily generates revenue through collaboration arrangements with strategic partners for the development and commercialization of product candidates. Commencing January 1, 2018, the Company recognized revenue in accordance with ASC 606 which replaced ASC 605, Multiple Element Arrangements The Company recognizes collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property, research and development services and options to purchase additional goods and/or services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Contracts that include an option to acquire additional goods and/or services are evaluated to determine if such option provides a material right to the customer that it would not have received without entering into the contract. If so, the option is accounted for as a separate performance obligation. If not, the option is considered a marketing offer which would be accounted for as a separate contract upon the customer’s election. The terms of the Company’s arrangements with customers typically include the payment of one or more of the following: (i) non-refundable, up-front payment, (ii) development, regulatory and commercial milestone payments, (iii) future options and (iv) royalties on net sales of licensed products. Accordingly, the transaction price is generally comprised of a fixed fee due at contract inception and variable consideration in the form of milestone payments due upon the achievement of specified events and tiered royalties earned when customers recognize net sales of licensed products. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes the most likely amount method to estimate the amount of variable consideration, to predict the amount of consideration to which it will be entitled for its one open contract. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. At the inception of each arrangement that includes development and regulatory milestone payments, the Company evaluates whether the associated event is considered probable of achievement and estimates the amount to be included in the transaction price using the most likely amount method. Milestone payments that are not within the control of the Company or the licensee, such as those dependent upon receipt of regulatory approval, are not considered to be probable of achievement until the triggering event occurs. At the end of each reporting period, the Company reevaluates the probability of achievement of each milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, the Company recognizes revenue upon the later of: (i) when the related sales occur or (ii) when the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any development, regulatory or commercial milestones or royalty revenue resulting from any of its collaboration arrangements. Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. However, certain components of variable consideration are allocated specifically to one or more particular performance obligations in a contact to the extent both of the following criteria are met: (i) the terms of the payment relate specifically to the efforts to satisfy the performance obligation or transfer the distinct good or service and (ii) allocating the variable amount of consideration entirely to the performance obligation or the distinct good or service is consistent with the allocation objective of the standard whereby the amount allocated depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services. The Company develops assumptions that require judgment to determine the standalone selling price for each performance obligation identified in each contract. The key assumptions utilized in determining the standalone selling price for each performance obligation may include forecasted revenues, development timelines, estimated research and development costs, discount rates, likelihood of exercise and probabilities of technical and regulatory success. Revenue is recognized based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good and/or service to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. As it relates to the Ares Trading Agreement (Note 6), the Company recognized the upfront payment associated with its one open contract as a contract liability upon receipt of payment as it requires deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts expected to be recognized as revenue within the twelve months following the balance sheet date are classified in current liabilities. Amounts not expected to be recognized as revenue within the twelve months following the balance sheet date are classified as contract liabilities, net of current portion. The Company determined that there were three performance obligations; the first performance obligation consists of the license and research development services and the other two performance obligations are material rights as it relates to potential future targets that have not yet been identified. As described above, the transaction price of $57.5 million was allocated to the performance obligations based on their relative standalone selling prices. There are multiple distinct performance obligations, including material rights; thus, the Company allocates the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Furthermore, the Company has not capitalized any contract costs under the guidance in ASC 340-40, Other Assets and Deferred Costs: Contracts with Customers The Company does not believe that any variable consideration should be included in the transaction price at the date of adoption of ASC 606 on January 1, 2018. Such assessment considered the application of the constraint to ensure that estimates of variable consideration would be included in the transaction price only to the extent the Company had a high degree of confidence that revenue would not be reversed in a subsequent reporting period. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as other changes in circumstances occur. Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front consideration received in July 2015 under ASC 605-25 versus ASC 606. Refer below for a summary of the amount by which each financial statement line item was affected by the impact of the cumulative adjustment: ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Changes in contract liability $ — $ — $ — The most significant change above relates to the Company’s collaboration revenue, which to date has been exclusively generated from its collaboration arrangement with Ares Trading and Precigen, formerly Intrexon (Note 8). Under ASC 605, the Company accounted for the up-front payment over the estimated period of performance of the research and development services which was estimated to be 9 years. In connection with the adoption of ASC 606, the Company uses cost-based input method to measure progress because such method best reflects the satisfaction of the performance obligation. In applying the cost-based input method of revenue recognition, the Company uses actual costs incurred relative to the budgeted costs to complete the research programs. These costs consist primarily of internal full-time equivalent effort and third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs. As a result, although the performance obligations noted above and identified under ASC 606 were generally consistent with the units of account identified under ASC 605, the timing of the allocation of the transaction price to the identified performance obligations under ASC 606 differed from the allocations of consideration under ASC 605. Accordingly, the transaction price ultimately allocated to each performance obligation under ASC 606 differed from the amounts allocated under ASC 605. Additionally, at December 31, 2018, the contract liability is $0 under both methods of revenue recognition (Note 7). Research and Development Costs Research and development expenditures are charged to the statement of operations as incurred. Such costs include proprietary research and development activities, purchased research and development, and expenses associated with research and development contracts, whether performed by the Company or contracted with independent third parties. Income Taxes Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. The Company evaluates this tax position on an annual basis. The Company also accrues for potential interest and penalties, related to unrecognized tax benefits in income tax expense (Note 10). Accounting for Stock-Based Compensation Stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award, and is recognized as expense over the employee’s requisite service period. Stock-based compensation expense is based on the number of awards ultimately expected to vest and is therefore reduced for an estimate of the awards that are expected to be forfeited prior to vesting. Consistent with prior years, the Company uses the Black-Scholes option pricing model which requires estimates of the expected term option holders will retain their options before exercising them and the estimated volatility of the Company’s common stock price over the expected term. The Company recognizes the full impact of its share-based employee payment plans in the statements of operations for each of the years ended December 31, 2018, 2017, and 2016 and did not capitalize any such costs on the balance sheets. The Company recognized $3.0 million, $2.5 million, and $3.0 million of compensation expense related to stock options during the years ended December 31, 2018, 2017, and 2016, respectively. In the years ended December 31, 2018, 2017, and 2016, the Company recognized $4.5 million, $6.0 million, and $5.5 million of compensation expense, respectively, related to restricted stock (Note 13). The total compensation expense relating to vesting of stock options and restricted stock awards for the years ended December 31, 2018, 2017, and 2016 was $7.5 million, $8.5 million, and $8.5 million, respectively. The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2018 2017 2016 Research and development $ 1,683 $ 2,401 $ 2,077 General and administrative 5,851 6,053 6,375 Share based employee compensation expense before tax 7,534 8,454 8,452 Income tax benefit — — — Net share based employee compensation expense $ 7,534 $ 8,454 $ 8,452 The fair value of each stock option is estimated at the date of grant using the Black-Scholes option pricing model. The estimated weighted-average fair value of stock options granted to employees in 2018, 2017, and 2016 was approximately $1.64, $3.94, and $4.43 per share, respectively. Assumptions regarding volatility, expected term, dividend yield and risk-free interest rate are required for the Black-Scholes model. The volatility assumption is based on the Company’s historical experience. The risk-free interest rate is based on a U.S. treasury note with a maturity similar to the option award’s expected life. The expected life represents the average period of time that options granted are expected to be outstanding. The Company calculated expected term using the simplified method described in SEC Staff Accounting Bulletin, or SAB, No. 107 and No. 110 as it continues to meet the requirements promulgated in SAB No. 110. The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below: 2018 2017 2016 Weighted average risk-free interest rate 2.55 - 3.06% 1.85 - 2.27% 1.27 - 2.09% Expected life in years 6 6 6 Expected volatility 80.75 - 84.71% 80.31 - 81.03% 79.15 - 82.95% Expected dividend yield 0 0 0 Net Loss Per Share Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2018 2017 2016 Basic Net loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Settlement of a related party relationship 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Earnings per share, basic $ 0.96 $ (0.53 ) $ (1.32 ) Diluted Net Loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Precigen license transaction 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Effect of dilutive securities Stock options 201,362 — — Unvested restricted common stock 124 — — Warrants — — — Dilutive potential common shares 201,486 — — Shares used in calculating diluted earnings per share 143,710,160 136,938,264 130,391,463 Earnings per share, diluted $ 0.96 $ (0.53 ) $ (1.32 ) Certain shares related to some of the Company’s outstanding common stock options, unvested restricted stock, preferred stock, and warrants have not been included in the computation of diluted net earnings (loss) per share for the years ended December 31, 2018, 2017 and 2016 as the result would be antidilutive. Such potential common shares at December 31, 2018, 2017, and 2016 consist of the following: December 31, 2018 2017 2016 Stock options 5,075,723 4,352,135 3,465,335 Unvested restricted stock 681,946 1,808,559 1,680,492 Preferred stock — 34,134,524 20,465,067 Warrants 18,939,394 — — 24,697,063 40,295,218 25,610,894 During the year ended December 31, 2018, the Company and Precigen, a wholly owned subsidiary Intrexon entered into a License Agreement to replace all existing agreements between the companies that will provide Ziopharm with certain exclusive and non-exclusive rights to technology controlled by Precigen, Inc. The License Agreement was dated October 5, 2018. In consideration of the Company entering into the License Agreement, Intrexon agreed to forfeit and return to the Company all shares of the Company’s Series 1 Preferred Stock held by or payable to Intrexon as of the date of the License Agreement (Note 7). New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations by requiring the recognition of a right-of-use assets and lease liabilities for most lease arrangements on the balance sheet. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The new standard is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The standard permits two transition methods, (1) to apply the new lease requirements at the beginning of the earliest period presented, or (2) to apply the new lease requirements at the effective date. Under both transition methods there is a cumulative effect adjustment. The Company intends to. It also intends to elect the package of practical expedients permitted under the transition guidance within the new standard, which, among other things, allows us to carry forward the historical lease classification. Additionally, the right-of-use asset is subject to an impairment analysis under ASC 360, Property, Plant, and Equipment In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows: Restricted Cash December 31, (in thousands) 2018 2017 2016 Cash and cash equivalents $ 61,729 $ 70,946 $ 81,053 Restricted cash included in prepaid expenses and other current assets — 388 — Restricted cash included in other non-current assets — — 388 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 61,729 $ 71,334 $ 81,441 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation Scope of Modification Accounting In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting In August 2018, the FASB issued ASU No. 2018-03, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment, net	4. Property and Equipment, net Property and equipment, net, consists of the following: December 31, (in thousands) 2018 2017 Office and computer equipment $ 1,249 $ 1,215 Software 1,030 913 Leasehold improvements 1,839 1,553 Research and development equipment 1,182 1,161 5,300 4,842 Less: accumulated depreciation (4,203 ) (3,631 ) Property and equipment, net $ 1,097 $ 1,211 Depreciation charged to the statement of operations for the years ended December 31, 2018, 2017, and 2016 was $573 thousand, $369 thousand and $290 thousand, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of the following: December 31, (in thousands) 2018 2017 Clinical consulting services $ 3,003 $ 3,022 Employee compensation 1,786 1,919 Preclinical services 1,247 2,210 Manufacturing services 1,164 902 Professional services 745 256 Accrued vacation 363 361 Payroll taxes and benefits 349 1,017 Other consulting services 106 222 Total $ 8,763 $ 9,909

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	6. Related Party Transactions Collaborations with Intrexon/ Precigen During the year ended December 31, 2018, the Company and Precigen entered into an Exclusive License Agreement (Note 7). During the year ended December 31, 2018, the Company issued an aggregate of 11,415 shares of Series 1 preferred stock to Intrexon, the holder of all of the outstanding shares of the Company’s Series 1 preferred stock, as monthly dividend payments. The Company recorded such shares of Series 1 preferred stock at a fair value of $18.9 million, which is a component of temporary equity and recorded a loss on the change of the derivative liabilities in the amount of $1.3 million. See Notes 3 and 12 for additional discussion regarding the accounting for and valuation of these derivative financial instruments. During the years ended December 31, 2018, 2017, and 2016, the Company expensed $8.1 million, $21.4 million, and $22.2 million, respectively, for services performed by Intrexon. As of December 31, 2018, and 2017, the Company recorded $1.9 million and $6.8 million, respectively, in current liabilities on its balance sheet for amounts due to Intrexon. Collaboration with Precigen and MD Anderson On January 13, 2015, the company, together with Intrexon, entered into the MD Anderson License . Pursuant to the MD Anderson License, the company, together with Precigen, hold an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell therapies, arising from the laboratory of Laurence Cooper, M.D., Ph.D., who became the Company’s Chief Executive Officer in May 2015 and was formerly a tenured professor of pediatrics at MD Anderson and is now currently a visiting scientist under that institution’s policies. In partial consideration for entering into the MD Anderson License, the Company issued MD Anderson an aggregate of 11,722,163 shares of common stock for which the Company incurred a $67.3 million charge recorded in 2015. The Company has determined that the rights acquired in the MD Anderson License represent in-process research and development with no alternative future use. During the year ending December 31, 2018, the Company made one quarterly payments totaling $2.7 million, bringing the total aggregate payments to $41.9 million under this arrangement. The net balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $27.8 million, of which $18.4 million is included in other current assets and the remaining $9.4 million is included in non-current assets at December 31, 2018. The classification is based on management’s current estimate of plans to utilize the prepaid balance and is subject to revision on a quarterly basis.

Settlement of a Related Party R

Settlement of a Related Party Relationship	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Settlement of relatedparty relationship	7. Settlement of a Related Party Relationship Exclusive License Agreement with Precigen On October 5 , 2018 , the Company entered into the license agreement with . As between the Company and , the terms of the License Agreement replace the terms of: (a) the Channel Agreement, including all amendments to the Channel ; (b) certain rights and obligations pursuant to the Ares Trading Agreement; (c) the MD Anderson License ; and (d) that certain Research and Development Agreement between the Company, and MD Anderson with an effective date of August 17 , 2015 (the Research and Development Agreement , and any amendments or statements of work thereto. Pursuant to the terms of the License Agreement, Precigen has granted the Company an exclusive, worldwide, royalty-bearing, sub-licensable license to research, develop and commercialize (i) products utilizing Precigen’s RheoSwitch ® Sleeping Beauty The Company is solely responsible for all aspects of the research, development and commercialization of the exclusively licensed products for the treatment of cancer. The Company is required to use commercially reasonable efforts to develop and commercialize IL-12 Products and CD19 Products and after a two-year period, the TCR Products. Precigen has also granted the Company an exclusive, worldwide, royalty-bearing, sub-licensable license to research, develop and commercialize products utilizing an additional construct that expresses RTS IL-12 for the treatment of cancer, referred to as Gorilla IL-12 Products. Ziopharm agreed to reimburse Precigen for certain historical costs of the licensed programs up to $1.0 million, payable quarterly. The Company determined that the fair value of this program was $1.0 million and this was expensed in accordance with ASC 730, Research and Development during the year ended December 31, 2018 and it has been included in accrued expense on the balance sheet. The agreement also calls for an annual license fee of $100 thousand as long as the agreement is effective. The Company will also make milestone payments totaling up to an additional $52.5 million for each exclusively licensed program upon the initiation of later stage clinical trials and upon the approval of exclusively licensed products in various jurisdictions. In addition, the Company will pay Precigen tiered royalties ranging from low-single digit to high-single digit on the net sales derived from the sales of any approved IL-12 Products and CAR Products. The Company will also pay Precigen royalties ranging from low-single digit to mid-single digit on the net sales derived from the sales of any approved TCR Products, up to a maximum royalty amount of $100.0 million in the aggregate. The Company will also pay Precigen 20% of any sublicensing income received by the Company relating to the licensed products. The Company is responsible for all development costs associated with each of the licensed products, other than Gorilla IL-12 Products. The Company and Precigen will share the development costs and operating profits for Gorilla IL-12 Products, with the Company responsible for 80% of the development costs and receiving 80% of the operating profits, and Precigen responsible for the remaining 20% of the development costs and receiving 20% of the operating profits. Precigen will pay the Company royalties ranging from low-single digits to mid-single digits on the net sales derived from the sale of Precigen’s CAR products, up to $50.0 million. In consideration of the Company entering into the License Agreement, Intrexon forfeited and returned to the Company all shares of the Company’s Series 1 preferred stock held by or payable to Intrexon as of the date of the License Agreement. In addition, Precigen is required to transfer all of Ziopharm’s rights and obligations under the Ares Trading Agreement to Intrexon (or its’ affiliate). As a result, Ziopharm shall not be responsible for any remaining obligations under the Merck Agreement. Additionally, Intrexon forfeited and returned to the Company all shares of the Company’s Series 1 preferred stock held by or payable to Intrexon as of the date of the License Agreement. The Company determined that this transaction represented a capital transaction between related parties. The Company fair valued the preferred stock and the derivative liability on the date of the transaction, noting a total fair value of $163.3 million. The relinquishment of the Ziopharm’s obligation under the Ares Trading Agreement was also considered part of the overall capital transaction. The Company recognized an additional credit to accumulated deficit of $49.5 million as a result of the relief of the obligation under the Ares Trading Agreement (Note 8). The total amount of the settlement was $212.8 million. The Company incurred approximately $7.4 million of transaction advisory costs with third-party vendors, of which $5.4 million was considered a direct cost associated with the Series 1 preferred stock extinguishment and is also included as part of the consideration transferred. The remaining $2.0 million of transaction costs were recognized as an expense during the year ended December 31, 2018. The Company recognized a net credit to accumulated deficit of $207.3 million, calculated as the difference in the carrying value of the Series 1 preferred stock, derivative liability, and contract liability, and the consideration transferred of $5.4 million, in connection with the transaction. This amount is included in net income available to common shareholders in the calculation of earnings per share (Note 3).

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Operating Leases Prior to December 31, 2012, the Company entered into an operating lease in New York, NY for office space. In accordance with this agreement, the Company entered into a letter of credit in the amount of $388 thousand, naming the Company’s landlord as beneficiary. In January 2012, the Company amended the lease agreement, adding additional office space. The collateral for the letter of credit was recorded in other current assets on the balance sheet as of December 31, 2017. The lease for office space in New York, NY expired in October 2018. On October 17, 2013, the Company entered into a sublease agreement to lease all of its New York office space to a subtenant. The Company recorded a loss on the sublease in the amount of $729 thousand for the year ended December 31, 2013, representing the remaining contractual obligation of $2.3 million, less $1.6 million in payments from its subtenant. The sublease agreement for the New York office space expired in October 2018 in conjunction with the Company’s lease expiring for the New York office space. In June 2012, the Company Company’s Boston office, which was originally set to expire in August 2016. On December 21, 2015 and April 15, 2016, the Company renewed the sublease for the Company’s corporate headquarters in Boston, MA through August 31, 2021. As of December 31, 2018 and 2017, a total security deposit of $128 thousand is included in deposits on the balance sheet. On January 30, 2018, the Company entered into a lease agreement for office space in Houston, TX at MD Anderson. Under the terms of the Houston lease agreement, approximately two hundred and ten square feet and are required to make rental payments at an average monthly rate of approximately $1 thousand through April 2021. All future rent expense incurred in Houston, will be deducted from at MD Anderson described in the license agreement section below. Future net minimum lease payments under operating leases as of December 31, 2018 are as follows (in thousands): 2019 723 2020 736 2021 488 Future minimum lease payments, net $ 1,947 Total rent expense was approximately $0.7 million, $0.7 million, and $0.3 million for the years ended December 31, 2018, 2017, and 2016, respectively. The Company records rent expense on a straight-line basis over the term of the lease. Accordingly, the Company has recorded a liability for deferred rent at December 31, 2018 and 2017 of $17 thousand ($13 thousand current and $4 thousand long-term) and $142 thousand ($141 thousand current and $1 thousand long-term) respectively, which is License Agreements Exclusive License Agreement with Precigen, Inc. On October 5, 2018, the Company entered into an exclusive license agreement, or the License Agreement, with Precigen, Inc., or Precigen, a wholly owned subsidiary of Intrexon Corporation, or Intrexon. As between the Company and Precigen, the terms of the License Agreement replace and supersede the terms of: (a) that certain Exclusive Channel Partner Agreement by and between the Company and Intrexon, dated January 6, 2011, as amended by the First Amendment to Exclusive Channel Partner Agreement effective September 13, 2011, the Second Amendment to the Exclusive Channel Partner Agreement effective March 27, 2015, and the Third Amendment to Exclusive Channel Partner Agreement effective June 29, 2016, which was subsequently assigned by Intrexon to Precigen; (b) certain rights and obligations pursuant to that certain License and Collaboration Agreement effective March 27, 2015 between ZIOPHARM, Intrexon and ARES TRADING Trading S.A., or Ares Trading, a subsidiary of Merck KGaA, or Merck, as assigned by Intrexon to Precigen, or the Ares Trading Agreement; (c) that certain License Agreement between the Company, Intrexon, and MD Anderson, with an effective date of January 13, 2015, or the MD Anderson License, which was subsequently assigned by Intrexon and assumed by Precigen effective as of January 1, 2018; and (d) that certain Research and Development Agreement between the Company, Intrexon and MD Anderson with an effective date of August 17, 2015, or the Research and Development Agreement, and any amendments or statements of work thereto. Pursuant to the terms of the License Agreement, Precigen has granted the Company an exclusive, worldwide, royalty-bearing, sub-licensable license to research, develop and commercialize (i) products utilizing Precigen’s RheoSwitch ® Sleeping Beauty The Company will be solely responsible for all aspects of the research, development and commercialization of the exclusively licensed products for the treatment of cancer. The Company are required to use commercially reasonable efforts to develop and commercialize IL-12 products and CD19 products and after a two-year period, the TCR Products. Precigen has also granted the Company an exclusive, worldwide, royalty-bearing, sub-licensable license to research, develop and commercialize products utilizing an additional construct that expresses RTS IL-12 for the treatment of cancer, referred to as Gorilla IL-12 Products. In consideration of the licenses and other rights granted by Precigen, the Company will pay Precigen an annual license fee of $100 thousand and has agreed to reimburse Precigen for certain historical costs of the licensed programs up to $1.0 million, payable quarterly. The Company will make milestone payments totaling up to an additional $52.5 million for each exclusively licensed program upon the initiation of later stage clinical trials and upon the approval of exclusively licensed products in various jurisdictions. In addition, the Company will pay Precigen tiered royalties ranging from low-single digit to high-single digit on the net sales derived from the sales of any approved IL-12 products and CAR products. The Company will also pay Precigen royalties ranging from low-single digit to mid-single digit on the net sales derived from the sales of any approved TCR products, up to a maximum royalty amount of $100.0 million in the aggregate. The Company will also pay Precigen 20% of any sublicensing income received by the Company relating to the licensed products. The Company is responsible for all development costs associated with each of the licensed products, other than Gorilla IL-12 products. ZIOPHARM and Precigen will share the development costs and operating profits for Gorilla IL-12 products, and ZIOPHARM is responsible for 80% of the development costs and receiving 80% of the operating profits, and Precigen responsible for the remaining 20% of the development costs and receiving 20% of the operating profits. Precigen will pay the Company royalties ranging from low-single digits to mid-single digits on the net sales derived from the sale of Precigen’s CAR products, up to $50.0 million. In consideration of entering into the License Agreement, Intrexon has forfeited and returned to the Company all shares of Series 1 preferred stock held by or payable to Intrexon as of the date of the License Agreement (Note 7). License Agreement—The University of Texas MD Anderson Cancer Center On January 13, 2015, , together with Intrexon, entered into the MD Anderson License with MD Anderson Pursuant to the MD Anderson License, the Company, together with Precigen, holds an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell therapies, non-viral gene transfer systems, genetic modification and/or propagation of immune cells and other cellular therapy approaches, Natural Killer, or NK Cells, and TCRs, arising from the laboratory of Laurence Cooper, M.D., Ph.D., who became the Company’s Chief Executive Officer in May 2015 and was formerly a tenured professor of pediatrics at MD Anderson and is now currently a visiting scientist under that institution’s policies. On August 17, 2015, Precigen and MD Anderson entered into the Research and Development Agreement, to formalize the scope and process for the transfer by MD Anderson, pursuant to the terms of the MD Anderson License, of certain existing research programs and related technology rights, as well as the terms and conditions for future collaborative research and development of new and ongoing research programs. Pursuant to the Research and Development Agreement, Precigen and MD Anderson have agreed to form a joint steering committee that will oversee and manage the new and ongoing research programs. Under the License Agreement with Precigen, ZIOPHARM and Precigen agreed that Precigen would no longer participate on the joint steering committee after the date of the License Agreement. As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the Research and Development Agreement for a period of three years and in an amount of no less than $15.0 million and no greater than $20.0 million per year. During the year ended December 31, 2018, the Company made payments in the aggregate amount of $2.7 million to MD Anderson compared to $13.0 million during the year ended December 31, 2017. The decrease in cash paid to MD Anderson during is a result of approved expenditures incurred by us being deducted from the January 2018 quarterly payment. The net balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $27.8 million, of which $18.4 million is included in other current assets and the remaining $9.4 million is included in non-current assets at December 31, 2018. The term of the MD Anderson License expires on the last to occur of (a) the expiration of all patents licensed thereunder, or (b) the twentieth anniversary of the date of the MD Anderson License; provided, however, that following the expiration of the term of the MD Anderson License, the Company, together with Precigen, shall then have a fully-paid up, royalty free, perpetual, irrevocable and sublicensable license to use the licensed intellectual property thereunder. After ten years from the date of the MD Anderson License and subject to a 90-day cure period, MD Anderson will have the right to convert the MD Anderson License into a non-exclusive license if and Precigen are not using commercially reasonable efforts to commercialize the licensed intellectual property on a case-by-case basis. After five years from the date of the MD Anderson License and subject to a 180-day cure period, MD Anderson will have the right to terminate the MD Anderson License with respect to specific technology(ies) funded by the government or subject to a third-party contract if the Company and Precigen are not meeting the diligence requirements in such funding agreement or contract, as applicable. MD Anderson may also terminate the agreement with written notice upon material breach by us and Precigen, if such breach has not been cured within 60 days of receiving such notice. In addition, the MD Anderson License will terminate upon the occurrence of certain insolvency events for both us and Precigen and may be terminated by the mutual written agreement of us, Precigen, and MD Anderson. Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute On January 10, 2017, the Company announced the signing of the CRADA with the NCI for the development of adoptive cell transfer, or ACT,-based immunotherapies genetically modified using the Sleeping Beauty Sleeping Beauty Exclusive Channel Partner Agreement with Precigen for the Cancer Programs From 2011 to 2018, the Company was party to various arrangements with Intrexon (now Precigen) in which the Company used Precigen’s technology to research and develop cancer treatments in return for various future profit sharing and royalty arrangements. These agreements were modified or terminated by the License Agreement described in Note 7. Exclusive Channel Collaboration Agreement with Precigen for GvHD On September 28, 2015, the Company entered into the GvHD Agreement with Intrexon (now Precigen), under which the Company would use Precigen’s technology directed towards in vivo In November 2017, the Company determined that the pursuit of GvHD as an indication was not a material part of its corporate strategy and therefore stopped pursuing the development of engineered cell therapy strategies, used either separately or in combination, for targeted treatment of GvHD. At such time, the Company reverted the rights under the GvHD program back to Precigen. Ares Trading License and Collaboration Agreement On March 27, 2015, the Company, together with Intrexon (now Precigen), signed the Ares Trading Agreement, with Ares Trading S.A., a subsidiary of the biopharmaceutical business of Merck KGaA, Darmstadt, Germany, through which the parties established a collaboration for the research and development and commercialization of certain products for the prophylactic, therapeutic, palliative or diagnostic use for cancer in humans. Precigen was entitled to receive $5.0 million, from Ares Trading, payable in equal quarterly installments over two years for each identified product candidate, which will be used to fund discovery work. The Company was responsible for costs exceeding the quarterly installments and all other costs of the preclinical research and development. For the year ended December 31, 2018, the Company expensed $0.1 Ares Trading paid a non-refundable upfront fee of $115.0 million to Intrexon as consideration for entry into the Ares Trading Agreement. Pursuant to the ECP Amendment, the Company was entitled to receive 50% of the upfront fee, or $57.5 million, which was received from Intrexon in July 2015. Under the License Agreement, Precigen agreed to perform all future obligations of the Company under the Ares Trading Agreement other than certain payment obligations. Accordingly, the Company recognized the remaining deferred revenue as part of the settlement of related party relationships as described in Note 7. Patent and Technology License Agreement—The University of Texas MD Anderson Cancer Center and the Texas A&M University System On August 24, 2004, the Company entered into a patent and technology license agreement with MD Anderson and the Texas A&M University System, which the Company refers to, collectively, as the Licensors. Under this agreement, were granted an exclusive, worldwide license to rights (including rights to U.S. and foreign patent and patent applications and related improvements and know-how) for the manufacture and commercialization of two classes of organic arsenicals (water- and lipid-based) for human and animal use. The class of water-based organic arsenicals includes darinaparsin. The Company issued options to purchase 50,222 shares outside of its stock option plans following the successful completion of certain clinical milestones, of which 37,666 shares have vested. The remaining 12,556 shares vested upon enrollment of the first patient in a multi-center pivotal clinical trial i.e. a human clinical trial intended to provide the substantial evidence of efficacy necessary to support the filing of an approvable New Drug Application, or NDA. An expense of $87 thousand was charged to research and development expense for the vesting event which occurred in March 2016. This trial was initiated by Solasia Pharma K.K., or Solasia, on March 28, 2016 and triggered a $1.0 million milestone payment to the Company from Solasia which was received in May 2016. An equivalent of $1.0 million milestone payment was subsequently made to MD Anderson and reported net. In addition, the Licensors are entitled to receive certain milestone payments. In addition, the Company may be required to make additional payments to the Licensors (as defined in the MD Anderson License) upon achievement of certain other milestones in varying amounts which, on a cumulative basis could total up to an additional $4.5 million. In addition, the Licensors are entitled to receive single digit percentage royalty payments on sales from a licensed product and will also be entitled to receive a portion of any fees that the Company may receive from a possible sublicense under certain circumstances. Collaboration Agreement with Solasia Pharma K.K. On March 7, 2011, the Company entered into a License and Collaboration Agreement with Solasia. Pursuant to the License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both intravenous and oral forms and related organic arsenic molecules, in all indications for human use in a pan-Asian/Pacific territory comprising Japan, China, Hong Kong, Macau, Republic of Korea, Taiwan, Singapore, Australia, New Zealand, Malaysia, Indonesia, Philippines and Thailand. As consideration for the license, the Company received an upfront payment of $5.0 million to be used exclusively for further clinical development of darinaparsin outside of the pan-Asian/Pacific territory and will be entitled to receive additional payments of up to $32.5 million in development-based milestones and up to $53.5 million in sales-based milestones. The Company will also be entitled to receive double digit royalty payments from Solasia based upon net sales of licensed products in the applicable territories, once commercialized, and a percentage of sublicense revenues generated by Solasia. The $5.0 million upfront payment received in March 2011 was amortized over the period of the research and development effort, which was completed in March 2016. On July 31, 2014, the Company entered into an amendment and restatement of the License and Collaboration Agreement granting Solasia an exclusive worldwide license to develop and commercialize darinaparsin, and related organoarsenic molecules, in both intravenous and oral forms in all indications for human use. In exchange, the Company will be eligible to receive from Solasia development- and sales-based milestones, a royalty on net sales of darinaparsin, once commercialized, and a percentage of any sublicense revenues generated by Solasia. Solasia will be responsible for all costs related to the development, manufacturing and commercialization of darinaparsin. The Company’s Licensors, as defined in the agreement, will receive a portion of all milestone and royalty payments made by Solasia to the Company in accordance with the terms of the license agreement with the Licensors. On March 28, 2016, Solasia initiated a multi-center pivotal clinical trial intended to provide substantial evidence of efficacy necessary to support the filing of an application for an NDA for darinaparsin in certain of the territories assigned to Solasia. The initiation of the trial on March 28, 2016 triggered a $1.0 million milestone payment from Solasia to the Company which was received in May 2016. The Company subsequently made an equivalent payment to MD Anderson as the ultimate licensor of darinaparsin (see above). License Agreement with Baxter Healthcare S.A. On November 3, 2006, the Company entered into a definitive Asset Purchase Agreement for indibulin and a License Agreement to proprietary nanosuspension technology with affiliates of Baxter Healthcare S.A. The purchase included the entire indibulin intellectual property portfolio as well as existing drug substance and capsule inventories. The terms of the Asset Purchase Agreement included an upfront cash payment and an additional payment for existing inventory. During the year ended December 31, 2017, the Company made the final payment of $250 thousand under the asset agreement. The Company is not actively pursuing the development of indibulin.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2018
Warrants Disclosure [Abstract]
Warrant	9. Warrants The Company assesses whether an equity classified financial instrument is indexed to an entity’s own stock for purposes of determining whether a financial instrument should be treated as a derivative. In connection with the November 2018 the Company issued warrants to purchase an aggregate of 18,939,394 shares of common stock which are exercisable six months after the closing. The warrants have an exercise price of $3.01 per share and have a five-year term. The relative fair value of the warrants was estimated at $18.4 million using a Black-Scholes model with the following assumptions: expected volatility of 71%, risk free interest rate of 2.99%, expected life of five years and no dividends. The Company assessed whether the warrants require accounting as derivatives. The Company determined that the warrants were indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with Topic 815, Derivatives and Hedging equity.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes There is no provision for income taxes because the Company has incurred operating losses since inception. The reported amount of income tax expense for the years differs from the amount that would result from applying domestic federal statutory tax rates to pretax losses primarily because of the changes in the valuation allowance. Significant components of the Company’s deferred tax assets at December 31, 2018 and 2017 are as follows: December 31, (in thousands) 2018 2017 Net operating loss carryforwards $ 106,430 $ 89,098 Start-up and organizational costs 33,977 37,488 Research and development credit carryforwards 33,684 32,395 Stock compensation 990 1,330 Capitalized acquisition costs 5,160 5,822 Deferred revenue — 11,126 Depreciation 132 136 Other 920 993 181,293 178,388 Less valuation allowance (181,293 ) (178,388 ) Effective tax rate $ — $ — Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. At December 31, 2018, the Company has aggregate net operating loss carryforwards for federal tax purposes of approximately $403.0 million and $344.0 million for Federal and state purposes, respectively, available to offset future federal and state taxable income to the extent permitted under the Internal Revenue Code, or IRC, expiring in varying amounts through 2038. Additionally, the Company has approximately $34.0 million of research and development credits at December 31, 2018, expiring in varying amounts through 2038, which may be available to reduce future taxes. In March 2016, the FASB issued ASU No. 2016-09, “Improvements to Employee Share-Based Payment Accounting” (ASU 2016-09), which is intended to simplify several aspects of accounting for share-based payment transactions, including the income tax effects, statutory withholding requirements, forfeitures, and classification on the statement of cash flows. ASU 2016-09 is effective for annual reporting periods after December 15, 2016, including interim reporting periods within each annual reporting period. The Company adopted this standard on January 1, 2017. The update revises requirements in the following areas: minimum statutory withholding, accounting for income taxes, and forfeitures. Prior to adoption, the Company recognized share-based compensation, net of estimated forfeitures, over the vesting period of the grant. Upon adoption of ASU 2016-09, the Company elected to change its accounting policy to recognize forfeitures as they occur. The new forfeiture policy election was adopted using a modified retrospective approach with a cumulative effect adjustment of $122 thousand recorded to retained earnings as of January 1, 2017. The update requires the Company to recognize the income tax effect of awards in the income statement when the awards vest or are settled without triggering a liability. The income tax related items had no effect on the current period presentation and the Company maintains a full valuation allowance against its deferred tax assets. As a result, an accumulated excess tax benefit of 10.2 million was recognized as a deferred tax asset with a full valuation allowance against it. Additionally, the Company continued to estimate the number of awards expected to be vested. The adoption had no material impact on the financial statements for the 2017 tax year or the interim periods within. In May 2014, the FASB issued an accounting standard update which provides for new revenue recognition guidance, superseding nearly all prior revenue recognition guidance. The new revenue standard outlines a single comprehensive model for accounting for revenue from contracts with customers and requires more detailed revenue disclosures. The Company adopted the new revenue standard on January 1, 2018 and as a result of the adoption increased deferred revenue by $8.1 million and decreased retained earnings by the same amount. Previously the Company had recorded revenue of $15.9 million and had deferred revenue of $41.5 million at December 31, 2017. The increase in the deferred revenue represented the recapture of revenue that was previously recorded and taxed. There was no impact to tax as the increase to the deferred tax asset was fully offset by the Company’s full valuation allowance. Under the IRC Section , certain substantial changes in the Company’s ownership may limit the amount of net operating loss that can be utilized in any one year to offset future taxable income. Section 382 of the IRC provides limits to which a corporation that has undergone a change in ownership (as defined) can utilize any net operating loss, or NOL, and general business tax credit carryforwards it may have. The Company commissioned an analysis to determine whether Section 382 could limit the use of its carryforwards in this manner. After completing the analysis, it was determined an ownership change had occurred in February 2007. As a result of this change, the Company’s NOL’s and general business tax credits from February 23, 2007 and prior would be completely limited under IRC Section 382. The deferred tax assets related to NOL’s and general business credits have been reduced by $11.2 million and $636 thousand, respectively, as a result of the change. The Company updated the IRC Section 382 analysis through December 31, 2018. There was no change in ownership at this time. The Company has provided a valuation allowance for the full amount of these net deferred 2018 Income taxes using the federal statutory income tax rate differ from the Company’s effective tax rate primarily due to non-deductible expenses related to the Company’s issuance of preferred stock along with the change in the valuation allowance on deferred tax assets. A reconciliation of income tax expense (benefit) at the statutory federal income tax rate and income taxes as reflected in the financial statements is as follows: Year Ended December 31, (in thousands) 2018 2017 2016 Federal income tax at statutory rates 21 % 34 % 34 % State income tax, net of federal tax benefit 4 % 4 % 1 % Research and development credits 2 % 3 % 3 % Stock compensation -1 % -1 % -1 % Channel rights 0 % 0 % -25 % Research and development true-up 0 % -7 % 0 % Officers compensation -1 % -2 % 0 % Other -2 % -3 % 0 % Federal rate change 3 % -124 % 0 % Change in valuation allowance -26 % 96 % -12 % Effective tax rate 0 % 0 % 0 % The Company adopted ASC740, “Accounting for Uncertain Tax Positions” on January 1, 2007. clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements in accordance with FASB Statement No. 109, “Accounting for Income Taxes.” ASC 740 prescribes a recognition threshold and measurement of a tax position taken or expected to be taken in a tax return. The Company did not establish any additional reserves for uncertain tax liabilities upon adoption of ASC 740. adjustments to its uncertain tax positions in the years ended December 31, 2018, 2017, and 2016. The Company has not recognized any interest and penalties in the statement of operations because of the Company’s net operating losses and tax credits that are available to be carried forward. When necessary, the Company will account for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. The Company does not expect the amounts of unrecognized benefits will change significantly within the next twelve months. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service and state jurisdictions for the years ended December 31, 1999 through 2018. The Tax Cuts and Jobs Act, or the “Tax Act,” was enacted in December 2017. The act significantly changes US tax law by, among other things, lowering US corporate income tax rates, implementing a territorial tax system, and imposing a one-time transition tax on deemed repatriated earnings of foreign subsidiaries. The Tax Act reduces the US corporate income tax rate from 35% to 21%, effective January 1, 2018. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. As a result of the reduction in the US corporate tax rate from 35% to 21% under the Tax Act, the Company revalued its ending net deferred tax assets at December 31, 2017. There was no impact as a result of the revaluation of the deferred tax assets as the calculated provisional tax benefit of approximately $67.0 million was offset by the Company’s subsequent change in valuation allowance.

Preferred Stock and Stockholder

Preferred Stock and Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Preferred Stock and Stockholders' Equity (Deficit)	11. Preferred Stock and Stockholders’ Equity (Deficit) On April 26, 2006, the date of the Company’s annual stockholders meeting that year, the shareholders approved the adoption of an Amended and Restated Certificate of Incorporation pursuant to which the Company has 280,000,000 shares of authorized capital stock, of which 250,000,000 shares are designated as common stock (par value $ 0.001 Common Stock On November 11, 2018, the Company entered into a securities purchase agreement with certain institutional and accredited investors, pursuant to which the Company agreed to issue and sell to the Investors an aggregate of 18,939,394 immediately separable units, with each unit being composed of (i) one share of the Company’s common stock, par value $0.001 per share, and (ii) a warrant to purchase one share of common stock, at a price per unit of $2.64, for net proceeds of approximately $47.1 million. On May 11, 2017, the Company sold in an underwritten offering an aggregate of 9,708,738 shares of its common stock. The price to the investor in the offering was $5.15 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the Company’s registration statement on Form S-3ASR (File No. 333-201826) previously filed with the SEC, and a prospectus supplement thereunder. The net proceeds from the offering were approximately $47.3 million after deducting underwriting commissions and estimated offering expenses payable by the Preferred Stock The Company’s Board of Directors are authorized to designate any series of Preferred Stock, to fix and determine the variations in relative rights, preferences, privileges and restrictions as between and among such series. On June 29, 2016, the Company entered into the 2016 ECP Amendment and 2016 GvHD Amendment with Intrexon (now Precigen) (Note 8). In consideration for the execution and delivery of the 2016 ECP Amendment and the 2016 GvHD Amendment, the Company issued to Intrexon 100,000 shares of its newly designated Series 1 preferred stock. Each share of the Company’s Series 1 preferred stock had a stated value of $ 1,200 During the year ended December 31, 2018, the Company and Precigen entered into the License Agreement to replace all existing agreements between the companies that will provide Ziopharm with certain exclusive and non-exclusive rights to technology controlled by Precigen. The License Agreement was dated October 5, 2018. In consideration of the Company entering into the License Agreement, Intrexon forfeited and returned to the Company all shares of the Company’s Series 1 preferred stock held by or payable to Intrexon as of the date of the License Agreement. (Notes 6 and 7)

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	12. Derivative Financial Instruments The Company determined that certain embedded features related to the Series 1 preferred stock were derivative financial instruments. The company values the embedded derivative financial instruments related to the Series 1 preferred stock as Level 3 financial liabilities (Note 3). On October 5, 2018, 1 preferred stock held by Intrexon, including any accrued dividends. The change in the derivative liability for the years ended December 31, 2018, 2017 and 2016 consists of the following: Fair Value Balance, $ 694 Dividends 44 Change in fair value 124 Balance, $ 862 Dividends 267 Change in fair value 1,295 Balance, $ 2,424 Dividends 223 Change in fair value (158 ) Settlement of a related party relationship (2,489 ) Balance, December 31, 2018 $ — The fair value of the Series 1 preferred stock dividends was estimated using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and then without derivatives subject to the valuation analysis (“without” scenario). The fair value of the derivatives was then estimated as the difference between the fair value of the preferred stock in the “with” scenario and the preferred stock in the “without” scenario. The model also takes into account, management estimates of clinical success/failure based upon market studies and probability of potential conversion and liquidation events. If these estimates were different, the valuations would change, and that change could be material. Inputs to the models included the following: December 31 , 2018 2017 Risk-free interest rate 2.50 - 3.13 % 1.92 - 2.12 % Expected dividend rate 0 0 Expected volatility 77.6 - 82.4 % 68.7 - 80.4 % Preferred stock conversion limit percentage of outstanding common stock 19.90 % 19.90 % Preferred conversion floor price $ 1.00 $ 1.00 See Note 3 for additional discussion regarding the accounting for and valuation of these derivative financial instruments.

Stock Option Plan

Stock Option Plan	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Stock Option Plan	13. Stock Option Plan The Company adopted the 2012 Equity Incentive Plan, or the 2012 Plan, in May 2012. As of December 31, 2018, the Company had outstanding options to its employees to purchase up to 4,146,135 shares of the Company’s common stock, to its directors to purchase up to 1,120,950 shares of the Company’s common stock, as well as options to consultants in connection with services rendered to purchase up to 10,000 shares of the Company’s common stock. Stock options to employees generally vest ratably in annual installments over three years, commencing on the first anniversary of the grant date and have contractual terms of ten years. Stock options to directors generally vest ratably over one or three years and have contractual terms of ten years. Stock options are valued using the Black-Scholes option pricing model and compensation is recognized based on such fair value over the period of vesting on a straight-line basis. The Company has also reserved an aggregate of 526,364 additional shares for issuance under options granted outside of the 2003 and 2012 Plans. Proceeds from the option exercises during the years ended December 31, 2018, 2017, and 2016 amounted to $0.2 million, $0.1 million and $0.7 million respectively. The intrinsic value of these options amounted to $0.1 million, $0.2 million and $0.8 million for years ended December 31, 2018, 2017 and 2016, respectively. Transactions under the 2012 Plan for the years ending December 31, 2018, 2017, and 2016 were as follows: (in thousands, except share and per share data) Number of Shares Weighted- Average Exercise Price Weighted- Average Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2015 3,481,468 $ 4.96 Granted 362,800 6.40 Exercised (234,833 ) 4.57 Cancelled (144,100 ) 6.43 Outstanding, December 31, 2016 3,465,335 5.07 Granted 688,800 5.27 Exercised (180,000 ) 3.67 Cancelled (122,000 ) 6.64 Outstanding, December 31, 2017 3,852,135 5.12 Granted 1,744,950 2.35 Exercised (104,167 ) 2.30 Cancelled (215,833 ) 5.72 Outstanding, December 31, 2018 5,277,085 $ 4.24 6.86 $ 88 Options exercisable, December 31, 2018 3,099,935 $ 5.15 4.93 $ 88 Options exercisable, December 31, 2017 2,925,502 $ 5.12 5.58 $ 1,152 Options available for future grant at December 31, 2018 3,895,923 In September 2017, the Company granted an option for 500,000 shares of its common stock, with an exercise price of $6.16 per share, which vests ratably in annual installments over three years, commencing on the first anniversary of the grant date and has a contractual term of ten years. This option was granted outside of the 2012 plan and therefore, is not included in the table above. The grant date fair value was $2.2 million. As of December 31, 2018, all 500,000 options are outstanding. At December 31, 2018, total unrecognized compensation costs related to non-vested stock options outstanding amounted to $5.1 million. The cost is expected to be recognized over a weighted-average period of 1.53 years. Restricted Stock In December 2018, the Company issued 30,000 shares of restricted stock to its employees, which vest ratably in annual installments over three years, commencing on the first anniversary of the grant date. In December 2017, the Company issued 838,000 shares of restricted stock to its employees, which vest ratably in annual installments over three years, commencing on the first anniversary of the grant date. In December 2016, the Company issued 625,750 shares of restricted stock to its employees, which vest ratably in annual installments over three years, commencing on the first anniversary of the grant date. In December 2018, the Company issued 120,321 shares of restricted stock to its non-employee directors, which vest in their entirety on the one-year anniversary of the grant date. In December 2017, the Company issued 69,032 shares of restricted stock to its non-employee directors, which vest in their entirety on the one-year anniversary of the grant date. In December 2016, the Company issued 86,020 shares of restricted stock to its non-employee directors, which vest in their entirety on the one-year anniversary of the grant date. In the year ended December 31, 2018, the Company repurchased 514,349 shares at average prices ranging from $1.70 to 4.41 to cover payroll taxes. In the year ended December 31, 2017, the Company repurchased 394,269 shares at average prices ranging from $4.14 to $7.12 to cover payroll taxes. In the year ended December 31, 2016, the Company repurchased 133,656 shares at average prices ranging from $5.35 to $7.74 to cover payroll taxes. A summary of the status of non-vested restricted stock as of December 31, 2018, 2017 and 2016 is as follows: Number of Shares Weighted-Average Grant Date Fair Value Non-vested, December 31, 2015 1,586,388 $ 9.00 Granted 711,770 5.35 Vested (617,666 ) 8.90 Cancelled — — Non-vested, December 31, 2016 1,680,492 7.49 Granted 907,032 4.14 Vested (778,965 ) 7.66 Cancelled — — Non-vested, December 31, 2017 1,808,559 5.74 Granted 150,321 1.87 Vested (1,005,377 ) 6.62 Cancelled (271,433 ) 5.00 Non-vested, December 31, 2018 682,070 $ 3.47 As of December 31, 2018, there was $2.6 million of total unrecognized stock-based compensation expense related to non-vested restricted stock arrangements. The expense is expected to be recognized over a weighted-average period of 1.33 years.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Postemployment Benefits [Abstract]
Employee Benefit Plan	14. Employee Benefit Plan The Company sponsors a qualified 401(k) retirement plan under which employees are allowed to contribute certain percentages of their pay, up to the maximum allowed under Section 401(k) of the IIRC. The Company may make contributions to this plan at its discretion. The Company contributed approximately $329 thousand, $90 thousand, and $75 thousand to this plan during the years ended December 31, 2018, 2017, and 2016, respectively.

Selected Quarterly Information

Selected Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Information (Unaudited)	15. Selected Quarterly Information (Unaudited) (in thousands, except per share amount) Year Ended December 31 , 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 146 $ — $ — $ — Total operating expenses 16,342 12,378 12,570 12,762 Loss from operations (16,196 ) (12,378 ) (12,570 ) (12,762 ) Preferred stock dividends (5,120 ) (5,462 ) (6,074 ) (342 ) Settlement of a related party relationship — — — 207,361 Net (loss) applicable to common shareholders (21,540 ) (17,493 ) (18,659 ) 194,538 Net income (loss) per share, basic $ (0.15 ) $ (0.12 ) $ (0.13 ) $ 1.29 Net income (loss) per share, diluted $ (0.15 ) $ (0.12 ) $ (0.13 ) $ 1.29 Year Ended December 31 , 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,597 $ 1,597 $ 1,598 $ 1,597 Total operating expenses 15,562 14,611 14,676 15,033 Loss from operations (13,965 ) (13,014 ) (13,078 ) (13,436 ) Preferred stock dividends (4,171 ) (4,865 ) (4,903 ) (4,999 ) Net (loss) applicable to common shareholders (19,658 ) (17,727 ) (17,604 ) (18,272 ) Loss per share, basic and diluted $ (0.15 ) $ (0.13 ) $ (0.13 ) $ (0.12 )

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America or U.S. GAAP.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The Company’s most significant estimates and judgments used in the preparation of the financial statements are: • Clinical trial expenses; • Collaboration agreements; • Fair value measurements of stock-based compensation and Series 1 preferred stock (and related dividends); and • Income taxes.
Subsequent Events	Subsequent Events The Company evaluated all events and transactions that occurred after the balance sheet date through the date of this filing. Except as disclosed below, the Company did not have any material subsequent events that impacted its financial statements or disclosures. On December 18, 2018, Ziopharm and TriArm Therapeutics, Ltd. (“TriArm”) announced that the companies plan to launch Eden BioCell, Ltd. (“Eden BioCell”) to lead clinical development and commercialization of Sleeping Beauty For the territory of China, Taiwan and Korea, Ziopharm will license the rights to Eden BioCell for third-generation Sleeping Beauty Sleeping Beauty In February 2019, the Company extended its CRADA with the NCI for the development of adoptive cell transfer, or ACT,-based immunotherapies genetically modified using the Sleeping Beauty
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents consist primarily of demand deposit accounts and deposits in short-term U.S. treasury money market mutual funds. Cash equivalents are stated at cost, which approximates fair market value.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company maintains cash accounts in commercial banks, which may, at times, exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Expenditures for maintenance and repairs are charged to expense while the costs of significant improvements are capitalized. Depreciation is provided using the straight-line method over the following estimated useful lives of the related assets, which is between three and five years. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheets and related gains or losses are reflected in the statements of operations.
Restricted Cash	Restricted Cash Restricted cash consists of $105 thousand, which is restricted as collateral for a line of credit and is included in other assets.
Long-Lived Assets	Long-Lived Assets The Company reviews the carrying values of its long-lived assets for possible impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable. Any long-lived assets held for disposal are reported at the lower of their carrying amounts or fair values less costs to sell.
Operating Segments	Operating Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Company’s Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment and does not track expenses on a program-by-program basis.
Warrants	Warrants The Company assesses whether an equity issued financial instrument is indexed to an entity’s own stock for purposes of determining whether a financial instrument should be treated as a derivative. In applying the methodology, the Company concluded that warrants issued by the Company have terms that meet the criteria to be considered indexed to the Company’s own stock and therefore are classified as equity on the Company’s balance sheet.
Fair Value Measurements	Fair Value Measurements The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 24,437 $ 24,437 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 66,156 $ 66,156 $ — $ — Derivative liabilities $ (2,424 ) $ — $ — $ (2,424 ) The cash equivalents represent deposits in a short-term United States treasury money market mutual fund quoted in an active market and classified as a Level 1 asset. As discussed further in Notes 6, 8, and 11, the Company issued Intrexon Corporation, or Intrexon, 100,000 shares of the Company’s Series 1 preferred stock, a class of preferred stock authorized by the Company’s board of directors, in consideration of the parties entering into a Third Amendment to Exclusive Channel Partner Agreement, or the 2016 ECP Amendment, amending the existing Exclusive Channel Partner Agreement, effective January 6, 2011 and as amended to date, which the Company refers to as the Channel Agreement, and an Amendment to Exclusive Channel Collaboration Agreement, or the 2016 GvHD Amendment, amending the existing Exclusive Channel Collaboration Agreement, effective September 28, 2015, which the Company refers to as the GvHD Agreement. The Series 1 preferred stock were financial liabilities that consist of a conversion option and a redemption feature and were classified as a Level 3 asset. There were no transfers between asset classes during the year ended December 31, 2018. At June 30, 2016, the Company’s Series 1 preferred stock was valued using a probability-weighted approach and a Monte Carlo simulation model. Additionally, the monthly dividends issued on the outstanding Series 1 preferred stock were valued using the same probability-weighted approach and a Monte Carlo simulation model. However, there is no adjustment or further revaluation after the initial valuation on the Series 1 preferred stock other than required periodic dividends. The Company’s Level 3 financial liabilities consisted of a conversion option and a redemption feature associated with the Company’s Series 1 preferred stock issued to Intrexon that had been bifurcated from the Series 1 preferred stock and were accounted for as derivative liabilities at fair value. The preferred stock derivative liabilities were valued using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and then without derivatives subject to the valuation analysis (“without” scenario). The fair value of the derivatives was then estimated as the difference between the fair value of the preferred stock in the “with” scenario and the preferred stock in the “without” scenario. See Note 8 for additional disclosures on the 2016 ECP Amendment and 2016 GvHD Amendments and Note 11 for additional disclosure on the rights and preferences of the Series 1 preferred stock and valuation methodology. All shares of the Series 1 preferred stock were forfeited by Intrexon on October 5, 2018 in conjunction with the Company’s entry into an Exclusive License Agreement with Precigen, Inc., a wholly owned subsidiary of Intrexon (“Precigen”).
Revenue Recognition from Collaboration Agreements	Revenue Recognition from Collaboration Agreements The Company adopted Accounting Standards Codification, or ASC Topic 606, Revenue from Contracts with Customers, The Company primarily generates revenue through collaboration arrangements with strategic partners for the development and commercialization of product candidates. Commencing January 1, 2018, the Company recognized revenue in accordance with ASC 606 which replaced ASC 605, Multiple Element Arrangements The Company recognizes collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property, research and development services and options to purchase additional goods and/or services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Contracts that include an option to acquire additional goods and/or services are evaluated to determine if such option provides a material right to the customer that it would not have received without entering into the contract. If so, the option is accounted for as a separate performance obligation. If not, the option is considered a marketing offer which would be accounted for as a separate contract upon the customer’s election. The terms of the Company’s arrangements with customers typically include the payment of one or more of the following: (i) non-refundable, up-front payment, (ii) development, regulatory and commercial milestone payments, (iii) future options and (iv) royalties on net sales of licensed products. Accordingly, the transaction price is generally comprised of a fixed fee due at contract inception and variable consideration in the form of milestone payments due upon the achievement of specified events and tiered royalties earned when customers recognize net sales of licensed products. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes the most likely amount method to estimate the amount of variable consideration, to predict the amount of consideration to which it will be entitled for its one open contract. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. At the inception of each arrangement that includes development and regulatory milestone payments, the Company evaluates whether the associated event is considered probable of achievement and estimates the amount to be included in the transaction price using the most likely amount method. Milestone payments that are not within the control of the Company or the licensee, such as those dependent upon receipt of regulatory approval, are not considered to be probable of achievement until the triggering event occurs. At the end of each reporting period, the Company reevaluates the probability of achievement of each milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, the Company recognizes revenue upon the later of: (i) when the related sales occur or (ii) when the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any development, regulatory or commercial milestones or royalty revenue resulting from any of its collaboration arrangements. Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. However, certain components of variable consideration are allocated specifically to one or more particular performance obligations in a contact to the extent both of the following criteria are met: (i) the terms of the payment relate specifically to the efforts to satisfy the performance obligation or transfer the distinct good or service and (ii) allocating the variable amount of consideration entirely to the performance obligation or the distinct good or service is consistent with the allocation objective of the standard whereby the amount allocated depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services. The Company develops assumptions that require judgment to determine the standalone selling price for each performance obligation identified in each contract. The key assumptions utilized in determining the standalone selling price for each performance obligation may include forecasted revenues, development timelines, estimated research and development costs, discount rates, likelihood of exercise and probabilities of technical and regulatory success. Revenue is recognized based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good and/or service to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. As it relates to the Ares Trading Agreement (Note 6), the Company recognized the upfront payment associated with its one open contract as a contract liability upon receipt of payment as it requires deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts expected to be recognized as revenue within the twelve months following the balance sheet date are classified in current liabilities. Amounts not expected to be recognized as revenue within the twelve months following the balance sheet date are classified as contract liabilities, net of current portion. The Company determined that there were three performance obligations; the first performance obligation consists of the license and research development services and the other two performance obligations are material rights as it relates to potential future targets that have not yet been identified. As described above, the transaction price of $57.5 million was allocated to the performance obligations based on their relative standalone selling prices. There are multiple distinct performance obligations, including material rights; thus, the Company allocates the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Furthermore, the Company has not capitalized any contract costs under the guidance in ASC 340-40, Other Assets and Deferred Costs: Contracts with Customers The Company does not believe that any variable consideration should be included in the transaction price at the date of adoption of ASC 606 on January 1, 2018. Such assessment considered the application of the constraint to ensure that estimates of variable consideration would be included in the transaction price only to the extent the Company had a high degree of confidence that revenue would not be reversed in a subsequent reporting period. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as other changes in circumstances occur. Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front consideration received in July 2015 under ASC 605-25 versus ASC 606. Refer below for a summary of the amount by which each financial statement line item was affected by the impact of the cumulative adjustment: ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Changes in contract liability $ — $ — $ — The most significant change above relates to the Company’s collaboration revenue, which to date has been exclusively generated from its collaboration arrangement with Ares Trading and Precigen, formerly Intrexon (Note 8). Under ASC 605, the Company accounted for the up-front payment over the estimated period of performance of the research and development services which was estimated to be 9 years. In connection with the adoption of ASC 606, the Company uses cost-based input method to measure progress because such method best reflects the satisfaction of the performance obligation. In applying the cost-based input method of revenue recognition, the Company uses actual costs incurred relative to the budgeted costs to complete the research programs. These costs consist primarily of internal full-time equivalent effort and third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs. As a result, although the performance obligations noted above and identified under ASC 606 were generally consistent with the units of account identified under ASC 605, the timing of the allocation of the transaction price to the identified performance obligations under ASC 606 differed from the allocations of consideration under ASC 605. Accordingly, the transaction price ultimately allocated to each performance obligation under ASC 606 differed from the amounts allocated under ASC 605. Additionally, at December 31, 2018, the contract liability is $0 under both methods of revenue recognition (Note 7).
Research and Development Costs	Research and Development Costs Research and development expenditures are charged to the statement of operations as incurred. Such costs include proprietary research and development activities, purchased research and development, and expenses associated with research and development contracts, whether performed by the Company or contracted with independent third parties.
Income Taxes	Income Taxes Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. The Company evaluates this tax position on an annual basis. The Company also accrues for potential interest and penalties, related to unrecognized tax benefits in income tax expense (Note 10).
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation Stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award, and is recognized as expense over the employee’s requisite service period. Stock-based compensation expense is based on the number of awards ultimately expected to vest and is therefore reduced for an estimate of the awards that are expected to be forfeited prior to vesting. Consistent with prior years, the Company uses the Black-Scholes option pricing model which requires estimates of the expected term option holders will retain their options before exercising them and the estimated volatility of the Company’s common stock price over the expected term. The Company recognizes the full impact of its share-based employee payment plans in the statements of operations for each of the years ended December 31, 2018, 2017, and 2016 and did not capitalize any such costs on the balance sheets. The Company recognized $3.0 million, $2.5 million, and $3.0 million of compensation expense related to stock options during the years ended December 31, 2018, 2017, and 2016, respectively. In the years ended December 31, 2018, 2017, and 2016, the Company recognized $4.5 million, $6.0 million, and $5.5 million of compensation expense, respectively, related to restricted stock (Note 13). The total compensation expense relating to vesting of stock options and restricted stock awards for the years ended December 31, 2018, 2017, and 2016 was $7.5 million, $8.5 million, and $8.5 million, respectively. The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2018 2017 2016 Research and development $ 1,683 $ 2,401 $ 2,077 General and administrative 5,851 6,053 6,375 Share based employee compensation expense before tax 7,534 8,454 8,452 Income tax benefit — — — Net share based employee compensation expense $ 7,534 $ 8,454 $ 8,452 The fair value of each stock option is estimated at the date of grant using the Black-Scholes option pricing model. The estimated weighted-average fair value of stock options granted to employees in 2018, 2017, and 2016 was approximately $1.64, $3.94, and $4.43 per share, respectively. Assumptions regarding volatility, expected term, dividend yield and risk-free interest rate are required for the Black-Scholes model. The volatility assumption is based on the Company’s historical experience. The risk-free interest rate is based on a U.S. treasury note with a maturity similar to the option award’s expected life. The expected life represents the average period of time that options granted are expected to be outstanding. The Company calculated expected term using the simplified method described in SEC Staff Accounting Bulletin, or SAB, No. 107 and No. 110 as it continues to meet the requirements promulgated in SAB No. 110. The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below: 2018 2017 2016 Weighted average risk-free interest rate 2.55 - 3.06% 1.85 - 2.27% 1.27 - 2.09% Expected life in years 6 6 6 Expected volatility 80.75 - 84.71% 80.31 - 81.03% 79.15 - 82.95% Expected dividend yield 0 0 0
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2018 2017 2016 Basic Net loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Settlement of a related party relationship 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Earnings per share, basic $ 0.96 $ (0.53 ) $ (1.32 ) Diluted Net Loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Precigen license transaction 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Effect of dilutive securities Stock options 201,362 — — Unvested restricted common stock 124 — — Warrants — — — Dilutive potential common shares 201,486 — — Shares used in calculating diluted earnings per share 143,710,160 136,938,264 130,391,463 Earnings per share, diluted $ 0.96 $ (0.53 ) $ (1.32 ) Certain shares related to some of the Company’s outstanding common stock options, unvested restricted stock, preferred stock, and warrants have not been included in the computation of diluted net earnings (loss) per share for the years ended December 31, 2018, 2017 and 2016 as the result would be antidilutive. Such potential common shares at December 31, 2018, 2017, and 2016 consist of the following: December 31, 2018 2017 2016 Stock options 5,075,723 4,352,135 3,465,335 Unvested restricted stock 681,946 1,808,559 1,680,492 Preferred stock — 34,134,524 20,465,067 Warrants 18,939,394 — — 24,697,063 40,295,218 25,610,894 During the year ended December 31, 2018, the Company and Precigen, a wholly owned subsidiary Intrexon entered into a License Agreement to replace all existing agreements between the companies that will provide Ziopharm with certain exclusive and non-exclusive rights to technology controlled by Precigen, Inc. The License Agreement was dated October 5, 2018. In consideration of the Company entering into the License Agreement, Intrexon agreed to forfeit and return to the Company all shares of the Company’s Series 1 Preferred Stock held by or payable to Intrexon as of the date of the License Agreement (Note 7).
New Accounting Pronouncements	New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations by requiring the recognition of a right-of-use assets and lease liabilities for most lease arrangements on the balance sheet. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The new standard is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The standard permits two transition methods, (1) to apply the new lease requirements at the beginning of the earliest period presented, or (2) to apply the new lease requirements at the effective date. Under both transition methods there is a cumulative effect adjustment. The Company intends to. It also intends to elect the package of practical expedients permitted under the transition guidance within the new standard, which, among other things, allows us to carry forward the historical lease classification. Additionally, the right-of-use asset is subject to an impairment analysis under ASC 360, Property, Plant, and Equipment In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows: Restricted Cash December 31, (in thousands) 2018 2017 2016 Cash and cash equivalents $ 61,729 $ 70,946 $ 81,053 Restricted cash included in prepaid expenses and other current assets — 388 — Restricted cash included in other non-current assets — — 388 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 61,729 $ 71,334 $ 81,441 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation Scope of Modification Accounting In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting In August 2018, the FASB issued ASU No. 2018-03, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 24,437 $ 24,437 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 66,156 $ 66,156 $ — $ — Derivative liabilities $ (2,424 ) $ — $ — $ (2,424 )
Impact of Topic 606 Adoption on Financial Statements	Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front consideration received in July 2015 under ASC 605-25 versus ASC 606. Refer below for a summary of the amount by which each financial statement line item was affected by the impact of the cumulative adjustment: ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Changes in contract liability $ — $ — $ —
Share-Based Compensation Expense Included in Statements of Operations	The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2018 2017 2016 Research and development $ 1,683 $ 2,401 $ 2,077 General and administrative 5,851 6,053 6,375 Share based employee compensation expense before tax 7,534 8,454 8,452 Income tax benefit — — — Net share based employee compensation expense $ 7,534 $ 8,454 $ 8,452
Assumptions for Volatility, Expected life, Dividend Yield and Risk-free Interest Rate	The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below: 2018 2017 2016 Weighted average risk-free interest rate 2.55 - 3.06% 1.85 - 2.27% 1.27 - 2.09% Expected life in years 6 6 6 Expected volatility 80.75 - 84.71% 80.31 - 81.03% 79.15 - 82.95% Expected dividend yield 0 0 0
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method	Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2018 2017 2016 Basic Net loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Settlement of a related party relationship 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Earnings per share, basic $ 0.96 $ (0.53 ) $ (1.32 ) Diluted Net Loss $ (53,117 ) $ (54,323 ) $ (165,297 ) Preferred stock dividends (16,998 ) (18,938 ) (7,123 ) Precigen license transaction 207,361 — — Net income / (loss) applicable to common shareholders $ 137,246 $ (73,261 ) $ (172,420 ) Weighted-average common shares outstanding 143,508,674 136,938,264 130,391,463 Effect of dilutive securities Stock options 201,362 — — Unvested restricted common stock 124 — — Warrants — — — Dilutive potential common shares 201,486 — — Shares used in calculating diluted earnings per share 143,710,160 136,938,264 130,391,463 Earnings per share, diluted $ 0.96 $ (0.53 ) $ (1.32 )
Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share	December 31, 2018 2017 2016 Stock options 5,075,723 4,352,135 3,465,335 Unvested restricted stock 681,946 1,808,559 1,680,492 Preferred stock — 34,134,524 20,465,067 Warrants 18,939,394 — — 24,697,063 40,295,218 25,610,894
Restrictions on Cash and Cash Equivalents [Table Text Block]	The following table provides a reconciliation of cash, cash equivalents, and restricted cash within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows. December 31, (in thousands) 2018 2017 2016 Cash and cash equivalents $ 61,729 $ 70,946 $ 81,053 Restricted cash included in prepaid expenses and other current assets — 388 — Restricted cash included in other non-current assets — — 388 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 61,729 $ 71,334 $ 81,441

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Component of Property and Equipment, Net	Property and equipment, net, consists of the following: December 31, (in thousands) 2018 2017 Office and computer equipment $ 1,249 $ 1,215 Software 1,030 913 Leasehold improvements 1,839 1,553 Research and development equipment 1,182 1,161 5,300 4,842 Less: accumulated depreciation (4,203 ) (3,631 ) Property and equipment, net $ 1,097 $ 1,211

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Component of Accrued Expenses	Accrued expenses consist of the following: December 31, (in thousands) 2018 2017 Clinical consulting services $ 3,003 $ 3,022 Employee compensation 1,786 1,919 Preclinical services 1,247 2,210 Manufacturing services 1,164 902 Professional services 745 256 Accrued vacation 363 361 Payroll taxes and benefits 349 1,017 Other consulting services 106 222 Total $ 8,763 $ 9,909

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Future Net Minimum Lease Payments under Operating Leases	Future net minimum lease payments under operating leases as of December 31, 2018 are as follows (in thousands): 2019 723 2020 736 2021 488 Future minimum lease payments, net $ 1,947

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Significant Component of Deferred Tax Assets	Significant components of the Company’s deferred tax assets at December 31, 2018 and 2017 are as follows: December 31, (in thousands) 2018 2017 Net operating loss carryforwards $ 106,430 $ 89,098 Start-up and organizational costs 33,977 37,488 Research and development credit carryforwards 33,684 32,395 Stock compensation 990 1,330 Capitalized acquisition costs 5,160 5,822 Deferred revenue — 11,126 Depreciation 132 136 Other 920 993 181,293 178,388 Less valuation allowance (181,293 ) (178,388 ) Effective tax rate $ — $ —
Reconciliation of Income Tax Expense (Benefit)	A reconciliation of income tax expense (benefit) at the statutory federal income tax rate and income taxes as reflected in the financial statements is as follows: Year Ended December 31, (in thousands) 2018 2017 2016 Federal income tax at statutory rates 21 % 34 % 34 % State income tax, net of federal tax benefit 4 % 4 % 1 % Research and development credits 2 % 3 % 3 % Stock compensation -1 % -1 % -1 % Channel rights 0 % 0 % -25 % Research and development true-up 0 % -7 % 0 % Officers compensation -1 % -2 % 0 % Other -2 % -3 % 0 % Federal rate change 3 % -124 % 0 % Change in valuation allowance -26 % 96 % -12 % Effective tax rate 0 % 0 % 0 %

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Change in Derivative Liability	The change in the derivative liability for the years ended December 31, 2018, 2017 and 2016 consists of the following: Fair Value Balance, $ 694 Dividends 44 Change in fair value 124 Balance, $ 862 Dividends 267 Change in fair value 1,295 Balance, $ 2,424 Dividends 223 Change in fair value (158 ) Settlement of a related party relationship (2,489 ) Balance, December 31, 2018 $ —
Series 1 Preferred Stock
Fair Value Assumptions Used in Probability Weighted Approach and Monte Carlo Simulation Model	The fair value of the Series 1 preferred stock dividends was estimated using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and then without derivatives subject to the valuation analysis (“without” scenario). The fair value of the derivatives was then estimated as the difference between the fair value of the preferred stock in the “with” scenario and the preferred stock in the “without” scenario. The model also takes into account, management estimates of clinical success/failure based upon market studies and probability of potential conversion and liquidation events. If these estimates were different, the valuations would change, and that change could be material. Inputs to the models included the following: December 31 , 2018 2017 Risk-free interest rate 2.50 - 3.13 % 1.92 - 2.12 % Expected dividend rate 0 0 Expected volatility 77.6 - 82.4 % 68.7 - 80.4 % Preferred stock conversion limit percentage of outstanding common stock 19.90 % 19.90 % Preferred conversion floor price $ 1.00 $ 1.00

Stock Option Plan (Tables)

Stock Option Plan (Tables)	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Transaction under Stock Option Plan	Transactions under the 2012 Plan for the years ending December 31, 2018, 2017, and 2016 were as follows: (in thousands, except share and per share data) Number of Shares Weighted- Average Exercise Price Weighted- Average Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2015 3,481,468 $ 4.96 Granted 362,800 6.40 Exercised (234,833 ) 4.57 Cancelled (144,100 ) 6.43 Outstanding, December 31, 2016 3,465,335 5.07 Granted 688,800 5.27 Exercised (180,000 ) 3.67 Cancelled (122,000 ) 6.64 Outstanding, December 31, 2017 3,852,135 5.12 Granted 1,744,950 2.35 Exercised (104,167 ) 2.30 Cancelled (215,833 ) 5.72 Outstanding, December 31, 2018 5,277,085 $ 4.24 6.86 $ 88 Options exercisable, December 31, 2018 3,099,935 $ 5.15 4.93 $ 88 Options exercisable, December 31, 2017 2,925,502 $ 5.12 5.58 $ 1,152 Options available for future grant at December 31, 2018 3,895,923
Summary of Non-Vested Restricted Stock	A summary of the status of non-vested restricted stock as of December 31, 2018, 2017 and 2016 is as follows: Number of Shares Weighted-Average Grant Date Fair Value Non-vested, December 31, 2015 1,586,388 $ 9.00 Granted 711,770 5.35 Vested (617,666 ) 8.90 Cancelled — — Non-vested, December 31, 2016 1,680,492 7.49 Granted 907,032 4.14 Vested (778,965 ) 7.66 Cancelled — — Non-vested, December 31, 2017 1,808,559 5.74 Granted 150,321 1.87 Vested (1,005,377 ) 6.62 Cancelled (271,433 ) 5.00 Non-vested, December 31, 2018 682,070 $ 3.47

Selected Quarterly Informatio_2

Selected Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Information	Year Ended December 31 , 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 146 $ — $ — $ — Total operating expenses 16,342 12,378 12,570 12,762 Loss from operations (16,196 ) (12,378 ) (12,570 ) (12,762 ) Preferred stock dividends (5,120 ) (5,462 ) (6,074 ) (342 ) Settlement of a related party relationship — — — 207,361 Net (loss) applicable to common shareholders (21,540 ) (17,493 ) (18,659 ) 194,538 Net income (loss) per share, basic $ (0.15 ) $ (0.12 ) $ (0.13 ) $ 1.29 Net income (loss) per share, diluted $ (0.15 ) $ (0.12 ) $ (0.13 ) $ 1.29 Year Ended December 31 , 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,597 $ 1,597 $ 1,598 $ 1,597 Total operating expenses 15,562 14,611 14,676 15,033 Loss from operations (13,965 ) (13,014 ) (13,078 ) (13,436 ) Preferred stock dividends (4,171 ) (4,865 ) (4,903 ) (4,999 ) Net (loss) applicable to common shareholders (19,658 ) (17,727 ) (17,604 ) (18,272 ) Loss per share, basic and diluted $ (0.15 ) $ (0.13 ) $ (0.13 ) $ (0.12 )

Organization and Going Concern

Organization and Going Concern - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Accumulated deficit	$ (566,329)	$ (712,442)
Cash and cash equivalents	$ 61,729	$ 70,946	$ 81,053

Financings - Additional Informa

Financings - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 11, 2018	May 11, 2017	Dec. 31, 2018	Dec. 31, 2017	Apr. 26, 2006
Class of Stock [Line Items]
Stock issued during period		9,708,738
Issuance & sale of common stock in public offering price per share		$ 5.15
Sale of stock price per share		$ 4.893
Net proceeds from issuance of common stock		$ 47,300
Common stock, par value	$ 0.001		$ 0.001	$ 0.001	$ 0.001
Gross proceeds received			$ 47,101	$ 47,270
Securities Purchase Agreement [Member]
Class of Stock [Line Items]
Stock issued during period	18,939,394
Common stock, par value	$ 0.001
par value per share	$ 2.64
Gross proceeds received	$ 47,100

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 02, 2018	Jun. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 28, 2019	Sep. 30, 2018	Jan. 01, 2018
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			$ 7,534	$ 8,454	$ 8,452
Weighted average fair value of stock option granted			$ 1.64	$ 3.94	$ 4.43
Accumulated deficit			$ (566,329)	$ (712,442)
Transaction Price			57,500
Deferred revenue - current portion				6,389			$ 49,500
Impact On Assets and Liabilities			1,700
Payments to Acquire Joint Venture			35,000
Contract liability			$ (146)	(6,389)	$ (6,861)
Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								$ 8,100
Research and Development Services Contract Term			9 years
Contract liability	$ 8,100
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			$ 3,000	2,500	3,000
Restricted Stock
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			4,500	$ 6,000	$ 5,500
Current Assets | Lease Obligations
Summary Of Significant Accounting Policies [Line Items]
Restricted cash			$ 105
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life			3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life			5 years
Subsequent Event | CRADA agreement
Summary Of Significant Accounting Policies [Line Items]
Committed Amount						$ 5,000
ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								(720,573)
Deferred revenue - current portion								622
Contract liability			$ 0
ASU 2014-09 | Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								(8,131)
Deferred revenue - current portion								$ (5,767)
Contract liability			$ 0
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Issuance of stock in a license agreement (in shares)		100,000	11,415

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 24,437	$ 66,156
Derivative liabilities		(2,424)
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 24,437	66,156
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		$ (2,424)

Impact of Topic 606 Adoption on

Impact of Topic 606 Adoption on Financial Statements (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 02, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion			$ 49,500			$ 6,389					$ 6,389
Contract liability, net of current portion						35,139					35,139
Accumulated deficit		$ (566,329)				(712,442)				$ (566,329)	(712,442)
Collaboration revenue		0	0	$ 0	$ 146	1,597	$ 1,598	$ 1,597	$ 1,597	146	6,389	$ 6,861
Net loss		$ 194,538	$ (18,659)	$ (17,493)	$ (21,540)	(18,272)	(17,604)	(17,727)	(19,658)	(53,117)	(54,323)	(165,297)
Net income (loss) applicable to common shareholders										$ 137,246	$ (73,261)	$ (172,420)
Net income (loss) per share—basic		$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)
Net income (loss) per share—diluted		$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)
Net loss		$ 194,538	$ (18,659)	$ (17,493)	$ (21,540)	$ (18,272)	$ (17,604)	$ (17,727)	$ (19,658)	$ (53,117)	$ (54,323)	$ (165,297)
Changes in contract liability										(146)	$ (6,389)	$ (6,861)
ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion													$ 622
Contract liability, net of current portion													49,037
Accumulated deficit													(720,573)
Changes in contract liability										0
Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accumulated deficit													8,100
Changes in contract liability	$ 8,100
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion													(5,767)
Contract liability, net of current portion													13,898
Accumulated deficit													$ (8,131)
Collaboration revenue										(4,732)
Net loss										(4,732)
Net income (loss) applicable to common shareholders										$ (4,732)
Net income (loss) per share—basic										$ (0.03)
Net income (loss) per share—diluted										$ (0.03)
Net loss										$ (4,732)
Changes in contract liability										0
Calculated under Revenue Guidance in Effect before Topic 606 | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Collaboration revenue										4,878
Net loss										(48,385)
Net income (loss) applicable to common shareholders										$ 141,978
Net income (loss) per share—basic										$ 0.99
Net income (loss) per share—diluted										$ 0.99
Net loss										$ (48,385)
Changes in contract liability										$ 0

Stock-Based Compensation Expens

Stock-Based Compensation Expense Included in Statement of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 7,534	$ 8,454	$ 8,452
Income tax benefit	0	0	0
Net share based employee compensation expense	7,534	8,454	8,452
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,683	2,401	2,077
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 5,851	$ 6,053	$ 6,375

Fair Value of Stock Options Ass

Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate, Minimum	2.55%	1.85%	1.27%
Risk-free interest rate, Maximum	3.06%	2.27%	2.09%
Expected life in years	6 years	6 years	6 years
Expected volatility, Minimum	80.75%	80.31%	79.15%
Expected volatility, Maximum	84.71%	81.03%	82.95%
Expected dividend yield	0.00%	0.00%	0.00%

Earning Per share Basic and Dil

Earning Per share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share, Basic [Abstract]
Net loss	$ 194,538	$ (18,659)	$ (17,493)	$ (21,540)	$ (18,272)	$ (17,604)	$ (17,727)	$ (19,658)	$ (53,117)	$ (54,323)	$ (165,297)
Preferred stock dividends	$ (342)	$ (6,074)	$ (5,462)	$ (5,120)	(4,999)	(4,903)	(4,865)	(4,171)	(16,998)	(18,938)	(7,123)
Settlement of a related party relationship									207,361
Net income (loss) applicable to common stockholders									$ 137,246	$ (73,261)	$ (172,420)
Weighted-average common shares outstanding									143,508,674	136,938,264	130,391,463
Earnings per share, basic	$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)
Earnings Per Share, Diluted [Abstract]
Net loss	$ 194,538	$ (18,659)	$ (17,493)	$ (21,540)	(18,272)	(17,604)	(17,727)	(19,658)	$ (53,117)	$ (54,323)	$ (165,297)
Preferred stock dividends	$ (342)	$ (6,074)	$ (5,462)	$ (5,120)	$ (4,999)	$ (4,903)	$ (4,865)	$ (4,171)	(16,998)	(18,938)	(7,123)
Precigen license transaction									207,361
Net income (loss) applicable to common stockholders									$ 137,246	$ (73,261)	$ (172,420)
Weighted-average common shares outstanding									143,710,160	136,938,264	130,391,463
Effect of dilutive securities
Stock options									201,362
Unvested restricted common stock									124
Warrants
Dilutive potential common shares									$ 201,486
Shares used in calculating diluted earnings per share									143,710,160	136,938,264	130,391,463
Earnings per share, diluted	$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)

Potential Dilutive Shares Exclu

Potential Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	24,697,063	40,295,218	25,610,894
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	18,939,394
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	5,075,723	4,352,135	3,465,335
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	681,946	1,808,559	1,680,492
Series 1 Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		34,134,524	20,465,067

Statement of Cash and Cash Equi

Statement of Cash and Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Cash and Cash Equivalents and Restricted Cash [Line Items]
Cash and cash equivalents	$ 61,729	$ 70,946	$ 81,053
Restricted cash included in prepaid expenses and other current assets		388
Restricted cash included in other non-current assets			388
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	$ 61,729	$ 71,334	$ 81,441	$ 140,717

Component of Property and Equip

Component of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 5,300	$ 4,842
Less: accumulated depreciation	(4,203)	(3,631)
Property and equipment, net	1,097	1,211
Office and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	1,249	1,215
Software
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	1,030	913
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	1,839	1,553
Research and development equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 1,182	$ 1,161

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation	$ 575	$ 369	$ 290

Component of Accrued Expenses (

Component of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Clinical consulting services	$ 3,003	$ 3,022
Employee compensation	1,786	1,919
Preclinical services	1,247	2,210
Manufacturing services	1,164	902
Professional services	745	256
Accrued vacation	363	361
Payroll taxes and benefits	349	1,017
Other consulting services	106	222
Total	$ 8,763	$ 9,909

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 29, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Change in fair value of derivative liability		$ (124)	$ 158	$ (1,295)	$ (124)
Research and development expense			34,134	45,084	157,791
MD Anderson License and the Research and Development Agreement Member [Member]
Related Party Transaction [Line Items]
Research and development service agreement aggregate quarterly payments			2,700	13,000
Research and development service agreement aggregate payments			41,900
Cash resources on hand			27,800
MD Anderson License and the Research and Development Agreement Member [Member] | Other Current Assets [Member]
Related Party Transaction [Line Items]
Cash resources on hand			18,400
MD Anderson License and the Research and Development Agreement Member [Member] | Non Current Assets [Member]
Related Party Transaction [Line Items]
Cash resources on hand			9,400
Series 1 Preferred Stock
Related Party Transaction [Line Items]
Temporary equity, fair value			18,900
Change in fair value of derivative liability			(1,300)
License Agreement
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)						11,722,163
Research and development expense						$ 67,300
Quarterly Payment | MD Anderson License and the Research and Development Agreement Member [Member]
Related Party Transaction [Line Items]
Research and development service agreement aggregate quarterly payments			2,700
Intrexon Corporation/Precigen
Related Party Transaction [Line Items]
Amounts expensed for services incurred			8,100	21,400	$ 22,200
Amount due to related party, current			1,900	$ 6,800
Research and development expense			$ 1,000
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)	100,000		11,415

Settlement of a Related Party_2

Settlement of a Related Party Relationship - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 05, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Transaction advisory costs recognized as expense						$ 2,000
Related Party Transaction, Amounts of Transaction		$ 207,361	$ 0	$ 0	$ 0
Research and development expense						34,134	$ 45,084	$ 157,791
Preferred Stock Redemption Discount						207,361
Gorilla IL-12 Products
Percentage of development cost shared by other party	80.00%
Percentage of operating profit shared by other party	80.00%
Intrexon Corporation/Precigen
Annual Licensing fee	$ 100
Reimbursement of historical costs	1,000
Preferred Stock, Contract Liability, Derivative Liability	163,300
Increase in accumulated deficit	49,500
Related Party Transaction, Amounts of Transaction	212,800
Research and development expense						$ 1,000
Additional milestone payment for exclusively licensed program to be paid	52,500
Maximum Royalty payable	$ 100,000
Percentage of sublicensing income	20.00%
Royalty payment to be received	$ 50,000
Intrexon Corporation/Precigen | Gorilla IL-12 Products
Percentage of development cost shared by other party	20.00%
Percentage of operating profit shared by other party	20.00%
Third Party Vendor
Transaction advisory costs recognized as expense	$ 7,400
Series 1 Preferred Stock [Member]
Transaction advisory costs recognized as expense	5,400
Series 1 Preferred Stock [Member] | Intrexon Corporation/Precigen
Consideration transferred	5,400
Preferred Stock Redemption Discount	$ 207,300

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands

Oct. 05, 2018USD ($)

Jan. 13, 2015USD ($)

May 07, 2011USD ($)

Mar. 07, 2011USD ($)

Jul. 31, 2015USD ($)

Dec. 31, 2012

Dec. 31, 2011

Aug. 24, 2004Patent

Dec. 31, 2018USD ($)shares

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2013USD ($)

Dec. 31, 2017USD ($)

Feb. 28, 2019USD ($)

Jan. 30, 2018USD ($)ft²

Mar. 31, 2016USD ($)

Dec. 31, 2014USD ($)shares

Commitments and Contingencies Disclosure [Line Items]

Operating lease expiration month and year

2018-10

Total rent expense

$ 700

$ 700

$ 300

$ 40

Deferred rent - current portion

13

141

141

Deferred rent-non-current portion

4

1

1

Deferred rent liability net

17

142

142

Research and development expense

34,134

$ 45,084

157,791

Research and development arrangement Terms

Pursuant to the Research and Development Agreement, the Company, Intrexon (now Precigen) and MD Anderson formed a joint steering committee that will oversee and manage the new and ongoing research programs. As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the Research and Development Agreement for a period of three years and in an amount of no less than $15.0 million and no greater than $20.0 million per year.

Cash balance

61,729

$ 70,946

$ 81,053

$ 70,946

Agreement commencement date

2015-05

MD Anderson License and the Research and Development Agreement Member [Member]

Commitments and Contingencies Disclosure [Line Items]

Research and development service agreement aggregate quarterly payments

2,700

$ 13,000

Cash resources on hand

27,800

CRADA Agreement [Member]

Commitments and Contingencies Disclosure [Line Items]

Obligations due under contract

2,500

Quarterly payments under contract

625

Total Payments

$ 2,500

Gorilla IL12 Products [Member] | Parent [Member]

Commitments and Contingencies Disclosure [Line Items]

Percentage of development costs

80.00%

Percentage of operating profits

80.00%

CAR Products [Member]

Commitments and Contingencies Disclosure [Line Items]

Amount of royalties receivable

$ 50,000

The University of Texas MD Anderson Cancer Center and The Texas A & M University System

Commitments and Contingencies Disclosure [Line Items]

Milestone maximum payment

$ 4,500

Number of products | Patent

2

Options to purchase common stock | shares

50,222

Shares vested | shares

37,666

The University of Texas MD Anderson Cancer Center and The Texas A & M University System | Research and Development Expense

Commitments and Contingencies Disclosure [Line Items]

Issuance of common stock in a license agreement

$ 87

The University of Texas MD Anderson Cancer Center and The Texas A & M University System | Upon enrollment of the first patient in a multi-center pivotal clinical trial

Commitments and Contingencies Disclosure [Line Items]

Shares vested | shares

12,556

Solasia

Commitments and Contingencies Disclosure [Line Items]

Upfront payment received

$ 5,000

$ 5,000

Milestone payment received

$ 1,000

Milestone Payments Payable

$ 1,000

Solasia | Development-based milestones

Commitments and Contingencies Disclosure [Line Items]

Expected Additional milestone payments to be received

32,500

Solasia | Sales-based milestones

Commitments and Contingencies Disclosure [Line Items]

Expected Additional milestone payments to be received

$ 53,500

Baxter Healthcare Corporation | Upon the successful U.S. IND application for indibulin

Commitments and Contingencies Disclosure [Line Items]

Installment payments

250

ARES Trading License

Commitments and Contingencies Disclosure [Line Items]

Research and development expense

$ 1,600

Agreement termination, notice period

90 days

Subsequent Event | CRADA Agreement [Member]

Commitments and Contingencies Disclosure [Line Items]

Additional commitment

$ 5,000

Prepaid Expenses and Other Current Assets | MD Anderson License

Commitments and Contingencies Disclosure [Line Items]

Cash balance

$ 18,400

Other Noncurrent Assets | MD Anderson License

Commitments and Contingencies Disclosure [Line Items]

Cash balance

9,400

Intrexon Corporation

Commitments and Contingencies Disclosure [Line Items]

Licensing fee

$ 115,000

Research and development expense

$ 1,000

Milestone payment receivable period

2 years

Upfront payment received

$ 57,500

Percentage of upfront fee Payable

50.00%

Annual Licensing fee

100

Reimbursement of historical costs

1,000

Expected additional milestones payable

52,500

Intrexon Corporation | License [Member]

Commitments and Contingencies Disclosure [Line Items]

Annual Licensing fee

$ 100

Intrexon Corporation | Gorilla IL12 Products [Member]

Commitments and Contingencies Disclosure [Line Items]

Percentage of development costs

20.00%

Percentage of operating profits

20.00%

Intrexon Corporation | T-cell receptor

Commitments and Contingencies Disclosure [Line Items]

Maximum royalty amount

$ 100,000

Portion of income payable to related party

20.00%

Minimum | MD Anderson License and the Research and Development Agreement Member [Member]

Commitments and Contingencies Disclosure [Line Items]

Research and development expense

$ 15,000

Maximum | MD Anderson License and the Research and Development Agreement Member [Member]

Commitments and Contingencies Disclosure [Line Items]

Research and development expense

$ 20,000

New York, NY

Commitments and Contingencies Disclosure [Line Items]

Letter of credit

$ 388

Loss on sublease

$ 729

Remaining contractual obligation

2,300

Sublease revenue from subtenant

$ 1,600

Boston, MA

Commitments and Contingencies Disclosure [Line Items]

Operating lease expiration month and year

2016-08

Security deposits

$ 128

Sublease term amendment

Aug. 31, 2021

Houston, TX

Commitments and Contingencies Disclosure [Line Items]

Operating lease area | ft²

210

Operating Leases Future Minimum Monthly Payment Due Through Year 2021

$ 1

Future Minimum Lease Payments u

Future Minimum Lease Payments under Operating Leases (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 723
2,020	736
2,021	488
Future minimum lease payments, net	$ 1,947

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 11, 2018
Number of securities into which the class of warrant converted				18,939,394
Warrant Exercise Per share				$ 2.64
Fair Value Assumptions Expected volatility Rate Maximum	84.71%	81.03%	82.95%
Fair Value Assumptions Risk Free Interest Rate Maximum	3.06%	2.27%	2.09%
Fair Value Assumptions Expected Term1	6 years	6 years	6 years
Fair Value Assumptions Expected Dividend Rate	0.00%	0.00%	0.00%
Private Placement [Member]
Number of securities into which the class of warrant converted	18,939,394
Warrant Exercise Per share	$ 3.01
fair value of adjustment of warrants	$ 18.4
Fair Value Assumptions Expected volatility Rate Maximum	71.00%
Fair Value Assumptions Risk Free Interest Rate Maximum	2.99%
Fair Value Assumptions Expected Term1	5 years
Fair Value Assumptions Expected Dividend Rate	0.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 02, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2013
Income Taxes [Line Items]
Net operating loss carryforwards			$ 106,430	$ 89,098
Research and development credit carryforwards			$ 33,684	32,395
Net operating loss carryforwards, expiration date			2,038
Accumulated excess tax benefit recognised as deferred tax asset			$ 0	$ 0
Increase (decrease) in deferred tax assets			$ (2,900)
Effective income tax rate			21.00%	34.00%	34.00%
Increase (decrease) in deferred revenue			$ (146)	$ (6,389)	$ (6,861)
Revenues				15,900
Deferred revenue				$ 41,500
Difference between revenue guidance in effect before and after topic 606
Income Taxes [Line Items]
Increase (decrease) in deferred revenue	$ 8,100
ASU 2016-09
Income Taxes [Line Items]
Accumulated excess tax benefit recognised as deferred tax asset					10,200
Accumulated Deficit | ASU 2016-09
Income Taxes [Line Items]
Cumulative-effect adjustment from adoption of ASU 2016-09					$ 122
Tax Cuts And Jobs Act of 2017
Income Taxes [Line Items]
Effective income tax rate			35.00%
Change in tax rate in income tax expense benefit			$ 67,000
Tax Cuts And Jobs Act of 2017 | Scenario, Forecast
Income Taxes [Line Items]
Effective income tax rate		21.00%
Research Tax Credit Carryforward
Income Taxes [Line Items]
Research and development credit carryforwards			34,000
Net Operating Loss Carryforwards
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets						$ (11,200)
General Business Credits
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets						$ (636)
Domestic Tax Authority
Income Taxes [Line Items]
Net operating loss carryforwards			$ 403,000
Net operating loss carryforwards, expiration date			2,038
Federal and State
Income Taxes [Line Items]
Net operating loss carryforwards			$ 344,000

Significant Component of Deferr

Significant Component of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 106,430	$ 89,098
Start-up and organizational costs	33,977	37,488
Research and development credit carryforwards	33,684	32,395
Stock compensation	990	1,330
Capitalized acquisition costs	5,160	5,822
Deferred revenue	0	11,126
Depreciation	132	136
Other	920	993
Deferred Tax Assets Gross	181,293	178,388
Less valuation allowance	(181,293)	(178,388)
Effective tax rate	$ 0	$ 0

Reconciliation of Income Tax Ex

Reconciliation of Income Tax Expense (Benefit) (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax at statutory rates	21.00%	34.00%	34.00%
State income tax, net of federal tax benefit	4.00%	4.00%	1.00%
Research and development credits	2.00%	3.00%	3.00%
Stock compensation	(1.00%)	(1.00%)	(1.00%)
Channel rights	0.00%	0.00%	(25.00%)
Research and development true-up	0.00%	(7.00%)	0.00%
Officers compensation	(1.00%)	(2.00%)	0.00%
Other	(2.00%)	(3.00%)	0.00%
Federal rate change	3.00%	(124.00%)	0.00%
Change in valuation allowance	(26.00%)	96.00%	(12.00%)
Effective tax rate	0.00%	0.00%	0.00%

Preferred Stock and Stockhold_2

Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Nov. 11, 2018	May 11, 2017	Jun. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Apr. 26, 2006
Equity [Line Items]
Shares of authorized capital stock						280,000,000
Common stock, shares authorized				250,000,000	250,000,000	250,000,000
Common stock par value per share	$ 0.001			$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares authorized				30,000,000	30,000,000	30,000,000
Preferred stock par value				$ 0.001	$ 0.001	$ 0.001
Stock issued during period		9,708,738
Issuance & sale of common stock in public offering price per share		$ 5.15
Net proceeds from issuance of common stock		$ 47.3
Number of securities into which the class of warrant converted	18,939,394
Warrant Exercise Price per share	$ 2.64
Proceeds from warrant Exercise	$ 47.1
Series 1 Preferred Stock
Equity [Line Items]
Preferred stock, stated value				$ 1,200	$ 1,200
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Equity [Line Items]
Issuance of common stock in licensing agreement (in shares)			100,000	11,415
Preferred stock, stated value			$ 1,200

Change in Derivative Liability

Change in Derivative Liability (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Beginning Balance	$ 694	$ 2,424	$ 862
Dividends	44	223	267
Change in fair value	124	(158)	1,295	$ 124
Settlement of a related party relationship		(2,489)
Ending Balance	$ 862	$ 0	$ 2,424	$ 862

Fair Value Assumptions Used in

Fair Value Assumptions Used in Probability Weighted Approach and Monte Carlo Simulation Model for Derivatives (Detail) - Series 1 Preferred Stock - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Preferred stock conversion limit - percentage of outstanding common stock	19.90%	19.90%
Preferred conversion floor price	$ 1	$ 1
Measurement Input, Expected Dividend Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	0.00%	0.00%
Minimum | Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	2.50%	1.92%
Minimum | Measurement Input, Price Volatility [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	77.60%	68.70%
Maximum | Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	3.13%	2.12%
Maximum | Measurement Input, Price Volatility [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	82.40%	80.40%

Stock Option Plan - Additional

Stock Option Plan - Additional information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance				5,284,988
Outstanding options issued	3,852,135			5,277,085	3,852,135	3,465,335	3,481,468
Proceeds from stock options exercised				$ 240	$ 88	$ 714
Total intrinsic value of options				$ 100	$ 200	$ 800
Stock options, granted				1,744,950	688,800	362,800
Stock options granted exercise price				$ 2.35	$ 5.27	$ 6.40
Options available for future grant				3,895,923
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock			71,166,676,667	514,349	394,269	133,656
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock, price per share				$ 4.41	$ 7.12	$ 7.74
Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock, price per share				$ 1.70	$ 4.14	$ 5.35
Restricted Stock | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award granted				30,000
Restricted Stock | Non Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award granted	838,000			120,321	69,032	86,020
Unvested Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested restricted stock outstanding				$ 5,100
Expected recognition period				1 year 6 months 11 days
Unvested Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected recognition period				1 year 3 months 29 days
Share-based payment award granted				150,321	907,032	711,770
Unrecognized stock-based compensation expense related to non-vested restricted stock arrangements				$ 2,600
the "2012 Plan"
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance				14,000,000
the "2012 Plan" | Employees | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued				4,146,135
the "2012 Plan" | Director | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued				1,120,950
the "2012 Plan" | Consultants | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued				10,000
Outside 2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance				526,364
Outstanding options issued				500,000
Stock options, granted		500,000
Stock options granted exercise price		$ 6.16
Share Based compensation arrangement by share based payment award options grants grant date fair value		$ 2,200

Stock Option Activity Under Sto

Stock Option Activity Under Stock Option Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Beginning Balance	3,852,135	3,465,335	3,481,468
Granted	1,744,950	688,800	362,800
Exercised	(104,167)	(180,000)	(234,833)
Cancelled	(215,833)	(122,000)	(144,100)
Ending Balance	5,277,085	3,852,135	3,465,335
Options exercisable, at end of period	3,099,935	2,925,502
Weighted Average Exercise Price
Beginning Balance	$ 5.12	$ 5.07	$ 4.96
Granted	2.35	5.27	6.40
Exercised	2.30	3.67	4.57
Cancelled	5.72	6.64	6.43
Ending Balance	4.24	5.12	$ 5.07
Options exercisable, at end of period	$ 5.15	$ 5.12
Options available for future grant	3,895,923
Weighted Average Contractual Term (Years)
Outstanding, at end of period	6 years 10 months 10 days
Options exercisable, at end of period	4 years 11 months 5 days	5 years 6 months 29 days
Aggregate Intrinsic Value
Outstanding, at end of period	$ 88
Options exercisable, at end of period	$ 88	$ 1,152

Summary of Non-Vested Restricte

Summary of Non-Vested Restricted Stock (Detail) - Unvested Restricted Common Stock - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Beginning Balance	1,808,559	1,680,492	1,586,388
Granted	150,321	907,032	711,770
Vested	(1,005,377)	(778,965)	(617,666)
Cancelled	(271,433)	0	0
Ending Balance	682,070	1,808,559	1,680,492
Weighted Average Grant Date Fair Value
Beginning Balance	$ 5.74	$ 7.49	$ 9
Granted	1.87	4.14	5.35
Vested	6.62	7.66	8.90
Cancelled	5	0	0
Ending Balance	$ 3.47	$ 5.74	$ 7.49

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Defined benefit plan contributions by employer	$ 329	$ 90	$ 75

Selected Quarterly Informatio_3

Selected Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 0	$ 0	$ 0	$ 146	$ 1,597	$ 1,598	$ 1,597	$ 1,597	$ 146	$ 6,389	$ 6,861
Total operating expenses	12,762	12,570	12,378	16,342	15,033	14,676	14,611	15,562	54,052	59,882	172,168
Loss from operations	(12,762)	(12,570)	(12,378)	(16,196)	(13,436)	(13,078)	(13,014)	(13,965)	(53,906)	(53,493)	(165,307)
Preferred stock dividends	(342)	(6,074)	(5,462)	(5,120)	(4,999)	(4,903)	(4,865)	(4,171)	(16,998)	(18,938)	(7,123)
Settlement of a related party relationship	207,361	0	0	0
Net income (loss) applicable to common shareholders	$ 194,538	$ (18,659)	$ (17,493)	$ (21,540)	$ (18,272)	$ (17,604)	$ (17,727)	$ (19,658)	$ (53,117)	$ (54,323)	$ (165,297)
Net income (loss) per share, basic	$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)
Net income (loss) per share, diluted	$ 1.29	$ (0.13)	$ (0.12)	$ (0.15)					$ 0.96	$ (0.53)	$ (1.32)
Loss per share, basic and diluted					$ (0.12)	$ (0.13)	$ (0.13)	$ (0.15)