Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2019	Oct. 31, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Entity Registrant Name	ZIOPHARM ONCOLOGY INC
Entity Central Index Key	0001107421
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	ZIOP
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		181,030,020
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Address, State or Province	MA

BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 88,419	$ 61,729
Receivables	3,441	1,864
Prepaid expenses and other current assets	23,739	20,692
Total current assets	115,599	84,285
Property and equipment, net	828	1,097
Operating lease right of use assets	1,283
Deposits	130	128
Other non-current assets	109	9,541
Total assets	117,949	95,051
Current liabilities:
Accounts payable	926	707
Accrued expenses	9,573	8,763
Lease liability—current portion	677
Deferred rent—current portion		13
Total current liabilities	11,176	9,483
Lease liability—noncurrent portion	647
Deferred rent—noncurrent portion		4
Total liabilities	11,823	9,487
Commitments and contingencies (Note 7)
Stockholders' equity:
Common stock, $0.001 par value; 250,000,000 shares authorized; 181,030,020 and 161,066,136 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	181	161
Additional paid-in capital	774,324	651,732
Accumulated deficit	(668,379)	(566,329)
Total stockholders' equity	106,126	85,564
Total liabilities and stockholders' equity	$ 117,949	$ 95,051

BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	181,030,020	161,066,136
Common stock, shares outstanding	181,030,020	161,066,136

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Collaboration revenue				$ 146
Operating expenses:
Research and development	$ 8,641	$ 8,263	$ 28,115	25,935
General and administrative	4,807	4,307	13,707	15,355
Total operating expenses	13,448	12,570	41,822	41,290
Loss from operations	(13,448)	(12,570)	(41,822)	(41,144)
Other income, net	203	150	523	462
Change in fair value of derivative liabilities		(165)		46
Non-cash inducement warrant expense	(60,751)		(60,751)
Net loss	(73,996)	(12,585)	(102,050)	(40,636)
Preferred stock dividends		(6,074)		(16,656)
Net loss applicable to common stockholders	$ (73,996)	$ (18,659)	$ (102,050)	$ (57,292)
Basic and diluted net loss per share	$ (0.43)	$ (0.13)	$ (0.62)	$ (0.41)
Weighted average common shares outstanding used to compute basic and diluted net loss per share	170,613,712	141,185,404	164,053,029	141,020,025

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, 2017	$ (96,806)	$ 143	$ 615,493	$ (712,442)	$ 143,992
Balance (in shares) at Dec. 31, 2017		142,658,037			119,644
Adjustment for implementation of ASU No. 2014-09, Revenue from contracts with customers	(8,131)			(8,131)
Stock-based compensation	6,850		6,850
Exercise of employee stock options	240		240
Exercise of employee stock options (in shares)		104,166
Cancelled restricted common stock (in shares)		(70,867)
Repurchase of restricted common stock	(1,275)	$ (1)	(1,274)
Repurchase of restricted common stock (Shares)		(311,566)
Preferred stock dividends			(16,656)		$ 16,437
Preferred stock dividends	(16,656)
Preferred stock dividends (in shares)					11,205
Net loss	(40,636)			(40,636)
Balance at Sep. 30, 2018	(156,414)	$ 142	604,653	(761,209)	$ 160,429
Balance (in shares) at Sep. 30, 2018		142,379,770			130,849
Balance at Jun. 30, 2018	(139,235)	$ 142	609,247	(748,624)	$ 154,428
Balance (in shares) at Jun. 30, 2018		142,379,770			127,002
Stock-based compensation	1,480		1,480
Preferred stock dividends			(6,074)		$ 6,001
Preferred stock dividends	(6,074)
Preferred stock dividends (in shares)					3,847
Net loss	(12,585)			(12,585)
Balance at Sep. 30, 2018	(156,414)	$ 142	604,653	(761,209)	$ 160,429
Balance (in shares) at Sep. 30, 2018		142,379,770			130,849
Balance at Dec. 31, 2018	85,564	$ 161	651,732	(566,329)
Balance (in shares) at Dec. 31, 2018		161,066,136
Stock-based compensation	4,741		4,741
Exercise of employee stock options	$ 1,020		1,020
Exercise of employee stock options (in shares)	482,500	352,652
Restricted stock awards	$ 1,000	$ 1	999
Restricted stock awards (in shares)		1,408,536
Issuance of common stock upon exercise of warrants, net	52,499	$ 18	52,481
Issuance of common stock upon exercise of warrants, net (in shares)		17,803,031
Issuance of inducement warrants	60,751		60,751
Cancelled restricted common stock (in shares)		(74,599)
Restricted stock buy-back at vesting to cover taxes	(370)		(370)
Restricted stock buy-back at vesting to cover taxes (in shares)		(165,178)
Issuance of common stock in connection with at the market offering, net	2,971	$ 1	2,970
Issuance of common stock in connection with at the market offering, net (in shares)		639,442
Net loss	(102,050)			(102,050)
Balance at Sep. 30, 2019	106,126	$ 181	774,324	(668,379)
Balance (in shares) at Sep. 30, 2019		181,030,020
Balance at Jun. 30, 2019	61,995	$ 162	656,216	(594,383)
Balance (in shares) at Jun. 30, 2019		162,477,963
Stock-based compensation	1,486		1,486
Exercise of employee stock options	420		420
Exercise of employee stock options (in shares)		94,584
Restricted stock awards (in shares)		15,000
Issuance of common stock upon exercise of warrants, net	52,499	$ 18	52,481
Issuance of common stock upon exercise of warrants, net (in shares)		17,803,031
Issuance of inducement warrants	60,751		60,751
Issuance of common stock in connection with at the market offering, net	2,971	$ 1	2,970
Issuance of common stock in connection with at the market offering, net (in shares)		639,442
Net loss	(73,996)			(73,996)
Balance at Sep. 30, 2019	$ 106,126	$ 181	$ 774,324	$ (668,379)
Balance (in shares) at Sep. 30, 2019		181,030,020

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (102,050)	$ (40,636)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	453	412
Stock-based compensation	5,741	6,850
Change in fair value of derivative liabilities		(46)
Non-cash inducement warrant expense	60,751
(Increase) decrease in:
Receivables	(1,577)	(1,002)
Prepaid expenses and other current assets	(3,047)	5,406
Other noncurrent assets	9,432	(4,684)
Deposits	(2)
Increase (decrease) in:
Accounts payable	219	(3,148)
Accrued expenses	810	(532)
Deferred revenue		(146)
Deferred rent	17	(112)
Other liabilities	7
Net cash used in operating activities	(29,246)	(37,638)
Cash flows from investing activities:
Purchases of property and equipment	(184)	(545)
Net cash used in investing activities	(184)	(545)
Cash flows from financing activities:
Proceeds from exercise of stock options	1,020	240
Repurchase of common stock	(370)	(1,275)
Issuance of common stock in connection with at the market offering, net	2,971
Issuance of common stock upon exercise of warrants, net	52,499
Net cash provided by (used in) financing activities	56,120	(1,035)
Net increase (decrease) in cash and cash equivalents, and restricted cash	26,690	(39,218)
Cash and cash equivalents, and restricted cash, beginning of period	61,729	71,335
Cash and cash equivalents, and restricted cash, end of period	88,419	32,117
Supplementary disclosure of cash flow information:
Compensation paid in restricted stock, gross	$ 1,000
Series 1 Preferred Stock
Supplementary disclosure of noncash investing and financing activities:
Payment of dividends in preferred stock		$ 16,656

Business

9 Months Ended

Sep. 30, 2019

Accounting Policies [Abstract]

Business

1. Business

Overview

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 conducting research and development and raising capital to fund those efforts. The Company’s fiscal year ends on December 31.

The Company has operated at a loss since its inception in 2003 and has no recurring revenues from operations. The Company anticipates that losses will continue for the foreseeable future. As of September 30, 2019, the Company had approximately $88.4 million of cash and cash equivalents and the Company’s accumulated deficit was approximately $668.4 million. Given its current development plans, the Company anticipates cash resources will be sufficient to fund operations into the first half of 2021. The Company’s ability to continue operations after its current cash resources are exhausted depends on its ability to obtain additional financing or to achieve profitable operations, as to which no assurances can be given. Cash requirements may vary materially from those now planned because of changes in the Company’s focus and direction of its research and development programs, competitive and technical advances, patent developments, regulatory changes or other developments. If adequate additional funds are not available when required, or if the Company is unsuccessful in entering into partnership agreements for further development of its product candidates, management may need to curtail its development efforts and planned operations to conserve cash.

Basis of Presentation

The accompanying unaudited interim financial statements have been prepared in accordance with the instructions to Form

10-Q

pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. Certain information and note disclosures required by generally accepted accounting principles in the United States have been condensed or omitted pursuant to such rules and regulations.

It is management’s opinion that the accompanying unaudited interim financial statements reflect all adjustments (which are normal and recurring) that are necessary for a fair statement of the results for the interim periods. The unaudited interim financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2018, included in the Company’s Annual Report on Form

10-K

for the fiscal year ended December 31, 2018 filed with the SEC on March 5, 2019, or the Form

10-K.

The

year-end

balance sheet data was derived from the audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States.

The results disclosed in the statements of operations for the three and nine months ended September 30, 2019 are not necessarily indicative of the results to be expected for the full fiscal year.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States 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 its financial statements are:

•

Clinical trial expenses;

•

Collaboration agreements and revenue recognition;

•

Fair value measurements of stock-based compensation and Series 1 preferred stock; 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 October 22, 2019, the Company entered into the 2019 Research and Development Agreement, or the 2019 Agreement, with

The University of Texas M.D. Anderson Cancer Center, or

MD Anderson

pursuant to which the parties agreed to collaborate with respect to

the Company’s

Sleeping Beauty

immunotherapy program, which uses

non-viral

gene transfer to stably express and clinically evaluate neoantigen-specific TCRs in T cells. Under the 2019 Agreement, the parties will, among other things, collaborate on programs to expand

the Company’s

TCR library and conduct clinical trials.

The Company will own all intellectual property developed under the 2019 Agreement and will retain all rights to intellectual property for oncology products manufactured using

non-viral

gene transfer technologies under the Agreement, including the Company’s

Sleeping Beauty

technology. The Company has granted MD Anderson an exclusive license for such intellectual property outside the field of oncology and to develop and commercialize autologous TCR products manufactured using viral gene transfer technologies, and a

non-exclusive

license for allogeneic TCR products manufactured using viral-based technologies.

The Company has agreed, beginning on January

1, 2021, to reimburse MD Anderson up to a total of $20.0

million for development costs under the 2019 Agreement. In addition, the Company will pay MD Anderson royalties on net sales of its TCR products at rates in the low single digits. The Company is required to make performance-based payments upon the successful completion of clinical and regulatory benchmarks relating to its TCR products. The aggregate potential benchmark payments are $36.5

million, of which only $3.0

million will be due prior to the first marketing approval of the Company’s TCR products. The royalty rates and benchmark payments owed to MD Anderson may be reduced upon the occurrence of certain events. The Company also agreed that it will sell the Company’s TCR products to MD Anderson at preferential prices and will sell its TCR products in Texas exclusively to MD Anderson for a limited period of time following the first commercial sale of the Company’s TCR products.

The 2019 Agreement will terminate on December 31, 2026 and either party may terminate the 2019 Agreement following written notice of a material breach. The 2019 Agreement also contains customary provisions related to indemnification obligations, confidentiality and other matters. In connection with the execution of the 2019 Agreement, on October

22, 2019, the Company issued MD Anderson a warrant to purchase 3,333,333 shares of our common stock, or the Warrant. The Warrant has an initial exercise price of $0.001 per share, expires on December 31, 2026 and vests upon the occurrence of certain clinical milestones.

Also, in connection with the execution of the 2019 Agreement, on October 22, 2019, the

Company and MD Anderson

entered into the Fifth Amendment to

the

Research and Development Agreement, or

the Fifth Amendment, which amended the Research and Development Agreement, dated August 17, 2015

by and

between the

Company and MD Anderson

, or

the 2015 Agreement. The

2015

Agreement governed the research and development activities of the parties for

the Company’s

chimeric antigen receptor

(CAR-T)

program. The Fifth Amendment extended the term of the

2015

Agreement until December 31, 2026 and amended the terms of the

2015

Agreement to allow cash resources on hand at MD Anderson under the 2015 Agreement to now be used for development costs under the

2019

Agreement.

Financings

9 Months Ended

Sep. 30, 2019

Text Block [Abstract]

Financings

2. Financings

At-the-Market

Offering

During the three and nine months ended September 30, 2019, the Company sold an aggregate of 639,442 shares of its common stock. The offering was made pursuant to the Company’s effective registration statement on Form

S-3ASR

(Registration Statement No. 333-232283) previously filed with the SEC, and a prospectus supplement thereunder. The net proceeds from the offering were approximately $3.0 million after deducting underwriting discounts and estimated offering expenses payable by the Company.

November 2018 Private Placement and 2019 Inducement Warrants

On November 11, 2018,

the Com

pany

entered into a securities purchase agreement with certain institutional and accredited investors

pursuant

which it sold

an aggregate of 18,939,394 immediately separable units at a price per unit of $2.64

to such investors

, for net proceeds of approximately $47.1 million. Each unit was comprised of (i) one share of our common stock, par value $0.001 per share and (ii) a warrant to purchase one share of common stock. The securities issued by

the Company

pursuant to the securities purchase agreement and to be issued upon exercise of the warrants were not registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. When issuing the units,

the Company

relied on the private placement exemption from registration provided by Section 4(a)(2) of the Securities Act and by Rule 506 of Registration D, promulgated thereunder and on similar exemptions under applicable state laws and filed a Form D with the SEC on November 19, 2018. On February 7, 2019,

the Company

filed a registration statement on Form

S-3

registering the resale of shares issued pursuant to the securities purchase agreement and the resale of shares that may be issued upon exercise of the warrants.

On July 26, 2019 and September 1

, 2019, the Company entered into agreements for the exercise of the warrants issued in November 2018 to purchase common stock in a private placement. Pursuant to the terms of the agreement

, investors exercise

warrants for an aggregate of 17,803,031 shares of common stock, at an exercise price of $3.01 per share. The Company issued new warrants to purchase up to 17,803,031 additional shares of common stock

as an

inducement for warrant holders to exercise their 2018 warrants early.

The

new

warrants will become exercisable six months following the date of issuance, will expire on the fifth anniversary of the initial exercise date, and have an exercise price of $7.00

(

Note 14).

Proceeds from the

exercise of the warr

nts,

before deducting placement agent

fees

and other

rel

ted

expenses of $1.1 million were approximately $52.5 million.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2019

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

3. Summary of Significant Accounting Policies

The Company’s significant accounting policies were identified in the Company’s Form

10-K.

There have been no material changes in those policies since the filing of its Form

10-K

except as noted below.

Leases

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, and the Company adopted the standard on January 1, 2019.

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. The Company adopted Topic 842 as of January 1, 2019 using the effective date method, in which it did not restate prior periods. Upon adoption, the Company elected the package of practical expedients permitted under the transition guidance within Topic 842 which, among other things, allowed it to carry forward the historical lease classification.

The adoption of Topic 842 on January 1, 2019 resulted in recognition of approximately $1.6 million of

right-of-use

assets and $1.6 million of lease liabilities on the Company’s balance sheets. The adoption did not have a material impact on the Company’s statements of operations or accumulated deficit.

New Accounting Pronouncements

In August 2018, the FASB issued ASU

No. 2018-13,

Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

, or ASU

2018-03.

The guidance in this ASU modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. Under the new guidance, transfers between asset classes and the valuation related to level 3 assets is modified. The new standard is effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within each annual reporting period. The Company is currently evaluating the impact of the adoption of this ASU on the financial statements.

In June 2018, the FASB issued ASU

No. 2018-07,

Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting

, or ASU

2018-07.

The guidance in this ASU expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The new standard was effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within each annual reporting period. The Company adopted this ASU on January 1, 2019. The adoption did not have a material impact on the Company’s financial statements.

Variable Interest Entities

The Company reviews each legal entity formed by parties related to the Company to determine whether or not the entity is a Variable Interest Entity, or VIE. If the entity is a VIE, the Company assesses whether or not it is the primary beneficiary of that VIE based on a number of factors, including (i) which party has the power to direct the activities of the VIE that most significantly affect its economic performance, (ii) the parties’ contractual rights and responsibilities pursuant to any contractual agreements and (iii) which party has the obligation to absorb losses or the right to receive benefits from the VIE. If the Company determines that it is the primary beneficiary of a VIE, it consolidates the financial statements of the VIE into its consolidated financial statements at the time that determination is made. The Company evaluates whether it continues to be the primary beneficiary of any consolidated VIEs on a quarterly basis. If the Company determines that it is no longer the primary beneficiary of a consolidated VIE, or no longer has a variable interest in the VIE, the Company deconsolidates the VIE in the period that the determination is made

Fair Value Measurements

9 Months Ended

Sep. 30, 2019

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The Company accounts for its financial assets and liabilities using fair value measurements. The authoritative accounting guidance defines fair value, establishes a framework for measuring fair value under generally accepted accounting principles and enhances disclosures about fair value measurements. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value as follows:

•

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 September 30, 2019 and December 31, 2018 were as follows:


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of September 30, 2019		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	73,198	$	73,198	$	—	$	—



($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of December 31, 2018		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	24,437	$	24,437	$	—	$	—

The cash equivalents represent deposits in short-term United States treasury money market mutual fund

quoted in an active market and classified as a Level 1 asset

Net Loss per Share

9 Months Ended

Sep. 30, 2019

Earnings Per Share [Abstract]

Net Loss per Share

5. Net Loss per Share

Basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding for the period. The Company’s potentially dilutive shares, which include outstanding common stock options, unvested restricted stock and preferred stock, have not been included in the computation of diluted net loss per share for any of the periods presented as the result would be anti-dilutive. Such potentially dilutive shares of common stock at September 30, 2019 and 2018 consisted of the following:


	September 30,
	2019		2018
Stock options		4,995,549		4,569,468
Inducement stock options		965,000		—
Unvested restricted stock		1,569,579		1,164,352
Warrants		18,939,394		—
Preferred stock		—		52,583,921

		26,469,522		58,317,741

On October 5, 2018, the Company and Precigen, Inc., or Precigen, a wholly owned subsidiary of Intrexon Corporation, or Intrexon, entered into an exclusive license agreement, or the License Agreement, to replace all existing agreements between the companies that provides the Company with certain exclusive and

non-exclusive

rights to technology controlled by Precigen. 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

)

Revenue Recognition

9 Months Ended

Sep. 30, 2019

Revenue from Contract with Customer [Abstract]

Revenue Recognition

6. Revenue Recognition

The Company adopted Accounting Standards Codification, or ASC Topic 606,

Revenue from Contracts with Customers,

or ASC 606, using the modified retrospective approach on January 1, 2018. The Company completed its assessment and the implementation resulted in a cumulative effect adjustment to accumulated deficit as of January 1, 2018 of approximately $8.1 million and a corresponding increase to the contract liability (formerly deferred revenue). The adjustment to the Company’s financial statements due to the adoption of ASC 606 is related to the Company’s License and Collaboration Agreement with Ares Trading S.A., a subsidiary of Merck KGaA, or the Ares Trading Agreement (Note 6), which was the Company’s sole open revenue contract outstanding at January 1, 2018. The remaining revenue under the Ares Trading Agreement was recognized in 2018.

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

, as used in historical years. The core principle of ASC 606 is that an entity should recognize revenue to depict the transfer of promised goods and/or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and/or services. To determine the appropriate amount of revenue to be recognized for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following steps: (i) identify the contract(s) with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) each performance obligation is satisfied.

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. 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 (Note 6).

The Company did 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

re-evaluated

the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period since adoption, as applicable.

On October 5, 2018, the Company entered into the license agreement with Precigen (Note 7). As between the Company and Precigen, the terms of the License Agreement replace the terms of: (a) the Channel Agreement previously entered into with Intrexon Corporation, of the Channel Agreement, including all amendments to the Channel Agreement; (b) certain rights and obligations pursuant to the Ares Trading Agreement; (c) the MD Anderson License (Note 7); and (d) the 2015 Agreement and any amendments or statements of work thereto.

In partial consideration of the Company entering into the License Agreement, Precigen is required to use diligent good faith efforts to transfer the Company’s rights and obligations under the Ares Trading Agreement to Intrexon (or its affiliate). As a result, the Company has very limited remaining obligations under the Ares Trading Agreement, and following the Company’s entry into the License Agreement, will not be recognizing any additional revenue under the Ares Trading Agreement

Commitments and Contingencies

9 Months Ended

Sep. 30, 2019

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

7. Commitments and Contingencies

License Agreements

Exclusive License Agreement with Precigen, Inc.

On October 5, 2018, the Company entered into the License Agreement, with Precigen. 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 the Company, Intrexon and Areas 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) th

2015 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

gene switch, or RTS, for the treatment of cancer, referred to as

IL-12

Products, (ii) CAR products directed to (A) CD19 for the treatment of cancer, referred to as CD19 Products, and (B) a second target, subject to the rights of Merck to pursue such target under the Ares Trading Agreement, and (iii) TCR products designed for neoantigens for the treatment of cancer. Precigen has also granted the Company an exclusive, worldwide, royalty-bearing,

sub-licensable

license for certain patents relating to the

Sleeping Beauty

technology to research, develop and commercialize TCR products for both neoantigens and shared antigens for the treatment of cancer, referred to as TCR Products.

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 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.

In consideration of the licenses and other rights granted by Precigen, the Company will pay Precigen an annual license fee of $0.1 million 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. 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.

There have been no royalties from net sales under the License Agreement for the three and nine months ended September 30, 2019.

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

License Agreement—The University of Texas MD Anderson Cancer Center

On January 13, 2015, the Company, together with Intrexon, entered into the MD Anderson License with MD Anderson (which Intrexon subsequently assigned to Precigen). 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

On August 17, 2015, the Company, Precigen and MD Anderson entered into the

2015

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

2015

Agreement, the Company, Precigen and MD Anderson formed a joint steering committee to oversee and manage the new and ongoing research programs. Under the License Agreement with Precigen, the Company 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

2015

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. On October 22, 2019, the Company entered into the Fifth Amendment, which extended the term of the 2015 Agreement until December 31, 2026 and amended the terms of the 2015 Agreement to allow cash resources on hand at MD Anderson under the 2015 Agreement to now be used for development costs under the 2019 Agreement. During the nine months ended September 30, 2019 and 2018, the Company expensed approximately

$4.7 million and $4.0 million, respectively, for its research programs being conducted in Houston. The net balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $21.5 million which is classified under prepaid

expenses

and other current assets on the balance sheet at September 30, 2019. At December 31, 2018, the net balance of cash resources on hand at MD Anderson available to offset expenses and future costs was $27.8 million, of which $18.4 million was included in prepaid

expenses

and other current assets and the remaining $9.4 million was included in

non-current

assets.

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 the Company 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 the Company 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 the Company and Precigen and may be terminated by the mutual written agreement of the Company, Precigen, and MD Anderson.

License Agreement with the National Cancer Institute

On May 28, 2019, the Company entered into a patent license agreement, or the Patent License, with the National Cancer Institute, or the NCI. Pursuant to the Patent License, the Company holds an exclusive, worldwide license to certain intellectual property to develop and commercialize patient-derived (autologous), peripheral blood

T-cell

therapy products engineered by transposon-mediated gene transfer to express TCRs reactive to mutated KRAS, p53 and EGFR. In addition, pursuant to the Patent License, the Company holds an exclusive, worldwide license to certain intellectual property for manufacturing technologies to develop and commercialize autologous, peripheral blood

T-cell

therapy products engineered by

non-viral

gene transfer to express TCRs, as well as a

non-exclusive,

worldwide license to certain additional manufacturing technologies.

Pursuant to the terms of the Patent License, the Company is required to pay the NCI a cash payment in the aggregate amount of $1.5

million

payable in $0.5 million installments within sixty days, six-months, and

the

twelve-month anniversary of the effective date of the agreement

for the Patent License

. The Company also agreed to reimburse the NCI for past patent expenses in the aggregate amount of

approximately $46 thousand. During the three and nine months ended September 30, 2019, the Company made payments under the Patent License for $0.5 million. At September 30, 2019, the Company included the remaining $1.0 million for the Patent License as current liabilities on the Company’s balance sheet.

The terms of the Patent License also require the Company to pay the NCI minimum annual royalties in the amount of $0.3 million, which amount will be reduced to $0.1 million once the aggregate minimum annual royalties paid by the Company equals $1.5 million. The first minimum annual royalty payment is payable on the date that is eighteen months following the date of the Patent License.

The Company is also required to make performance-based payments upon successful completion of clinical and regulatory benchmarks relating to the licensed products. The aggregate potential benchmark payments are $4.3 million, of which aggregate payments of $3.0 million are due only after marketing approval in the United States or in Europe, Japan, Australia, China or India. The first benchmark payment of $0.1 million will be due upon the initiation of the Company’s first sponsored phase 1 clinical trial of a licensed product or licensed process in the field of use licensed under the Patent License.

In addition, the Company is required to pay the NCI

one-time

benchmark payments following aggregate net sales of licensed products at certain net sales up to $1.0

billion. The aggregate potential amount of these benchmark payments is $12.0

million. The Company must also pay the NCI royalties on net sales of products covered by the Patent License at rates in the low to

mid-single

digits depending upon the technology included in a licensed product. To the extent the Company enters into a sublicensing agreement relating to a licensed product, the Company is required to pay the NCI a percentage of all consideration received from a sublicensee, which percentage will decrease based on the stage of development of the licensed product at the time of the sublicense.

The Patent License will expire upon expiration of the last patent contained in the licensed patent rights, unless terminated earlier. The NCI may terminate or modify the Patent License in the event of a material breach, including if the Company does not meet certain milestones by certain dates, or upon certain insolvency events that remain uncured following the date that is 90 days following written notice of such breach or insolvency event. The Company may terminate the Patent License, or any portion thereof, in the Company’s sole discretion at any time upon 60 days’ written notice to the NCI. In addition, the NCI has the right to: (i) require the Company to sublicense the rights to the product candidates covered by the Patent License upon certain conditions, including if the Company is not reasonably satisfying required health and safety needs and (ii) terminate or modify the Patent License, including if the Company is not satisfying requirements for public use as specified by federal regulations.

Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute

On January 10, 2017, the Company announced the signing of a Cooperative Research and Development Agreement, or CRADA, with the NCI for the development of adoptive cell transfer, or ACT,-based immunotherapies genetically modified using the

Sleeping Beauty

transposon/transposase system to express TCRs for the treatment of solid tumors. The principal goal of the CRADA is to develop and evaluate ACT for patients with advanced cancers using autologous peripheral blood lymphocytes, or PBL, genetically modified using the

non-viral

Sleeping Beauty

system to express TCRs that recognize neoantigens expressed within a patient’s cancer. Research conducted under the CRADA will be at the direction of Steven A. Rosenberg, M.D., Ph.D., Chief of the Surgery Branch at the NCI, in collaboration with the Company’s researchers.

In February 2019, the Company extended the CRADA with the NCI for two years, committing an additional $5.0 million to this program through January 2022. The remaining obligation, as of September 30, 2019, to the NCI under the CRADA is $5.6 million over the next two years, payable in $0.6 million payments on a quarterly basis. The Company made payments of $0.6 million and $1.9 million, during the three and nine months ended September 30, 2019 and 2018, respectively.

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 9.

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, 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 three and nine months ended September 30,

2018

, the Company expensed $36 thousand under the Ares Trading Agreement. The Company did not incur any costs under the agreement for the nine months ended September 30, 2019 as there are no continuing obligations to reimburse Precigen for expenses under the Ares Trading Agreement under the terms of the License Agreement with Precigen.

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 Third Amendment to Exclusive Channel Partner Agreement, or the 2016 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 a related party relationship as described in Note

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, the Company was 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.

Under the terms of the agreement, the Company may be required to make additional payments to the Licensors 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 which was amended on July 31, 2014 to include an exclusive worldwide license. 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

As consideration for the license, the Company is 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.

Related Party Transactions

9 Months Ended

Sep. 30, 2019

Related Party Transactions

8. Related Party Transactions

Collaborations with Intrexon/ Precigen

During the three and nine months ended September 30, 2018, the Company issued an aggregate of 3,847 and 11,205 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, respectively. At September 30, 2018, the Company recorded such shares of Series 1 preferred stock at a fair value of $6.1 million which is a component of temporary equity. During the nine months ended September 30, 2018, the Company recorded a gain on the change of the derivative liabilities in the amount of $0.2 million

(Note 12)

During the nine months ended September 30, 2019 and 2018, the Company expensed $1.7 million and $6.7 million, respectively, for services performed by Precigen. As of September 30, 2019 and December 31, 2018, the Company recorded $0.8 million and $1.9 million, respectively, in current liabilities on its balance sheet for amounts due to Precigen.

On October 5, 2018, the Company entered into the License Agreement, the terms of which replaced the terms of the Channel Agreement

(Note 9)

Collaboration with Precigen and MD Anderson

On January 13, 2015, the Company, together with Intrexon, entered into the MD Anderson License with MD Anderson (which Intrexon subsequently assigned to Precigen). 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,

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. 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 nine months ended September 30, 2018, the Company made one quarterly payment totaling $2.7 million, bringing the total aggregate payments to $41.9 million under this arrangement. The balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $21.5 million

which is classified under prepaid expenses and other current assets at September 30, 2019. The classification is based on management’s current estimate of plans to utilize the prepaid expense balance and is subject to revision on a quarterly basis.

Settlement of a Related Party Relationship

9 Months Ended

Sep. 30, 2019

Settlement of relatedparty relationship

9. Settlement of a Related Party Relationship

Exclusive License Agreement with Precigen

On October 5, 2018, the Company entered into the license agreement with Precigen. As between the Company and Precigen, the terms of the License Agreement replace the terms of: (a) the Channel Agreement, including all amendments to the Channel Agreement; (b) certain rights and obligations pursuant to the Ares Trading Agreement; (c) the MD Anderson License; and (d) the

2015

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

gene switch, or RTS, for the treatment of cancer, referred to as

IL-12

Products, (ii) CAR products directed to (A) CD19 for the treatment of cancer, referred to as CD19 Products, and (B) a second target, subject to the terms of the Ares Trading Agreement, and (iii) TCR Products designed for neoantigens for the treatment of cancer. Precigen has also granted the Company an exclusive, worldwide, royalty-bearing,

sub-licensable

license for certain patents relating to the

Sleeping Beauty

technology to research, develop and commercialize TCR Products.

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 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 was included in accrued expense on the balance sheet. The accrued balance is $0.8 million at September 30, 2019.

The agreement also calls for an annual license fee of $0.1 million 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

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). See Note

for further information regarding the Company’s remaining obligations under the Ares Trading Agreement.

The Company determined that this transaction represented a capital transaction between related parties. The Company calculated the fair value of 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 Company’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

). 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

Leases

9 Months Ended

Sep. 30, 2019

Leases, Operating [Abstract]

Leases

10. Leases

The Company adopted Topic 842 on January 1, 2019 using the effective date method, in which it did not restate prior periods. Upon adoption, the Company elected the package of practical expedients permitted under the transition guidance within Topic 842 which, among other things, allowed it to carry forward the historical lease classification. The Company does not allocate consideration in its leases to lease and

non-lease

components and does not record leases on its balance sheets with terms of 12 months or less.

The Company uses its estimated incremental borrowing rate, which is derived from information available at the lease commencement date, in determining the present value of lease payments. The Company’s incremental borrowing rate represents the rate of interest that it would have to pay to borrow over a similar term an amount equal to the lease payments in a similar economic environment. The Company considers publicly available data for instruments with similar terms and characteristics when determining its incremental borrowing rates.

The adoption of Topic 842 resulted in recognition of approximately $1.6 million of

right-of-use

assets and $1.6 million of lease liabilities on the Company’s balance sheets. The adoption did not have a material impact on the Company’s statements of operations or accumulated deficit. The Company will review the classification of newly entered leases as either an operating or a finance lease and recognize a related

right-of-use

asset and lease liabilities on its balance sheets upon commencement.

In June 2012, the Company entered into a master lease for the Company’s corporate headquarters in Boston office, which was originally set to expire in August 2016, but renewed through

August 31, 2021

. As of September 30, 2019, and December 31, 2018, a total security deposit of $0.1 million is included in deposits on the Company’s balance sheet.

On January 30, 2018, the Company entered into a lease agreement for office space in Houston at MD Anderson. Under the terms of the Houston lease agreement, the Company leases 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 the Company’s prepayments at MD Anderson.

On March 12, 2019, the Company entered into a lease agreement for office space in Houston. Under the terms of the Houston lease agreement, the Company leases approximately one thousand and thirty-eight square feet and is required to make rental payments at an average monthly rate of approximately $2 thousand through April 2021.

The components of lease expense were as follows:


(in thousands)	Three Months Ended September 30, 2019			Nine Months Ended September 30, 2019
Operating lease cost	$	184		$	585

Total lease cost	$	184		$	585

Weighted-average remaining lease term (years)		2. 15			2.15
Weighted-average discount rate		8.00	%		8.00	%

Cash paid for amounts included in the measurement of the lease liabilities were $0.5 million for the nine months ended September 30, 2019.

As of September 30, 2019, the maturities of the Company’s operating lease liabilities were as follows (in thousands):


Maturity of Lease Liabilities	Operating Leases
2019(excluding the nine months ended September 30, 2019)	$	188
2020		755
2021		491

Total lease payments	$	1,434
Less: Imputed Interest and Adjustments		110

Present value of lease payments	$	1,324

Disclosures related to periods prior to adoption of the New Lease Standard

Prior to the adoption of ASC 842, the Company recorded rent expense on a straight-line basis over the term of the lease under ASC 840. Total rent expense for the three and nine months ended September 30, 2018 was approximately $0.1 million and $0.5 million, respectively.

For comparative purposes, the Company’s aggregate future minimum

non-cancellable

commitments under operating leases as of December 31, 2018 were as follows:


2019		723
2020		736
2021		488

Future minimum lease payments, net	$	1,947

Stock-Based Compensation

9 Months Ended

Sep. 30, 2019

Text Block [Abstract]

Stock-Based Compensation

11. Stock-Based Compensation

The Company recognized stock-based compensation expense on all employee and

non-employee

awards as follows:


	For the three months ended September 30,				For the nine months ended September 30,
(in thousands)	2019		2018		2019		2018
Research and development	$	339	$	552	$	1,068	$	1,765
General and administrative		1,147		928		3,673		5,085
Stock-based compensation expense	$	1,486	$	1,480	$	4,741	$	6,850

The Company granted an aggregate of 140,000 and 1,835,755 stock options during the three and nine months ended September 30, 2019 with a weighted-average grant date fair value of $3.05 and $1.90 per share, respectively. The Company granted an aggregate of 300,500 and 506,000 stock options during the three and nine months ended September 30, 2018 with a weighted average grant date fair value of $2.11 and $2.49 per share, respectively.

On January 6, 2019, the Company paid an accrued annual performance bonus by issuing 446,428 shares of common stock.

On June 13, 2019 the Company extended the contractual life of 52,500 fully vested stock options held by a director of the Company. Additionally, on June 13, 2019, the Company accelerated the vesting and extended the contractual life of 126,700 stock options held by a director. These extensions and acceleration of vesting resulted in additional stock compensation expense of $0 and $0.4 million in the three and nine months ended September 30, 2019.

On February 15, 2018, the Company extended the contractual life of 751,667 fully vested stock options held by an officer of the Company by an additional nine months. Additionally, on March 12, 2018, the Company extended the contractual life of 117,500 fully vested stock options held by a director. These extensions did not result in additional stock compensation expense for the three months ended September 30, 2018. Additional stock compensation expense of $0.5 million was recorded for the nine months ended September 30, 2018.

For the three months ended September 30, 2019 and 2018, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions:


	For the three months ended September 30,
	2019	2018
Risk-free interest rate	1.39 - 1.92%	2.82 - 2.98%
Expected life in years	6.25	6
Expected volatility	72.87 - 78.34%	82.27 - 83.08%
Expected dividend yield	0	0

Stock option activity under the Company’s stock option plan for the nine months ended September 30, 2019 is 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, 2018		5,277,085		$	4.24
Granted		1,835,755			2.69
Exercised		(482,500	)		3.48
Cancelled		(1,634,791	)		4.11

Outstanding, September 30, 2019		4,995,549		$	3.78		7.84	$	6,025

Options exercisable, September 30, 2019		2,581,327		$	4.59		6.60	$	2,425

Options exercisable, December 31, 2018		3,099,935		$	5.15		4.93	$	88

Options available for future grant		3,971,940

At September 30, 2019, total unrecognized compensation costs related to unvested stock options outstanding amounted to $6.7 million. The cost is expected to be recognized over a weighted-average period of 1.78 years.

A summary of the status of unvested restricted stock for the nine months ended September 30, 2019 is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Non-vested, December 31, 2018		682,070		$	3.47
Granted		1,408,536			2.26
Vested		(446,428	)		2.24
Cancelled		(74,599	)		3.41

Non-vested, Se ptember 30, 2019		1,569,579		$	2.91

At September 30, 2019, total unrecognized compensation costs related to unvested restricted stock outstanding amounted to $2.8 million. The cost is expected to be recognized over a weighted-average period of 1.48 years.

Preferred Stock

9 Months Ended

Sep. 30, 2019

Equity [Abstract]

Preferred Stock

12. Preferred Stock

The Company’s Board of Directors is 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 Amendment to Exclusive Channel Collaboration Agreement, or the 2016 GvHD Amendment, with Intrexon (now Precigen) (Note

). 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, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other recapitalization. The Series 1 preferred stock had certain rights, preferences, privileges and obligations, including dividend rights, conversion rights, consent rights with respect to certain Company actions, and rights to preferential payments in the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or a change of control or sale, lease, transfer or exclusive license of all or substantially all of the Company’s assets prior to the conversion of the Series 1 preferred stock.

On October 5, 2018, the Company and Precigen entered into the License Agreement to replace all existing agreements between the companies, which provides the Company with certain exclusive and

non-exclusive

rights to technology controlled by Precigen. 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

and

Warrants

9 Months Ended

Sep. 30, 2019

Warrants Disclosure [Abstract]

Warrant

14. Warrants

In connection with the Company’s November 2018 private placement which provided net proceeds of approximately $47.1 million, the Company issued warrants to purchase an aggregate of 18,939,394 shares of common stock which became exercisable

six

months after the closing of the private placement. 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 (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with Financial Accounting Standards

Board (“FASB”) Accounting

Standards Codification (“ASC”) Topic 815,

Derivatives and Hedging

. As such, the Company has concluded the warrants meet the scope exception for determining whether the instruments require accounting as derivatives and should be classified in stockholders’ equity.

On July 26, 2019 and September 12, 2019, the Company entered into agreements with existing investors for the exercise of previously issued warrants to purchase common stock in a private placement. Pursuant to the terms of the agreements, investors exercised their 2018 warrants for an aggregate of 17,803,031 shares of common stock, at an exercise price of $3.01 per share. The warrants exercised were originally issued by the Company in a private placement that closed in November 2018 (Note 2). Proceeds from the warrant exercise, after deducting placement agent fees and other related expenses of $1.1 million were approximately $52.5 million. The Company issued the participating investors new warrants to purchase up to 17,803,031 additional shares of common stock as an inducement for the warrant holders to exercise their 2018 warrants early. The 2019 warrants will become exercisable six months following the date of issuance, will expire on the fifth anniversary of the initial exercise date, and have an exercise price of $7.00. The 2019 warrants were valued using a Black-Scholes valuation model and resulted in a $60.8 million non-cash charge to the Company’s statement of operations for the three and nine months ended September 30, 2019.

The Company assessed whether the 2019 warrants require accounting as derivatives. The Company determined that the warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with FASB ASC Topic 815,

Derivatives and Hedging

Joint Venture

9 Months Ended

Sep. 30, 2019

Equity Method Investments and Joint Ventures [Abstract]

Joint Venture

15. Joint Venture

On December 18, 2018, the Company entered into a Framework Agreement with TriArm Therapeutics, Ltd., or TriArm, whereby the parties will launch Eden BioCell, Ltd., or Eden BioCell, to lead clinical development and commercialization of certain Sleeping Beauty-generated CAR-T therapies as set forth in a separate license agreement.

On January 3, 2019, Eden BioCell was incorporated in Hong Kong as a private company. Eden BioCell, the Company and TriArm entered into a Share Subscription Agreement on January 23, 2019, where the Company and TriArm agreed to contribute certain intellectual property, services and cash (only with respect to TriArm) to Eden BioCell to subscribe for a certain number of newly issued ordinary shares in the share capital of Eden BioCell. On the closing date, upon the issuance and subscription of the shares, in respect of the aforementioned consideration, 10,000,000 ordinary shares were issued to the Company and 10,000,000 ordinary shares were issued to TriArm.

The closing of the transaction occurred on July 5, 2019. The Framework Agreement and Share Subscription Agreements were each respectively amended to be effective as of this date. Upon consummation of the joint venture, Eden BioCell and the Company also entered into a license agreement, pursuant to which the Company licensed the rights to Eden BioCell for third-generation

Sleeping Beauty

-generated CAR-T therapies targeting the CD19 antigen for the territory of China (including Macau and Hong Kong), Taiwan and Korea. Eden BioCell will be responsible for certain milestone and royalty payments to related to the Company’s license agreements with MD Anderson and Precigen, Inc. (Note 7). TriArm entered into a Master Services Agreement with Eden BioCell and contributed $10.0 million of cash on the closing date. TriArm also committed to contribute an additional $25.0 million to Eden BioCell over time through the achievement of specified milestones. TriArm and the Company each received a 50% equity interest in the joint venture in exchange for their contributions to Eden BioCell.

As of July 5, 2019, as a result of the design and purpose of Eden BioCell, the Company determined that Eden BioCell was considered a

varia

ble interest

entity

, or VIE,

and concluded that it is not the primary beneficiary of the VIE as it did not have the power to direct the activities of the VIE that most significantly impact its performance. Rather, the Company accounts for the equity interest in Eden BioCell under the equity method of accounting as it has the ability to exercise significant influence over the operations of Eden BioCell.

The Company determined that Eden BioCell was not a customer and therefore, accounted for the transaction as the transfer of nonfinancial assets to be

recognized at their fair value on the contribution date.

The fair value of the

intellectual property contributed to Eden BioCell

had a de minimis value due to the early stage of the technology and the likelihood of clinical success. Due to

the

de minimis fair value of the

intellectual property contributed

, the Company did not record a gain or loss on this transaction and recognized a value of $0 for their equity-method investment.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2019

Accounting Policies [Abstract]

Leases

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

The adoption of Topic 842 on January 1, 2019 resulted in recognition of approximately $1.6 million of

right-of-use

assets and $1.6 million of lease liabilities on the Company’s balance sheets. The adoption did not have a material impact on the Company’s statements of operations or accumulated deficit.

New Accounting Pronouncements

In August 2018, the FASB issued ASU

No. 2018-13,

Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

, or ASU

2018-03.

In June 2018, the FASB issued ASU

No. 2018-07,

Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting

, or ASU

2018-07.

Variable Interest Entities

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2019

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 were as follows:


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of September 30, 2019		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	73,198	$	73,198	$	—	$	—



($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of December 31, 2018		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	24,437	$	24,437	$	—	$	—

Leases (Tables)

9 Months Ended

Sep. 30, 2019

Leases, Operating [Abstract]

Components of Lease Expense

The components of lease expense were as follows:


(in thousands)	Three Months Ended September 30, 2019			Nine Months Ended September 30, 2019
Operating lease cost	$	184		$	585

Total lease cost	$	184		$	585

Weighted-average remaining lease term (years)		2. 15			2.15
Weighted-average discount rate		8.00	%		8.00	%

Lessee, Operating Lease, Liability, Maturity

As of September 30, 2019, the maturities of the Company’s operating lease liabilities were as follows (in thousands):


Maturity of Lease Liabilities	Operating Leases
2019 (excluding the nine months ended September 30, 2019)	$	188
2020		755
2021		491

Total lease payments	$	1,434
Less: Imputed Interest and Adjustments		110

Present value of lease payments	$	1,324

Future Net Minimum Lease Payments under Operating Leases

For comparative purposes, the Company’s aggregate future minimum

non-cancellable

commitments under operating leases as of December 31, 2018 were as follows:


2019		723
2020		736
2021		488

Future minimum lease payments, net	$	1,947

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Text Block [Abstract]

Stock-Based Compensation Expense on All Employee and Non-Employee Awards

The Company recognized stock-based compensation expense on all employee and

non-employee

awards as follows:


	For the three months ended September 30,				For the nine months ended September 30,
(in thousands)	2019		2018		2019		2018
Research and development	$	339	$	552	$	1,068	$	1,765
General and administrative		1,147		928		3,673		5,085

Stock-based compensation expense	$	1,486	$	1,480	$	4,741	$	6,850

Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model

For the three months ended September 30, 2019 and 2018, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions:


	For the three months ended September 30,
	2019	2018
Risk-free interest rate	1.39 - 1.92%	2.82 - 2.98%
Expected life in years	6.25	6
Expected volatility	72.87 - 78.34%	82.27 - 83.08%
Expected dividend yield	0	0

Stock Option Activity under Stock Option Plan

Stock option activity under the Company’s stock option plan for the nine months ended September 30, 2019 is 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, 2018		5,277,085		$	4.24

Granted		1,835,755			2.69
Exercised		(482,500	)		3.48
Cancelled		(1,634,791	)		4.11

Outstanding, September 30, 2019		4,995,549		$	3.78		7.84	$	6,025

Options exercisable, September 30, 2019		2,581,327		$	4.59		6.60	$	2,425

Options exercisable, December 31, 2018		3,099,935		$	5.15		4.93	$	88

Options available for future grant		3,971,940

Summary of Unvested Restricted Stock

A summary of the status of unvested restricted stock for the nine months ended September 30, 2019 is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Non-vested, December 31, 2018		682,070		$	3.47
Granted		1,408,536			2.26
Vested		(446,428	)		2.24
Cancelled		(74,599	)		3.41

Non-vested, Se ptember 30, 2019		1,569,579		$	2.91

Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 22, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Cash and cash equivalents		$ 88,419		$ 88,419		$ 61,729
Accumulated deficit		(668,379)		(668,379)		$ (566,329)
Research and development expense		$ 8,641	$ 8,263	$ 28,115	$ 25,935
Subsequent Event [Member] \| Two Thousand Nineteen Agreement [Member]
Number of shares issued for warrants	3,333,333
Exercise price of warrants	$ 0.001
License agreement termination date	Dec. 31, 2026
Warrants expire date	Dec. 31, 2026
Subsequent Event [Member] \| MD Anderson License and the Research and Development Agreement Member [Member] \| Two Thousand Nineteen Agreement [Member]
Research and development expense	$ 20,000
Subsequent Event [Member] \| MD Anderson License and the Research and Development Agreement Member [Member] \| Two Thousand Nineteen Agreement [Member] \| Performance Based Payments Member [Member]
Aggregate Benchmark Payments Payable	36,500
Subsequent Event [Member] \| MD Anderson License and the Research and Development Agreement Member [Member] \| Two Thousand Nineteen Agreement [Member] \| Performance Based Payments Member [Member] \| Post Marketing Approval [Member]
Aggregate Benchmark Payments Payable	$ 3,000

Financings - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	9 Months Ended
	Sep. 12, 2019	Nov. 11, 2018	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock, par value			$ 0.001	$ 0.001	$ 0.001
Gross proceeds received			$ 2,971	$ 2,971
Proceeds from private placement	$ 52,500
At The Market Offering [Member]
Class of Stock [Line Items]
Stock issued during period			639,442	639,442
Sale of stock consideration received on transaction			$ 3,000	$ 3,000
Private Placement [Member]
Class of Stock [Line Items]
Class of warrant or right, number of securities called by warrants or rights	17,803,031		18,939,394	18,939,394
Warrant Exercise Price per share	$ 3.01		$ 3.01	$ 3.01
Placement agent fees and other expenses	$ 1,100
Private Placement [Member] \| New Warrants [Member]
Class of Stock [Line Items]
Class of warrant or right, number of securities called by warrants or rights	17,803,031
Warrant Exercise Price per share	$ 7.00
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		$ 47,100