Alaunos Therapeutics (TCRT) 10-K26 Feb 152014 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Dec. 31, 2014	Feb. 10, 2015	Jun. 30, 2014
Document Information [Line Items]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	ZIOP
Entity Registrant Name	ZIOPHARM ONCOLOGY INC
Entity Central Index Key	1107421
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		114,694,324
Entity Public Float			$327,143,169

BALANCE_SHEETS

BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$42,803	$68,204
Receivables	145	145
Prepaid expenses and other current assets	1,139	1,948
Total current assets	44,087	70,297
Property and equipment, net	531	801
Deposits	128	128
Other non current assets	491	528
Total assets	45,237	71,754
Current liabilities:
Accounts payable	2,004	422
Accrued expenses	7,182	6,357
Deferred revenue - current portion	1,360	800
Deferred rent - current portion	280	212
Total current liabilities	10,826	7,791
Deferred revenue		1,933
Deferred rent	570	851
Warrant liabilities		11,776
Other long term liabilities		20
Total liabilities	11,396	22,371
Commitments and contingencies (note 8)
Stockholders' equity:
Common stock, $0.001 par value; 250,000,000 shares authorized; 104,452,105 and 100,159,618 shares issued and outstanding at December 31, 2014 and 2013, respectively	104	100
Additional paid-in capital - common stock	406,349	386,511
Additional paid-in capital - warrants issued		3,603
Accumulated Deficit	-372,612	-340,831
Total stockholders' equity	33,841	49,383
Total liabilities and stockholders' equity	$45,237	$71,754

BALANCE_SHEETS_Parenthetical

BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jan. 12, 2011	Apr. 26, 2006
Common stock, par value	$0.00	$0.00	$0.00	$0.00
Common stock, shares authorized	250,000,000	250,000,000		250,000,000
Common stock, shares issued	104,452,105	100,159,618
Common stock, shares outstanding	104,452,105	100,159,618

STATEMENTS_OF_OPERATIONS

STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue	$1,373	$800	$800
Operating expenses:
Research and development	32,706	42,852	83,446
General and administrative	12,166	15,661	19,523
Total operating expenses	44,872	58,513	102,969
Loss from operations	-43,499	-57,713	-102,169
Other income (expense), net	-5	-579	-13
Change in fair value of warrants	11,723	1,185	6,050
Net loss	($31,781)	($57,107)	($96,132)
Basic and diluted net loss per share	($0.31)	($0.66)	($1.22)
Weighted average common shares outstanding used to compute basic and diluted net loss per share	101,130,710	85,943,175	78,546,112

STATEMENTS_OF_CHANGES_IN_STOCK

STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Employee Stock Option	Common Stock	Common Stock	Additional Paid-in Capital Common Stock	Additional Paid-in Capital Common Stock	Additional Paid-in Capital Warrants	Deficit Accumulated During the Development Stage	Registered direct offering	Registered direct offering	Registered direct offering	Collaboration Agreement	Collaboration Agreement	Collaboration Agreement
In Thousands, except Share data	Total	Employee Stock Option	Common Stock	Employee Stock Option	Additional Paid-in Capital Common Stock	Employee Stock Option	Additional Paid-in Capital Warrants	Deficit Accumulated During the Development Stage	Registered direct offering	Common Stock	Additional Paid-in Capital Common Stock	Collaboration Agreement	Common Stock	Additional Paid-in Capital Common Stock
Beginning Balance at Dec. 31, 2011	$71,607		$69		$246,519		$12,611	($187,592)
Beginning Balance (in shares) at Dec. 31, 2011			69,206,044
Stock-based compensation	4,880				4,880
Exercise of warrants to purchase common stock (in shares)	259,660		259,660
Issuance of common stock (in shares)										10,114,401			3,636,926
Issuance of common stock									49,170	11	49,159	18,694	3	18,691
Exercise of warrants to purchase common stock	742				1,011		-269
Exercise of employee stock options (in shares)	8,300			8,300
Exercise of employee stock options		30				30
Issuance of restricted common stock			258,032
Repurchase of shares of restricted common stock (in shares)			-123,153
Repurchase of shares of restricted common stock	-546				-546
Cancelled/ Forfeiture of unvested restricted common stock			-123,370
Expired warrants					5,433		-5,433
Net loss	-96,132							-96,132
Ending Balance at Dec. 31, 2012	48,445		83		325,177		6,909	-283,724
Ending Balance (in shares) at Dec. 31, 2012			83,236,840
Stock-based compensation	3,507				3,507
Exercise of warrants to purchase common stock (in shares)	112,808		112,808
Issuance of common stock (in shares)										16,445,000
Issuance of common stock									53,880	16	53,864
Exercise of warrants to purchase common stock	200				396		-196
Exercise of employee stock options (in shares)	570,168			570,168
Exercise of employee stock options		956		1		955
Issuance of restricted common stock			75,272
Repurchase of shares of restricted common stock (in shares)			-116,723
Repurchase of shares of restricted common stock	-498				-498
Cancelled/ Forfeiture of unvested restricted common stock			-163,747
Expired warrants					3,110		-3,110
Net loss	-57,107							-57,107
Ending Balance at Dec. 31, 2013	49,383		100		386,511		3,603	-340,831
Ending Balance (in shares) at Dec. 31, 2013			100,159,618
Stock-based compensation	4,743				4,743
Exercise of warrants to purchase common stock (in shares)	3,725,277		3,747,254
Exercise of warrants to purchase common stock	10,654		4		13,963		-3,313
Exercise of employee stock options (in shares)	613,138			613,138
Exercise of employee stock options		1,386				1,386
Issuance of restricted common stock			66,828
Repurchase of shares of restricted common stock (in shares)			-112,333
Repurchase of shares of restricted common stock	-544				-544
Cancelled/ Forfeiture of unvested restricted common stock			-22,400
Expired warrants					290		-290
Net loss	-31,781							-31,781
Ending Balance at Dec. 31, 2014	$33,841		$104		$406,349		$0	($372,612)
Ending Balance (in shares) at Dec. 31, 2014			104,452,105

STATEMENTS_OF_CHANGES_IN_STOCK1

STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (Registered direct offering, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Registered direct offering
Issuance of common stock, issuance expenses	$3,678	$3,426

STATEMENTS_OF_CASH_FLOWS

STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net loss	($31,781)	($57,107)	($96,132)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	462	738	658
Stock-based compensation	4,743	3,507	4,880
Change in fair value of warrants	-11,723	-1,185	-6,050
Loss on disposal of fixed assets		585	48
Common stock issued in exchange for in-process research and development			18,694
(Increase) decrease in:
Receivables		-87	21
Prepaid expenses and other current assets	809	4,964	-5,599
Other noncurrent assets	37	473	-230
Deposits		4	-43
Increase (decrease) in:
Accounts payable	1,582	-1,087	-218
Accrued expenses	827	-10,159	5,695
Deferred revenue	-1,373	-800	-800
Deferred rent	-213	625	244
Other noncurrent liabilities	-20	20
Net cash used in operating activities	-36,650	-59,509	-78,832
Cash flows from investing activities:
Purchases of property and equipment	-193	-132	-1,559
Proceeds from sale of property and equipment		1
Net cash used in investing activities	-193	-131	-1,559
Cash flows from financing activities:
Proceeds from exercise of stock options	1,386	956	30
Payments to employees for repurchase of restricted common stock	-544	-498	-546
Proceeds from exercise of warrants	10,600	200	330
Proceeds from issuance of common stock and warrants, net		53,880	49,170
Net cash provided by financing activities	11,442	54,538	48,984
Net decrease in cash and cash equivalents	-25,401	-5,102	-31,407
Cash and cash equivalents, beginning of period	68,204	73,306	104,713
Cash and cash equivalents, end of period	42,803	68,204	73,306
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:
Exercise of liability-classified warrants to common shares	54		412
Warrants
Supplementary disclosure of noncash investing and financing activities:
Exercise of equity-classified warrants to common shares	$692	$196	$269

Organization

Organization	12 Months Ended
	Dec. 31, 2014
Organization	1	Organization
	ZIOPHARM Oncology, Inc., which we refer to as “ZIOPHARM” or the “Company”, is a biopharmaceutical company that seeks to acquire, develop and commercialize, on its own or with commercial partners, a diverse portfolio of cancer therapies that can address unmet medical needs through synthetic biology.
	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 minimal revenues. The Company anticipates that losses will continue for the foreseeable future. At December 31, 2014, the Company’s accumulated deficit was approximately $372.6 million. Taking into account the receipt of approximately $94.6 million in net proceeds from the February 2015 public offering of common stock, and given the development plans, the Company anticipates cash resources will be sufficient to fund operations into the first quarter of 2017. 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. Additional financing will be required to continue operations after the Company exhausts its current cash resources and to continue its long-term plans for clinical trials and new product development. There can be no assurance that any such financing can be obtained by the Company, or if obtained, what the terms thereof may be, or that any amount that the Company is able to raise will be adequate to support the Company’s working capital requirements until it achieves profitable operations.

Financings

Financings	12 Months Ended
	Dec. 31, 2014
Financings	2	Financings
	On February 3, 2015, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC, as representative of the several underwriters named therein, relating to the issuance and sale of 10,000,000 shares of our common stock. The price to the public in the offering was $8.75 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $8.225 per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 1,500,000 shares of common stock at a purchase price of $8.225 per share. The offering was made pursuant to the Company’s effective registration statement on Form S-3 (Registration Statement No. 333-201826) previously filed with the SEC, and a prospectus supplement thereunder. The underwriters purchased the 10,000,000 shares and the additional 1,500,000 shares on February 9 and February 17, 2015, respectively. The net proceeds from the offering were approximately $94.2 million after deducting underwriting discounts and estimated offering expenses payable by the Company.
	On October 23, 2013, the Company entered into an underwriting agreement with J. P. Morgan Securities LLC, as representative of the several underwriters named therein, relating to the issuance and sale of 14,300,000 shares of our common stock. The price to the public in the offering was $3.50 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $3.29 per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 2,145,000 shares of common stock at a purchase price of $3.29 per share, and the underwriters elected to exercise such option in full. The offering was made pursuant to the Company’s effective registration statement on Form S-3 (Registration Statement No. 333-177793) previously filed with the SEC, and a prospectus supplement thereunder. The underwriters purchased the 14,300,000 shares and the additional 2,145,000 shares on October 29, 2013. The net proceeds from the offering were approximately $53.9 million after deducting underwriting discounts and estimated offering expenses payable by the Company.

	On January 20, 2012, the Company entered into an underwriting agreement with J. P. Morgan Securities LLC, as representative of the several underwriters named therein, relating to the issuance and sale of 9,650,000 shares of our common stock. The price to the public in the offering was $5.20 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $4.888 per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 1,447,500 shares of common stock at a purchase price of $4.888 per share. The offering was made pursuant to the Company’s effective registration statement on Form S-3 (Registration Statement No. 333-177793) previously filed with the SEC, and a prospectus supplement thereunder. The underwriters purchased the 9,650,000 shares on January 25, 2012 and purchased an additional 464,401 shares on January 31, 2012 pursuant to the partial exercise of their option to purchase additional shares, resulting in our issuing a total of 10,114,401 shares. The net proceeds from the offering were approximately $49.2 million after deducting underwriting discounts and estimated offering expenses payable by the Company.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2014
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 (“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 our financial statements are:

		•		Clinical trial expenses;

		•		Fair value measurements for stock based compensation and warrants; and

		•		Income taxes.
	Subsequent Events
	On January 13, 2015, the Company, together with Intrexon, entered into a license agreement, or the License, with The University of Texas M.D. Anderson Cancer Center (“MD Anderson”). Pursuant to the License, the Company and Intrexon hold an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel chimeric antigen receptor (CAR) T-cell therapies arising from the laboratory of Laurence Cooper, M.D., Ph.D., professor of pediatrics at MD Anderson, as well as either co-exclusive or non-exclusive licenses under certain related technologies.
	Pursuant to the terms of the License, MD Anderson will receive, within sixty days of the date of the License, consideration of $50 million in shares of our common stock (or 10,124,561 shares), and $50 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the Company’s and Intrexon’s common stock ending on the date prior to the announcement of the entry into the License, collectively referred to as the License Shares, pursuant to the terms of the License Shares Securities Issuance Agreement described below. The Company and Intrexon also agreed to reimburse MD Anderson for out of pocket expenses for maintaining patents covering the licensed technologies.
	In addition, pursuant to the License, MD Anderson has agreed to transfer to us certain existing research programs described in the License and to grant to Intrexon and us certain additional technology rights related thereto. In connection with such transfer, the terms of the License also require us and Intrexon to enter into a research and development agreement with MD Anderson pursuant to which the Company will provide funding for certain research and development activities of MD Anderson for a period of three years, in an amount between $15 and $20 million per year. The first quarterly payment of $3.75 million due under this arrangement is required to be made by us within 60 days of the date of the License.
	The term of the 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 License; provided, however, that following the expiration of the term, the Company and Intrexon 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 License and subject to a 90 day cure period, MD Anderson will have the right to convert the License into a non-exclusive license if the Company and Intrexon 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 License and subject to a 180 day cure period, MD Anderson will have the right to terminate the License with respect to specific technology(ies) funded by the government or subject to a third party contract if the Company and Intrexon are not meeting the diligence requirements in such funding agreement or contract, as applicable. Subject to a 30 day cure period, MD Anderson has the right to terminate the License if the Company and Intrexon fail to timely deliver the shares due in consideration for the License. MD Anderson may also terminate the agreement with written notice upon material breach by us and Intrexon, if such breach has not been cured within 60 days of receiving such notice. In addition, the License will terminate upon the occurrence of certain insolvency events for both us and Intrexon and may be terminated by the mutual written agreement of us, Intrexon and MD Anderson.
	On January 9, 2015, in order to induce MD Anderson to enter into the License on an accelerated schedule, the Company and Intrexon entered into a letter agreement, or the Letter Agreement, pursuant to which MD Anderson will receive consideration of $7.5 million in shares of the our common stock (or 1,597,602 shares), and $7.5 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the our and Intrexon’s common stock ending on the date prior to the Letter Agreement, collectively referred to as the Incentive Shares, in the event that the License was entered into on or prior to 8:00 am pacific time on January 14, 2015, referred to as the Accelerated Closing Deadline. The Incentive Shares will be issued to MD Anderson within sixty days of the date of the License pursuant to the terms of the Incentive Shares Securities Issuance Agreement described below.
	In connection with the entry into the License, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the License Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the License Shares to MD Anderson in consideration for the License. The closing of the issuance and sale of the License Shares under the License Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.
	In connection with the entry into the Letter Agreement, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the Incentive Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the Incentive Shares to MD Anderson in consideration for the execution and delivery of the License on or prior to the Accelerated Closing Deadline in connection with the Letter Agreement. The closing of the issuance and sale of the Incentive Shares under the Incentive Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.
	Also in connection with the License and the issuance of the License Shares and the Incentive Shares, on January 13, 2015, the Company and MD Anderson entered into a Registration Rights Agreement, or the Registration Rights Agreement, pursuant to which the Company agreed to file a “resale” registration statement, or the Registration Statement, registering the resale of the License Shares, the Incentive Shares and any other shares of our common stock held by MD Anderson on the date that the Registration Statement is filed, within 15 days of the closing under the License Shares Securities Issuance Agreement. Under the Registration Rights Agreement, the Company is obligated to use our reasonable best efforts to cause the Registration Statement to be declared effective as promptly as practicable after filing and in no event later than 120 days of the closing under the License Shares Securities Issuance Agreement and to maintain the effectiveness of the Registration Statement until all securities therein are sold or are otherwise can be sold pursuant to Rule 144, without any restrictions.
	Our director, Randall J. Kirk, is the CEO, a director, and the largest stockholder of Intrexon, which is a party to the License. Mr. Kirk is also one of our principal stockholders.
	On February 3, 2015, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC (see Note 2 above).
	The Company evaluated all other events and transactions that occurred after the balance sheet date through the date of this filing. Except as disclosed above, the Company did not have any other material subsequent events that impacted its financial statements or disclosures.
	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
	Other assets include $388 thousand that is restricted as collateral for the Company’s facility leases and $103 thousand that is restricted as collateral for a line of credit.
	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.
	Warrants
	The Company applies the accounting standard which provides guidance in assessing whether an equity-based 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 certain warrants issued by the Company have terms that do not meet the criteria to be considered indexed to the Company’s own stock and therefore are classified as liabilities in the Company’s balance sheet. The liability classified warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of “Other income, net” in the accompanying Statement of Operations. Fair value is measured using the binomial valuation model. In December 2011, the Company switched from the Black-Scholes valuation model to the binomial valuation model as it provides a better evaluation of the fair market value of the Company’s liability-classified warrants.
	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, 2014 and 2013 are as follows:


	($ in thousands)		Fair Value Measurements at Reporting Date Using
	Description		Balance as of			Quoted Prices in			Significant Other			Significant
			December 31,			Active Markets for			Observable			Unobservable
			2014			Identical			Inputs			Inputs
						Assets/Liabilities			(Level 2)			(Level 3)
						(Level 1)
	Cash equivalents		$	37,290		$	37,290		$	—		$	—

	Warrant liability		$	—		$	—		$	—		$	—



	($ in thousands)		Fair Value Measurements at Reporting Date Using
	Description		Balance as of			Quoted Prices in			Significant Other			Significant
			December 31,			Active Markets for			Observable			Unobservable Inputs
			2013			Identical			Inputs (Level 2)			(Level 3)
			Assets/Liabilities
			(Level 1)
Cash equivalents			$	66,794		$	66,794		$	—		$	—

Warrant liability		$	11,776		$	—		$	11,776		$	—

The cash equivalents consist primarily of short term U.S. treasury money market mutual funds which are actively traded. The warrants were valued using a binomial valuation model. As of December 31, 2014, all liability classified warrants had expired. See Note 9 to the financial statements, Warrants, for additional disclosure on the valuation methodology and significant assumptions.
Revenue Recognition
The Company receives revenue from a collaboration agreement (see Note 8 to the financial statements, Commitments and Contingencies). Collaboration arrangements typically include payments for one or more of the following: non-refundable, upfront license fees, funding of research and development efforts, milestone payments if specified objectives are achieved and/or profit-sharing or royalties on product sales. Arrangements containing multiple elements are divided into separate units of accounting if certain criteria are met, including whether the delivered element has stand-alone value to the collaborative partner. The consideration received is then allocated among the separate units based on their respective fair values and the applicable revenue recognition criteria are applied to each of the separate units.
Revenue from non-refundable, upfront research and development fees is reported as research and development revenue and is recognized on a straight-line basis over the contracted or estimated period of performance, which is typically the development term. Research and development funding is earned over the period of effort.
Milestone payments are recognized as research and development revenue upon achievement of the milestone only if (1) the milestone payment is non-refundable, (2) substantive effort is involved in achieving the milestone and (3) the amount of the milestone is reasonable in relation to the effort expended or the risk associated with achievement of the milestone. If any of these conditions are not met, the milestone payment is deferred and recognized as revenue over the estimated remaining period of performance under the contract as the Company completes its performance obligations.
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 (see Note 10 to the financial statements, Income Taxes).
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, 2014, 2013, and 2012 and did not capitalize any such costs on the balance sheets. The Company recognized $3.7 million, $2.3 million, and $3.1 million of compensation expense related to vesting of employee stock options during the years ended December 31, 2014, 2013, and 2012, respectively. In the years ended December 31, 2014, 2013, and 2012, the Company recognized $1.0 million, $1.2 million, and $1.7 million of compensation expense, respectively, related to vesting of restricted stock (see Note 12 to the financial statements, Stock Option Plan). In the years ended December 31, 2014, 2013, and 2012, the Company recognized $4.7 million, $3.5 million, and $4.9 million of compensation expense, respectively, related to vesting of all employee and director awards. The following table presents share-based compensation expense included in the Company’s Statements of Operations:


		Year ended December 31,
(in thousands)		2014			2013			2012
Research and development		$	1,416		$	792		$	1,917
General and administrative			3,327			2,715			2,963

Share based employee compensation expense before tax			4,743			3,507			4,880
Income tax benefit			—			—			—

Net share based employee compensation expense		$	4,743		$	3,507		$	4,880

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 2014, 2013, and 2012 was approximately $3.58, $2.51, and $3.06 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 Staff Accounting Bulletin No. 110. The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below:


		2014		2013	2012
Weighted average risk-free interest rate		1.74 - 2.11%		1.00 - 2.10%	0.79 - 1.13%
Expected life in years		6		6	6
Expected volatility		85.22 - 94.55%		83.40 - 95.96%	83.36 - 83.53%
Expected dividend yield		0		0	0
Net Loss Per Share
Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding for the period. The Company’s potential dilutive shares, which include outstanding common stock options, unvested restricted stock and warrants, have not been included in the computation of diluted net loss per share for any of the periods presented as the result would be antidilutive. Such potential common shares at December 31, 2014, 2013, and 2012 consist of the following:


		December 31,
		2014			2013			2012
Stock options			6,505,664			6,747,303			7,147,303
Unvested restricted stock			144,508			352,865			733,739
Warrants			—			10,539,767			11,197,454

			6,650,172			17,639,935			19,078,496

New Accounting Pronouncements
In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40) in which management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable). When management identifies conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern, management should consider whether its plans that are intended to mitigate those relevant conditions or events will alleviate the substantial doubt. This update is effective for annual periods beginning after December 15, 2016, and early application is permitted for any annual or interim period thereafter.
On June 10, 2014, the FASB issued ASU 2014-10, Development Stage Entities (Topic 915), which simplifies financial reporting for development stage entities by eliminating requirements specific to development stage entities. As a result, entities in a development stage will no longer need to present inception-to-date information about income statement line items, cash flows, and equity transactions. Instead, the new guidance clarifies how these entities should tailor existing disclosures to explain the risks and uncertainties related to their activities. This update is effective for annual periods beginning after December 15, 2014, and early application is permitted for any annual or interim period for which the entity’s financial statements have not yet been issued. The Company adopted this guidance prior to issuing the financial statements in this Quarterly Report on Form 10-Q. The adoption of ASU 2014-10 impacted presentation and disclosure only and did not have any impact on financial position or results of operations.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), which clarifies the principles for recognizing revenue and develops a common revenue standard for U.S. GAAP and IFRS. This standard removes inconsistencies and weaknesses between U.S. GAAP and IFRS in revenue requirements, provides a more robust framework for addressing revenue issues, improves comparability of revenue recognition practices across entities, industries, jurisdictions, and capital markets, provides more useful information to users of financial statements through improved disclosure requirements, and simplifies the preparation of financial statements by reducing the number of requirements to which an entity must refer. This update is effective for annual periods beginning after December 15, 2016, including interim periods within that reporting period and early application is not permitted. The company believes that the adoption of this standard will not have an impact on our financial position or results of operations.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2014
Restructuring	4	Restructuring
	The Company underwent restructuring activities during the year ended December 31, 2013 which included a reduction in workforce and office space, resulting in sublease agreements in Boston and New York. As a result, the Company incurred restructuring charges of $1.7 million, $0.6 million was included in general and administrative expenses and $1.1 million was included in research and development expenses. The Company also incurred charges for exit and disposal activities from the Boston and New York sublease agreements which resulted in an aggregate loss of $0.8 million recorded in general and administrative expenses, and a loss on the disposal of fixed assets of $0.6 million, recorded in Other income in the Statement of Operations for the year ended December 31, 2013.
	On October 17, 2013, the Company entered into a sublease agreement to lease 7,259 square feet in our New York office to a subtenant. The Company remains primarily liable to pay rent on the original lease. Accordingly, 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 our subtenant. The Company retired assets in this subleased area as a result of this sublease with a net book value of $392 thousand, and recorded a loss on disposal of fixed assets for the same amount for the year ended December 31, 2013.
	On August 30, 2013, the Company entered into a sublease agreement to lease 5,249 square feet in our Boston office to a subtenant. The Company remains primarily liable to pay rent on the original lease. The Company recorded a loss on the sublease in the amount of $42 thousand for the year ended December 31, 2013, representing the remaining contractual obligation of $367 thousand, less $325 thousand in payments from our subtenant. The Company retired assets in this subleased area as a result of this sublease with a net book value of $194 thousand, and recorded a loss on disposal of fixed assets. The company previously held a security deposit of $20 thousand in accordance with the sublease, which was recorded in other non-current assets and other liabilities on the balance sheet for the year ended December 31, 2013. This sublease tenant vacated the lease in October 2014. As of December 31, 2014, the company applied the $20 thousand deposit against outstanding rent. The company is actively pursuing a subtenant to lease a portion of the space in the Boston Office that was vacated by a previous subtenant.
	On July 16, 2012, the Company announced that it restructured its management team and closed its Germantown, MD office. As a result of this action, the Company recorded a restructuring charge, consisting primarily of severance, stock based compensation associated with stock option modifications (see Note 12 to the financial statements, Stock Option Plan) and health benefit continuation costs of approximately $1.3 million. These costs are included in general and administrative expense for the year ended December 31, 2012.

Property_and_Equipment_net

Property and Equipment, net	12 Months Ended
Property and Equipment, net	Dec. 31, 2014
Property and Equipment, net	5	Property and Equipment, net
	Property and equipment, net, consists of the following:


		December 31,
	(in thousands)	2014			2013
	Office and computer equipment	$	1,094		$	1,076
	Software		874			884
	Leasehold improvements		927			841
	Manufacturing equipment		251			153

			3,146			2,954
	Less: accumulated depreciation		(2,615	)		(2,153	)

	Property and equipment, net	$	531		$	801

	Depreciation and amortization charged to the Statement of Operations for the years ended December 31, 2014, 2013, and 2012 was: $462 thousand, $738 thousand and, $658 thousand, respectively.

Accrued_Expenses

Accrued Expenses	12 Months Ended
Accrued Expenses	Dec. 31, 2014
Accrued Expenses	6	Accrued Expenses
	Accrued expenses consist of the following:


		December 31,
	(in thousands)	2014		2013
	Clinical consulting services	$	2,802	$	3,751
	Preclinical services		2,027		513
	Employee compensation		768		252
	Professional services		422		582
	Payroll taxes and benefits		417		255
	Manufacturing services		308		547
	Other consulting services		226		230
	Accrued vacation		212		227

	Accrued expenses	$	7,182	$	6,357

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions	7	Related Party Transactions
	On January 6, 2011, the Company entered into an Exclusive Channel Partner Agreement, or Channel Agreement, with Intrexon Corporation, or Intrexon (see Note 8 to the financial statements, Commitments and Contingencies, for additional disclosure relating to the Channel Agreement). Our director, Randall J. Kirk, is the CEO, a director, and the largest stockholder of Intrexon. During the year ended December 31, 2012, the Company paid Intrexon approximately $11.4 million, of which $6.6 million was for preclinical and clinical research services already incurred and the remaining $4.8 million was for services expected to be incurred within a year. This amount was included as part of prepaid expenses and other current assets on the balance sheet as of December 31, 2012. During the year ended December 31, 2013, the Company expensed $7.8 million for services performed by Intrexon, of which $4.8 million was applied to the prepaid balance in other current assets, $2.4 million was paid to Intrexon and $0.6 million was recorded in accrued expenses. As of December 31, 2013, the prepaid balance in other current assets on the accompanying balance sheet has been reduced to $0. During the year ended December 31, 2014, the Company expensed $12.0 million for services performed by Intrexon, of which $10.1 million was paid to Intrexon and $1.9 million was recorded in accounts payable and accrued expenses. As of December 31, 2014, the prepaid balance in other current assets on the accompanying balance sheet has been reduced to $0.
	On January 25, 2012, Intrexon purchased 1,923,075 shares of common stock in the Company’s public offering (see Note 2 to the financial statements, Financings).
	On November 7, 2012, the Company issued 3,636,926 shares of common stock to Intrexon (see Note 11 to the financial statements, Preferred Stock and Stockholders’ Equity).
	On October 29, 2013, Intrexon purchased 2,857,143 shares of common stock in the Company’s public offering (see Note 2 to the financial statements, Financings).
	On February 2, 2015, Intrexon purchased 1,440,000 shares of common stock in the Company’s public offering (see Note 2 to the financial statements, Financings).
	Intrexon’s purchases were made on terms that were the same as others participating in the above financings.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
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, consisting of 6,251 square feet of 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 1,008 square feet of office space. As of December 31, 2012, the Company occupied 7,259 square feet of space in New York, NY, and maintained a $388 thousand letter of credit. The collateral for the letter of credit is recorded in other non-current assets on the balance sheet as of December 31, 2014. The lease for office space in New York, NY expires in October 2018.

	On October 17, 2013, the Company entered into a sublease agreement to lease 7,259 square feet in our New York office to a subtenant. The Company remains primarily liable to pay rent on the original lease. 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 our subtenant. The Company retired assets in this subleased area as a result of this sublease with a net book value of $392 thousand, and recorded a loss on disposal of fixed assets for the same amount for the year ended December 31, 2013. The Company continues to maintain a $388 thousand letter of credit. The collateral for the letter of credit is recorded in other non-current assets on the balance sheet as of December 31, 2014. The lease for office space in New York, NY expires in October 2018.

	Prior to December 31, 2012, the Company entered into separate operating lease agreements for various spaces in a building in Boston, MA. That space consisted of 5,249 square feet on the first floor, 8,538 square feet on the second floor, and 6,959 square feet on the third floor. In June 2012, the Company re-negotiated a master lease for the entire Boston office space, added 9,800 square feet of office space on the fourth floor, surrendered 4,113 square feet from the second floor, and incorporated all floors’ lease agreements under the same master agreement expiring in August 2016. The Company provided an additional $41 thousand security deposit for the additional space on the fourth floor. As of December 31, 2012, a total security deposit of $127 thousand was paid to its landlord for security deposits for these agreements.



	On August 30, 2013, the Company entered into a sublease agreement to lease 5,249 square feet in our Boston office to a subtenant. The Company remains primarily liable to pay rent on the original lease. The Company recorded a loss on the sublease in the amount of $42 thousand for the year ended December 31, 2013, representing the remaining contractual obligation of $367 thousand, less $325 thousand in payments from our subtenant. The Company retired assets in this subleased area as a result of this sublease with a net book value of $194 thousand, and recorded a loss on disposal of fixed assets. The company previously held a security deposit of $20 thousand in accordance with the sublease, which was recorded in other non-current assets and other liabilities on the balance sheet for the year ended December 31, 2013. This sublease tenant vacated the lease in October 2014. As of December 31, 2014, the company applied the $20 thousand deposit against outstanding rent. The company is actively pursuing a subtenant to lease a portion of the space in the Boston Office that was vacated by a previous subtenant.

	As of December 31, 2014, the Company occupies 21,184 square feet of space in its Boston, MA office and has paid a total of $127 thousand for security deposits, which are recorded in other non-current assets on the balance sheet.

	In April 2011, the Company entered into an operating lease for office space in Germantown, MD, consisting of 2,227 square feet. As of December 31, 2011, the Company recorded the $4 thousand security deposit in other non-current assets on the balance sheet. The lease would have expired in March 2014; however, on July 16, 2012, the Germantown, Maryland office was closed. In June 2013, the Company paid off the remainder of the Germantown, Maryland lease obligation.

	Future net minimum lease payments under operating leases as of December 31, 2014 are as follows (in thousands):



	2015		$	1,235
	2016			997
	2017			501
	2018			424
	2019			—

				3,157
	Less: contractual sublease income			(1,224	)

	Future minimum lease payments, net		$	1,933


	Total rent expense was approximately $1.2 million, $1.0 million, and $1.1 million for the years ended December 31, 2014, 2013, and 2012. 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, 2014 and 2013 of $850 thousand ($280 thousand current and $570 long-term) and $1.1 million ($212 thousand current and $851 long-term) respectively, which is recorded in deferred rent on the balance sheet.

	License Agreements

	Exclusive Channel Partner Agreement with Intrexon Corporation

	On January 6, 2011, the Company entered into an Exclusive Channel Partner Agreement, or the Channel Agreement, with Intrexon that governs a “channel partnering” arrangement in which the Company uses Intrexon’s technology directed towards in vivo expression of effectors in connection with the development of Ad-RTS-IL-12 + veledimex and DC-RTS-IL-12 + veledimex and generally to research, develop and commercialize products, in each case in which DNA is administered to humans for expression of anti-cancer effectors for the purpose of treatment or prophylaxis of cancer, which the Company collectively refer to as the Cancer Program. The Channel Agreement establishes committees comprised of representatives of us and Intrexon that govern activities related to the Cancer Program in the areas of project establishment, chemistry, manufacturing and controls, clinical and regulatory matters, commercialization efforts and intellectual property.

	The Channel Agreement grants us a worldwide license to use patents and other intellectual property of Intrexon in connection with the research, development, use, importing, manufacture, sale, and offer for sale of products involving DNA administered to humans for expression of anti-cancer effectors for the purpose of treatment or prophylaxis of cancer, which we collectively refer to as the ZIOPHARM Products. Such license is exclusive with respect to any clinical development, selling, offering for sale or other commercialization of ZIOPHARM Products, and otherwise is non-exclusive. Subject to limited exceptions, the Company may not sublicense the rights described without Intrexon’s written consent.

	Under the Channel Agreement, and subject to certain exceptions, the Company is responsible for, among other things, the performance of the Cancer Program, including development, commercialization and certain aspects of manufacturing of ZIOPHARM Products. Intrexon is responsible for the costs of establishing manufacturing capabilities and facilities for the bulk manufacture of products developed under the Cancer Program, certain other aspects of manufacturing and costs of discovery-stage research with respect to platform improvements and costs of filing, prosecution and maintenance of Intrexon’s patents.

	Subject to certain expense allocations and other offsets provided in the Channel Agreement, the Company will pay Intrexon on a quarterly basis 50% of net profits derived in that quarter from the sale of ZIOPHARM Products, calculated on a ZIOPHARM Product-by- ZIOPHARM Product basis. The Company has likewise agreed to pay Intrexon on a quarterly basis 50% of revenue obtained in that quarter from a sublicensor in the event of a sublicensing arrangement. In addition, in partial consideration for each party’s execution and delivery of the Channel Agreement, the Company entered into a Stock Purchase Agreement with Intrexon.

	Upon termination of the Channel Agreement, the Company may continue to develop and commercialize any ZIOPHARM Product that, at the time of termination:


		•		Is being commercialized by us;


		•		Has received regulatory approval;


		•		Is a subject of an application for regulatory approval that is pending before the applicable regulatory authority; or


		•		Is the subject of at least an ongoing Phase 2 clinical trial (in the case of a termination by Intrexon due to an uncured breach or a voluntary termination by us), or an ongoing Phase 1 clinical trial in the field (in the case of a termination by us due to an uncured breach or a termination by Intrexon following an unconsented assignment by us or our election not to pursue development of a Superior Therapy).



Our obligation to pay 50% of net profits or revenue described above with respect to these “retained” products will survive termination of the Channel Agreement.

License Agreement—The University of Texas M. D. Anderson Cancer Center

On January 13, 2015, the Company, together with Intrexon, entered into a license agreement, or the License, with MD Anderson. Pursuant to the License, the Company and Intrexon hold an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel chimeric antigen receptor (CAR) T-cell therapies arising from the laboratory of Laurence Cooper, M.D., Ph.D., professor of pediatrics at MD Anderson, as well as either co-exclusive or non-exclusive licenses under certain related technologies.

Pursuant to the terms of the License, MD Anderson will receive, within sixty days of the date of the License, consideration of $50 million in shares of our common stock (or 10,124,561 shares), and $50 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the Company’s and Intrexon’s common stock ending on the date prior to the announcement of the entry into the License, collectively referred to as the License Shares, pursuant to the terms of the License Shares Securities Issuance Agreement described below. The Company and Intrexon also agreed to reimburse MD Anderson for out of pocket expenses for maintaining patents covering the licensed technologies.

In addition, pursuant to the License, MD Anderson has agreed to transfer to us certain existing research programs described in the License and to grant to Intrexon and us certain additional technology rights related thereto. In connection with such transfer, the terms of the License also require us and Intrexon to enter into a research and development agreement with MD Anderson pursuant to which the Company will provide funding for certain research and development activities of MD Anderson for a period of three years, in an amount between $15 and $20 million per year. The first quarterly payment of $3.75 million due under this arrangement is required to be made by us within 60 days of the date of the License.

The term of the 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 License; provided, however, that following the expiration of the term, the Company and Intrexon 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 License and subject to a 90 day cure period, MD Anderson will have the right to convert the License into a non-exclusive license if the Company and Intrexon 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 License and subject to a 180 day cure period, MD Anderson will have the right to terminate the License with respect to specific technology(ies) funded by the government or subject to a third party contract if the Company and Intrexon are not meeting the diligence requirements in such funding agreement or contract, as applicable. Subject to a 30 day cure period, MD Anderson has the right to terminate the License if the Company and Intrexon fail to timely deliver the shares due in consideration for the License. MD Anderson may also terminate the agreement with written notice upon material breach by us and Intrexon, if such breach has not been cured within 60 days of receiving such notice. In addition, the License will terminate upon the occurrence of certain insolvency events for both us and Intrexon and may be terminated by the mutual written agreement of us, Intrexon and MD Anderson.

On January 9, 2015, in order to induce MD Anderson to enter into the License on an accelerated schedule, the Company and Intrexon entered into a letter agreement, or the Letter Agreement, pursuant to which MD Anderson will receive consideration of $7.5 million in shares of common stock (or 1,597,602 shares), and $7.5 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the our and Intrexon’s common stock ending on the date prior to the Letter Agreement, collectively referred to as the Incentive Shares, in the event that the License was entered into on or prior to 8:00 am pacific time on January 14, 2015, referred to as the Accelerated Closing Deadline. The Incentive Shares will be issued to MD Anderson within sixty days of the date of the License pursuant to the terms of the Incentive Shares Securities Issuance Agreement described below.

In connection with the entry into the License, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the License Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the License Shares to MD Anderson in consideration for the License. The closing of the issuance and sale of the License Shares under the License Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.

In connection with the entry into the Letter Agreement, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the Incentive Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the Incentive Shares to MD Anderson in consideration for the execution and delivery of the License on or prior to the Accelerated Closing Deadline in connection with the Letter Agreement. The closing of the issuance and sale of the Incentive Shares under the Incentive Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.

Also in connection with the License and the issuance of the License Shares and the Incentive Shares, on January 13, 2015, the Company and MD Anderson entered into a Registration Rights Agreement, or the Registration Rights Agreement, pursuant to which the Company agreed to file a “resale” registration statement, or the Registration Statement, registering the resale of the License Shares, the Incentive Shares and any other shares of our common stock held by MD Anderson on the date that the Registration Statement is filed, within 15 days of the closing under the License Shares Securities Issuance Agreement. Under the Registration Rights Agreement, the Company is obligated to use our reasonable best efforts to cause the Registration Statement to be declared effective as promptly as practicable after filing and in no event later than 120 days of the closing under the License Shares Securities Issuance Agreement and to maintain the effectiveness of the Registration Statement until all securities therein are sold or are otherwise can be sold pursuant to Rule 144, without any restrictions.

License Agreement with DEKK-Tec, Inc.

On October 15, 2004, the Company entered into a license agreement with DEKK-Tec, Inc., pursuant to which it was granted an exclusive, worldwide license for palifosfamide.

In consideration for the license rights, DEKK-Tec is entitled to receive payments upon achieving certain milestones in varying amounts which on a cumulative basis may total $4.0 million. Of the aggregate milestone payments, most will be creditable against future royalty payments as referenced below. Additionally, the Company issued DEKK-Tec an option to purchase 27,616 shares of the Company’s common stock for $0.02 per share, of which 13,808 options are still outstanding. DEKK-Tec is entitled to receive single digit percentage royalty payments on the sales of palifosfamide should it be approved for commercial sale. The Company’s obligation to pay royalties will terminate on a country-by-country basis upon the expiration of all valid claims of patents in such country covering licensed product, subject to earlier termination in the event of defaults by the parties under the license agreement. No milestones under the license agreement have been reached or expensed since 2010.



License Agreement with Southern Research Institute

On December 22, 2004, the Company entered into an Option Agreement with the Southern Research Institute, or SRI, pursuant to which the Company was granted an exclusive option to obtain an exclusive license to SRI’s interest in certain intellectual property, including exclusive rights related to certain isophosphoramide mustard analogs. On February 5, 2007, the Company exercised its option and entered into the exclusive license agreement. Under the license agreement, the Company is required to remit minimum annual royalty payments of $25 thousand until the first commercial sale of a licensed product. These payments were made for the years ended December 31, 2014, 2013, and 2012. The Company may be required to make payments upon achievement of certain milestones in varying amounts which on a cumulative basis could total up to $775 thousand. In addition, SRI will be entitled to receive single digit percentage royalty payments on the sales of a licensed product in any country until all licensed patents rights in that country which are utilized in the product have expired. No milestones under the license agreement were reached or expensed since the agreement’s inception.

Patent and Technology License Agreement—The University of Texas M. D. 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 The Board of Regents of the University of Texas System, acting on behalf of The University of Texas M. D. Anderson Cancer Center 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.

The Company issued options to purchase 50,222 shares outside the 2003 Stock Option Plan for $0.002 per share following the successful completion of certain clinical milestones, of which 37,666 have vested. The remaining 12,556 shares will vest 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. In addition, the Licensors are entitled to receive certain milestone payments. The Company may be required to make additional payments 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.

The license agreement also contains other provisions customary and common in similar agreements within the industry, such as the right to sublicense the Company rights under the agreement. On July 31, 2014, the Company amended and restated the License and Collaboration Agreement between the Company and Solasia Pharma K.K. or Solasia, granting to 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. Solasia will be responsible for all costs related to the development, manufacturing and commercialization of darinaparsin. The Licensors will receive a portion of all milestone and royalty payments made by Solasia to the Company in accordance with the terms of the Company’s license agreement with the Licensors.

Collaboration Agreement with Solasia Pharma K.K.

On March 7, 2011, the Company entered into a License and Collaboration Agreement with Solasia Pharma K.K., or Solasia.



Pursuant to the License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both IV and oral forms and related organic arsenic molecules, in all indications for human use in a pan- Asian/Pacific territory comprised of 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. Under the License and Collaboration Agreement, the Company provided Solasia with drug product to conduct clinical trials. These transfers were accounted for as a reduction of research and development costs and an increase in collaboration receivables. The agreement provides that Solasia will be responsible for the development and commercialization of darinaparsin in the pan-Asian/Pacific territory.

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 will receive a portion of all milestone and royalty payments made by Solasia to the Company in accordance with the terms of the Company’s license agreement with the Licensors.

The $5.0 million upfront payment received in March 2011 is being amortized over the period of the Company’s research and development effort. The Company originally estimated this period to be 75 months. In accordance with the amended and restated License and Collaboration Agreement with Solasia, the Company is no longer obligated to continue their research and development efforts in connection with the upfront payment. However, there are certain deliverables that are included in the amended and restated License and Collaboration Agreement including transfer of intellectual property and prior research and development results, which were originally estimated by management to be completed by March 31, 2015 when the amended and restated License and Collaboration Agreement was signed in July 2014. Management reassessed the period of performance related to the remaining transitional services to be completed under the agreement and determined that the services are now expected to be completed by December 31, 2015. As a result, the Company has determined that the estimated remaining period for delivering the transitional services at September 30, 2014 was 15 months through December 31, 2015. Accordingly, the Company has recorded $1.4 million in revenue during the twelve months ended December 31, 2014 while the remaining deferred revenue balance of $1.4 million at December 31, 2014 has been classified as current.

License Agreement with Baxter Healthcare Corporation

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 each of the years ended December 31, 2014, 2013, and 2012, the installment payments of $250 thousand were met and expensed.

Collaboration Agreement with Harmon Hill, LLC

On April 8, 2008, the Company signed a collaboration agreement for Harmon Hill, LLC, or Harmon Hill, to provide consulting and other services for the development and commercialization of oncology therapeutics by ZIOPHARM.

The Company expensed $200 thousand during the year ended December 31, 2012 under this agreement. This agreement expired on November 8, 2012.

On June 27, 2013, the Company signed a new collaboration agreement with Harmon Hill to provide consulting and other services for the development and commercialization of oncology therapeutics by ZIOPHARM, effective April 1, 2013. Under the agreement the Company has agreed to pay Harmon Hill $15 thousand per month for the consulting services. Subject to renewal or extension by the parties, the term of the agreement is for a one year period. The Company expensed $135 thousand and $180 thousand for the years ended December 31, 2013 and 2014, respectively.

CRO Services Agreement with Novella Clinical, Inc.

On December 4, 2008, the Company entered into a Master Clinical Research Organization Services Agreement with Novella Clinical, Inc., or Novella, under which Novella provides CRO services in support of our clinical trials. The work order for the newest trial being conducted by Novella was signed on November 2, 2012. Novella was entitled to cumulative payments of up to $790 thousand under these arrangements, which is payable in varying amounts upon Novella achieving specified milestones. During the year ended December 31, 2012, the Company expensed $256 thousand upon the achievement of various milestones. During the year ended December 31, 2013, two database related milestones and one site activation related milestone were met and expensed totaling $136 thousand.

On August 18, 2014 and November 6, 2014, the Company signed two amendments of the Master Clinical Research Organization Services Agreement with Novella. The amendments reflect the removal of data management, statistical and clinical study report services, as well as a change in the timeline and scope of clinical trial support. During the year ended December 31, 2014, three clinical milestones were met and expensed totaling $236 thousand.

CRO Services Agreement with MS Clinical Services, LLC.

On July 24, 2014, the Company entered into a Master Clinical Research Organization Services Agreement with MS Clinical Services, LLC., or Medsource, under which Medsource provides CRO services in support of our clinical trials. There are no milestones associated with this agreement.



CRO Services Agreement with PPD Development, L. P.

The Company was party to a Master Clinical Research Organization Services Agreement with PPD Development, L. P., or PPD, dated January 29, 2010, a related work order dated June 25, 2010 and a related work order dated April 8, 2011 under which PPD provides clinical research organization, or CRO, services in support of the Company’s clinical trials. During the years ended December 31, 2012 and 2013, the Company expensed $3.8 million and $9.2 million respectively. There are no remaining milestones related to this agreement.

CRO Services Agreement with Pharmaceutical Research Associates, Inc.

On December 13, 2011, the Company entered into a Master Clinical Research Organization Services Agreement with Pharmaceutical Research Associates, Inc., or PRA, under which PRA provides CRO services in support of our clinical trials. During the years ended December 31, 2012 and 2013, the Company expensed $7.3 million and $2.2 million, respectively. There are no remaining milestones related to this agreement.

Warrants

Warrants	12 Months Ended
Warrants	Dec. 31, 2014
Warrants	9	Warrants
	The Company has issued both warrants that are accounted for as liabilities and warrants that are accounted for as equity instruments.
	The Company follows accounting standards that provide guidance in assessing 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 and classified as a liability. Accounting standards require that liability classified warrants be recorded at their fair value at each financial reporting period and the resulting gain or loss be recorded as other income (expense) in the Statements of Operations. Fair value is measured using the binomial valuation model.
	In connection with the December 2009 public offering, the Company issued warrants to purchase an aggregate of 8,206,520 shares of common stock (including the investor warrants and 464,520 warrants issued to the Underwriters). The investor warrants were exercisable immediately and the underwriter warrants exercisable six months after the date of issuance. The warrants had an exercise price of $4.02 per share and a 5 year term. The fair value of the warrants was estimated at $22.9 million using a Black-Scholes model with the following assumptions: expected volatility of 105%, risk free interest rate of 2.14%, expected life of 5 years and no dividends.
	Subject to certain exceptions, these warrants provide for anti-dilution protection should common stock or common stock equivalents be subsequently issued at a price less than the exercise price of the warrants then in effect, which was initially $4.02 per share. This provision was triggered in 2013 when stock was sold at $3.50 per share in our 2013 public offering. Accordingly, the outstanding warrants were increased by 184,367 warrants to 8,235,076 warrants.
	The Company assessed whether the 2009 Warrants required accounting as derivatives. The Company determined that the warrants were not indexed to the Company’s own stock in accordance with accounting standards codification Topic 815, Derivatives and Hedging. As such, the Company concluded the warrants did not meet the scope exception for determining whether the instruments required accounting as derivatives and should be classified in liabilities.
	On December 31, 2013, the liability-classified warrants were valued at $11.8 million using a Binomial/Monte Carlo valuation model. The decrease in the fair value of the warrant liabilities of $1.2 million for the year ended December 31, 2013 was recorded as Other income, net in the Statements of Operations.

	On December 31, 2012, the liability-classified warrants were valued at $13.0 million using a Binomial/Monte Carlo valuation model. The decrease in the fair value of the warrant liabilities of $6.1 million for the year ended December 31, 2012 was recorded as Other income, net in the Statements of Operations.
	The following pricing assumptions were used in the Binomial/Monte Carlo valuation model at December 31, 2013 and 2012:


		December 31, 2013			December 31, 2012
	Risk-free interest rate		0.13	%		0.25	%
	Expected life in years		0.94			1.94
	Expected volatility		80	%		70	%
	Expected dividend yield		0			0
	Warrants accounted for as equity instruments include the following issuances:
	In connection with its 2009 private placement, the Company issued warrants to purchase an aggregate of 2,910,954 shares of common stock (including 138,617 warrants issued to the placement agents) which were exercisable immediately. The warrants have an exercise price of $2.04 per share and have a 5 year term. The fair value of the warrants was estimated at $4.2 million using a Black-Scholes model with the following assumptions: expected volatility of 105%, risk free interest rate of 2.41%, expected life of 5 years and no dividends. The fair value of the warrants was recorded in the equity section of the balance sheet. In October 2009, 136,986 of these warrants were exercised.
	During 2012, no new warrants were issued. However, 553,914 warrants were exercised for 259,660 shares of common stock. Of these warrants, 186,297 were equity-classified and 373,617 were liability-classified. Additionally, 1,359,317 equity-classified warrants and 579 liability-classified warrants expired without being exercised.
	During 2013, no new warrants were issued. However 135,346 warrants were exercised for 112,808 shares of common stock. Of these warrants, all 135,346 were equity-classified; there were no liability-classified warrants exercised. Additionally, 706,708 equity-classified warrants expired without being exercised.
	During 2014, no new warrants were issued. However 4,004,907 warrants were exercised for 3,725,277 shares of common stock. Of these warrants, 2,249,062 were equity-classified and 1,755,845 were liability-classified warrants. Additionally, 12,329 equity-classified warrants and 6,479,231 liability-classified warrants expired without being exercised.
	All warrants have expired and none are outstanding as of December 31, 2014.

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2014
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, 2014 and 2013 are as follows:



			December 31,
	(in thousands)		2014			2013
	Net operating loss carryforwards		$	79,050		$	66,209
	Start-up and organizational costs			38,562			41,529
	Research and development credit carryforwards			26,112			25,058
	Stock compensation			1,181			1,028
	Capitalized acquisition costs			11,376			12,323
	Deferred revenue			534			1,074
	Depreciation			208			129
	Other			1,547			1,254

				158,570			148,604
	Less valuation allowance			(158,570	)		(148,604	)

	Net deferred tax assets		$	—		$	—


	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, 2014, the Company has aggregate net operating loss carryforwards for federal tax purposes of approximately $206.9 million available to offset future federal taxable income to the extent permitted under the Internal Revenue Code of 1986, as amended, or IRC, expiring in varying amounts through 2033. Additionally, the Company has approximately $26.0 million of research and development credits at December 31, 2014, expiring in varying amounts through 2033, which may be available to reduce future taxes.

	Under the IRC Section 382, certain substantial changes in the Company’s ownership may limit the amount of net operating loss carryforwards that can be utilized in any one year to offset future taxable income. The net operating loss carryforwards for the year ended December 31, 2014 includes approximately $4.4 million resulting from excess tax deductions from stock options. Pursuant to ASC 740, the deferred tax asset relating to excess tax benefits generated from exercises of stock options was not recognized for financial statement purposes.

	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, 2014. It was determined a change of ownership occurred on February 28, 2011. The Company’s NOL’s were not further limited as a result of the change.

	The Company has provided a valuation allowance for the full amount of these net deferred tax assets, since it is more likely than not that these future benefits will not be realized. However, these deferred tax assets may be available to offset future income tax liabilities and expenses. The valuation allowance increased by $10.0 million primarily due to net operating loss carryforwards, start-up and organizational costs, and the increase in research and development credits.

	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)		2014			2013			2012
	Federal income tax at statutory rates			34	%		34	%		34	%
	State income tax, net of federal tax benefit			2	%		4	%		5	%
	Research and development credits			3	%		9	%		10	%
	Stock compensation			-4	%		-2	%		-1	%
	Uncertain tax position adjustment			0	%		0	%		0	%
	Federal R&D tax grant			0	%		0	%		0	%
	Other			-4	%		1	%		2	%
	Increase in valuation allowance			-31	%		-46	%		-49	%

	Effective tax rate			0	%		0	%		0	%


	The Company adopted ASC740, “Accounting for Uncertain Tax Positions” on January 1, 2007. ASC740 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. A summary of the company’s adjustments to its uncertain tax positions in the years ended December 31, 2014, 2013, and 2012 are as follows:



	(in thousands)
	Balance at December 31, 2011		$	275
	Increase/Decrease for tax positions related to the current year			—
	Increase/Decrease for tax positions related to prior years			—
	Decreases for settlements with applicable taxing authorities			—
	Decreases for lapses of statute of limitations			—

	Balance at December 31, 2012		$	275
	Increase/Decrease for tax positions related to the current year			—
	Increase/Decrease for tax positions related to prior years			(37	)
	Decreases for settlements with applicable taxing authorities			—
Decreases for lapses of statute of limitations			—

Balance at December 31, 2013		$	238
Increase/Decrease for tax positions related to the current year			—
Increase/Decrease for tax positions related to prior years			—
Decreases for settlements with applicable taxing authorities			—
Decreases for lapses of statute of limitations			—

Balance at December 31, 2014		$	238




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 2014.

Preferred_Stock_and_Stockholde

Preferred Stock and Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Preferred Stock and Stockholders' Equity	11	Preferred Stock and Stockholders’ Equity
	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 $.001 per share), and 30,000,000 shares are designated as preferred stock (par value $.001 per share), which the Company refers to as the Preferred Stock.
	Common Stock
	On January 6, 2011, and in conjunction with the Company’s execution and delivery of a Channel Agreement, the Company entered into a Stock Purchase Agreement and Registration Rights Agreement. On January 12, 2011, and pursuant to that Stock Purchase Agreement, the Company sold 2,426,235 shares of the Company’s common stock in a private placement for a total purchase price of $11.6 million, or $4.80 per share. The Company simultaneously issued an additional 3,636,926 shares of its common stock for a cash purchase price equal to the $0.001 par value of such shares, which price was deemed paid in partial consideration for the execution and delivery of the Channel Agreement.
	On January 20, 2012, pursuant to an underwriting agreement between the Company and J. P. Morgan Securities LLC, as representative of the several underwriters named therein, the Company completed the sale of an aggregate 10,114,401 shares of the Company’s common stock at a price of $5.20 per share in a public offering. The total gross proceeds resulting from the 2012 public offering were approximately $52.6 million, before deducting selling commissions and expenses (see Note 2 to the financial statements, Financings).
	On November 7, 2012, the Company issued 3,636,926 shares of our common stock, which we refer to as the Milestone Shares, to Intrexon under the terms of its Stock Purchase Agreement with Intrexon dated January 6, 2011. Under the terms of the Stock Purchase Agreement with Intrexon, the Company agreed to issue the Milestone Shares under certain conditions upon dosing of the first patient in a ZIOPHARM-conducted Phase 2 clinical trial in the Unites States, or similar study as the parties may agree in a country other than the United States, of a product candidate that is created, produced, developed or identified directly or indirectly by us during the term of the Channel Agreement and that, subject to certain exceptions, involves DNA administered to humans for expression of anti-cancer effectors for the purpose of treatment or prophylaxis of cancer. On October 24, 2012, the Company initiated dosing in a Phase 2 study of Ad-RTS-IL-12 + veledimex for unresectable Stage III or IV melanoma, triggering the issuance of the Milestone Shares.
	On October 29, 2013, pursuant to an underwriting agreement between the Company and J. P. Morgan Securities LLC, as representative of the several underwriters named therein, the Company completed the sale of an aggregate 16,445,000 shares of the Company’s common stock at a price of $3.50 per share in a public offering. The total gross proceeds resulting from this public offering were approximately $57.6 million, before deducting selling commissions and expenses (see Note 2 to the financial statements, Financings).
	As of December 31, 2014, the Company had 104,452,105 shares of common stock issued and outstanding and no shares of Preferred Stock issued and outstanding.
	On February 3, 2015, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC, as representative of the several underwriters named therein, relating to the issuance and sale of 10,000,000 shares of our common stock. The price to the public in the offering was $8.75 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $8.225 per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 1,500,000 shares of common stock at a purchase price of $8.225 per share. The offering was made pursuant to the Company’s effective registration statement on Form S-3 (Registration Statement No. 333-201826) previously filed with the SEC, and a prospectus supplement thereunder. The underwriters purchased the 10,000,000 shares and the additional 1,500,000 shares on February 9 and 17, 2015, respectively. The net proceeds from the offering were approximately $94.2 million after deducting underwriting discounts and estimated offering expenses payable by the Company.
	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.

Stock_Option_Plan

Stock Option Plan	12 Months Ended
Stock Option Plan	Dec. 31, 2014
Stock Option Plan	12	Stock Option Plan
	The Company adopted the 2003 Stock Option Plan, or the 2003 Plan, in 2003, and it was approved by the Company’s stockholders on December 21, 2004. Upon approval of the 2012 Equity Incentive Plan, no additional stock awards may be granted under the 2003 Plan.
	The Company adopted the 2012 Equity Incentive Plan, or the 2012 Plan, in May 2012, under which the Company initially reserved for the issuance of 4,000,000 shares of its common stock. The 2012 Plan was approved by the Company’s stockholders on June 20, 2012. On June 18, 2014, the date of the Company’s annual stockholders meeting, the Company’s stockholders approved an amendment to the 2012 Plan increasing the total shares reserved by 5,000,000 shares, for a total of 9,000,000 shares.
	As of December 31, 2014, the Company had outstanding options issued to its employees to purchase up to 5,112,800 shares of the Company’s common stock, to its directors to purchase up to 902,529 shares of the Company’s common stock, as well as options to consultants in connection with services rendered to purchase up to 490,334 shares of the Company’s common stock.
	Stock options to employees generally vest ratably over three years and have contractual terms of ten years. Stock options to directors generally vest ratably over two 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 26,364 additional shares for issuance under options granted outside of the 2003 Stock Option Plan. The options were granted to The University of Texas M. D. Anderson Cancer Center and DEKK-Tec, Inc. (see Note 8 to the financial statements, Commitments and Contingencies).

	Proceeds from the option exercises during the years ended December 31, 2014, 2013, and 2012 amounted to $1.4 million, $956 thousand, and $30 thousand, respectively. The intrinsic value of these options amounted to $2.6 million, $1.4 million and $11 thousand for years ended December 31, 2014, 2013 and 2012, respectively.
	Transactions under the Plan for the years ending December 31, 2014, 2013, and 2012 were as follows:


	(in thousands, except share and per share data)	Number of			Weighted-		Weighted-	Aggregate
		Shares			Average Exercise		Average	Intrinsic Value
					Price		Contractual
							Term (Years)
	Outstanding, December 31, 2011		5,138,486			4.08
	Granted		2,309,650			4.36
	Exercised		(8,300	)		3.61
	Cancelled		(292,533	)		5.7

	Outstanding, December 31, 2012		7,147,303			4.11
	Granted		2,649,900			3.28
	Exercised		(570,168	)		1.68
	Cancelled		(2,479,732	)		4.58

	Outstanding, December 31, 2013		6,747,303			3.81
	Granted		1,099,300			4.95
	Exercised		(613,138	)		2.26
	Cancelled		(727,801	)		4.54

	Outstanding, December 31, 2014		6,505,664		$	4.07	7.19	$9,084

	Vested and unvested expected to vest at December 31, 2014		6,485,430		$	4.1	5.8	$9,056

	Options exercisable, December 31, 2014		3,781,162		$	4.1	5.8	$4,130

	Options exercisable, December 31, 2013		3,471,935		$	4.01	5.03	$2,654

	Options available for future grant		4,585,769

	At December 31, 2014, total unrecognized compensation costs related to non-vested stock options outstanding amounted to $7.9 million. The cost is expected to be recognized over a weighted-average period of 1.62 years.
	Restricted Stock
	In December 2014, the Company issued 66,828 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 2013, the Company issued 75,272 shares of restricted stock to its non-employee directors, which vested in their entirety on the one year anniversary of the grant date. In January, February and May 2012, the Company issued 101,500, 43,802 and 25,000 shares of restricted stock to employees, which vested ratably in annual installments over three years, respectively, commencing on the first anniversary of the grant date. In December 2012, the Company also issued 87,730 shares of restricted stock to its non-employee directors, which vested ratably in annual installments over three years, commencing on the first anniversary of the grant date.
	In January, February and December 2014, the Company repurchased 16,031, 14,600 and 81,702 shares at average prices of $4.37, $4.40 and $5.04 per share, respectively, to cover payroll taxes. In January, March, May and December 2013, the Company repurchased 52,018, 5,400, 2,623, and 56,683 shares at average prices of $4.28, $4.50, $1.65 and $4.37 per share, respectively, to cover payroll taxes. In July and December 2012, the Company repurchased 15,740 and 107,413 shares at $6.06 and $4.19 per share, respectively, to cover payroll taxes. A summary of the status of non-vested restricted stock as of December 31, 2014, 2013 and 2012 is as follows:


		Number of Shares			Weighted-Average
		Number of Shares			Grant Date Fair Value
	Non-vested, December 31, 2011		950,906		$	4.34
	Granted		258,032			4.39
	Vested		(351,829	)		4.32
	Cancelled		(123,370	)		4.34

	Non-vested, December 31, 2012		733,739			4.37
	Granted		75,272			4.34
	Vested		(292,399	)		4.31
	Cancelled		(163,747	)		4.42

	Non-vested, December 31, 2013		352,865			4.38
	Granted		66,828			5.07
	Vested		(253,835	)		4.38
	Cancelled		(21,350	)		4.41

	Non-vested, December 31, 2014		144,508		$	4.7

As of December 31, 2014, there was $471 thousand 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 1.00 years.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plan	13	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 $79 thousand, $139 thousand, and $266 thousand to this plan during the years ended December 31, 2014, 2013, and 2012, respectively.

Selected_Quarterly_Information

Selected Quarterly Information (Unaudited)	12 Months Ended
Selected Quarterly Information (Unaudited)	Dec. 31, 2014
Selected Quarterly Information (Unaudited)	14	Selected Quarterly Information (Unaudited)
	(in thousands, except per share amount)


	Year Ended December 31, 2014	First			Second			Third			Fourth
	Year Ended December 31, 2014	Quarter			Quarter			Quarter			Quarter
	Revenue	$	200		$	200		$	633		$	340
	Total operating expenses		9,984			11,377			12,575			10,936
	Loss from operations		(9,784	)		(11,177	)		(11,942	)		(10,596	)
	Change in fair value of warrants		82			5,600			5,847			194
	Net (loss)		(9,711	)		(5,576	)		(6,093	)		(10,401	)
	Loss per share, basic and diluted	$	(0.10	)	$	(0.06	)	$	(0.06	)	$	(0.09	)


	Year Ended December 31, 2013	First			Second			Third			Fourth
	Year Ended December 31, 2013	Quarter			Quarter			Quarter			Quarter
	Revenue	$	200		$	200		$	200		$	200
	Total operating expenses		23,783			18,496			9,315			6,919
	Loss from operations		(23,583	)		(18,296	)		(9,115	)		(6,719	)
	Change in fair value of warrants		10,788			(403	)		(7,407	)		(1,793	)
	Net (loss)		(12,799	)		(18,692	)		(16,713	)		(8,903	)
	Loss per share, basic and diluted	$	(0.15	)	$	(0.22	)	$	(0.20	)	$	(0.09	)

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Basis of Presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“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 our financial statements are:

•

Clinical trial expenses;

•

Fair value measurements for stock based compensation and warrants; and

•

Income taxes.

Subsequent Events

On January 13, 2015, the Company, together with Intrexon, entered into a license agreement, or the License, with The University of Texas M.D. Anderson Cancer Center (“MD Anderson”). Pursuant to the License, the Company and Intrexon hold an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel chimeric antigen receptor (CAR) T-cell therapies arising from the laboratory of Laurence Cooper, M.D., Ph.D., professor of pediatrics at MD Anderson, as well as either co-exclusive or non-exclusive licenses under certain related technologies.

Pursuant to the terms of the License, MD Anderson will receive, within sixty days of the date of the License, consideration of $50 million in shares of our common stock (or 10,124,561 shares), and $50 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the Company’s and Intrexon’s common stock ending on the date prior to the announcement of the entry into the License, collectively referred to as the License Shares, pursuant to the terms of the License Shares Securities Issuance Agreement described below. The Company and Intrexon also agreed to reimburse MD Anderson for out of pocket expenses for maintaining patents covering the licensed technologies.

In addition, pursuant to the License, MD Anderson has agreed to transfer to us certain existing research programs described in the License and to grant to Intrexon and us certain additional technology rights related thereto. In connection with such transfer, the terms of the License also require us and Intrexon to enter into a research and development agreement with MD Anderson pursuant to which the Company will provide funding for certain research and development activities of MD Anderson for a period of three years, in an amount between $15 and $20 million per year. The first quarterly payment of $3.75 million due under this arrangement is required to be made by us within 60 days of the date of the License.

The term of the 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 License; provided, however, that following the expiration of the term, the Company and Intrexon 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 License and subject to a 90 day cure period, MD Anderson will have the right to convert the License into a non-exclusive license if the Company and Intrexon 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 License and subject to a 180 day cure period, MD Anderson will have the right to terminate the License with respect to specific technology(ies) funded by the government or subject to a third party contract if the Company and Intrexon are not meeting the diligence requirements in such funding agreement or contract, as applicable. Subject to a 30 day cure period, MD Anderson has the right to terminate the License if the Company and Intrexon fail to timely deliver the shares due in consideration for the License. MD Anderson may also terminate the agreement with written notice upon material breach by us and Intrexon, if such breach has not been cured within 60 days of receiving such notice. In addition, the License will terminate upon the occurrence of certain insolvency events for both us and Intrexon and may be terminated by the mutual written agreement of us, Intrexon and MD Anderson.

On January 9, 2015, in order to induce MD Anderson to enter into the License on an accelerated schedule, the Company and Intrexon entered into a letter agreement, or the Letter Agreement, pursuant to which MD Anderson will receive consideration of $7.5 million in shares of the our common stock (or 1,597,602 shares), and $7.5 million in shares of Intrexon’s common stock in each case based on a trailing 20 day volume weighted average of the closing price of the our and Intrexon’s common stock ending on the date prior to the Letter Agreement, collectively referred to as the Incentive Shares, in the event that the License was entered into on or prior to 8:00 am pacific time on January 14, 2015, referred to as the Accelerated Closing Deadline. The Incentive Shares will be issued to MD Anderson within sixty days of the date of the License pursuant to the terms of the Incentive Shares Securities Issuance Agreement described below.

In connection with the entry into the License, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the License Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the License Shares to MD Anderson in consideration for the License. The closing of the issuance and sale of the License Shares under the License Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.

In connection with the entry into the Letter Agreement, on January 13, 2015, the Company entered into a Securities Issuance Agreement with MD Anderson, or the Incentive Shares Securities Issuance Agreement, pursuant to which the Company agreed to issue and sell the Incentive Shares to MD Anderson in consideration for the execution and delivery of the License on or prior to the Accelerated Closing Deadline in connection with the Letter Agreement. The closing of the issuance and sale of the Incentive Shares under the Incentive Shares Securities Issuance Agreement will occur within sixty days of the date of the License, subject to customary closing conditions.

Also in connection with the License and the issuance of the License Shares and the Incentive Shares, on January 13, 2015, the Company and MD Anderson entered into a Registration Rights Agreement, or the Registration Rights Agreement, pursuant to which the Company agreed to file a “resale” registration statement, or the Registration Statement, registering the resale of the License Shares, the Incentive Shares and any other shares of our common stock held by MD Anderson on the date that the Registration Statement is filed, within 15 days of the closing under the License Shares Securities Issuance Agreement. Under the Registration Rights Agreement, the Company is obligated to use our reasonable best efforts to cause the Registration Statement to be declared effective as promptly as practicable after filing and in no event later than 120 days of the closing under the License Shares Securities Issuance Agreement and to maintain the effectiveness of the Registration Statement until all securities therein are sold or are otherwise can be sold pursuant to Rule 144, without any restrictions.

Our director, Randall J. Kirk, is the CEO, a director, and the largest stockholder of Intrexon, which is a party to the License. Mr. Kirk is also one of our principal stockholders.

On February 3, 2015, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC (see Note 2 above).

The Company evaluated all other events and transactions that occurred after the balance sheet date through the date of this filing. Except as disclosed above, the Company did not have any other material subsequent events that impacted its financial statements or disclosures.

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

Other assets include $388 thousand that is restricted as collateral for the Company’s facility leases and $103 thousand that is restricted as collateral for a line of credit.

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.

Warrants

The Company applies the accounting standard which provides guidance in assessing whether an equity-based 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 certain warrants issued by the Company have terms that do not meet the criteria to be considered indexed to the Company’s own stock and therefore are classified as liabilities in the Company’s balance sheet. The liability classified warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of “Other income, net” in the accompanying Statement of Operations. Fair value is measured using the binomial valuation model. In December 2011, the Company switched from the Black-Scholes valuation model to the binomial valuation model as it provides a better evaluation of the fair market value of the Company’s liability-classified warrants.

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, 2014 and 2013 are as follows:

($ in thousands)

Fair Value Measurements at Reporting Date Using

Description

Balance as of

Quoted Prices in

Significant Other

Significant

December 31,

Active Markets for

Observable

Unobservable

2014

Identical

Inputs

Assets/Liabilities

(Level 2)

(Level 3)

(Level 1)

Cash equivalents

37,290

—

Warrant liability

—

($ in thousands)

Fair Value Measurements at Reporting Date Using

Description

Balance as of

Quoted Prices in

Significant Other

Significant

December 31,

Active Markets for

Observable

Unobservable Inputs

2013

Identical

Inputs (Level 2)

(Level 3)

Assets/Liabilities

(Level 1)

Cash equivalents

66,794

—

Warrant liability

11,776

—

11,776

—

The cash equivalents consist primarily of short term U.S. treasury money market mutual funds which are actively traded. The warrants were valued using a binomial valuation model. As of December 31, 2014, all liability classified warrants had expired. See Note 9 to the financial statements, Warrants, for additional disclosure on the valuation methodology and significant assumptions.

Revenue Recognition

The Company receives revenue from a collaboration agreement (see Note 8 to the financial statements, Commitments and Contingencies). Collaboration arrangements typically include payments for one or more of the following: non-refundable, upfront license fees, funding of research and development efforts, milestone payments if specified objectives are achieved and/or profit-sharing or royalties on product sales. Arrangements containing multiple elements are divided into separate units of accounting if certain criteria are met, including whether the delivered element has stand-alone value to the collaborative partner. The consideration received is then allocated among the separate units based on their respective fair values and the applicable revenue recognition criteria are applied to each of the separate units.

Revenue from non-refundable, upfront research and development fees is reported as research and development revenue and is recognized on a straight-line basis over the contracted or estimated period of performance, which is typically the development term. Research and development funding is earned over the period of effort.

Milestone payments are recognized as research and development revenue upon achievement of the milestone only if (1) the milestone payment is non-refundable, (2) substantive effort is involved in achieving the milestone and (3) the amount of the milestone is reasonable in relation to the effort expended or the risk associated with achievement of the milestone. If any of these conditions are not met, the milestone payment is deferred and recognized as revenue over the estimated remaining period of performance under the contract as the Company completes its performance obligations.

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 (see Note 10 to the financial statements, Income Taxes).

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, 2014, 2013, and 2012 and did not capitalize any such costs on the balance sheets. The Company recognized $3.7 million, $2.3 million, and $3.1 million of compensation expense related to vesting of employee stock options during the years ended December 31, 2014, 2013, and 2012, respectively. In the years ended December 31, 2014, 2013, and 2012, the Company recognized $1.0 million, $1.2 million, and $1.7 million of compensation expense, respectively, related to vesting of restricted stock (see Note 12 to the financial statements, Stock Option Plan). In the years ended December 31, 2014, 2013, and 2012, the Company recognized $4.7 million, $3.5 million, and $4.9 million of compensation expense, respectively, related to vesting of all employee and director awards. The following table presents share-based compensation expense included in the Company’s Statements of Operations:

Year ended December 31,

(in thousands)

2014

2013

2012

Research and development

1,416

792

1,917

General and administrative

3,327

2,715

2,963

Share based employee compensation expense before tax

4,743

3,507

4,880

Income tax benefit

—

Net share based employee compensation expense

4,743

3,507

4,880

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 2014, 2013, and 2012 was approximately $3.58, $2.51, and $3.06 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 Staff Accounting Bulletin No. 110. The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below:

2014

2013

2012

Weighted average risk-free interest rate

1.74 - 2.11%

1.00 - 2.10%

0.79 - 1.13%

Expected life in years

Expected volatility

85.22 - 94.55%

83.40 - 95.96%

83.36 - 83.53%

Expected dividend yield

Net Loss Per Share

Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding for the period. The Company’s potential dilutive shares, which include outstanding common stock options, unvested restricted stock and warrants, have not been included in the computation of diluted net loss per share for any of the periods presented as the result would be antidilutive. Such potential common shares at December 31, 2014, 2013, and 2012 consist of the following:

December 31,

2014

2013

2012

Stock options

6,505,664

6,747,303

7,147,303

Unvested restricted stock

144,508

352,865

733,739

Warrants

—

10,539,767

11,197,454

6,650,172

17,639,935

19,078,496

New Accounting Pronouncements

In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40) in which management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable). When management identifies conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern, management should consider whether its plans that are intended to mitigate those relevant conditions or events will alleviate the substantial doubt. This update is effective for annual periods beginning after December 15, 2016, and early application is permitted for any annual or interim period thereafter.

On June 10, 2014, the FASB issued ASU 2014-10, Development Stage Entities (Topic 915), which simplifies financial reporting for development stage entities by eliminating requirements specific to development stage entities. As a result, entities in a development stage will no longer need to present inception-to-date information about income statement line items, cash flows, and equity transactions. Instead, the new guidance clarifies how these entities should tailor existing disclosures to explain the risks and uncertainties related to their activities. This update is effective for annual periods beginning after December 15, 2014, and early application is permitted for any annual or interim period for which the entity’s financial statements have not yet been issued. The Company adopted this guidance prior to issuing the financial statements in this Quarterly Report on Form 10-Q. The adoption of ASU 2014-10 impacted presentation and disclosure only and did not have any impact on financial position or results of operations.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), which clarifies the principles for recognizing revenue and develops a common revenue standard for U.S. GAAP and IFRS. This standard removes inconsistencies and weaknesses between U.S. GAAP and IFRS in revenue requirements, provides a more robust framework for addressing revenue issues, improves comparability of revenue recognition practices across entities, industries, jurisdictions, and capital markets, provides more useful information to users of financial statements through improved disclosure requirements, and simplifies the preparation of financial statements by reducing the number of requirements to which an entity must refer. This update is effective for annual periods beginning after December 15, 2016, including interim periods within that reporting period and early application is not permitted. The company believes that the adoption of this standard will not have an impact on our financial position or results of operations.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2014
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, 2014 and 2013 are as follows:


	($ in thousands)	Fair Value Measurements at Reporting Date Using
	Description	Balance as of			Quoted Prices in		Significant Other		Significant
		December 31,			Active Markets for		Observable		Unobservable
		2014			Identical		Inputs		Inputs
					Assets/Liabilities		(Level 2)		(Level 3)
					(Level 1)
	Cash equivalents	$	37,290		$	37,290	$	—	$	—

	Warrant liability	$	—		$	—	$	—	$	—



	($ in thousands)	Fair Value Measurements at Reporting Date Using
	Description	Balance as of			Quoted Prices in		Significant Other		Significant
		December 31,			Active Markets for		Observable		Unobservable Inputs
		2013			Identical		Inputs (Level 2)		(Level 3)
					Assets/Liabilities
					(Level 1)
	Cash equivalents	$	66,794		$	66,794	$	—	$	—

	Warrant liability	$	11,776		$	—	$	11,776	$	—

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)	2014			2013		2012
	Research and development	$	1,416		$	792	$	1,917
	General and administrative		3,327			2,715		2,963

	Share based employee compensation expense before tax		4,743			3,507		4,880
	Income tax benefit		—			—		—

	Net share based employee compensation expense	$	4,743		$	3,507	$	4,880

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:


		2014		2013	2012
	Weighted average risk-free interest rate	1.74 - 2.11%		1.00 - 2.10%	0.79 - 1.13%
	Expected life in years	6		6	6
	Expected volatility	85.22 - 94.55%		83.40 - 95.96%	83.36 - 83.53%
	Expected dividend yield	0		0	0
Potential Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share	The Company’s potential dilutive shares, which include outstanding common stock options, unvested restricted stock and warrants, have not been included in the computation of diluted net loss per share for any of the periods presented as the result would be antidilutive. Such potential common shares at December 31, 2014, 2013, and 2012 consist of the following:


		December 31,
		2014			2013		2012
	Stock options		6,505,664			6,747,303		7,147,303
	Unvested restricted stock		144,508			352,865		733,739
	Warrants		—			10,539,767		11,197,454

			6,650,172			17,639,935		19,078,496

Property_and_Equipment_net_Tab

Property and Equipment, net (Tables)	12 Months Ended
Property and Equipment, net (Tables)	Dec. 31, 2014
Component of Property and Equipment, Net	Property and equipment, net, consists of the following:


		December 31,
	(in thousands)	2014			2013
	Office and computer equipment	$	1,094		$	1,076
	Software		874			884
	Leasehold improvements		927			841
	Manufacturing equipment		251			153

			3,146			2,954
	Less: accumulated depreciation		(2,615	)		(2,153	)

	Property and equipment, net	$	531		$	801

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
Accrued Expenses (Tables)	Dec. 31, 2014
Component of Accrued Expenses	Accrued expenses consist of the following:


		December 31,
	(in thousands)	2014		2013
	Clinical consulting services	$	2,802	$	3,751
	Preclinical services		2,027		513
	Employee compensation		768		252
	Professional services		422		582
	Payroll taxes and benefits		417		255
	Manufacturing services		308		547
	Other consulting services		226		230
	Accrued vacation		212		227

	Accrued expenses	$	7,182	$	6,357

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2014
Future Net Minimum Lease Payments under Operating Leases	Future net minimum lease payments under operating leases as of December 31, 2014 are as follows (in thousands):


	2015	$	1,235
	2016		997
	2017		501
	2018		424
	2019		—

			3,157
	Less: contractual sublease income		(1,224	)

	Future minimum lease payments, net	$	1,933

Warrants_Tables

Warrants (Tables)	12 Months Ended
Warrants (Tables)	Dec. 31, 2014
Assumptions Used in Binomial and Monte Carlo Valuation Model	The following pricing assumptions were used in the Binomial/Monte Carlo valuation model at December 31, 2013 and 2012:


		December 31, 2013			December 31, 2012
	Risk-free interest rate		0.13	%		0.25	%
	Expected life in years		0.94			1.94
	Expected volatility		80	%		70	%
	Expected dividend yield		0			0

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2014
Significant Component of Deferred Tax Assets	Significant components of the Company’s deferred tax assets at December 31, 2014 and 2013 are as follows:



		December 31,
	(in thousands)	2014			2013
	Net operating loss carryforwards	$	79,050		$	66,209
	Start-up and organizational costs		38,562			41,529
	Research and development credit carryforwards		26,112			25,058
	Stock compensation		1,181			1,028
	Capitalized acquisition costs		11,376			12,323
	Deferred revenue		534			1,074
	Depreciation		208			129
	Other		1,547			1,254

			158,570			148,604
	Less valuation allowance		(158,570	)		(148,604	)

	Net deferred tax assets	$	—		$	—

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)	2014			2013			2012
	Federal income tax at statutory rates		34	%		34	%		34	%
	State income tax, net of federal tax benefit		2	%		4	%		5	%
	Research and development credits		3	%		9	%		10	%
	Stock compensation		-4	%		-2	%		-1	%
	Uncertain tax position adjustment		0	%		0	%		0	%
	Federal R&D tax grant		0	%		0	%		0	%
	Other		-4	%		1	%		2	%
	Increase in valuation allowance		-31	%		-46	%		-49	%

	Effective tax rate		0	%		0	%		0	%

Summary of Adjustments to Uncertain Tax Position	A summary of the company’s adjustments to its uncertain tax positions in the years ended December 31, 2014, 2013, and 2012 are as follows:


	(in thousands)
	Balance at December 31, 2011	$	275
	Increase/Decrease for tax positions related to the current year		—
	Increase/Decrease for tax positions related to prior years		—
	Decreases for settlements with applicable taxing authorities		—
	Decreases for lapses of statute of limitations		—

	Balance at December 31, 2012	$	275
	Increase/Decrease for tax positions related to the current year		—
	Increase/Decrease for tax positions related to prior years		(37	)
	Decreases for settlements with applicable taxing authorities		—
	Decreases for lapses of statute of limitations		—

	Balance at December 31, 2013	$	238
	Increase/Decrease for tax positions related to the current year		—
	Increase/Decrease for tax positions related to prior years		—
	Decreases for settlements with applicable taxing authorities		—
	Decreases for lapses of statute of limitations		—

	Balance at December 31, 2014	$	238

Stock_Option_Plan_Tables

Stock Option Plan (Tables)	12 Months Ended
Stock Option Plan (Tables)	Dec. 31, 2014
Transaction under Stock Option Plan	Transactions under the Plan for the years ending December 31, 2014, 2013, and 2012 were as follows:


	(in thousands, except share and per share data)	Number of			Weighted-		Weighted-	Aggregate
		Shares			Average Exercise		Average	Intrinsic Value
					Price		Contractual
							Term (Years)
	Outstanding, December 31, 2011		5,138,486			4.08
	Granted		2,309,650			4.36
	Exercised		(8,300	)		3.61
	Cancelled		(292,533	)		5.7

	Outstanding, December 31, 2012		7,147,303			4.11
	Granted		2,649,900			3.28
	Exercised		(570,168	)		1.68
	Cancelled		(2,479,732	)		4.58

	Outstanding, December 31, 2013		6,747,303			3.81
	Granted		1,099,300			4.95
	Exercised		(613,138	)		2.26
	Cancelled		(727,801	)		4.54

	Outstanding, December 31, 2014		6,505,664		$	4.07	7.19	$9,084

	Vested and unvested expected to vest at December 31, 2014		6,485,430		$	4.1	5.8	$9,056

	Options exercisable, December 31, 2014		3,781,162		$	4.1	5.8	$4,130

	Options exercisable, December 31, 2013		3,471,935		$	4.01	5.03	$2,654

	Options available for future grant		4,585,769

Summary of Nonvested Restricted Stock	A summary of the status of non-vested restricted stock as of December 31, 2014, 2013 and 2012 is as follows:


		Number of Shares			Weighted-Average
		Number of Shares			Grant Date Fair Value
	Non-vested, December 31, 2011		950,906		$	4.34
	Granted		258,032			4.39
	Vested		(351,829	)		4.32
	Cancelled		(123,370	)		4.34

	Non-vested, December 31, 2012		733,739			4.37
	Granted		75,272			4.34
	Vested		(292,399	)		4.31
	Cancelled		(163,747	)		4.42

	Non-vested, December 31, 2013		352,865			4.38
	Granted		66,828			5.07
	Vested		(253,835	)		4.38
	Cancelled		(21,350	)		4.41

	Non-vested, December 31, 2014		144,508		$	4.7

Selected_Quarterly_Information1

Selected Quarterly Information (Unaudited) (Tables)	12 Months Ended
Selected Quarterly Information (Unaudited) (Tables)	Dec. 31, 2014
Selected Quarterly Information	(in thousands, except per share amount)


	Year Ended December 31, 2014	First			Second			Third			Fourth
	Year Ended December 31, 2014	Quarter			Quarter			Quarter			Quarter
	Revenue	$	200		$	200		$	633		$	340
	Total operating expenses		9,984			11,377			12,575			10,936
	Loss from operations		(9,784	)		(11,177	)		(11,942	)		(10,596	)
	Change in fair value of warrants		82			5,600			5,847			194
	Net (loss)		(9,711	)		(5,576	)		(6,093	)		(10,401	)
	Loss per share, basic and diluted	$	(0.10	)	$	(0.06	)	$	(0.06	)	$	(0.09	)


	Year Ended December 31, 2013	First			Second			Third			Fourth
	Year Ended December 31, 2013	Quarter			Quarter			Quarter			Quarter
	Revenue	$	200		$	200		$	200		$	200
	Total operating expenses		23,783			18,496			9,315			6,919
	Loss from operations		(23,583	)		(18,296	)		(9,115	)		(6,719	)
	Change in fair value of warrants		10,788			(403	)		(7,407	)		(1,793	)
	Net (loss)		(12,799	)		(18,692	)		(16,713	)		(8,903	)
	Loss per share, basic and diluted	$	(0.15	)	$	(0.22	)	$	(0.20	)	$	(0.09	)

Organization_Additional_Inform

Organization - Additional Information (Detail) (USD $)	12 Months Ended
Organization - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Nature Of Operations [Line Items]
Accumulated Deficit	($372,612,000)	($340,831,000)
Expected net proceeds from issuance of common stock	$94,600,000

Financings_Additional_Informat

Financings - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 12, 2011	Dec. 31, 2014	Oct. 29, 2013	Oct. 23, 2013	Jan. 31, 2012	Jan. 25, 2012	Jan. 20, 2012	Feb. 17, 2015	Feb. 09, 2015	Feb. 03, 2015
Class of Stock [Line Items]
Stock issued during period	3,636,926
Expected net proceeds from issuance of common stock		$94.60
J.P. Morgan Securities Inc.
Class of Stock [Line Items]
Stock issued during period			2,145,000	14,300,000	464,401	9,650,000
Issuance & sale of common stock in public offering price per share				$3.50			$5.20
Option granted, exercisable period				30 days			30 days
Option to purchase common stock				2,145,000			1,447,500
Sale of stock price per share				$3.29			$4.89
Net proceeds from issuance of common stock			53.9		49.2
Issuance & sale of common stock in public offering							9,650,000
J.P. Morgan Securities Inc. \| Total
Class of Stock [Line Items]
Stock issued during period					10,114,401
J.P. Morgan Securities Inc. \| Subsequent Event
Class of Stock [Line Items]
Stock issued during period								1,500,000	10,000,000	10,000,000
Issuance & sale of common stock in public offering price per share										$8.75
Option granted, exercisable period										30 days
Option to purchase common stock										1,500,000
Sale of stock price per share										$8.22
Expected net proceeds from issuance of common stock								$94.20

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 13, 2015	Jan. 09, 2015
Summary Of Significant Accounting Policies [Line Items]
Research and Development Expense	$32,706,000	$42,852,000	$83,446,000
Stock based compensation expenses	4,743,000	3,507,000	4,880,000
Weighted average fair value of stock option granted	$3.58	$2.51	$3.06
Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Research and development arrangement Terms				In connection with such transfer, the terms of the License also require us and Intrexon to enter into a research and development agreement with MD Anderson pursuant to which the Company will provide funding for certain research and development activities of MD Anderson for a period of three years
Research and Development Service Agreement Quarterly Payment				3,750,000
Period of milestone payment				60 days
Subsequent Event \| Letter Agreement
Summary Of Significant Accounting Policies [Line Items]
Incentive shares issued period					60 days
Subsequent Event \| Letter Agreement \| Ziopharm
Summary Of Significant Accounting Policies [Line Items]
Cash consideration for license agreement					1,597,602
Cash consideration for license agreement					7,500,000
Subsequent Event \| Letter Agreement \| Intrexon Corporation
Summary Of Significant Accounting Policies [Line Items]
Cash consideration for license agreement					7,500,000
Subsequent Event \| License Agreement \| Md Anderson Cancer Center
Summary Of Significant Accounting Policies [Line Items]
Contingent consideration of common stock payable period				60 days
Subsequent Event \| License Agreement \| Ziopharm
Summary Of Significant Accounting Policies [Line Items]
Cash consideration for license agreement				10,124,561
Cash consideration for license agreement				50,000,000
Subsequent Event \| License Agreement \| Intrexon Corporation
Summary Of Significant Accounting Policies [Line Items]
Cash consideration for license agreement				50,000,000
Employee Stock Option
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	3,700,000	2,300,000	3,100,000
Restricted Stock
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	1,000,000	1,200,000	1,700,000
Employee and Director Awards
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	4,700,000	3,500,000	4,900,000
Other Assets \| Lease Obligations
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	388,000
Other Noncurrent Assets \| Line of Credit
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	103,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life	3 years
Minimum \| Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Research and Development Expense				15,000,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life	5 years
Maximum \| Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Research and Development Expense				$20,000,000

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (Fair Value, Measurements, Recurring, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$37,290	$66,794
Warrant liability		11,776
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	37,290	66,794
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability		$11,776

StockBased_Compensation_Expens

Stock-Based Compensation Expense Included in Statement of Operations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$4,743	$3,507	$4,880
Income tax benefit	0	0	0
Net share based employee compensation expense	4,743	3,507	4,880
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,416	792	1,917
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$3,327	$2,715	$2,963

Fair_Value_of_Stock_Options_As

Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, Minimum	1.74%	1.00%	0.79%
Risk-free interest rate, Maximum	2.11%	2.10%	1.13%
Expected life in years	6 years	6 years	6 years
Expected volatility, Minimum	85.22%	83.40%	83.36%
Expected volatility, Maximum	94.55%	95.96%	83.53%
Expected dividend yield	0.00%	0.00%	0.00%

Potential_Dilutive_Shares_Excl

Potential Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	6,650,172	17,639,935	19,078,496
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	6,505,664	6,747,303	7,147,303
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	144,508	352,865	733,739
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		10,539,767	11,197,454

Restructuring_Additional_Infor

Restructuring - Additional Information (Detail) (USD $)	12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Aug. 30, 2013	Dec. 31, 2014	Oct. 17, 2013
	Dec. 31, 2013	Dec. 31, 2012	sqft	Dec. 31, 2014	sqft
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$1,700,000
Loss on disposition of business	800,000
Loss on disposal of fixed assets	600,000
Loss on disposal of fixed assets	-585,000	-48,000
Severance and Health Benefit Continuation Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		1,300,000
Boston, MA
Restructuring Cost and Reserve [Line Items]
Area under sublease agreement			5,249
Loss on sublease	42,000
Remaining contractual obligation	367,000
Sublease revenue from subtenant	325,000
Loss on disposal of fixed assets	-194,000
Security deposit	20,000	127,000		127,000
Date of sublease vacated for lease				2014-10
Amount applied for deposit				20,000
New York, NY
Restructuring Cost and Reserve [Line Items]
Area under sublease agreement					7,259
Loss on sublease	729,000
Remaining contractual obligation	2,300,000
Sublease revenue from subtenant	1,600,000
Loss on disposal of fixed assets	-392,000
General and Administrative Expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	600,000
Research and Development Expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$1,100,000

Component_of_Property_and_Equi

Component of Property and Equipment, Net (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Office and computer equipment	$1,094	$1,076
Software	874	884
Leasehold improvements	927	841
Manufacturing equipment	251	153
Property and equipment, Gross	3,146	2,954
Less: accumulated depreciation	-2,615	-2,153
Property and equipment, net	$531	$801

Property_and_Equipment_net_Add

Property and Equipment, net - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$462	$738	$658

Component_of_Accrued_Expenses_

Component of Accrued Expenses (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accrued Liabilities [Line Items]
Clinical consulting services	$2,802	$3,751
Preclinical services	2,027	513
Employee compensation	768	252
Professional services	422	582
Payroll taxes and benefits	417	255
Manufacturing services	308	547
Other consulting services	226	230
Accrued vacation	212	227
Accrued expenses	$7,182	$6,357

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	0 Months Ended				12 Months Ended			0 Months Ended
	Jan. 12, 2011	Oct. 29, 2013	Nov. 07, 2012	Jan. 25, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 02, 2015
Related Party Transaction [Line Items]
Prepaid expenses and other current assets					$1,139,000	$1,948,000
Stock issued during period	3,636,926
Intrexon Corporation
Related Party Transaction [Line Items]
Payments for services					10,100,000	2,400,000	11,400,000
Amounts paid for services incurred					12,000,000	7,800,000	6,600,000
Prepaid expenses and other current assets					0	4,800,000	4,800,000
Accrued expense					$1,900,000	$600,000
Stock issued during period		2,857,143	3,636,926	1,923,075
Intrexon Corporation \| Subsequent Event
Related Party Transaction [Line Items]
Stock issued during period								1,440,000

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Jan. 13, 2015

Jan. 09, 2015

Aug. 24, 2004

Dec. 31, 2004

Jan. 06, 2011

Mar. 07, 2011

Jun. 27, 2013

Aug. 30, 2013

Dec. 31, 2011

Oct. 17, 2013

Nov. 02, 2012

Oct. 15, 2014

Jun. 30, 2012

Jan. 31, 2012

Apr. 30, 2011

Patent

sqft

Commitments and Contingencies Disclosure [Line Items]

Loss on disposal of fixed assets

($585,000)

($48,000)

Total rent Expense

1,200,000

1,000,000

1,100,000

Deferred rent - current portion

280,000

212,000

280,000

212,000

Deferred rent-non-current portion

570,000

851,000

570,000

851,000

Deferred rent liability net

850,000

1,100,000

850,000

1,100,000

Research and Development Expense

32,706,000

42,852,000

83,446,000

Deferred revenue - current portion

1,360,000

800,000

1,360,000

800,000

Research contract revenue

340,000

633,000

200,000

1,373,000

800,000

Estimated upfront payment for research and development funding earning period

75 months

Subsequent Event

Commitments and Contingencies Disclosure [Line Items]

Research and development arrangement Terms

In connection with such transfer, the terms of the License also require us and Intrexon to enter into a research and development agreement with MD Anderson pursuant to which the Company will provide funding for certain research and development activities of MD Anderson for a period of three years

Research and Development Service Agreement Quarterly Payment

3,750,000

Period of milestone payment

60 days

Subsequent Event | License Agreement | Ziopharm

Commitments and Contingencies Disclosure [Line Items]

Cash consideration for license agreement

10,124,561

Cash consideration for license agreement

50,000,000

Subsequent Event | License Agreement | Intrexon Corporation

Commitments and Contingencies Disclosure [Line Items]

Cash consideration for license agreement

50,000,000

Subsequent Event | Letter Agreement

Commitments and Contingencies Disclosure [Line Items]

Incentive shares issued period

60 days

Subsequent Event | Letter Agreement | Ziopharm

Commitments and Contingencies Disclosure [Line Items]

Cash consideration for license agreement

1,597,602

Cash consideration for license agreement

7,500,000

Subsequent Event | Letter Agreement | Intrexon Corporation

Commitments and Contingencies Disclosure [Line Items]

Cash consideration for license agreement

7,500,000

Subsequent Event | Minimum

Commitments and Contingencies Disclosure [Line Items]

Research and Development Expense

15,000,000

Subsequent Event | Maximum

Commitments and Contingencies Disclosure [Line Items]

Research and Development Expense

20,000,000

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

Commitments and Contingencies Disclosure [Line Items]

Milestone maximum payment

4,500,000

Option to purchase common stock

50,222

Sale of stock price per share

$0.00

Number of products

The University of Texas M.D. 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 expected to vest

12,556

Novella Clinical, Inc.

Commitments and Contingencies Disclosure [Line Items]

Milestone maximum payment

790,000

Number of amendments signed

Novella Clinical, Inc. | Upon the achievement of various milestones

Commitments and Contingencies Disclosure [Line Items]

Installment payments

256,000

Novella Clinical, Inc. | Upon two database related milestones

Commitments and Contingencies Disclosure [Line Items]

Installment payments

136,000

Novella Clinical, Inc. | Upon three clinical milestones

Commitments and Contingencies Disclosure [Line Items]

Installment payments

236,000

Intrexon Corporation

Commitments and Contingencies Disclosure [Line Items]

Contract termination description

Our obligation to pay 50% of net profits or revenue described above with respect to these "retained" products will survive termination of the Channel Agreement.

Intrexon Corporation | Quarterly Payment

Commitments and Contingencies Disclosure [Line Items]

Percent of company net profit

50.00%

Percentage of revenue agreed to pay which is obtained from sublicensor

50.00%

DEKK Tec Inc

Commitments and Contingencies Disclosure [Line Items]

Milestone maximum payment

4,000,000

Option to purchase common stock

27,616

Sale of stock price per share

$0.02

Outstanding options to purchase common stock

13,808

Southern Research Institute

Commitments and Contingencies Disclosure [Line Items]

Milestone maximum payment

775,000

Royalty payment

25,000

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

Commitments and Contingencies Disclosure [Line Items]

Installment payments

250,000

PPD Development L. P.

Commitments and Contingencies Disclosure [Line Items]

Installment payments

9,200,000

3,800,000

Pharmaceutical Research Associates Inc | Upon the achievement of various milestones

Commitments and Contingencies Disclosure [Line Items]

Installment payments

2,200,000

7,300,000

Solasia

Commitments and Contingencies Disclosure [Line Items]

Upfront payment received

5,000,000

Solasia | Development-based milestones

Commitments and Contingencies Disclosure [Line Items]

Expected Additional milestone payments to be received

32,500,000

Solasia | Sales-based milestones

Commitments and Contingencies Disclosure [Line Items]

Expected Additional milestone payments to be received

53,500,000

Harmon Hill LLC | Collaboration Agreement

Commitments and Contingencies Disclosure [Line Items]

Other expense

200,000

Payment for consulting services fee

180,000

135,000

Harmon Hill LLC | Collaboration Agreement | Monthly Payment

Commitments and Contingencies Disclosure [Line Items]

Payment for consulting services fee

15,000

Md Anderson Cancer Center | Subsequent Event | License Agreement

Commitments and Contingencies Disclosure [Line Items]

Contingent consideration of common stock payable period

60 days

Boston, MA

Commitments and Contingencies Disclosure [Line Items]

Office space under operating lease

21,184

Operating lease expiration month and year

2016-08

Area under sublease agreement

5,249

Loss on sublease

42,000

Remaining contractual obligation

367,000

Sublease revenue from subtenant

325,000

Loss on disposal of fixed assets

-194,000

Security deposits

127,000

20,000

127,000

20,000

127,000

Security deposit from subtenant

20,000

Boston, MA | The first floor

Commitments and Contingencies Disclosure [Line Items]

Operating lease space

5,249

Boston, MA | The second floor

Commitments and Contingencies Disclosure [Line Items]

Office space under operating lease

4,113

Operating lease space

8,538

Boston, MA | The third floor

Commitments and Contingencies Disclosure [Line Items]

Operating lease space

6,959

Boston, MA | The four floor

Commitments and Contingencies Disclosure [Line Items]

Office space under operating lease

9,800

Security deposits

41,000

New York, NY

Commitments and Contingencies Disclosure [Line Items]

Office space under operating lease

7,259

6,251

Letter of credit

388,000

Additional office space under operating lease

1,008

Operating lease expiration month and year

2018-10

Area under sublease agreement

7,259

Loss on sublease

729,000

Remaining contractual obligation

2,300,000

Sublease revenue from subtenant

1,600,000

Loss on disposal of fixed assets

-392,000

Germantown, MD

Commitments and Contingencies Disclosure [Line Items]

Office space under operating lease

2,227

Operating lease expiration month and year

2014-03

Security deposits

4,000

Office closing date

16-Jul-12

Future_Minimum_Lease_Payments_

Future Minimum Lease Payments under Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Operating Leased Assets [Line Items]
2015	$1,235
2016	997
2017	501
2018	424
2019	0
Operating Leases, Future Minimum Payments Due, Total	3,157
Less: contractual sublease income	-1,224
Future minimum lease payments, net	$1,933

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (USD $)	12 Months Ended				1 Months Ended
Warrants - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2009	Oct. 31, 2009
Class of Warrant or Right [Line Items]
Warrants to purchase an aggregate of shares of common stock	184,367			8,206,520
Warrant term				5 years
Estimated fair value of warrant				$22,900,000
Warrants outstanding	8,235,076
Other income (expense)	-5,000	-579,000	-13,000
Warrants exercised	4,004,907	135,346	553,914
Conversion of Warrants to Common Stock	3,725,277	112,808	259,660
Warrants
Class of Warrant or Right [Line Items]
Expected volatility				105.00%
Risk-free interest rate				2.14%
Expected life in years				5 years
Expected dividend yield				0.00%
Liability
Class of Warrant or Right [Line Items]
Warrants outstanding	1,755,845	0	373,617
Classified warrants		11,800,000	13,000,000
Warrants expired	6,479,231		579
Equity
Class of Warrant or Right [Line Items]
Warrants outstanding	2,249,062	135,346	186,297
Warrants expired	12,329	706,708	1,359,317
Liability Warrants
Class of Warrant or Right [Line Items]
Other income (expense)		-1,200,000	-6,100,000
Registered direct offering
Class of Warrant or Right [Line Items]
Sale of stock price per share		$3.50
Private Placement
Class of Warrant or Right [Line Items]
Warrants to purchase an aggregate of shares of common stock				2,910,954
Warrant exercise price				$2.04
Warrant exercisable Period				5 years
Estimated fair value of warrant				$4,200,000
Warrants exercised					136,986
Private Placement \| Warrants
Class of Warrant or Right [Line Items]
Expected volatility				105.00%
Risk-free interest rate				2.41%
Expected life in years				5 years
Expected dividend yield				0.00%
J. P. Morgan Securities LLC
Class of Warrant or Right [Line Items]
Warrants issued				464,520
Warrant exercise price				$4.02
Warrant exercisable Period				6 months
Placement Agents \| Private Placement
Class of Warrant or Right [Line Items]
Warrants to purchase an aggregate of shares of common stock				138,617

Assumptions_Used_In_Binomial_V

Assumptions Used In Binomial Valuation Model and Black-Scholes Valuation Model (Detail) (Warrants)	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2013	Dec. 31, 2012
Class of Warrant or Right [Line Items]
Risk-free interest rate	2.14%
Expected life in years	5 years
Expected dividend yield	0.00%
Black Scholes Option Pricing Model
Class of Warrant or Right [Line Items]
Risk-free interest rate		0.13%	0.25%
Expected life in years		11 months 9 days	1 year 11 months 9 days
Expected volatility		80.00%	70.00%
Expected dividend yield		0.00%	0.00%

Significant_Component_of_Defer

Significant Component of Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred Tax Assets [Line Items]
Net operating loss carryforwards	$79,050	$66,209
Start-up and organizational costs	38,562	41,529
Research and development credit carryforwards	26,112	25,058
Stock compensation	1,181	1,028
Capitalized acquisition costs	11,376	12,323
Deferred revenue	534	1,074
Depreciation	208	129
Other	1,547	1,254
Deferred Tax Assets Gross	158,570	148,604
Less valuation allowance	-158,570	-148,604
Net deferred tax assets	$0	$0

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
Income Taxes - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Net operating loss carryforwards	$79,050,000	$66,209,000
Research and development credit carryforwards	26,112,000	25,058,000
Net Operating loss Carryforwards resulting from excess tax deduction	4,400,000
Increase (decrease) in valuation allowance	10,000,000
Net Operating Loss Carryforwards
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets	-11,200,000
General Business Credits
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets	-636,000
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	206,900,000
Net operating loss carryforwards, expiration date	2033
Research and Development Credit
Income Taxes [Line Items]
Net operating loss carryforwards, expiration date	2033
Research and development credit carryforwards	$26,000,000

Reconciliation_of_Income_Tax_E

Reconciliation of Income Tax Expense (Benefit) (Detail)	12 Months Ended
Reconciliation of Income Tax Expense (Benefit) (Detail)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Effective Tax Rate [Line Items]
Federal income tax at statutory rates	34.00%	34.00%	34.00%
State income tax, net of federal tax benefit	2.00%	4.00%	5.00%
Research and development credits	3.00%	9.00%	10.00%
Stock compensation	-4.00%	-2.00%	-1.00%
Uncertain tax position adjustment	0.00%	0.00%	0.00%
Federal R&D tax grant	0.00%	0.00%	0.00%
Other	-4.00%	1.00%	2.00%
Increase in valuation allowance	-31.00%	-46.00%	-49.00%
Effective tax rate	0.00%	0.00%	0.00%

Summary_of_Adjustments_to_Unce

Summary of Adjustments to Uncertain Tax Position (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Beginning Balance	$238	$275	$275
Increase/Decrease for tax positions related to the current year	0	0	0
Increase/Decrease for tax positions related to prior years		-37
Decreases for settlements with applicable taxing authorities	0	0	0
Decreases for lapses of statute of limitations	0	0	0
Ending Balance	$238	$238	$275

Preferred_Stock_and_Stockholde1

Preferred Stock and Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended			12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Oct. 29, 2013	Jan. 20, 2012	Jan. 12, 2011	Dec. 31, 2014	Oct. 23, 2013	Jan. 31, 2012	Jan. 25, 2012	Feb. 17, 2015	Feb. 09, 2015	Feb. 03, 2015	Nov. 07, 2012	Feb. 02, 2015	Dec. 31, 2013	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			$0.00	$0.00									$0.00	$0.00
Preferred stock, shares authorized														30,000,000
Preferred stock par value														$0.00
Common Stock Shares Sold	16,445,000	10,114,401	2,426,235
Proceeds from issuance of common stock	$57.60	$52.60	$11.60
Common stock price per share	$3.50	$5.20	$4.80
Common Stock Additional Shares Issued			3,636,926
Common stock, shares issued				104,452,105									100,159,618
Common stock, shares outstanding				104,452,105									100,159,618
Preferred stock, shares issued				0
Preferred stock, shares outstanding				0
Expected net proceeds from issuance of common stock				94.6
J.P. Morgan Securities Inc.
Equity [Line Items]
Common Stock Additional Shares Issued	2,145,000				14,300,000	464,401	9,650,000
Issuance & sale of common stock in public offering price per share		$5.20			$3.50
Sale of stock price per share		$4.89			$3.29
Option granted, exercisable period		30 days			30 days
Option to purchase common stock		1,447,500			2,145,000
Subsequent Event \| J.P. Morgan Securities Inc.
Equity [Line Items]
Common Stock Additional Shares Issued								1,500,000	10,000,000	10,000,000
Issuance & sale of common stock in public offering price per share										$8.75
Sale of stock price per share										$8.22
Option granted, exercisable period										30 days
Option to purchase common stock										1,500,000
Expected net proceeds from issuance of common stock								$94.20
Intrexon Corporation
Equity [Line Items]
Common Stock Additional Shares Issued	2,857,143						1,923,075				3,636,926
Intrexon Corporation \| Subsequent Event
Equity [Line Items]
Common Stock Additional Shares Issued												1,440,000

Stock_Option_Plan_Additional_i

Stock Option Plan - Additional information (Detail) (USD $)

12 Months Ended

1 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Feb. 28, 2014

Jan. 31, 2014

Dec. 31, 2013

31-May-13

Mar. 31, 2013

Jan. 31, 2013

Dec. 31, 2012

Jul. 31, 2012

31-May-12

Feb. 29, 2012

Jan. 31, 2012

Dec. 31, 2011

Jun. 18, 2014

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock reserved for future issuance

26,364

Outstanding options issued

6,505,664

6,747,303

7,147,303

6,505,664

6,747,303

7,147,303

5,138,486

Proceeds from stock options exercised

$1,386,000

$956,000

$30,000

Total intrinsic value of options

2,600,000

1,400,000

11,000

Employees

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

3 years

Contractual terms

10 years

Director

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Contractual terms

10 years

Director | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

3 years

Director | Minimum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

2 years

Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Repurchase of shares of restricted common stock

81,702

14,600

16,031

56,683

2,623

5,400

52,018

107,413

15,740

Repurchase of shares of restricted common stock, price per share

$5.04

$4.40

$4.37

$1.65

$4.50

$4.28

$4.19

$6.06

Restricted Stock | Employees

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

3 years

Share-based payment award granted

25,000

43,802

101,500

Restricted Stock | Non Employee Directors

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

1 year

3 years

Share-based payment award granted

66,828

75,272

87,730

Non Vested Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation costs related to non-vested restricted stock outstanding

7,900,000

Expected recognition period

1 year 7 months 13 days

Unvested Restricted Common Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expected recognition period

1 year

Share-based payment award granted

66,828

75,272

258,032

Unrecognized stock-based compensation expense related to non-vested restricted stock arrangements

$471,000

the "2012 Plan"

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock reserved for future issuance

9,000,000

4,000,000

5,000,000

the "2012 Plan" | Employees | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Outstanding options issued

5,112,800

the "2012 Plan" | Director | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Outstanding options issued

902,529

the "2012 Plan" | Consultants | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Outstanding options issued

490,334

Stock_Option_Activity_Under_St

Stock Option Activity Under Stock Option Plan (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of Shares
Beginning Balance	6,747,303	7,147,303	5,138,486
Granted	1,099,300	2,649,900	2,309,650
Exercised	-613,138	-570,168	-8,300
Cancelled	-727,801	-2,479,732	-292,533
Ending Balance	6,505,664	6,747,303	7,147,303
Vested and unvested expected to vest at end of period	6,485,430
Weighted Average Exercise Price
Beginning Balance	$3.81	$4.11	$4.08
Granted	$4.95	$3.28	$4.36
Exercised	$2.26	$1.68	$3.61
Cancelled	$4.54	$4.58	$5.70
Ending Balance	$4.07	$3.81	$4.11
Vested and unvested expected to vest at end of period	$4.10
Options exercisable, at end of period	$4.10	$4.01
Options exercisable, at end of period	3,781,162	3,471,935
Options available for future grant	4,585,769
Weighted Average Contractual Term (Years)
Outstanding, at end of period	7 years 2 months 9 days
Vested and unvested expected to vest at end of period	5 years 9 months 18 days
Options exercisable, at end of period	5 years 9 months 18 days	5 years 11 days
Aggregate Intrinsic Value
Outstanding, at end of period	$9,084
Vested and unvested expected to vest at end of period	9,056
Options exercisable, at end of period	$4,130	$2,654

Summary_of_Unvested_Restricted

Summary of Unvested Restricted Stock (Detail) (Unvested Restricted Common Stock, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Unvested Restricted Common Stock
Number of Shares
Beginning Balance	352,865	733,739	950,906
Granted	66,828	75,272	258,032
Vested	-253,835	-292,399	-351,829
Cancelled	-21,350	-163,747	-123,370
Ending Balance	144,508	352,865	733,739
Weighted Average Grant Date Fair Value
Beginning Balance	$4.38	$4.37	$4.34
Granted	$5.07	$4.34	$4.39
Vested	$4.38	$4.31	$4.32
Cancelled	$4.41	$4.42	$4.34
Ending Balance	$4.70	$4.38	$4.37

Employee_Benefit_Plan_Addition

Employee Benefit Plan - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Defined benefit plan contributions by employer	$79	$139	$266

Selected_Quarterly_Information2

Selected Quarterly Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Line Items]
Revenue	$340	$633	$200	$200	$200	$200	$200	$200	$1,373	$800	$800
Total operating expenses	10,936	12,575	11,377	9,984	6,919	9,315	18,496	23,783	44,872	58,513	102,969
Loss from operations	-10,596	-11,942	-11,177	-9,784	-6,719	-9,115	-18,296	-23,583	-43,499	-57,713	-102,169
Change in fair value of warrants	194	5,847	5,600	82	-1,793	-7,407	-403	10,788	11,723	1,185	6,050
Net (loss)	($10,401)	($6,093)	($5,576)	($9,711)	($8,903)	($16,713)	($18,692)	($12,799)	($31,781)	($57,107)	($96,132)
Loss per share, basic and diluted	($0.09)	($0.06)	($0.06)	($0.10)	($0.09)	($0.20)	($0.22)	($0.15)	($0.31)	($0.66)	($1.22)