Gyre Therapeutics (GYRE) 10-Q 7 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 31, 2014
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Trading Symbol	'TRGT	'
Entity Registrant Name	'TARGACEPT INC	'
Entity Central Index Key	'0001124105	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	33,793,735

Balance_Sheets

Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$43,417	$54,485
Investments in marketable securities - short term	54,298	37,844
Current receivables	28	278
Prepaid expenses	1,004	999
Total current assets	98,747	93,606
Investments in marketable securities - long term	25,120	51,448
Property and equipment, net	541	682
Intangible assets	89	97
Other assets	18	40
Total assets	124,515	145,873
Current liabilities:	'	'
Accounts payable	853	1,296
Accrued expenses	5,920	8,830
Current portion of long-term debt	699	853
Current portion of deferred revenue	25	'
Total current liabilities	7,497	10,979
Long-term debt, net of current portion	'	283
Total liabilities	7,497	11,262
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Common stock, $0.001 par value, 100,000,000 shares authorized and 33,793,735 and 33,718,179 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively	34	34
Preferred stock, $0.001 par value, 5,000,000 shares authorized and 0 shares issued and outstanding at June 30, 2014 and December 31, 2013	'	'
Capital in excess of par value	420,642	415,123
Accumulated other comprehensive income	110	87
Accumulated deficit	-303,768	-280,633
Total stockholders' equity	117,018	134,611
Total liabilities and stockholders' equity	$124,515	$145,873

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	33,793,735	33,718,179
Common stock, shares outstanding	33,793,735	33,718,179
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Statements_of_Comprehensive_In

Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Operating revenues:	'	'	'	'
License fees and milestones from collaborations	'	'	'	$3,536
Grant revenue	36	'	123	'
Net operating revenues	36	'	123	3,536
Operating expenses:	'	'	'	'
Research and development (including stock-based compensation of $464 and $597 for the three months ended June 30, 2014 and 2013, respectively; and $848 and $1,376 for the six months ended June 30, 2014 and 2013, respectively)	5,408	9,454	14,488	17,774
General and administrative (including stock-based compensation of $521 and $655 for the three months ended June 30, 2014 and 2013, respectively; and $962 and $1,490 for the six months ended June 30, 2014 and 2013, respectively)	2,867	3,034	5,630	6,524
Total operating expenses	8,275	12,488	20,118	24,298
Loss from operations	-8,239	-12,488	-19,995	-20,762
Other income (expense):	'	'	'	'
Interest income	154	131	332	355
Interest expense	-6	-14	-15	-30
Total other income (expense)	148	117	317	325
Loss before taxes	-8,091	-12,371	-19,678	-20,437
Income tax expense	-45	'	-3,457	'
Net loss	-8,136	-12,371	-23,135	-20,437
Basic and diluted net loss per share	($0.24)	($0.37)	($0.69)	($0.61)
Weighted average common shares outstanding-basic and diluted	33,786,686	33,626,980	33,766,911	33,621,691
Net loss	-8,136	-12,371	-23,135	-20,437
Unrealized gain (loss) on available-for-sale securities, net	44	-202	23	-215
Comprehensive loss	($8,092)	($12,573)	($23,112)	($20,652)

Statements_of_Comprehensive_In1

Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Research and Development Expense	'	'	'	'
Stock-based compensation	$464	$597	$848	$1,376
General and Administrative Expense	'	'	'	'
Stock-based compensation	$521	$655	$962	$1,490

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities	'	'
Net loss	($23,135,000)	($20,437,000)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Recognition of deferred revenue	-123,000	-3,536,000
Amortization of premium on marketable securities, net	451,000	530,000
Depreciation and amortization	138,000	383,000
Stock-based compensation expense	1,810,000	2,866,000
Income tax expense from other comprehensive income	45,000	'
Changes in operating assets and liabilities:	'	'
Current receivables	251,000	1,272,000
Other assets	9,000	-412,000
Accounts payable and accrued expenses	-3,353,000	-401,000
Deferred revenue	148,000	'
Net cash used in operating activities	-23,759,000	-19,735,000
Investing activities	'	'
Purchase of investments in marketable securities	-7,146,000	-35,927,000
Proceeds from sale of investments in marketable securities	16,544,000	36,943,000
Purchase of property and equipment	'	-92,000
Proceeds from sale of property and equipment	21,000	'
Net cash provided by investing activities	9,419,000	924,000
Financing activities	'	'
Principal payments on long-term debt	-437,000	-422,000
Excess tax benefits from stock-based compensation	3,412,000	0
Proceeds from issuance of common stock, net	297,000	52,000
Net cash provided by (used in) financing activities	3,272,000	-370,000
Net decrease in cash and cash equivalents	-11,068,000	-19,181,000
Cash and cash equivalents at beginning of period	54,485,000	82,240,000
Cash and cash equivalents at end of period	$43,417,000	$63,059,000

The_Company_and_Nature_of_Oper

The Company and Nature of Operations	6 Months Ended
	Jun. 30, 2014
The Company and Nature of Operations	'
	1. The Company and Nature of Operations
	Targacept, Inc., or the Company, is a Delaware corporation formed on March 7, 1997. The Company is a biopharmaceutical company engaged in the development of novel NNR Therapeutics™ to treat patients suffering from serious nervous system and gastrointestinal/ genitourinary diseases and disorders. The Company’s NNR Therapeutics selectively target neuronal nicotinic receptors, which it refers to as NNRs. Its facilities are located in Winston-Salem, North Carolina.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s audited financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2013. In the opinion of the Company’s management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented have been included. Operating results for the three and six months ended June 30, 2014 are not necessarily indicative of the results that may be expected for the full year, for any other interim period or for any future year.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported in the financial statements and accompanying notes. Actual results could differ from these estimates.
	Fair Value Measurement
	The Company follows Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 820, Fair Value Measurements and Disclosures, or ASC 820, for application to financial assets. ASC 820 defines fair value, provides a consistent framework for measuring fair value under GAAP and requires fair value financial statement disclosures. ASC 820 applies only to the measurement and disclosure of financial assets that are required or permitted to be measured and reported at fair value under other ASC topics (except for standards that relate to share-based payments such as ASC Topic 718, Compensation – Stock Compensation).
	The valuation techniques required by ASC 820 may be based on either observable or unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, and unobservable inputs reflect the Company’s market assumptions. These inputs are classified into the following hierarchy:
	Level 1 Inputs – quoted prices (unadjusted) in active markets for identical assets that the reporting entity has the ability to access at the measurement date;
	Level 2 Inputs – inputs other than quoted prices included within Level 1 that are observable for the asset, either directly or indirectly; and
	Level 3 Inputs – unobservable inputs for the assets.
	The following tables present the Company’s investments in marketable securities (including, if applicable, those classified on the Company’s balance sheet as cash equivalents) that are measured at fair value on a recurring basis as of June 30, 2014 and December 31, 2013, respectively:
	June 30, 2014	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	33,658		$	—		$	—
	Corporate debt securities		—			38,249			—
	Municipal bonds		—			2,106			—
	Certificates of deposit		5,000			—			—
	Accrued interest		405			—			—
	Total investments in marketable securities	$	39,063		$	40,355		$	—
	December 31, 2013	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	37,029		$	—		$	—
	Corporate debt securities		—			43,347			—
	Municipal bonds		—			3,509			—
	Certificates of deposit		5,000			—			—
	Accrued interest		407			—			—
	Total investments in marketable securities	$	42,436		$	46,856		$	—
	Corporate debt securities and municipal bonds are valued based on various observable inputs such as benchmark yields, reported trades, broker/dealer quotes, benchmark securities and bids.
	Investments in Marketable Securities
	Consistent with its investment policy, the Company invests its cash allocated to fund its short-term liquidity requirements with prominent financial institutions in bank depository accounts and institutional money market funds and the Company invests the remainder of its cash in corporate debt securities and municipal bonds rated at least A quality or equivalent, U.S. Treasury notes and bonds, U.S. and state government agency-backed securities and certificates of deposit.
	The Company determines the appropriate classification of marketable securities at the time of purchase and reevaluates its classification as of each balance sheet date. All marketable securities owned during the six months ended June 30, 2014 and 2013 were classified as available-for-sale. The cost of securities sold is based on the specific identification method. Investments in marketable securities are recorded as of each balance sheet date at fair value, with unrealized gains and, to the extent deemed temporary, unrealized losses included in stockholders’ equity. Interest and dividend income on investments in marketable securities, accretion of discounts and amortization of premiums and realized gains and losses are included in interest income in the statement of comprehensive income (loss).
	An investment in marketable securities is considered to be impaired when a decline in fair value below its cost basis is determined to be other than temporary. The Company evaluates whether a decline in fair value of an investment in marketable securities below its cost basis is other than temporary using available evidence. In the event that the cost basis of the investment exceeds its fair value, the Company evaluates, among other factors, the amount and duration of the period that the fair value is less than the cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, and operational and financing cash flow factors, overall market conditions and trends, the Company’s intent to sell the investment and whether it is more likely than not the Company would be required to sell the investment before its anticipated recovery. If a decline in fair value is determined to be other than temporary, the Company records an impairment charge in the statement of comprehensive income (loss) and establishes a new cost basis in the investment.
	Revenue Recognition
	The Company uses the revenue recognition guidance established by ASC Topic 605, Revenue Recognition, or ASC 605. In determining the accounting for collaboration and alliance agreements, the Company follows the provisions of ASC 605, Subtopic 25, Multiple Element Arrangements, or ASC 605-25. ASC 605-25 provides guidance on whether an arrangement that involves multiple revenue-generating activities or deliverables should be divided into separate units of accounting for revenue recognition purposes and, if division is required, how the arrangement consideration should be allocated among the separate units of accounting. If the arrangement constitutes separate units of accounting according to the separation criteria of ASC 605-25, the consideration received is allocated among the separate units of accounting and the applicable revenue recognition criteria must be applied to each unit. If the arrangement constitutes a single unit of accounting, the revenue recognition policy must be determined for the entire arrangement and the consideration received is recognized over the period of inception through the date on which the last deliverable within the single unit of accounting is expected to be delivered. Revisions to the estimated period of recognition are reflected in revenue prospectively.
	Collaboration research and development revenue is earned and recognized as research or development is performed and related expenses are incurred. Non-refundable upfront fees, which may include, for example, an initial payment upon effectiveness of the contractual relationship, payment representing a common stock purchase premium or payment to secure a right for a future license, are recorded as deferred revenue and recognized into revenue as license fees and milestones from collaborations on a straight-line basis over the estimated period of the Company’s substantive performance obligations. If the Company does not have substantive performance obligations, it recognizes non-refundable upfront fees into revenue through the date the deliverable is satisfied.
	Revenue for non-refundable payments based on the achievement of milestone events under collaboration agreements is recognized in accordance with ASC 605, Subtopic 28, Milestone Method, or ASC 605-28. Milestone events under the Company’s collaboration agreements may include research, development, regulatory, commercialization or sales events. Under ASC 605-28, a milestone payment is recognized as revenue when the applicable event is achieved if the event meets the definition of a milestone and the milestone is determined to be substantive. ASC 605-28 defines a milestone event as an event having all of the following characteristics: (1) there is substantive uncertainty regarding achievement of the milestone event at the inception of the arrangement; (2) the event can only be achieved based, in whole or in part, on either the company’s performance or a specific outcome resulting from the company’s performance; and (3) if achieved, the event would result in additional payment due to the company. The Company also treats events that can only be achieved based, in whole or in part, on either a third party’s performance or a specific outcome resulting from a third party’s performance as milestone events if the criteria of ASC 605-28 are otherwise satisfied. A milestone is considered substantive if it meets all of the following criteria: (A) the payment is commensurate with either the Company’s performance to achieve the milestone or with the enhancement of the value of the delivered item; (B) the payment relates solely to past performance; and (C) the payment is reasonable relative to all of the deliverables and payment terms within the arrangement. If any of these conditions is not met, the milestone payment is deferred and recognized on a straight-line basis over a period determined as discussed above.
	Research and development costs that are reimbursable under collaboration agreements are recorded in accordance with ASC 605, Subtopic 45, Principal Agent Considerations. Amounts reimbursed under a cost sharing arrangement are reflected as a reduction of research and development expense.
	Grant payments received prior to the Company’s performance of work required by the terms of the award are recorded as deferred revenue and recognized as grant revenue as the Company performs the work and incurs qualifying costs.
	Income Taxes
	The Company uses the liability method in accounting for income taxes as required by ASC Topic 740, Income Taxes, or ASC 740. Under ASC 740, deferred tax assets and liabilities are recorded for operating loss and tax credit carryforwards and for the future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the results of operations in the period that includes the enactment date. A valuation allowance is recorded to reduce the carrying amounts of deferred tax assets unless it is more likely than not that the assets will be realized. ASC 740 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. ASC 740 requires interim income tax expense or benefit to be calculated using an estimated annual effective tax rate. If a reliable estimate of the annual effective tax rate cannot be made, the Company considers the effective tax rate for the year to date to be the best estimate. Accordingly, the income tax provisions for the three and six months ended June 30, 2014 were determined based on the actual year-to-date effective tax rate because a reliable estimate of the annual effective tax rate cannot be made. ASC 740 also provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosures and transition. The Company’s policy is to classify any interest recognized in accordance with ASC 740 as interest expense and to classify any penalties recognized in accordance with ASC 740 as an expense other than income tax expense.
	Net Income or Loss Per Share
	The Company computes net income or loss per share in accordance with ASC Topic 260, Earnings Per Share, or ASC 260. Under the provisions of ASC 260, basic net income or loss per share, or Basic EPS, is computed by dividing net income or loss by the weighted average number of common shares outstanding. Diluted net income or loss per share, or Diluted EPS, is computed by dividing net income or loss by the weighted average number of common shares outstanding plus, in the case of diluted net income per share, dilutive common share equivalents outstanding. The calculations of Basic EPS and Diluted EPS are set forth in the table below (in thousands, except share and per share amounts).
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Basic and diluted:
	Net loss	$	(8,136	)	$	(12,371	)	$	(23,135	)	$	(20,437	)
	Weighted average common shares - basic and diluted		33,786,686			33,626,980			33,766,911			33,621,691
	Basic and diluted EPS	$	(0.24	)	$	(0.37	)	$	(0.69	)	$	(0.61	)
	Common share equivalents consist of the incremental common shares that would be outstanding upon the exercise of stock options, calculated using the treasury stock method. For the three- and six-month periods ended June 30, 2014 and 2013, the Company excluded all common share equivalents from the calculation of Diluted EPS because the Company had a net loss in those periods. As a result, Diluted EPS is identical to Basic EPS for those periods. If the Company had been in a net income position for the three months ended June 30, 2014 and 2013, 4,785,391 and 4,708,306 shares subject to outstanding stock options, respectively, may have been included in the calculation of common share equivalents using the treasury stock method. If the Company had been in a net income position for the six months ended June 30, 2014 and 2013, 4,873,288 and 4,743,069 shares subject to outstanding stock options, respectively, may have been included in the calculation of common share equivalents using the treasury stock method.
	Common Stock and Stock-Based Compensation
	The Company issued 75,556 shares of common stock upon the exercise of stock options during the six months ended June 30, 2014. The Company issued 103,098 shares of common stock upon the exercise of stock options during the year ended December 31, 2013.
	During the six months ended June 30, 2014, the Company granted to employees options to purchase an aggregate of 842,368 shares of common stock. These stock options have an estimated aggregate fair value, using the Black-Scholes-Merton formula, of $3,286,000. The Company is recording this amount, as adjusted for forfeitures, as stock-based compensation on a straight line basis over 16 quarters beginning on the last day of the respective quarters in which the grants were made.
	Accumulated Other Comprehensive Income or Loss
	Accumulated other comprehensive income or loss, as presented in stockholders’ equity on the Company’s balance sheet, reflects the cumulative net unrealized gains or losses on available-for-sale securities for all periods. The table below reflects changes in accumulated other comprehensive income for the six months ended June 30, 2014, in thousands.
	Accumulated other comprehensive income, January 1, 2014	$	87
	Unrealized loss on available-for-sale securities, net		(17	)
Net realized gains on available-for-sale securities reclassified out of other comprehensive income		(5	)
Income taxes		45
Accumulated other comprehensive income, June 30, 2014	$	110
Intellectual Property
The Company capitalizes the costs of intellectual property acquired or licensed from external sources as intangible assets if, at the time of acquisition, the intellectual property has reached technological feasibility. The cost of intellectual property acquired or licensed from external sources that has not reached technological feasibility at the time of acquisition or that has no expected future use is charged to research and development expense as incurred. The Company records all other charges related to the filing, prosecution and maintenance of patents to expense as incurred.
Commitments and Contingencies
Under an employment agreement with a former executive officer and a related separation agreement and release, the Company paid severance equal to the departing executive’s regular base salary as of March 31, 2013 for nine months, a pro rata percentage of the departing executive’s target bonus for 2013, and the departing executive’s health and life insurance benefits coverage provided to him as of March 31, 2013 for nine months. These payments and benefits, which represent an aggregate amount of $306,000, were recorded as general and administrative expense for the six months ended June 30, 2013.
Recent Accounting Pronouncements
In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, or ASU 2014-09. ASU 2014-09 develops a common revenue standard for GAAP and International Financial Reporting Standards and supersedes most current revenue recognition guidance. ASU 2014-09 outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and requires a company to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company is currently evaluating the impact that the implementation of ASU 2014-09 will have on the Company’s financial statements.

Investments_in_Marketable_Secu

Investments in Marketable Securities	6 Months Ended
	Jun. 30, 2014
Investments in Marketable Securities	'
	3. Investments in Marketable Securities
	The following is a reconciliation of amortized cost to fair value of available-for-sale marketable securities (including those classified on the Company’s balance sheet as cash equivalents) held at June 30, 2014 and December 31, 2013:
	June 30, 2014	Amortized		Gross		Gross			Fair Value
		Cost		Unrealized		Unrealized
				Gains		Losses
	Security type	(in thousands)
	Marketable Securities - Short term
	U.S. Treasury and U.S. or state government agency-backed securities	$	25,801	$	28	$	—		$	25,829
	Corporate debt securities		22,154		75		—			22,229
	Municipal bonds		930		4		—			934
	Certificates of deposit		5,000		—		—			5,000
	Accrued interest		306		—		—			306
	Marketable Securities - Long term
	U.S. Treasury and U.S. or state government agency-backed securities		7,822		8		(1	)		7,829
	Corporate debt securities - long term		15,979		41		—			16,020
	Municipal bonds		1,168		4		—			1,172
	Accrued interest		99		—		—			99
	Total available-for-sale marketable securities	$	79,259	$	160	$	(1	)	$	79,418
	December 31, 2013	Amortized		Gross		Gross			Fair Value
		Cost		Unrealized		Unrealized
				Gains		Losses
	Security type	(in thousands)
	Marketable Securities - Short term
	U.S. Treasury and U.S. or state government agency-backed securities	$	16,352	$	39	$	—		$	16,391
	Corporate debt securities		14,307		35		—			14,342
	Municipal bonds		1,910		3					1,913
	Certificates of deposit		5,000		—		—			5,000
	Accrued interest		198		—		—			198
	Marketable Securities - Long term
	U.S. Treasury and U.S. or state government agency-backed securities		20,628		14		(4	)		20,638
	Corporate debt securities		28,909		101		(5	)		29,005
	Municipal bonds		1,598		4		(6	)		1,596
	Accrued interest		209		—		—			209
	Total available-for-sale marketable securities	$	89,111	$	196	$	(15	)	$	89,292
	As of June 30, 2014, the Company held investments in marketable securities with unrealized gains of $160,000 and unrealized losses of $1,000. For the investments in an unrealized loss position, the duration of the loss was less than 12 months and the investments are not considered to be other-than-temporarily impaired. The Company’s investments in marketable securities as of June 30, 2014, will reach maturity between July 2014 and December 2016, with a weighted average maturity date in April 2015.

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Taxes	'
	4. Income Taxes
	Because the Company has incurred cumulative net operating losses since inception, all tax years remain open to examination by U.S. federal, North Carolina and Massachusetts tax authorities. An examination of the Company’s 2010 federal income tax return was completed in 2014 and resulted in an adjustment that increased taxable income for 2010 by $15,064,000, decreased taxable income for 2011 by $1,076,000, and decreased taxable income for 2012 by $13,988,000. The examination adjustment had no cumulative effect on federal net operating loss carryforwards. Exercises of stock options may result in tax deductions for stock-based compensation in excess of expense recorded for the stock options under GAAP. For interim periods within years for which taxable net income is forecasted, the Company recognizes the income tax benefit related to the excess tax deductions as an increase to capital in excess of par value, which based on ASC 740 results in an offsetting charge in the same amount to income tax expense. The examination adjustment to the Company’s 2010 federal income tax return resulted in the realization of an additional $3,412,000 of excess tax deductions and an offsetting charge to income tax expense for the six months ended June 30, 2014. The Company did not recognize any income tax expense for the six months ended June 30, 2013.
	As of June 30, 2014, the Company had $3,497,000 remaining of cumulative tax deductions for periods of net loss from exercises of stock options in excess of expense recorded for the stock options under GAAP. The benefit of these excess tax deductions had not begun to be realized as of June 30, 2014 because the Company incurred operating losses in the years in which the respective stock options were exercised and has incurred cumulative net operating losses since inception. Accordingly, the tax benefit will not be recognized as an increase to capital in excess of par value until the excess deductions reduce income taxes payable.

Collaboration_Agreement

Collaboration Agreement	6 Months Ended
	Jun. 30, 2014
Collaboration Agreement	'
	5. Collaboration Agreement
	AstraZeneca AB
	In December 2005, the Company entered into a collaborative research and license agreement with AstraZeneca AB, or AstraZeneca, that was initially focused in cognitive disorders. In March 2013, the Company and AstraZeneca amended the agreement. As amended, the agreement permits AstraZeneca to pursue development and commercialization of compounds it has licensed from the Company in any therapeutic area.
	The Company is eligible to receive license fees and milestone payments under the agreement. The amount of license fees and milestone payments depends on the timing and achievement of specified milestone events.
	AstraZeneca paid the Company an initial fee of $10,000,000 in February 2006. The initial fee included $5,000,000 for grants of licenses to develop and commercialize the Company’s product candidate TC-1734 (formerly known also as AZD3480), which the Company recognized on a straight-line basis over the estimated development period for TC-1734. In September 2010, the Company and AstraZeneca amended the agreement to enable the Company to conduct a clinical trial of TC-1734 in mild to moderate Alzheimer’s disease and to provide for respective roles and responsibilities and associated financial terms for such a study. Under the 2010 amendment, the Company received from AstraZeneca cumulative payments of $6,000,000 during 2010 and 2011. At that time, the Company began recognizing the portion of the $5,000,000 received for grants of licenses not yet recognized and the payments received under the 2010 amendment into revenue on a straight-line basis over the period of the Company’s substantive performance obligations under the agreement as amended.
	In March 2013, AstraZeneca exercised its right to terminate TC-1734 from the collaboration. As a result, the Company recognized into revenue during the first quarter of 2013 all of the initial fee and payments received under the 2010 amendment that had not yet been recognized as of the date of AstraZeneca’s action, totaling $3,142,000. The Company recognized an aggregate of $3,536,000 of the initial fee and the payments received under the 2010 amendment into revenue during the six months ended June 30, 2013.
	The Company is eligible to receive additional payments from AstraZeneca if specified milestone events under the agreement are achieved for the Company’s product candidate AZD1446 (TC-6683). The amounts of the contingent milestone payments vary depending on the applicable indication pursued and may be an additional $7,000,000 or $14,000,000 if development milestone events are achieved, an additional $8,000,000 or $10,000,000 if a regulatory milestone event is achieved, up to an additional $12,000,000 or $49,000,000 if first commercial sale milestone events are achieved and, in specified circumstances, up to an additional $30,000,000 if sales-related milestone events are achieved.
	Based solely on projected activities and timelines, the Company expects that the earliest a contingent milestone payment could be earned under the agreement with respect to AZD1446 is in the first half of 2015, in which case the payment would be $2,000,000 if a development milestone event is achieved. The likelihood that the Company will earn that milestone amount or achieve any particular milestone event with respect to AZD1446 in the first half of 2015 or in any future period is uncertain, and the Company may not earn any milestone amount or achieve any milestone event with respect to AZD1446 in the first half of 2015 or ever. The Company considers that each of the potential milestone events under the agreement with respect to AZD1446 would be substantive because the applicable criteria of its revenue recognition policy (see Note 2) would be satisfied.
	AstraZeneca has paid the Company an aggregate of $88,120,000 under the agreement since its inception, including the initial fee and payments upon the achievement of milestone events, to maintain option rights and for research services rendered in the completed preclinical research collaboration. This entire amount had been fully recognized into revenue in previous periods.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s audited financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2013. In the opinion of the Company’s management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented have been included. Operating results for the three and six months ended June 30, 2014 are not necessarily indicative of the results that may be expected for the full year, for any other interim period or for any future year.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported in the financial statements and accompanying notes. Actual results could differ from these estimates.
Fair Value Measurement	'
	Fair Value Measurement
	The Company follows Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 820, Fair Value Measurements and Disclosures, or ASC 820, for application to financial assets. ASC 820 defines fair value, provides a consistent framework for measuring fair value under GAAP and requires fair value financial statement disclosures. ASC 820 applies only to the measurement and disclosure of financial assets that are required or permitted to be measured and reported at fair value under other ASC topics (except for standards that relate to share-based payments such as ASC Topic 718, Compensation – Stock Compensation).
	The valuation techniques required by ASC 820 may be based on either observable or unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, and unobservable inputs reflect the Company’s market assumptions. These inputs are classified into the following hierarchy:
	Level 1 Inputs – quoted prices (unadjusted) in active markets for identical assets that the reporting entity has the ability to access at the measurement date;
	Level 2 Inputs – inputs other than quoted prices included within Level 1 that are observable for the asset, either directly or indirectly; and
	Level 3 Inputs – unobservable inputs for the assets.
	The following tables present the Company’s investments in marketable securities (including, if applicable, those classified on the Company’s balance sheet as cash equivalents) that are measured at fair value on a recurring basis as of June 30, 2014 and December 31, 2013, respectively:
	June 30, 2014	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	33,658		$	—		$	—
	Corporate debt securities		—			38,249			—
	Municipal bonds		—			2,106			—
	Certificates of deposit		5,000			—			—
	Accrued interest		405			—			—
	Total investments in marketable securities	$	39,063		$	40,355		$	—
	December 31, 2013	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	37,029		$	—		$	—
	Corporate debt securities		—			43,347			—
	Municipal bonds		—			3,509			—
	Certificates of deposit		5,000			—			—
	Accrued interest		407			—			—
	Total investments in marketable securities	$	42,436		$	46,856		$	—
	Corporate debt securities and municipal bonds are valued based on various observable inputs such as benchmark yields, reported trades, broker/dealer quotes, benchmark securities and bids.
Investments in Marketable Securities	'
	Investments in Marketable Securities
	Consistent with its investment policy, the Company invests its cash allocated to fund its short-term liquidity requirements with prominent financial institutions in bank depository accounts and institutional money market funds and the Company invests the remainder of its cash in corporate debt securities and municipal bonds rated at least A quality or equivalent, U.S. Treasury notes and bonds, U.S. and state government agency-backed securities and certificates of deposit.
	The Company determines the appropriate classification of marketable securities at the time of purchase and reevaluates its classification as of each balance sheet date. All marketable securities owned during the six months ended June 30, 2014 and 2013 were classified as available-for-sale. The cost of securities sold is based on the specific identification method. Investments in marketable securities are recorded as of each balance sheet date at fair value, with unrealized gains and, to the extent deemed temporary, unrealized losses included in stockholders’ equity. Interest and dividend income on investments in marketable securities, accretion of discounts and amortization of premiums and realized gains and losses are included in interest income in the statement of comprehensive income (loss).
	An investment in marketable securities is considered to be impaired when a decline in fair value below its cost basis is determined to be other than temporary. The Company evaluates whether a decline in fair value of an investment in marketable securities below its cost basis is other than temporary using available evidence. In the event that the cost basis of the investment exceeds its fair value, the Company evaluates, among other factors, the amount and duration of the period that the fair value is less than the cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, and operational and financing cash flow factors, overall market conditions and trends, the Company’s intent to sell the investment and whether it is more likely than not the Company would be required to sell the investment before its anticipated recovery. If a decline in fair value is determined to be other than temporary, the Company records an impairment charge in the statement of comprehensive income (loss) and establishes a new cost basis in the investment.
Revenue Recognition	'
	Revenue Recognition
	The Company uses the revenue recognition guidance established by ASC Topic 605, Revenue Recognition, or ASC 605. In determining the accounting for collaboration and alliance agreements, the Company follows the provisions of ASC 605, Subtopic 25, Multiple Element Arrangements, or ASC 605-25. ASC 605-25 provides guidance on whether an arrangement that involves multiple revenue-generating activities or deliverables should be divided into separate units of accounting for revenue recognition purposes and, if division is required, how the arrangement consideration should be allocated among the separate units of accounting. If the arrangement constitutes separate units of accounting according to the separation criteria of ASC 605-25, the consideration received is allocated among the separate units of accounting and the applicable revenue recognition criteria must be applied to each unit. If the arrangement constitutes a single unit of accounting, the revenue recognition policy must be determined for the entire arrangement and the consideration received is recognized over the period of inception through the date on which the last deliverable within the single unit of accounting is expected to be delivered. Revisions to the estimated period of recognition are reflected in revenue prospectively.
	Collaboration research and development revenue is earned and recognized as research or development is performed and related expenses are incurred. Non-refundable upfront fees, which may include, for example, an initial payment upon effectiveness of the contractual relationship, payment representing a common stock purchase premium or payment to secure a right for a future license, are recorded as deferred revenue and recognized into revenue as license fees and milestones from collaborations on a straight-line basis over the estimated period of the Company’s substantive performance obligations. If the Company does not have substantive performance obligations, it recognizes non-refundable upfront fees into revenue through the date the deliverable is satisfied.
	Revenue for non-refundable payments based on the achievement of milestone events under collaboration agreements is recognized in accordance with ASC 605, Subtopic 28, Milestone Method, or ASC 605-28. Milestone events under the Company’s collaboration agreements may include research, development, regulatory, commercialization or sales events. Under ASC 605-28, a milestone payment is recognized as revenue when the applicable event is achieved if the event meets the definition of a milestone and the milestone is determined to be substantive. ASC 605-28 defines a milestone event as an event having all of the following characteristics: (1) there is substantive uncertainty regarding achievement of the milestone event at the inception of the arrangement; (2) the event can only be achieved based, in whole or in part, on either the company’s performance or a specific outcome resulting from the company’s performance; and (3) if achieved, the event would result in additional payment due to the company. The Company also treats events that can only be achieved based, in whole or in part, on either a third party’s performance or a specific outcome resulting from a third party’s performance as milestone events if the criteria of ASC 605-28 are otherwise satisfied. A milestone is considered substantive if it meets all of the following criteria: (A) the payment is commensurate with either the Company’s performance to achieve the milestone or with the enhancement of the value of the delivered item; (B) the payment relates solely to past performance; and (C) the payment is reasonable relative to all of the deliverables and payment terms within the arrangement. If any of these conditions is not met, the milestone payment is deferred and recognized on a straight-line basis over a period determined as discussed above.
	Research and development costs that are reimbursable under collaboration agreements are recorded in accordance with ASC 605, Subtopic 45, Principal Agent Considerations. Amounts reimbursed under a cost sharing arrangement are reflected as a reduction of research and development expense.
	Grant payments received prior to the Company’s performance of work required by the terms of the award are recorded as deferred revenue and recognized as grant revenue as the Company performs the work and incurs qualifying costs.
Income Taxes	'
	Income Taxes
	The Company uses the liability method in accounting for income taxes as required by ASC Topic 740, Income Taxes, or ASC 740. Under ASC 740, deferred tax assets and liabilities are recorded for operating loss and tax credit carryforwards and for the future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the results of operations in the period that includes the enactment date. A valuation allowance is recorded to reduce the carrying amounts of deferred tax assets unless it is more likely than not that the assets will be realized. ASC 740 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. ASC 740 requires interim income tax expense or benefit to be calculated using an estimated annual effective tax rate. If a reliable estimate of the annual effective tax rate cannot be made, the Company considers the effective tax rate for the year to date to be the best estimate. Accordingly, the income tax provisions for the three and six months ended June 30, 2014 were determined based on the actual year-to-date effective tax rate because a reliable estimate of the annual effective tax rate cannot be made. ASC 740 also provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosures and transition. The Company’s policy is to classify any interest recognized in accordance with ASC 740 as interest expense and to classify any penalties recognized in accordance with ASC 740 as an expense other than income tax expense.
Net Income or Loss Per Share	'
	Net Income or Loss Per Share
	The Company computes net income or loss per share in accordance with ASC Topic 260, Earnings Per Share, or ASC 260. Under the provisions of ASC 260, basic net income or loss per share, or Basic EPS, is computed by dividing net income or loss by the weighted average number of common shares outstanding. Diluted net income or loss per share, or Diluted EPS, is computed by dividing net income or loss by the weighted average number of common shares outstanding plus, in the case of diluted net income per share, dilutive common share equivalents outstanding. The calculations of Basic EPS and Diluted EPS are set forth in the table below (in thousands, except share and per share amounts).
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Basic and diluted:
	Net loss	$	(8,136	)	$	(12,371	)	$	(23,135	)	$	(20,437	)
	Weighted average common shares - basic and diluted		33,786,686			33,626,980			33,766,911			33,621,691
	Basic and diluted EPS	$	(0.24	)	$	(0.37	)	$	(0.69	)	$	(0.61	)
	Common share equivalents consist of the incremental common shares that would be outstanding upon the exercise of stock options, calculated using the treasury stock method. For the three- and six-month periods ended June 30, 2014 and 2013, the Company excluded all common share equivalents from the calculation of Diluted EPS because the Company had a net loss in those periods. As a result, Diluted EPS is identical to Basic EPS for those periods. If the Company had been in a net income position for the three months ended June 30, 2014 and 2013, 4,785,391 and 4,708,306 shares subject to outstanding stock options, respectively, may have been included in the calculation of common share equivalents using the treasury stock method. If the Company had been in a net income position for the six months ended June 30, 2014 and 2013, 4,873,288 and 4,743,069 shares subject to outstanding stock options, respectively, may have been included in the calculation of common share equivalents using the treasury stock method.
Common Stock and Stock-Based Compensation	'
	Common Stock and Stock-Based Compensation
	The Company issued 75,556 shares of common stock upon the exercise of stock options during the six months ended June 30, 2014. The Company issued 103,098 shares of common stock upon the exercise of stock options during the year ended December 31, 2013.
	During the six months ended June 30, 2014, the Company granted to employees options to purchase an aggregate of 842,368 shares of common stock. These stock options have an estimated aggregate fair value, using the Black-Scholes-Merton formula, of $3,286,000. The Company is recording this amount, as adjusted for forfeitures, as stock-based compensation on a straight line basis over 16 quarters beginning on the last day of the respective quarters in which the grants were made.
Accumulated Other Comprehensive Income or Loss	'
	Accumulated Other Comprehensive Income or Loss
	Accumulated other comprehensive income or loss, as presented in stockholders’ equity on the Company’s balance sheet, reflects the cumulative net unrealized gains or losses on available-for-sale securities for all periods. The table below reflects changes in accumulated other comprehensive income for the six months ended June 30, 2014, in thousands.
	Accumulated other comprehensive income, January 1, 2014	$	87
	Unrealized loss on available-for-sale securities, net		(17	)
	Net realized gains on available-for-sale securities reclassified out of other comprehensive income		(5	)
	Income taxes		45
	Accumulated other comprehensive income, June 30, 2014	$	110
Intellectual Property	'
	Intellectual Property
	The Company capitalizes the costs of intellectual property acquired or licensed from external sources as intangible assets if, at the time of acquisition, the intellectual property has reached technological feasibility. The cost of intellectual property acquired or licensed from external sources that has not reached technological feasibility at the time of acquisition or that has no expected future use is charged to research and development expense as incurred. The Company records all other charges related to the filing, prosecution and maintenance of patents to expense as incurred.
Commitments and Contingencies	'
	Commitments and Contingencies
	Under an employment agreement with a former executive officer and a related separation agreement and release, the Company paid severance equal to the departing executive’s regular base salary as of March 31, 2013 for nine months, a pro rata percentage of the departing executive’s target bonus for 2013, and the departing executive’s health and life insurance benefits coverage provided to him as of March 31, 2013 for nine months. These payments and benefits, which represent an aggregate amount of $306,000, were recorded as general and administrative expense for the six months ended June 30, 2013.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, or ASU 2014-09. ASU 2014-09 develops a common revenue standard for GAAP and International Financial Reporting Standards and supersedes most current revenue recognition guidance. ASU 2014-09 outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and requires a company to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company is currently evaluating the impact that the implementation of ASU 2014-09 will have on the Company’s financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2014
Investments In Marketable Securities Measured at Fair Value On Recurring Basis	'
	The following tables present the Company’s investments in marketable securities (including, if applicable, those classified on the Company’s balance sheet as cash equivalents) that are measured at fair value on a recurring basis as of June 30, 2014 and December 31, 2013, respectively:
	June 30, 2014	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	33,658		$	—		$	—
	Corporate debt securities		—			38,249			—
	Municipal bonds		—			2,106			—
	Certificates of deposit		5,000			—			—
	Accrued interest		405			—			—
	Total investments in marketable securities	$	39,063		$	40,355		$	—
	December 31, 2013	Quoted Prices in			Other			Unobservable
		Active Markets			Observable			Inputs
		(Level 1)			Inputs			(Level 3)
					(Level 2)
		(in thousands)
	U.S. Treasury and U.S. or state government agency-backed securities	$	37,029		$	—		$	—
	Corporate debt securities		—			43,347			—
	Municipal bonds		—			3,509			—
	Certificates of deposit		5,000			—			—
	Accrued interest		407			—			—
	Total investments in marketable securities	$	42,436		$	46,856		$	—
Summary of Calculations of Basic EPS and Diluted EPS	'
	The calculations of Basic EPS and Diluted EPS are set forth in the table below (in thousands, except share and per share amounts).
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Basic and diluted:
	Net loss	$	(8,136	)	$	(12,371	)	$	(23,135	)	$	(20,437	)
	Weighted average common shares - basic and diluted		33,786,686			33,626,980			33,766,911			33,621,691
	Basic and diluted EPS	$	(0.24	)	$	(0.37	)	$	(0.69	)	$	(0.61	)
Changes in Accumulated Other Comprehensive Income or Loss	'
	The table below reflects changes in accumulated other comprehensive income for the six months ended June 30, 2014, in thousands.
	Accumulated other comprehensive income, January 1, 2014	$	87
	Unrealized loss on available-for-sale securities, net		(17	)
	Net realized gains on available-for-sale securities reclassified out of other comprehensive income		(5	)
	Income taxes		45
	Accumulated other comprehensive income, June 30, 2014	$	110

Investments_in_Marketable_Secu1

Investments in Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2014
Reconciliation of Amortized Cost to Fair Value of Available-For-Sale Marketable Securities	'
	The following is a reconciliation of amortized cost to fair value of available-for-sale marketable securities (including those classified on the Company’s balance sheet as cash equivalents) held at June 30, 2014 and December 31, 2013:
	June 30, 2014	Amortized		Gross		Gross			Fair Value
		Cost		Unrealized		Unrealized
				Gains		Losses
	Security type	(in thousands)
	Marketable Securities - Short term
	U.S. Treasury and U.S. or state government agency-backed securities	$	25,801	$	28	$	—		$	25,829
	Corporate debt securities		22,154		75		—			22,229
	Municipal bonds		930		4		—			934
	Certificates of deposit		5,000		—		—			5,000
	Accrued interest		306		—		—			306
	Marketable Securities - Long term
	U.S. Treasury and U.S. or state government agency-backed securities		7,822		8		(1	)		7,829
	Corporate debt securities - long term		15,979		41		—			16,020
	Municipal bonds		1,168		4		—			1,172
	Accrued interest		99		—		—			99
	Total available-for-sale marketable securities	$	79,259	$	160	$	(1	)	$	79,418
	December 31, 2013	Amortized		Gross		Gross			Fair Value
		Cost		Unrealized		Unrealized
				Gains		Losses
	Security type	(in thousands)
	Marketable Securities - Short term
	U.S. Treasury and U.S. or state government agency-backed securities	$	16,352	$	39	$	—		$	16,391
	Corporate debt securities		14,307		35		—			14,342
	Municipal bonds		1,910		3					1,913
	Certificates of deposit		5,000		—		—			5,000
	Accrued interest		198		—		—			198
	Marketable Securities - Long term
	U.S. Treasury and U.S. or state government agency-backed securities		20,628		14		(4	)		20,638
	Corporate debt securities		28,909		101		(5	)		29,005
	Municipal bonds		1,598		4		(6	)		1,596
	Accrued interest		209		—		—			209
	Total available-for-sale marketable securities	$	89,111	$	196	$	(15	)	$	89,292

Company_and_Nature_of_Operatio

Company and Nature of Operations - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2014
Organization and Nature of Operations [Line Items]	'
Corporation formed	7-Mar-97

Investments_in_Marketable_Secu2

Investments in Marketable Securities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	$79,418	$89,292
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	39,063	42,436
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | US Treasury and Government	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	33,658	37,029
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Certificates of Deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	5,000	5,000
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Accrued Interest	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	405	407
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	40,355	46,856
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Corporate Debt Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	38,249	43,347
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Municipal Bonds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investments in marketable securities	$2,106	$3,509

Summary_of_Calculations_of_Bas

Summary of Calculations of Basic EPS and Diluted EPS (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Basic and diluted:	'	'	'	'
Net loss	($8,136)	($12,371)	($23,135)	($20,437)
Weighted average common shares - basic and diluted	33,786,686	33,626,980	33,766,911	33,621,691
Basic and diluted EPS	($0.24)	($0.37)	($0.69)	($0.61)

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Significant Accounting Policies [Line Items]	'	'	'	'	'
Shares subject to outstanding stock options	4,785,391	4,708,306	4,873,288	4,743,069	'
Shares issued upon exercise of stock options	'	'	75,556	'	103,098
Options granted to purchase common stock	'	'	842,368	'	'
Fair value shares issued under stock option program	'	'	$3,286,000	'	'
One-time Termination Benefits | General and Administrative Expense | Executive Officer	'	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'	'
Executive's severance cost	'	'	'	306,000	'

Changes_in_Accumulated_Other_C

Changes in Accumulated Other Comprehensive Income Loss (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Accumulated other comprehensive income, January 1, 2014	$87
Unrealized loss on available-for-sale securities, net	-17
Net realized gains on available-for-sale securities reclassified out of other comprehensive income	-5
Income taxes	45
Accumulated other comprehensive income, June 30, 2014	$110

Investments_in_Marketable_Secu3

Investments in Marketable Securities (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$79,259	$89,111
Gross Unrealized Gains	160	196
Gross Unrealized Losses	-1	-15
Fair Value	79,418	89,292
Marketable Securities - Short term | US Treasury and Government	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	25,801	16,352
Gross Unrealized Gains	28	39
Fair Value	25,829	16,391
Marketable Securities - Short term | Corporate Debt Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	22,154	14,307
Gross Unrealized Gains	75	35
Fair Value	22,229	14,342
Marketable Securities - Short term | Municipal Bonds	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	930	1,910
Gross Unrealized Gains	4	3
Fair Value	934	1,913
Marketable Securities - Short term | Certificates of Deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	5,000	5,000
Fair Value	5,000	5,000
Marketable Securities - Short term | Accrued Interest	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	306	198
Fair Value	306	198
Marketable Securities - Long term | US Treasury and Government	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	7,822	20,628
Gross Unrealized Gains	8	14
Gross Unrealized Losses	-1	-4
Fair Value	7,829	20,638
Marketable Securities - Long term | Corporate Debt Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	15,979	28,909
Gross Unrealized Gains	41	101
Gross Unrealized Losses	'	-5
Fair Value	16,020	29,005
Marketable Securities - Long term | Municipal Bonds	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,168	1,598
Gross Unrealized Gains	4	4
Gross Unrealized Losses	'	-6
Fair Value	1,172	1,596
Marketable Securities - Long term | Accrued Interest	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	99	209
Fair Value	$99	$209

Investments_in_Marketable_Secu4

Investments in Marketable Securities - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Investment [Line Items]	'	'
Unrealized gains on marketable securities	$160,000	$196,000
Unrealized losses on marketable securities	$1,000	'
Maturity date of investments in marketable securities, range start	'2014-07	'
Maturity date of investments in marketable securities, range end	'2016-12	'
Weighted average maturity date	'2015-04	'

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Income Tax [Line Items]	'	'
Excess tax benefits from stock-based compensation	$3,412,000	$0
Cumulative tax deductions for periods of net loss from exercises of stock options	3,497,000	'
2010	'	'
Income Tax [Line Items]	'	'
Increase (decrease) in taxable income	15,064,000	'
2011	'	'
Income Tax [Line Items]	'	'
Increase (decrease) in taxable income	-1,076,000	'
2012	'	'
Income Tax [Line Items]	'	'
Increase (decrease) in taxable income	($13,988,000)	'

Collaboration_Agreements_Addit

Collaboration Agreements - Additional Information (Detail) (AstraZeneca, USD $)

1 Months Ended

101 Months Ended

6 Months Ended

24 Months Ended

6 Months Ended

Feb. 28, 2006

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2011

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Clinical Trial TC-1734

Clinical Trial TC-1734

Accelerated Portion

Development Milestone Events

Development Milestone Events

Development Milestone Events

Regulatory Milestone Events

Regulatory Milestone Events

First Commercial Sale Milestone Events

First Commercial Sale Milestone Events

Sales Milestone

AZD 1446

AZD 1446

AZD 1446

AZD 1446

AZD 1446

AZD 1446

AZD 1446

AZD 1446

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Maximum

Revenue Recognition, Multiple-deliverable Arrangements [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount received for research and development process

$10,000,000

'

'

$6,000,000

'

'

'

'

'

'

'

'

'

Allocation of initial fee to research collaboration

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Initial fee not yet recognized

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Recognized of initial fee as revenue and payments received under amendment

'

'

3,536,000

'

3,142,000

'

'

'

'

'

'

'

'

Additional payments receivable on milestone achievements

'

'

'

'

'

'

7,000,000

14,000,000

8,000,000

10,000,000

12,000,000

49,000,000

30,000,000

Contingent milestone payment

'

'

'

'

'

2,000,000

'

'

'

'

'

'

'

Aggregate amount received for research and development process

'

$88,120,000

'

'

'

'

'

'

'

'

'

'

'