Stockholders' Equity	12 Months Ended
Dec. 31, 2012
Stockholders' Equity [Abstract]
Stockholders' Equity	Note 5 — Stockholders’ Equity In June 2011, the Company entered into an At Market Issuance Sales Agreement (the “ATM Agreement”) with McNicoll, Lewis & Vlak (“MLV”) pursuant to which the Company may issue and sell $70,000 in shares of its common stock at current market prices under a Form S-3 registration statement with MLV acting as the sales agent. Subject to the terms and conditions of the ATM Agreement, MLV will use commercially reasonable efforts to sell the Company’s common stock from time to time, based upon the Company’s instruction, including any price, time or size limits or other customary parameters or conditions the Company may impose. The Company will pay MLV an aggregate commission rate of 2% or 3% of the gross proceeds of the sales price per share of any common stock sold under the ATM Agreement depending on the number of shares sold. On June 28, 2011, the Company filed a Registration Statement on Form S-3, which became effective on July 13, 2011, for the issuance and sale of up to $70,000 of equity or other securities. During 2011, the Company sold an aggregate of 437 shares of common stock at an average per share price of $2.65 for net proceeds of $1,027. During 2012, the Company sold an aggregate of 4,516 shares of common stock at an average per share price of $4.08 pursuant to the ATM Agreement for net proceeds of $17,805. On March 15, 2012, the Company issued 193 shares of restricted common stock in lieu of a cash payment to employees as payment for their annual incentive award earned in 2011. The number of shares issued was based on the total value of the annual incentive earned in 2011 of $1,542, less $535 in withholding taxes paid in cash on the employees’ behalf, divided by the closing common stock price on March 15, 2012 of $5.23 per share. In May 2010, the Company entered into an amendment to the License Agreement dated June 27, 2000, as subsequently amended (the “License Agreement”), by and among the Company and AECOM and IRL (the “Licensors”). The amendment further amended the License Agreement through which the Company obtained worldwide exclusive rights to develop and ultimately distribute any product candidates that might arise from research on a series of PNP inhibitors, including forodesine and ulodesine. Under the terms of the amendment, the Licensors agreed to accept a reduction of one-half in the percentage of future payments received from third-party sub licensees of the licensed PNP inhibitors that must be paid to the Licensors. This reduction does not apply to (i) any milestone payments the Company may receive in the future under its license agreement dated February 1, 2006 with Mundipharma International Holdings Limited (“Mundipharma”) and (ii) royalties received from the Company’s sub licensees in connection with the sale of licensed products, for which the original payment rate will remain in effect. The rate of royalty payments to the Licensors based on net sales of any resulting product made by the Company remains unchanged. In consideration for the modifications to the license agreement, the Company issued to the Licensors shares of its common stock with an aggregate value of $5,827 and paid the Licensors $90 in cash. The Company deferred the value of this consideration and is amortizing to research and development expense through September 2027, which is the date of expiration of the last-to-expire patent related to this agreement. Additionally, at the Company’s sole option and subject to certain agreed upon conditions, any future non-royalty payments due to be paid by the Company to the Licensors under the License Agreement may be made either in cash, in shares of its common stock, or in a combination of cash and shares.

Stockholders' Equity

12 Months Ended

Dec. 31, 2012

Note 5 — Stockholders’ Equity

In June 2011, the Company entered into an At Market Issuance Sales Agreement (the “ATM Agreement”) with McNicoll, Lewis & Vlak (“MLV”) pursuant to which the Company may issue and sell $70,000 in shares of its common stock at current market prices under a Form S-3 registration statement with MLV acting as the sales agent. Subject to the terms and conditions of the ATM Agreement, MLV will use commercially reasonable efforts to sell the Company’s common stock from time to time, based upon the Company’s instruction, including any price, time or size limits or other customary parameters or conditions the Company may impose. The Company will pay MLV an aggregate commission rate of 2% or 3% of the gross proceeds of the sales price per share of any common stock sold under the ATM Agreement depending on the number of shares sold. On June 28, 2011, the Company filed a Registration Statement on Form S-3, which became effective on July 13, 2011, for the issuance and sale of up to $70,000 of equity or other securities. During 2011, the Company sold an aggregate of 437 shares of common stock at an average per share price of $2.65 for net proceeds of $1,027. During 2012, the Company sold an aggregate of 4,516 shares of common stock at an average per share price of $4.08 pursuant to the ATM Agreement for net proceeds of $17,805.

On March 15, 2012, the Company issued 193 shares of restricted common stock in lieu of a cash payment to employees as payment for their annual incentive award earned in 2011. The number of shares issued was based on the total value of the annual incentive earned in 2011 of $1,542, less $535 in withholding taxes paid in cash on the employees’ behalf, divided by the closing common stock price on March 15, 2012 of $5.23 per share.

In May 2010, the Company entered into an amendment to the License Agreement dated June 27, 2000, as subsequently amended (the “License Agreement”), by and among the Company and AECOM and IRL (the “Licensors”). The amendment further amended the License Agreement through which the Company obtained worldwide exclusive rights to develop and ultimately distribute any product candidates that might arise from research on a series of PNP inhibitors, including forodesine and ulodesine. Under the terms of the amendment, the Licensors agreed to accept a reduction of one-half in the percentage of future payments received from third-party sub licensees of the licensed PNP inhibitors that must be paid to the Licensors. This reduction does not apply to (i) any milestone payments the Company may receive in the future under its license agreement dated February 1, 2006 with Mundipharma International Holdings Limited (“Mundipharma”) and (ii) royalties received from the Company’s sub licensees in connection with the sale of licensed products, for which the original payment rate will remain in effect. The rate of royalty payments to the Licensors based on net sales of any resulting product made by the Company remains unchanged.

In consideration for the modifications to the license agreement, the Company issued to the Licensors shares of its common stock with an aggregate value of $5,827 and paid the Licensors $90 in cash. The Company deferred the value of this consideration and is amortizing to research and development expense through September 2027, which is the date of expiration of the last-to-expire patent related to this agreement. Additionally, at the Company’s sole option and subject to certain agreed upon conditions, any future non-royalty payments due to be paid by the Company to the Licensors under the License Agreement may be made either in cash, in shares of its common stock, or in a combination of cash and shares.