Stockholders' Equity Common Stock

12 Months Ended

Dec. 31, 2011

Stockholders' Equity Common Stock [Abstract]

Stockholders' Equity Common Stock

4.      Stockholders' Equity

Common Stock

2009 Common Stock Financings

     On April 3, 2009, we sold 7,750,000 shares of our common stock in an underwritten public offering at a price of $6.30 per share. We received net proceeds from the offering of $47.0 million, after deducting $1.4 million of underwriting commissions and $473,000 of offering expenses.

     On October 13, 2009, we sold 14,000,000 shares of our common stock in an underwritten public offering at a price of $7.10 per share. We received net proceeds from the offering of $93.1 million, after deducting $5.7 million of underwriting commissions and $568,000 of offering expenses.

Common Stock Reserved for Future Issuance

At December 31, 2011, we have reserved shares of common stock for future issuance as follows:

			Shares of
		Available for	Common Stock
	Outstanding at	grant at	Reserved at
	December 31,	December 31,	December 31,
	2011	2011	2011
2001 Employee Stock Purchase Plan	-	2,000,963	2,000,963
2008 Equity Incentive Plan	10,696,871	10,428,262	21,125,133
Total for Equity Incentive Plans	10,696,871	12,429,225	23,126,096

     On June 22, 2010, we filed with the Delaware Secretary of State a Certificate of Amendment to our Restated Certificate of Incorporation to increase the number of shares of common stock authorized to 200,000,000 shares.

Stockholder Rights Plan

     In May 2003, we designated 1,000,000 shares of our authorized Preferred Stock as Series A Junior Participating Preferred Stock, par value $0.001 per share, pursuant to a Stockholder Rights Plan approved by our Board of Directors under which all stockholders of record as of May 28, 2003 received a dividend distribution of one preferred share purchase right, or a Right, for each outstanding share of our common stock. The Rights trade with the common stock and no separate Right certificates will be distributed until such time as the Rights become exercisable in accordance with the Stockholder Rights Plan. In general, the Rights become exercisable when (i) a person or group acquires 15% or more of our common stock or (ii) a tender offer or exchange offer by a person or group for 15% or more of our common stock is commenced or publicly announced. The Stockholder Rights Plan is intended as a means to guard against abusive takeover tactics and to provide for fair and equal treatment for all stockholders in the event that an unsolicited attempt is made to acquire us.

     On July 17, 2009, we filed with the Delaware Secretary of State a Certificate of Amendment to our Certificate of Designation of Series A Junior Participating Preferred Stock to increase the number of shares designated as Series A Junior Participating Preferred Stock thereunder from 1,000,000 shares to 1,500,000 shares. In accordance with the terms of our Amended and Restated Certificate of Incorporation, as amended, our Board of Directors has the authority to increase the number of shares of any series of preferred stock. The Certificate of Amendment was approved by our board of directors on July 16, 2009.

     In connection with an equity financing we completed in March 2005, we amended the Stockholder Rights Plan to provide that Warburg Pincus Private Equity VIII, L.P., or Warburg, and certain of its affiliates will be exempt from the Stockholder Rights Plan, unless Warburg and its affiliates become, without the prior consent of our Board of Directors, the beneficial owner of more than 44% of our common stock.

     In connection with the acquisition of shares of our common stock by Baker Brothers Life Sciences, L.P. and certain other affiliated funds, which are collectively referred to herein as "Baker," in the February 2007 Financing, we amended the Stockholder Rights Plan to provide that Baker will be exempt from the Stockholder Rights Plan, unless Baker becomes, without the Company's prior consent, the beneficial owner of more than 20% of our common stock.

     Until the Rights become exercisable, the Rights will have no dilutive impact on our earnings per share data. The Rights are protected by customary anti-dilution provisions. As of December 31, 2011, no shares of Series A Junior Participating Preferred Stock were issued or outstanding.