Note 10 - Common Stock and Common Stock Warrants

6 Months Ended

Jun. 30, 2013

Stockholders' Equity Note Disclosure [Text Block]

Stockholders' Equity Note Disclosure [Text Block]

10. Common Stock and Common Stock Warrants

The Company raised $0.5 million in gross proceeds during the first six months of 2013 through the issuance of the Company’s common stock to Immune. Approximately 3.8 million shares of the Company’s common stock were sold at a price of $0.13 per share. These shares have not been registered.

On September 24, 2012, the Company reduced the exercise price of its outstanding common stock purchase warrants that were issued in registered direct offerings that closed on February 10, 2012 and April 2, 2012, exercisable for an aggregate of 8,132,353 shares of common stock. The exercise price for all of the warrants was reduced to $0.10 per share. The Warrants issued in February 2012 had an original exercise price of $0.20 per share, and those issued in April 2012 had an original exercise price of $0.17 per share. All of the warrants were immediately exercised, resulting in proceeds of approximately $0.8 million in 2012.

Effective January 9, 2012, the Company reduced the exercise price and extended the expiration date of its outstanding Series B common stock purchase warrants that were issued in a registered direct offering that closed on June 30, 2010. The Series B warrants, which originally would have expired on the close of business on January 9, 2012, were exercisable for up to approximately 6.1 million shares of the Company’s common stock. The exercise price was reduced from $1.64 per share to $0.20 per share subject to no further adjustment other than for stock splits and stock dividends and the expiration date was extended to the close of business on April 9, 2012.  The modification resulted in a warrant amendment expense of $0.9 million which was calculated as the difference in the fair value of the warrants immediately before and after the modification using the Black-Scholes option pricing model (volatility – 110%, risk free rate – 0.01%, dividends – zero, weighted average life – 0.25 years). Approximately 3.9 million warrants were exercised for proceeds of approximately $0.7 million in 2012.