8. Common stock

12 Months Ended

Dec. 31, 2016

Notes to Financial Statements

Common stock - Note 8

8. COMMON STOCK

In December 2016, we raised approximately $2.1 million before issuance costs of approximately $18,000 through a registered direct offering of 2.0 million shares of our common stock.

In December 2016, we raised approximately $13.0 million before issuance costs of approximately $1.2 million through an underwritten public offering of approximately 12.1 million shares of our common stock.

In September 2016, we entered into a Common Stock Purchase Agreement with Lincoln Park granting us the right to sell shares of our common stock having an aggregate value of up to $17.0 million. Under the terms of the agreement, Lincoln Park made an initial purchase of $2.0 million in shares of common stock at a purchase price of $1.50 per share. Subject to various limitations and conditions set forth in the agreement, including a $1.00 minimum stock price, we may sell up to an additional $15.0 million in shares of common stock, from time to time, at our sole discretion to Lincoln Park over a twenty-four month period beginning September 2016. In consideration for entering into the agreement, we issued 522,556 shares of common stock, having a value of $721,000 based on the closing stock price on the date of grant, to Lincoln Park as a commitment fee. We incurred an additional $133,000 in issuance costs. As of December 31, 2016, $15.0 million in shares of common stock remain available under our Common Stock Purchase Agreement. In connection with our December 2016 underwritten public offering, we also agreed in the underwriting agreement not to issue shares pursuant to the Common Stock Purchase Agreement, or any other arrangement with Lincoln Park, for a period of six months from the date thereof.

In March 2016, we raised approximately $6.9 million before issuance costs of approximately $650,000 through an underwritten public offering of approximately 4.1 million shares of our common stock. The offering included the exercise in full of the underwriter's option to purchase up to an additional 529,411 shares of our common stock.

In May 2015, we entered into an ATM agreement with Meyers Associates, L.P. Under the terms of the agreement, we may, from time to time, at our discretion, offer and sell shares of our common stock having an aggregate value of up to $6.0 million. As of December 31, 2016, we have received gross proceeds of approximately $3.1 million before issuance costs of approximately $109,000 from the sale of 1.2 million shares of our common stock.

During the year ended December 31, 2015, we received approximately $3.3 million from the exercise of warrants to purchase 1.5 million shares of our common stock, which warrants were issued in connection with earlier financing transactions.

During the three months ended March 31, 2015, we received gross proceeds of approximately $1.0 million as part of an ATM agreement we entered into with Meyers Associates, L.P. in June 2014. We have completed sales under this agreement, having received total proceeds of approximately $4.5 million before issuance costs of approximately $206,000 from the sale of 2.0 million shares of our common stock.

In March 2014, we raised approximately $13.9 million before issuance costs of approximately $1.0 million through an underwritten offering of 7.2 million shares of our common stock and warrants to purchase 2.1 million shares of our common stock.

In February 2014, we issued 3.7 million shares of our common stock under the exchange provisions of the warrants issued in connection with our May and September 2013 financing activities. We recognized a loss of $5.0 million on the exchange as the fair market value of the common stock issued was greater than the obligation recorded due to an increase in our stock price since December 31, 2013.