15. Equity Line Financing, Controlled Equity Offering and Public Offering of Common Stock

On April 28, 2017, the Company sold 24.9 million units, each consisting of one share of the Company’s common stock, a Series A warrant to purchase one share of common stock, and a Series B warrant to purchase 0.75 shares of common stock, at a public offering price of $1.00 per unit for aggregate gross proceeds of $24.9 million in an underwritten firm commitment public offering. Net proceeds after issuance costs were $23.2 million, assuming no exercise of the warrants. The closing of the public offering occurred on May 3, 2017.

On December 16, 2016, the Company entered into a purchase agreement (the “LPC Purchase Agreement”) with Lincoln Park Capital Fund, LLC, (“Lincoln Park”), pursuant to which the Company had the right to sell to Lincoln Park up to an aggregate of $25.0 million in shares of the Company’s common stock, (the “Common Stock”), subject to certain limitations and conditions set forth in the LPC Purchase Agreement. Effective April 27, 2017, the Company terminated the LPC Purchase Agreement. The LPC Purchase Agreement provided the Company with an election to terminate the Purchase Agreement for any reason or for no reason by delivering a notice to Lincoln Park, and the Company did not incur any early termination penalties in connection with the termination of the LPC Purchase Agreement. Under the LPC Purchase Agreement, from time to time on any trading day the Company selected, the Company had the right, in its sole discretion, subject to the conditions and limitations in the LPC Purchase Agreement, to direct Lincoln Park to purchase up to 150,000 shares of Common Stock (each such purchase, a “Regular Purchase”) over the 36-month term of the LPC Purchase Agreement. The purchase price of shares of Common Stock pursuant to the LPC Purchase Agreement was based on the prevailing market price at the time of sale as set forth in the LPC Purchase Agreement. There were no trading volume requirements or restrictions under the Purchase Agreement. Lincoln Park’s obligation under each Regular Purchase was not to exceed $2.0 million. There was no upper limit on the price per share that Lincoln Park was to pay for Common Stock under the LPC Purchase Agreement, but in no event would shares be sold to Lincoln Park on a day the Company’s closing price was less than the floor price as set forth in the LPC Purchase Agreement. Both the amount and frequency of the Regular Purchases could have been increased upon the mutual agreement of the Company and Lincoln Park. The Company controlled the timing and amount of any sales of shares of Common Stock to Lincoln Park. The Company, in its sole discretion, could have directed Lincoln Park to purchase additional amounts as accelerated purchases if on the date of a Regular Purchase the closing sale price of the Common Stock was not below the threshold price as set forth in the LPC Purchase Agreement. The Company and Lincoln Park could mutually agree to increase the amount of Common Stock sold to Lincoln Park on any accelerated purchase date. The Company issued to Lincoln Park 345,421 shares of Common Stock as commitment shares in consideration for the LPC Purchase Agreement through April 27, 2017. Sales under the LPC Purchase Agreement for the year ended December 31, 2016 were 300,000 shares, with gross proceeds of $412,500 and net proceeds of $392,500. Sales under the LPC Purchase Agreement for the six months ended June 30, 2017 were 3,972,741 shares, with gross and net proceeds of $5,304,000.

On February 20, 2015, the Company entered into a Controlled Equity Offering^SM Sales Agreement (the “2015 Sales Agreement”) with Cantor Fitzgerald & Co. (“Cantor”), as sales agent, pursuant to which the Company sold through Cantor, from time to time, up to $25.0 million in shares of common stock in an at-the-market offering. The Company pays Cantor a commission of approximately 3% of the aggregate gross proceeds received from all sales of common stock under the Sales Agreement. Sales under the 2015 Sales Agreement have been fully sold as of February 9, 2016, with cumulative shares of 7,724,488, gross proceeds of $25.0 million and net proceeds of $24.0 million.

On February 9, 2016, the Company entered into a Controlled Equity Offering^SM Sales Agreement (the “2016 Sales Agreement”) with Cantor, as sales agent, pursuant to which the Company can sell through Cantor, from time to time, up to $43.6 million in shares of common stock in an at-the-market offering. The Company pays Cantor a commission of approximately 3% of the aggregate gross proceeds received from all sales of common stock under the 2016 Sales Agreement. Unless otherwise terminated earlier, the 2016 Sales Agreement continues until all shares available under the Sales Agreement have been sold. There were no sales under the Sales Agreements for the six months ended June 30, 2017.

The following table summarizes the total sales under the 2015 Sales Agreement and 2016 Sales Agreement for the periods indicated (in thousands, except per share amounts):

	2016 Sales Agreement		2015 Sales Agreement
	Year Ended December 31, 2016		Year Ended December 31, 2016		Year Ended December 31, 2015
Total shares of common stock sold		8,763.4		5,710.2		2,014.3
Average price per share	$	4.70	$	3.23	$	3.25
Gross proceeds	$	41,156	$	18,454	$	6,546
Commissions earned by Cantor	$	1,235	$	553	$	197
Other issuance costs	$	185	$	—	$	259