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

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 has 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. From time to time on any trading day the Company selects, the Company has 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 will be based on the prevailing market price at the time of sale as set forth in the LPC Purchase Agreement. There are no trading volume requirements or restrictions under the Purchase Agreement. Lincoln Park’s obligation under each Regular Purchase shall not exceed $2.0 million. There is no upper limit on the price per share that Lincoln Park must pay for Common Stock under the LPC Purchase Agreement, but in no event will shares be sold to Lincoln Park on a day the Company’s closing price is less than the floor price as set forth in the LPC Purchase Agreement. Both the amount and frequency of the Regular Purchases can be increased upon the mutual agreement of the Company and Lincoln Park. The Company will control the timing and amount of any sales of shares of Common Stock to Lincoln Park. The Company may, in its sole discretion, direct 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 is not below the threshold price as set forth in the LPC Purchase Agreement. The Company and Lincoln Park may 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 March 31, 2017. The Company shall issue pro rata up to an additional 119,551 shares of Common Stock to Lincoln Park as determined by the number of shares Common Stock purchased by Lincoln Park pursuant to the LPC Purchase Agreement. All sales of shares have been and will continue to be made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC. 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 three months ended March 31, 2017 were 3,972,741 shares, with gross and net proceeds of $5,304,000.

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. Prior to termination, the Company sold shares of its Common Stock to Lincoln Park under the LPC Purchase Agreement for gross proceeds of approximately $5.7 million.

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. All sales of shares were made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC. 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. All sales of shares have been and will continue to be made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC. 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 we no sales under the Sales Agreements for the three months ended March 31, 2017.

14. Equity Line Financing, Controlled Equity Offering and Public Offering of Common Stock (Continued)

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

As of March 31, 2017, the Company had two effective shelf registration statements on file with the SEC, each of which were initially filed to register up to $100.0 million of debt securities, common stock, preferred stock, or warrants, or any combination thereof for future financing transactions, one filed in January 2014 and the other filed in November 2014. In March 2016, the November 2014 shelf registration statement was increased by $50.0 million. From April 2014 through December 2016, we have raised $179.2 million in gross proceeds and approximately $168.8 million in net proceeds under such shelf registration statements through public offerings of our securities. As of March 31, 2017, we had $37.8 million available for future financings under such shelf registration statements. In addition, approximately $2.4 million was reserved for future issuances under the 2016 ATM Offering under the January 2014 shelf registration statement, which expired in April 2017, and $19.5 million was reserved for future issuances under the LPC Purchase Agreement, which was terminated in April 2017 (see above in this Note 14).

See Note 18 (Subsequent Events) for a description of an offering made under the November 2014 shelf registration statement in April 2017.