Common Stock

The voting dividend and liquidation rights of holders of shares of common stock are subject to and qualified by the rights, powers and preferences of the holders of the shares of preferred stock. The Company’s common stock has the following characteristics:

Voting

The holders of common stock shall have voting rights at all meetings of stockholders, each such holder being entitled to one vote for each share thereof held by such holder; provided, however, that, except as otherwise required by law, holders of common stock shall not be entitled to vote on any amendment to the Company’s certificate of incorporation that relates solely to the terms of one or more outstanding series of preferred stock if the holders of such affected series are entitled, either separately or together as a class with the holders of one or more such series, to vote thereon. There shall be no cumulative voting.

Dividends

Dividends may be declared and paid on the common stock from funds lawfully available thereof as and when determined by the Board and subject to any preferential dividend or other rights of any then outstanding preferred stock.

Liquidation

Upon the dissolution or liquidation of the Company, whether voluntary or involuntary, holders of common stock will be entitled to receive all assets of the Company available for distribution to its stockholders, subject to any preferential or other rights of any then outstanding preferred stock.

Reserved for Future Issuance

The Company has reserved the following shares of common stock:



	As of December 31,
	2017	2016
Unvested restricted stock	4,430	22,150
Restricted stock units	—	3,333
Options to purchase common stock	3,879,535	3,112,771
Warrants to purchase common stock	10,055,000	926,840
Employee stock purchase plan	59,461	68,609
	13,998,426	4,133,703

At-the-Market Facility

During the years ended December 31, 2017 and 2016, the Company did not sell any shares pursuant to the "at-the-market" sales agreement with Cowen and Company, LLC entered into in March 2015. For the year ended December 31, 2015, the Company had sold 1,446,781 shares pursuant to the sales agreement, resulting in proceeds of $12.7 million, net of commissions and issuance costs.

Secondary Public Offering

On November 1, 2017, the Company raised approximately $7.0 million of net proceeds from the sale of 5,525,000 units (each unit consisting of one share of common stock and one common warrant to purchase one share of common stock) and 4,475,000 pre-funded units (each pre-funded unit consisting of one pre-funded warrant to purchase one share of common stock and one common warrant to purchase one share of common stock) at a purchase price of $0.80 per unit and $0.79 per pre-funded unit (the "November 2017 Financing"). Each common warrant contained in a unit or pre-funded unit has an exercise price of $0.80 per share and is exercisable immediately and will expire five years from the date of issuance. Each pre-funded warrant contained in a pre-funded unit was exercisable for one share of common stock and the exercise price was $0.01 per share. As of December 31, 2017, the Company had issued 4,475,000 shares of the Company’s common stock pursuant to the exercise of all of the pre-funded warrants sold in connection with the November 2017 Financing.