STOCKHOLDERS' EQUITY	12 Months Ended
Dec. 31, 2017
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Common Stock Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 47,000,000 shares of common stock. Holders of our common stock are entitled to dividends as and when declared by the board of directors, subject to rights and holders of all classes of stock outstanding having priority rights to dividends. There have been no dividends declared to date. Each share of common stock is entitled to one vote. On April 25, 2016, we completed the private placement sale of 1,996,880 units at a price of $2.985 per unit to institutional and individual investors, which included existing investors, executives and board members. Each unit consists of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $2.86 for a period commencing 6 months and ending 36 months after the closing of the financing. We also issued to the placement agents in the financing, warrants to purchase an aggregate of 99,844 shares of our common stock at an exercise price of $2.86 for a period commencing 6 months and ending 36 months after the closing. Gross proceeds were $6.0 million with net proceeds of $5.2 million after deducting placement agent fees and offering expenses. We registered for resale by the investors the shares of common stock, and the shares of common stock issuable upon exercise of the warrants, purchased by the investors in the financing pursuant to a registration statement that was declared effective by the SEC in May 2016. On September 14, 2016, we completed the sale of 2,715,000 shares of common stock at a price of $4.25 per share in an underwritten public offering. We also issued to the underwriter warrants to purchase 135,750 shares of our common stock at an exercise price of $4.25 exercisable for a 2 year period commencing September 9, 2017. Gross proceeds were $11.5 million with net proceeds of $10.6 million after deducting underwriter fees and offering expenses. The shares were issued pursuant to a shelf registration statement that we filed with the SEC, which became effective in May 2016. On February 22, 2017, we completed the private placement sale of 1,626,898 units at a price of $4.61 per unit to one investor. Each unit consists of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $8.25 for a period commencing 6 months and ending 30 months after the closing of the financing. Gross proceeds were $7.5 million. We incurred $29,000 of legal expenses in connection with the financing. We registered for resale by the investor the shares of common stock, and the shares of common stock issuable upon exercise of the warrants, purchased by the investor in the financing pursuant to a registration statement that was declared effective by the SEC in April 2017. On October 2, 2017, we completed the private placement sale of 1,976,919 units. Each unit consisted of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $4.85 per share for a period commencing 6 months and ending 36 months from September 28, 2017, the date of the first closing of the offering. The sale closed in two rounds with the first closing on September 28, 2017 which included the private placement sale of 1,745,581 units at a price of $4.70 per unit to institutional and individual investors. Gross proceeds in the first closing were $8.2 million with net proceeds of $7.5 million after deducting placement agent fees and offering expenses. The second closing, completed on October 2, 2017, was for 231,338 units and gross proceeds of $1.1 million with net proceeds of $1.0 million after deducting placement agent fees and offering expenses. We also issued to the placement agent, warrants to purchase an aggregate of 98,846 shares of our common stock at an exercise price of $4.85 per share for a period commencing 6 months and ending 36 months from September 28, 2017. We have a Form S-3 universal shelf registration statement on file with the SEC. The universal shelf registration statement on Form S-3 permits us to sell, in one or more public offerings, shares of our common stock, shares of preferred stock or debt securities, or any combination of such securities and warrants to purchase securities, for proceeds in an aggregate amount of up to $35.0 million. As of December 31, 2017, we have raised a total of $11.5 million of gross proceeds from the sale of 2,715,000 shares of our common stock, leaving approximately $23.5 million of securities available for issuance pursuant to the Form S-3. The Form S-3 will expire in May 2019. Preferred Stock Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 3,000,000 shares of preferred stock. The board of directors has the authority, without action by our stockholders, to designate and issue shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. To-date, no preferred shares have been issued.

STOCKHOLDERS’ EQUITY

Common Stock

Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 47,000,000 shares of common stock. Holders of our common stock are entitled to dividends as and when declared by the board of directors, subject to rights and holders of all classes of stock outstanding having priority rights to dividends. There have been no dividends declared to date. Each share of common stock is entitled to one vote.

On April 25, 2016, we completed the private placement sale of 1,996,880 units at a price of $2.985 per unit to institutional and individual investors, which included existing investors, executives and board members. Each unit consists of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $2.86 for a period commencing 6 months and ending 36 months after the closing of the financing. We also issued to the placement agents in the financing, warrants to purchase an aggregate of 99,844 shares of our common stock at an exercise price of $2.86 for a period commencing 6 months and ending 36 months after the closing. Gross proceeds were $6.0 million with net proceeds of $5.2 million after deducting placement agent fees and offering expenses. We registered for resale by the investors the shares of common stock, and the shares of common stock issuable upon exercise of the warrants, purchased by the investors in the financing pursuant to a registration statement that was declared effective by the SEC in May 2016.

On September 14, 2016, we completed the sale of 2,715,000 shares of common stock at a price of $4.25 per share in an underwritten public offering. We also issued to the underwriter warrants to purchase 135,750 shares of our common stock at an exercise price of $4.25 exercisable for a 2 year period commencing September 9, 2017. Gross proceeds were $11.5 million with net proceeds of $10.6 million after deducting underwriter fees and offering expenses. The shares were issued pursuant to a shelf registration statement that we filed with the SEC, which became effective in May 2016.

On February 22, 2017, we completed the private placement sale of 1,626,898 units at a price of $4.61 per unit to one investor. Each unit consists of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $8.25 for a period commencing 6 months and ending 30 months after the closing of the financing. Gross proceeds were $7.5 million. We incurred $29,000 of legal expenses in connection with the financing. We registered for resale by the investor the shares of common stock, and the shares of common stock issuable upon exercise of the warrants, purchased by the investor in the financing pursuant to a registration statement that was declared effective by the SEC in April 2017.

On October 2, 2017, we completed the private placement sale of 1,976,919 units. Each unit consisted of one share of our common stock and one warrant to purchase one share of our common stock at an exercise price of $4.85 per share for a period commencing 6 months and ending 36 months from September 28, 2017, the date of the first closing of the offering. The sale closed in two rounds with the first closing on September 28, 2017 which included the private placement sale of 1,745,581 units at a price of $4.70 per unit to institutional and individual investors. Gross proceeds in the first closing were $8.2 million with net proceeds of $7.5 million after deducting placement agent fees and offering expenses. The second closing, completed on October 2, 2017, was for 231,338 units and gross proceeds of $1.1 million with net proceeds of $1.0 million after deducting placement agent fees and offering expenses. We also issued to the placement agent, warrants to purchase an aggregate of 98,846 shares of our common stock at an exercise price of $4.85 per share for a period commencing 6 months and ending 36 months from September 28, 2017.

We have a Form S-3 universal shelf registration statement on file with the SEC. The universal shelf registration statement on Form S-3 permits us to sell, in one or more public offerings, shares of our common stock, shares of preferred stock or debt securities, or any combination of such securities and warrants to purchase securities, for proceeds in an aggregate amount of up to $35.0 million. As of December 31, 2017, we have raised a total of $11.5 million of gross proceeds from the sale of 2,715,000 shares of our common stock, leaving approximately $23.5 million of securities available for issuance pursuant to the Form S-3. The Form S-3 will expire in May 2019.

Preferred Stock

Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 3,000,000 shares of preferred stock. The board of directors has the authority, without action by our stockholders, to designate and issue shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. To-date, no preferred shares have been issued.