As of March 31, 2019, the Company was authorized to issue 100 million shares of common stock par value $0.001 per share, of which 37,813,991 and 35,335,378 shares were issued outstanding as of March 31, 2019 and December 31, 2018, respectively.

Issuances Upon Warrant Exercises

From January 30, 2019 to February 26, 2019, 754,475 warrants were exercised at a price of $2.20 per share, for gross cash proceeds to the Company of $1.66 million. As a result, a total of 754,475 shares of common stock were issued.

On March 8, 2019, Cotterford Company Limited exercised 1,724,138 warrants at a price of $2.90 per share, for gross cash proceeds to the Company of $5 million. As a result, a total of 1,724,138 shares of common stock were issued.

Equity Distribution Agreement

On September 7, 2018, the Company entered into an equity distribution agreement with Oppenheimer & Co. Inc. (“Oppenheimer”), which agreement allows it to offer and sell shares of common stock having an aggregate offering price of up to $10.0 million from time to time pursuant to a shelf registration statement on Form S-3 (declared effective by the SEC on September 28, 2018, File No. 333-227248) through Oppenheimer acting as the Company’s agent and/or principal. As of March 31, 2019, the Company had not sold any shares under the equity distribution agreement.