The Company has authorized 150,000,000 shares of common stock, $0.0001 par value per share, of which 80,655,848 shares, and 64,672,893 shares were issued and outstanding as of June 30, 2020, and December 31, 2019, respectively.

On January 30, 2019, the Company consummated an underwritten public offering of shares of its common stock pursuant to which the Company sold an aggregate of 6,198,500 shares of its common stock, including 808,500 shares sold pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a purchase price of $6.50 per share with gross proceeds to the Company totaling $40,290,250, less issuance costs incurred of approximately $2,572,000.

On February 11, 2020, the Company consummated an underwritten public offering of shares of its common stock pursuant to which the Company sold an aggregate of 7,666,667 shares of its common stock, including 1,000,000 shares sold pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a purchase price of $6.00 per share with gross proceeds to the Company totaling $46,000,000, less estimated issuance costs incurred of approximately $3,147,000.

On April 7, 2020, the Company entered into the April 2020 Sale Agreement with Jefferies pursuant to which Jefferies is serving as the Company’s sales agent to sell up to $75,000,000 of shares of the Company’s common stock through an “at the market offering.” Sales of common stock under the April 2020 Sale Agreement were made pursuant to an effective registration statement for an aggregate offering of up to $75,000,000. During the second quarter of 2020, the Company sold 8,113,794 shares of its common stock under the April 2020 Sale Agreement for which the Company received net proceeds of approximately $43,702,000 through June 30, 2020 and had stock subscriptions receivable as of June 30, 2020 for approximately $16,676,000, for which the Company received the proceeds in July 2020. In July 2020, the Company sold an additional 1,053,286 shares of its common stock under the April 2020 Sale Agreement for net proceeds of approximately $8,148,000.

During the three and six months ended June 30, 2020, the Company issued 51,605 and 202,494 shares of common stock upon the exercise of stock options to purchase common stock and the Company received proceeds of $286,310 and $302,305 from these exercises, respectively. During the three and six months ended June 30, 2019, the Company issued 16,458 and 78,229 shares of common stock upon the exercise of stock options to purchase common stock and the Company received proceeds of $102,708 and $306,711 from these exercises, respectively.

During the three and six months ended June 30, 2019, warrants to purchase 200,000 shares and 1,283,500 shares of common stock were exercised on a cashless basis resulting in the issuance of 172,414 and 1,119,868 shares of common stock, respectively. No warrants were exercised during the three and six months ended June 30, 2020.