12. COMMON STOCK

The Company has authorized 300,000,000 shares of common stock, $0.0001 par value per share, of which 125,083,006 shares were issued and outstanding as of June 30, 2021. The Company had 150,000,000 shares authorized, and 98,852,696 shares issued and outstanding as of December 31, 2020.

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 an Open Market Sale Agreement^SM (the “April 2020 Sale Agreement”) with Jefferies pursuant to which Jefferies served 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 three and six months ended June 30, 2021, the Company did not sell any shares of its common stock under the April 2020 Sale Agreement. During the three and six months ended June 30, 2020, the Company sold 8,113,794 shares of its common stock under the April 2020 Sale Agreement for which the Company received gross proceeds of approximately $62,244,000, less estimated issuance costs incurred of approximately $2,052,000. The Company completed sales of the $75,000,000 of shares of the Company’s common stock under the April 2020 Sale Agreement prior to beginning to sell shares under the August 2020 Sale Agreement.

On August 7, 2020, the Company entered into the August 2020 Sale Agreement with Jefferies pursuant to which Jefferies is serving as the Company’s sales agent to sell shares of the Company’s common stock through an “at the market offering.” As of August 7, 2020, the Company was authorized to sell up to $150,000,000 of shares of the Company’s common stock pursuant to the August 2020 Sale Agreement. During the three months and six months ended June 30, 2021, the Company sold zero shares and 25,391,710 shares, respectively, of its common stock under the August 2020 Sale Agreement. The Company received gross proceeds of approximately $60,681,238, less issuance costs incurred of approximately $1,820,437 for the six months ended June 30, 2021. During the three and six months ended June 30, 2020, the Company did not sell any shares of its common stock under the August 2020 Sale Agreement.

During the three and six months ended June 30, 2021, the Company issued 50,000 and 838,600 shares of common stock upon the exercise of stock options to purchase common stock, respectively. During the three and six months ended June 30, 2021, the Company received proceeds of $50,000 and $944,800 from these exercises, respectively. 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.

No warrants were exercised during the three and six months ended June 30, 2021 and 2020.