Stockholders' Equity	9 Months Ended
Sep. 30, 2020
Stockholders' Equity
Stockholders' Equity	7. Stockholders’ Equity Issuances of Common Stock - On January 14, 2019, the Company entered into an underwriting agreement with Wainwright relating to an underwritten public offering of 429,616 shares of its common stock for gross proceeds of approximately $1.1 million (the "2019 Underwritten Offering"). The offering price to the public in the 2019 Underwritten Offering was $2.60 per share, and Wainwright agreed to purchase the shares in the 2019 Underwritten Offering from the Company pursuant to the underwriting agreement at a price of $2.418 per share. Additionally, the Company issued warrants to purchase up to 25,777 shares of its common stock in a private placement to Wainwright as compensation for its services as underwriter in connection with the 2019 Underwritten Offering. The 2019 Underwritten Offering closed on January 17, 2019. The net proceeds to the Company from the 2019 Underwritten Offering, after deducting the underwriting discounts and commissions and expenses and the Company's offering expenses, and excluding the proceeds, if any, from the exercise of the underwriter warrants, were approximately $0.9 million. On January 18, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 648,233 shares of its common stock for gross proceeds of approximately $1.7 million (the "January 2019 Registered Direct Offering"). In a concurrent private placement, the Company also agreed pursuant to the securities purchase agreement to issue to such investors Series A warrants to purchase up to 324,117 shares of its common stock (the "January 2019 Private Placement"). Additionally, the Company issued warrants to purchase up to 38,894 shares of its common stock in a private placement to Wainwright as compensation for its services as a placement agent in connection with the 2019 Registered Direct Offering and the 2019 Private Placement. The 2019 Registered Direct Offering and the 2019 Private Placement closed on January 23, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $1.5 million. On March 12, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 712,910 shares of its common stock for gross proceeds of approximately $18.5 million (the "March 2019 Registered Direct Offering"). Additionally, the Company issued warrants to purchase up to 42,775 shares of its common stock in a private placement to Wainwright as compensation for its services as a placement agent in connection with the March 2019 Registered Direct Offering. The March 2019 Registered Direct Offering closed on March 14, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $17.0 million. On November 21, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 808,080 shares of its common stock and warrants to purchase up to 606,060 shares of its common stock for gross proceeds of approximately $8.0 million under the Company's shelf registration statement on Form S-3 filed with the SEC, which was declared effective by the SEC on June 5, 2019 (File No. 333-231537) (the "2019 Shelf Registration Statement”) (the "November 2019 Registered Direct Offering"). Additionally, the Company issued warrants to purchase up to 48,485 shares of its common stock to Wainwright as compensation for its services as a placement agent in connection with the November 2019 Registered Direct Offering, which warrants and the common stock issuable upon exercise of such warrants were registered under the 2019 Shelf Registration Statement. The November 2019 Registered Direct Offering closed on November 25, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $7.3 million. During the fiscal year ended December 31, 2019, the Company issued an aggregate of 409,875 shares of its common stock pursuant to the exercise of warrants at a weighted average exercise price of approximately $2.67 per share. The net proceeds to the Company from the exercise of the warrants were approximately $1.1 million. At-The-Market Offering Agreement - On July 13, 2020, the Company entered into the Offering Agreement with Wainwright, as sales agent and/or principal, pursuant to which the Company may offer and sell, from time to time, through or to Wainwright, shares of the Company's common stock. Sales of shares of common stock under the Offering Agreement will be made pursuant to the 2019 Shelf Registration Statement and a related prospectus supplement filed with the SEC on July 14, 2020, for an aggregate offering price of up to $7.0 million, provided that the Company may be limited in the amount of securities that it can sell under the Offering Agreement pursuant to Instruction I.B.6 to Form S-3 for so long as the Company's public float remains less than $75.0 million. Under the Offering Agreement, Wainwright may sell shares by any method deemed to be an "at the market" offering as defined in Rule 415 under the Securities Act. The Company will pay Wainwright a commission of 3% of the aggregate gross proceeds from each sale of shares under the Offering Agreement and has agreed to provide Wainwright with customary indemnification and contribution rights. The Company has also agreed to reimburse Wainwright for certain specified expenses. As of September 30, 2020, the Company had not offered or sold any shares of its common stock under the Offering Agreement.

7. Stockholders’ Equity

Issuances of Common Stock - On January 14, 2019, the Company entered into an underwriting agreement with Wainwright relating to an underwritten public offering of 429,616 shares of its common stock for gross proceeds of approximately $1.1 million (the "2019 Underwritten Offering"). The offering price to the public in the 2019 Underwritten Offering was $2.60 per share, and Wainwright agreed to purchase the shares in the 2019 Underwritten Offering from the Company pursuant to the underwriting agreement at a price of $2.418 per share. Additionally, the Company issued warrants to purchase up to 25,777 shares of its common stock in a private placement to Wainwright as compensation for its services as underwriter in connection with the 2019 Underwritten Offering. The 2019 Underwritten Offering closed on January 17, 2019. The net proceeds to the Company from the 2019 Underwritten Offering, after deducting the underwriting discounts and commissions and expenses and the Company's offering expenses, and excluding the proceeds, if any, from the exercise of the underwriter warrants, were approximately $0.9 million.

On January 18, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 648,233 shares of its common stock for gross proceeds of approximately $1.7 million (the "January 2019 Registered Direct Offering"). In a concurrent private placement, the Company also agreed pursuant to the securities purchase agreement to issue to such investors Series A warrants to purchase up to 324,117 shares of its common stock (the "January 2019 Private Placement"). Additionally, the Company issued warrants to purchase up to 38,894 shares of its common stock in a private placement to Wainwright as compensation for its services as a placement agent in connection with the 2019 Registered Direct Offering and the 2019 Private Placement. The 2019 Registered Direct Offering and the 2019 Private Placement closed on January 23, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $1.5 million.

On March 12, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 712,910 shares of its common stock for gross proceeds of approximately $18.5 million (the "March 2019 Registered Direct Offering"). Additionally, the Company issued warrants to purchase up to 42,775 shares of its common stock in a private placement to Wainwright as compensation for its services as a placement agent in connection with the March 2019 Registered Direct Offering. The March 2019 Registered Direct Offering closed on March 14, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $17.0 million.

On November 21, 2019, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed to sell, in a registered direct offering, an aggregate of 808,080 shares of its common stock and warrants to purchase up to 606,060 shares of its common stock for gross proceeds of approximately $8.0 million under the Company's shelf registration statement on Form S-3 filed with the SEC, which was declared effective by the SEC on June 5, 2019 (File No. 333-231537) (the "2019 Shelf Registration Statement”) (the "November 2019 Registered Direct Offering"). Additionally, the Company issued warrants to purchase up to 48,485 shares of its common stock to Wainwright as compensation for its services as a placement agent in connection with the November 2019 Registered Direct Offering, which warrants and the common stock issuable upon exercise of such warrants were registered under the 2019 Shelf Registration Statement. The November 2019 Registered Direct Offering closed on November 25, 2019. The net proceeds to the Company from the offerings, after deducting the placement agent's fees and expenses, offering expenses, and excluding the proceeds, if any, from the exercise of the warrants issued in the offerings, were approximately $7.3 million.

During the fiscal year ended December 31, 2019, the Company issued an aggregate of 409,875 shares of its common stock pursuant to the exercise of warrants at a weighted average exercise price of approximately $2.67 per share. The net proceeds to the Company from the exercise of the warrants were approximately $1.1 million.

At-The-Market Offering Agreement - On July 13, 2020, the Company entered into the Offering Agreement with Wainwright, as sales agent and/or principal, pursuant to which the Company may offer and sell, from time to time, through or to Wainwright, shares of the Company's common stock. Sales of shares of common stock under the Offering Agreement will be made pursuant to the 2019 Shelf Registration Statement and a related prospectus supplement filed with the SEC on July 14, 2020, for an aggregate offering price of up to $7.0 million, provided that the Company may be limited in the amount of securities that it can sell under the Offering Agreement pursuant to Instruction I.B.6 to Form S-3 for so long as the Company's public float remains less than $75.0 million. Under the Offering Agreement, Wainwright may sell shares by any method deemed to be an "at the market" offering as defined in Rule 415 under the Securities Act. The Company will pay Wainwright a commission of 3% of the aggregate gross proceeds from each sale of shares under the Offering Agreement and has agreed to provide Wainwright with customary indemnification and contribution rights. The Company has also agreed to reimburse Wainwright for certain specified expenses. As of September 30, 2020, the Company had not offered or sold any shares of its common stock under the Offering Agreement.