Stockholders' Equity	12 Months Ended
Dec. 31, 2019
Stockholders’ Equity
Stockholders’ Equity	(7) Stockholders’ Equity Preferred Stock The Company’s board of directors are authorized to issue up to 10.0 million shares of preferred stock, with any rights, preferences and privileges as it may designate. As of December 31, 2019, no shares of preferred stock were issued. Common Stock On August 30, 2019, the Company entered into the 2019 Sales Agreement with the Agents pursuant to which the Company may sell, from time to time, up to $75.0 million of its common stock. From December 12, 2019 through March 4, 2020, the Company has sold and issued 353,171 shares of its common stock under the 2019 Sales Agreement in the open market at a weighted average selling price of $5.22 per share, resulting in gross proceeds of $1.8 million. Net proceeds after deducting commissions and offering expenses were $1.6 million. As of December 31, 2019, the Company sold and issued 13,381 shares of its common stock in the open market at a weighted-average selling price of $7.00, for gross and net proceeds of $0.1 million. From January 1, 2020 through March 4, 2020, the Company sold and issued 339,790 shares of its common stock in the open market at a weighted average selling price of $5.15 per share, for gross proceeds of $1.7 million and net proceeds, after deducting commissions and offering expenses, of $1.5 million. In the first quarter of 2019, the Company sold and issued 3,439,523 shares of common stock under the 2017 Sales Agreement with Jefferies in the open market at a weighted average selling price of $5.44 per share, resulting in gross proceeds of $18.7 million. Net proceeds received after deducting commissions and offering expenses were $18.1 million. In the second quarter of 2019, the Company sold and issued 2,082,031 shares of common stock under the 2017 Sales Agreement with Jefferies in the open market at a weighted average selling price of $13.50 per share, resulting in gross proceeds of $28.1 million. Net proceeds received after deducting commissions and offering expenses were $27.0 million. The last sale under the 2017 Sales Agreement was made on May 16, 2019. From June 2017 through May 16, 2019, the Company has cumulative gross proceeds of $50.0 million from shares sold in the open market under the 2017 Sales Agreement, which was terminated pursuant to its terms. In July 2018, the Company completed a follow-on public offering, selling 4,062,500 shares of its common stock at an offering price of $8.00 per share, resulting in gross proceeds of $32.5 million. Net proceeds received after deducting underwriting discounts and commissions and offering expenses were $29.9 million. In June 2017, the Company terminated the 2016 Sales Agreement and entered into the 2017 Sales Agreement with Jefferies pursuant to which the Company may sell, from time to time, up to $50.0 million of its common stock. During 2017, the Company sold and issued 296,594 shares of common stock in the open market at a weighted average selling price of $10.74 per share, for gross proceeds of $3.2 million. Net proceeds after deducting commissions and offering expenses were $3.0 million. In the first quarter of 2017, the Company completed an additional follow-on public offering, selling 3,220,000 shares at an offering price of $18.00 per share resulting in gross proceeds of $58.0 million. Net proceeds received after deducting underwriting and commissions and offering expenses were $54.2 million.

(7) Stockholders’ Equity

Preferred Stock

The Company’s board of directors are authorized to issue up to 10.0 million shares of preferred stock, with any rights, preferences and privileges as it may designate. As of December 31, 2019, no shares of preferred stock were issued.

Common Stock

On August 30, 2019, the Company entered into the 2019 Sales Agreement with the Agents pursuant to which the Company may sell, from time to time, up to $75.0 million of its common stock. From December 12, 2019 through March 4, 2020, the Company has sold and issued 353,171 shares of its common stock under the 2019 Sales Agreement in the open market at a weighted average selling price of $5.22 per share, resulting in gross proceeds of $1.8 million. Net proceeds after deducting commissions and offering expenses were $1.6 million. As of December 31, 2019, the Company sold and issued 13,381 shares of its common stock in the open market at a weighted-average selling price of $7.00, for gross and net proceeds of $0.1 million. From January 1, 2020 through March 4, 2020, the Company sold and issued 339,790 shares of its common stock in the open market at a weighted average selling price of $5.15 per share, for gross proceeds of $1.7 million and net proceeds, after deducting commissions and offering expenses, of $1.5 million.

In the first quarter of 2019, the Company sold and issued 3,439,523 shares of common stock under the 2017 Sales Agreement with Jefferies in the open market at a weighted average selling price of $5.44 per share, resulting in gross proceeds of $18.7 million. Net proceeds received after deducting commissions and offering expenses were $18.1 million. In the second quarter of 2019, the Company sold and issued 2,082,031 shares of common stock under the 2017 Sales Agreement with Jefferies in the open market at a weighted average selling price of $13.50 per share, resulting in gross proceeds of $28.1 million. Net proceeds received after deducting commissions and offering expenses were $27.0 million. The last sale under the 2017 Sales Agreement was made on May 16, 2019. From June 2017 through May 16, 2019, the Company has cumulative gross proceeds of $50.0 million from shares sold in the open market under the 2017 Sales Agreement, which was terminated pursuant to its terms.

In July 2018, the Company completed a follow-on public offering, selling 4,062,500 shares of its common stock at an offering price of $8.00 per share, resulting in gross proceeds of $32.5 million. Net proceeds received after deducting underwriting discounts and commissions and offering expenses were $29.9 million.

In June 2017, the Company terminated the 2016 Sales Agreement and entered into the 2017 Sales Agreement with Jefferies pursuant to which the Company may sell, from time to time, up to $50.0 million of its common stock. During 2017, the Company sold and issued 296,594 shares of common stock in the open market at a weighted average selling price of $10.74 per share, for gross proceeds of $3.2 million. Net proceeds after deducting commissions and offering expenses were $3.0 million.

In the first quarter of 2017, the Company completed an additional follow-on public offering, selling 3,220,000 shares at an offering price of $18.00 per share resulting in gross proceeds of $58.0 million. Net proceeds received after deducting underwriting and commissions and offering expenses were $54.2 million.