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Equity Financings and Warrants | 12 Months Ended
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Dec. 31, 2020
Equity [Abstract] |
Equity Financings and Warrants | (7) Equity Financings and Warrants Registered Direct Financing On June 3, 2020, the Company closed a registered direct offering with certain institutional and accredited investors of 348,000 shares of the Company’s common stock, at a purchase price of $9.00 per share, and pre-funded warrants to purchase 325,500 shares of common stock at a purchase price of $8.999 per warrant. All warrants were exercised by the closing date. No pre-funded warrants are outstanding as of December 31, 2020. The net proceeds were approximately $5.3 million, after deducting placement agent fees and other offering expenses. The Company paid JonesTrading Institutional Services LLC (JonesTrading) a placement agent fee equal to 8.0% of the aggregate gross proceeds and agreed to provide JonesTrading with customary indemnification and contribution rights. At the Market Equity Financing On January 11, 2017, the Company entered into a Capital on Demand TM Sales Agreement (the Sales Agreement) with JonesTrading, pursuant to which the Company may offer and sell, from time to time through JonesTrading, shares of the Company’s common stock, par value $0.001 per share (the Common Stock), having an aggregate offering price of up to $7.3 million. On August 21, 2017, January 25, 2019, March 11, 2019, May 9, 2019, May 20, 2019, June 28, 2019, July 2, 2020 and July 14, 2020, the Company amended its Capital on Demand Sales Agreement. The amendments, among other things, increased the maximum aggregate offering value of shares of the Company’s common stock which the Company may issue and sell from time to time under the Sales Agreement from $7.3 million to $32.4 million (the Shares). Under the amended Sales Agreement, JonesTrading may sell the Shares by any method permitted by law and deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including sales made directly on or through The NASDAQ Capital Market, on any other existing trading market for the Common Stock or to or through a market maker. In addition, under the amended Sales Agreement, JonesTrading may sell the Shares by any other method permitted by law, including in negotiated transactions. The Company may instruct JonesTrading not to sell Shares if the sales cannot be effected at or above the price designated by the Company from time to time. The Company is not obligated to make any sales of the Shares under the amended Sales Agreement. The offering of Shares pursuant to the amended Sales Agreement will terminate upon the earlier of (a) the sale of all of the Shares subject to the amended Sales Agreement or (b) the termination of the amended Sales Agreement by JonesTrading or the Company, as permitted therein. The Company paid JonesTrading a commission rate equal to 3.0% of the aggregate gross proceeds from each sale of Shares and agreed to provide JonesTrading with customary indemnification and contribution rights. The Company will also reimburse JonesTrading for certain specified expenses in connection with entering into and amending the Sales Agreement. Under the amended Sales Agreement, the Company sold an aggregate of 2,214,301 and 820,561 shares of Common Stock pursuant to the terms of such Sales Agreement, as amended, for net proceeds of approximately $14.4 million and $6.9 million during the years ended December 31, 2020 and 2019, respectively, including initial expenses for executing the “at the market offering” and commissions to the placement agent. On July 22, 2020, the Company entered into a new Capital on Demand TM Sales Agreement (the 2020 Sales Agreement) with JonesTrading, pursuant to which the Company may offer and sell, from time to time through JonesTrading, shares of the Company’s Common Stock, having an aggregate offering price of up to $54.0 million. As of December 31, 2020, the Company had sold an aggregate of 5,066,279 shares of its Common Stock pursuant to the terms of the 2020 Sales Agreement for net proceeds of approximately $28.9 million, after deducting expenses for executing the “at the market offering” and commissions paid to the placement agent. From January 1, 2021 through February 22, 2021, the Company sold an aggregate of 4,861,993 shares of its Common Stock pursuant to the terms of the 2020 Sales Agreement. Net proceeds received in the period were approximately $23.3 million, after deducting commissions paid to the placement agent. As of February 22, 2021, the Company had sold all shares available under its current prospectus to the Company’s registration statement on Form S-3 (No. 333‑238067). Warrants Warrants to purchase shares of common stock were granted as part of various financing and business agreements. All outstanding warrants were recorded in additional paid-in capital at their estimated fair market value at the date of grant using a Black-Scholes option-pricing model. As of December 31, 2020, these warrants, by year of expiration, are summarized below:
Year of Expiration |  | Number of Warrants |  |  | Weighted Average Exercise Price |
2022 |  |  | 133,401 |  |  | $ | 109.80 |

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