Stockholders' Equity (Deficit) | Stockholders' Equity (Deficit) Warrants In April and June 2020, pursuant to the Baker Bros. Purchase Agreement as discussed in Note 5- Convertible Notes As of June 30, 2021, warrants to purchase up to 67,877,107 shares of the Company’s common stock remain outstanding at a weighted average exercise price of $1.54 per share. These warrants are summarized below: Type of Warrants Underlying Common Stock to be Purchased Exercise Price Issue Date Exercise Period Common Warrants 878 $ 51.24 March 30, 2012 March 30, 2012 to March 30, 2022 Common Warrants 1,171 $ 51.24 August 17, 2012 August 17, 2012 to July 17, 2022 Common Warrants 7,806 $ 3.69 June 11, 2014 June 11, 2014 to June 11, 2024 Common Warrants 848,674 $ 7.50 May 24, 2018 May 24, 2018 to May 24 2025 Common Warrants 182 $ 7.50 June 26, 2018 June 26, 2018 to June 26, 2025 Common Warrants 1,666,667 $ 6.38 April 11, 2019 October 11, 2019 to April 11, 2026 Common Warrants 2,777,779 $ 6.38 June 10, 2019 December 10, 2019 to June 10, 2026 Common Warrants 3,073,770 $ 2.44 April 24, 2020 April 24, 2020 to April 24, 2025 Common Warrants 2,049,180 $ 2.44 June 9, 2020 June 9, 2020 to June 9, 2025 Common Warrants 57,451,000 $ 1.00 May 20, 2021 May 20, 2021 to May 22, 2023 Total 67,877,107 Common Stock Effective January 17, 2018, the Company amended and restated its certificate of incorporation, under which the Company is currently authorized to issue up to 300,000,000 shares of common stock, $0.0001 par value per share, and 5,000,000 shares of preferred stock, $0.0001 par value per share. Public Offerings On June 5, 2020, the Company completed an underwritten public offering (the 2020 Public Offering), whereby the Company issued 28,500,000 shares of common stock at a price to the public of $3.50 per share (the 2020 Public Offering Price). The Company received proceeds from the 2020 Public Offering of $93.2 million, net of underwriting discounts. In addition, the Company granted the underwriters a 30-day option to purchase up to an additional 4,275,000 shares of its common stock at the 2020 Public Offering Price, less applicable underwriting discounts. On June 10, 2020, the Company issued an additional 3,200,000 shares of common stock upon exercise of the underwriters’ option and received $10.5 million in proceeds from this exercise, net of underwriting discounts. The common stock issued in the 2020 Public Offering were registered pursuant to a shelf registration statement on Form S-3 filed with the SEC on November 18, 2019 and declared effective on December 2, 2019. On March 29, 2021, the Company completed an underwritten public offering (the March 2021 Public Offering), whereby the Company issued 17,142,857 shares of common stock at a price to the public of $1.75 per share (the March 2021 Public Offering Price). The Company received proceeds from the March 2021 Public Offering of approximately $28.0 million, net of underwriting discounts. In addition, the Company granted the underwriters a 30-day overallotment option to purchase up to an additional 2,571,428 shares of its common stock at the March 2021 Public Offering Price, less applicable underwriting discounts. On April 6, 2021, the underwriters exercised their overallotment option in full and the Company received proceeds of approximately $4.2 million, net of underwriting discounts. The common stock issued in the March 2021 Public Offering were registered pursuant to a shelf registration statement on Form S-3 filed with the SEC on March 4, 2021 and declared effective on March 11, 2021. On May 20, 2021, the Company completed an underwritten public offering (the May 2021 Public Offering), whereby the Company issued 50,000,000 shares of common stock at a price to the public of $1.00 per share and accompanying common warrants to purchase 50,000,000 shares of common stock. The common warrants have an exercise price of $1.00 per share and can be exercised any time through May 22, 2023. The Company received proceeds from the May 2021 Public Offering of approximately $46.8 million, net of underwriting discounts and fees. In addition, the Company granted the underwriters a 30-day overallotment option to purchase up to an additional 7,500,000 shares of its common stock at $0.99 per share, less applicable underwriting discounts, and/or common warrants to purchase 7,500,000 shares of common stock, at $0.01 per warrant, less applicable underwriting discounts. On May 20, 2021, the underwriters exercised their overallotment option to purchase warrants in full and the Company received proceeds of approximately $0.1 million, net of underwriting discounts. On May 21, 2021, the underwriters exercised their overallotment option to purchase common stock and the Company issued an additional 2,547,794 shares of common stock and received proceeds of approximately $2.4 million, net of underwriting discounts. The common stock issued in the May 2021 Public Offering were registered pursuant to a shelf registration statement on Form S-3 filed with the SEC on March 4, 2021 and declared effective on March 11, 2021. ATM Program In November 2019, the Company entered into an Equity Distribution Agreement (the Equity Distribution Agreement) with Piper Sandler & Co. (Piper Sandler), which provided the Company the ability to offer and sell, from time to time, shares of its common stock in ATM offerings (as defined in Rule 415 of the Securities Act of 1933, as amended) having an aggregate offering price up to $50 million through Piper Sandler acting as sales agent. On June 2, 2020, in connection with the aforementioned 2020 Public Offering, the Equity Distribution Agreement was terminated. During the six months ended June 30, 2021, the Company received no proceeds from the ATM program. During the six months ended June 30, 2020, the Company received proceeds of approximately $3.8 million in cash and cash equivalents (including $0.3 million that was included in other receivables in the condensed consolidated balance sheet at December 31, 2019), net of commissions, from the sale of 676,656 shares of its common stock. Common Stock Reserved for Future Issuance Common stock reserved for future issuance is as follows in common equivalent shares as of June 30, 2021: Common stock issuable upon the exercise of stock options outstanding 11,086,333 Common stock issuable upon the exercise of common stock warrants 67,877,107 Common stock available for future issuance under the 2019 ESPP 2,120,046 Common stock available for future issuance under the Amended and Restated 2014 Plan 1,386,769 Common stock available for future issuance under the Amended Inducement Plan 679,508 Total common stock reserved for future issuance 83,149,763 |