As of March 31, 2021, there were 114,563,212 shares of our common stock outstanding.

In August 2019, we sold (i) 18,525,000 shares of our common stock, par value $0.001 per share, (ii) 4,840 shares of our Series B Convertible Preferred Stock, par value $0.001 per share (“Series B Preferred Stock”) and (iii) warrants to purchase up to an aggregate of 5,841,250 shares of our common stock in an underwritten public offering (the “Offering”). Each share of common stock was sold together with a warrant to purchase 0.25 shares of common stock, at a combined price of $3.00 per share of common stock and the accompanying warrant. Each share of Series B Preferred Stock was sold together with a warrant to purchase 250 shares of

common stock, at a combined price of $3,000 per share and the accompanying warrant. Proceeds from the Offering were approximately $65.6 million, net of issuance costs of $4.5 million.

Investment funds associated with Bain Capital Life Sciences Investors, LLC (“Bain Capital Life Sciences”) purchased approximately $35.0 million of common stock, Series B Preferred Stock and warrants in the Offering at the public offering price. Pursuant to the Offering, (i) Bain Capital Life Sciences Fund, L.P. purchased 6,826,266 shares of common stock, 3,756 shares of Series B Preferred Stock and warrants to purchase 2,645,566 shares of common stock for a total purchase price of approximately $31.7 million and (ii) BCIP Life Sciences Associates, LP purchased 698,734 shares of common stock, 384 shares of Series B Preferred Stock and warrants to purchase 270,684 shares of common stock for a total purchase price of approximately $3.2 million (together, “Bain Life Sciences Funds”). Bain Capital Life Sciences is the general partner of Bain Life Sciences Funds. The participation by these investors was on the same terms as the other investors in the Offering.

Following the Offering, Andrew A. F. Hack, M.D., Ph.D and Managing Director of Bain Capital Life Sciences (a related party), was appointed to our board of directors.

On March 11, 2020, we entered into a warrant exchange agreement with Bain Life Sciences Funds pursuant to which we agreed that we would, upon future notice from Bain Life Sciences Funds, exchange all or a portion of the common stock warrants held by Bain Life Sciences Funds for warrants to purchase a new Series C convertible preferred stock (“Series C Warrants”). Each share of Series C convertible preferred stock would be convertible into 1,000 shares of common stock, with a conversion price of $4.50 and would have substantially identical rights to our Series B Preferred Stock. As of March 31, 2021, Bain Life Sciences Funds have not exercised their rights to exchange common stock warrants with Series C Warrants.

In May 2020, we completed an underwritten public offering of 16,100,000 shares of our common stock, par value $0.001 per share, including 2,100,000 shares sold pursuant to the full exercise of an overallotment option previously granted to the underwriters. All of the shares were offered at a price to the public of $5.00 per share. The net proceeds to us from this offering were approximately $75.4 million, after deducting the underwriting discount and other estimated offering expenses payable by us. Bain Life Sciences Funds purchased 1,000,000 shares of common stock in the underwritten public offering. Bain Capital Life Sciences is the general partner of Bain Life Sciences Funds. The participation by Bain Life Sciences Funds was on the same terms as the other investors in the offering.

On August 6, 2020, we entered into an at-the-market Sales Agreement (the “2020 ATM Agreement”) with Cowen and Company, LLC (“Cowen”), under which we may offer and sell from time to time, at our sole discretion, shares of our common stock having an aggregate offering price of up to $150 million through Cowen as our sales agent. We agreed to pay Cowen a commission of up to 3% of the gross sales proceeds of any common stock sold through Cowen under the 2020 ATM Agreement. For the three months ended March 31, 2021, we received net cash proceeds of $28.2 million resulting from sales of 2,878,567 shares of our common stock pursuant to the 2020 ATM Agreement. As of March 31, 2021, we had $120.5 million remaining under the 2020 ATM Agreement.

As of March 31, 2021, there were 4,140 shares of Series B Preferred Stock outstanding.

Each share of Series B Preferred Stock is convertible into 1,000 shares of common stock at any time at the holder’s option. However, the holder is prohibited from converting the Series B Preferred Stock into shares of common stock if, as a result of such conversion, the holder and its affiliates would own more than 4.99% of the total number of shares of common stock then issued and outstanding, which percentage may be changed at the holders’ election to a higher or lower percentage (not to exceed 19.99%) upon 61 days’ notice to the Company. In the event of liquidation, dissolution, or winding up, the holder of Series B Preferred Stock will receive payment on shares of Series B Preferred Stock (determined on an as-converted to common stock basis) equal to the amount that would be paid on our common stock. Shares of Series B Preferred Stock generally have no voting rights, except as required by law and except that the consent of holders of a majority of the outstanding Series B Preferred Stock is required to amend the terms of the Series B Preferred Stock. Holders of Series B Preferred Stock are not entitled to receive any dividends, unless and until specifically declared by our board of directors. The Series B Preferred Stock ranks on parity with our common stock as to distributions of assets upon liquidation, dissolution or winding up. The Series B Preferred Stock may rank senior to, on parity with or junior to any class or series of capital stock created in the future depending upon the specific terms of such future stock issuance.

The fair value of the common stock into which the Series B Preferred Stock is convertible exceeded the allocated purchase price of the Series B Preferred Stock by $3.3 million on the date of issuance, for which we recorded a deemed dividend. We recognized a deemed dividend equal to the number of shares of common stock into which the Series B Preferred Stock is convertible multiplied by the difference between the value of the common stock and the Series B Preferred Stock conversion price per share on the date of issuance, which is the date the stock first became convertible. The dividend was reflected as a one-time, non-cash, deemed dividend to the holders of Series B Preferred Stock on the date of issuance.

In the first quarter of 2021, 750,308 of our common stock warrants were exercised. As of March 31, 2021, the following common stock warrants were outstanding:

Warrants Issuance Date

Shares Issuable

(in thousands)

Expiration Date

Exercise Price

per Share

Outstanding as of

March 31, 2021

(in thousands)

August 12, 2019

5,091

February 12, 2022

4.50

5,091

Warrants were exercisable upon issuance. The holder is prohibited from exercising these warrants if, as a result of such exercise, the holder and its affiliates, would own more than 4.99% of the total number of shares of common stock then issued and outstanding, which percentage may be changed at the holders’ election to a higher or lower percentage (not to exceed 19.99%) upon 61 days’ notice to the Company.

The warrants contain provisions that may obligate us to repurchase them for an amount that does not represent fair value in the event of a change of control. Due to this provision, the warrants do not meet the criteria to be considered indexed to our own stock. Accordingly, we recorded the warrants as a derivative liability at fair value of $7.4 million on the issuance date, which was estimated using the Black-Scholes model.

The warrants will be revalued at each reporting period using the Black-Scholes model and the change in the fair value of the warrants will recognized as other income (expense) in the condensed consolidated statements of operations. At March 31, 2021, the estimated fair value of warrant liability was $31.7 million. For the three months ended March 31, 2021, we recognized the increase in the estimated fair value of warrant liability of $25.6 million as expense in other income (expense) in our condensed consolidated statements of operations.