Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Stockholders' Equity

Stockholders’ Equity

    As discussed in Note 11, on April 3, 2018, we completed the issuance and sale of 8,284,600 shares of our common stock under a Share Purchase Agreement with BMS. These shares are unregistered and subject to certain lock-up and stand-still provisions for a five-year period.

We currently have an effective shelf registration statement on Form S-3 (the 2021 Shelf Registration Statement) on file with the SEC, which expires in March 2024. The 2021 Shelf Registration Statement currently permits the offering, issuance and sale by us of up to an aggregate offering price of $300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination, all of which may be offered, issued and sold in “at-the-market” sales pursuant to an equity distribution agreement with Cowen and Company, LLC (the Equity Distribution Agreement). No securities have been sold under the 2021 Shelf Registration Statement or the Equity Distribution Agreement.

As of December 31, 2021, shares of common stock reserved for future issuance are as follows (in thousands):

Stock options, RSUs and PSUs outstanding	23,922
Shares available for future grant under the 2017 Performance Incentive Plan	1,142
Shares available for issuance under the employee stock purchase plan	1,043
Total common stock reserved for issuance	26,107