STOCKHOLDERS' EQUITY

3 Months Ended

Mar. 31, 2022

Equity [Abstract]

Stockholders' Equity

STOCKHOLDERS’ EQUITY

2017 Warrants — During the three months March 31, 2022 and 2021, warrant holders did not elect to exercise any warrants to purchase shares of common stock.. As of March 31, 2022 and December 31, 2021, the remaining warrant holders are entitled to purchase 1.4 million shares of common stock, respectively.

2015 Warrants — Warrant holders exercised an immaterial number of warrants to purchase shares of common stock during the three months March 31, 2022. Warrant holders did not elect to exercise any warrants to purchase shares of common stock during the three months ended March 31, 2021. As of March 31, 2022 and December 31, 2021, warrant holders are entitled to purchase 0.9 million shares of common stock, respectively.