Stockholders' Deficit

12 Months Ended

Dec. 31, 2021

Stockholders Equity Note [Abstract]

Stockholders' Deficit

7. Stockholders’ Deficit

Common Stock

As of December 31, 2021, the Company was authorized to issue 120,000,000 shares of common stock, $0.001 par value per share.

Common Stock Warrants

In October 2014 and March 2016, the Company issued warrants exercisable for 62,047 and 11,159,995 shares of common stock, respectively, at an exercise price of $1.75 per share to certain placement agents and existing investors in connection with financing arrangements. In April 2020, the common stock warrants issued in October 2014 expired unexercised. The common stock warrants issued in March 2016 expired unexercised on March 15, 2021. As of December 31, 2020, 3,948,569 common stock warrants issued in March 2016 were outstanding.

Common Stock Reserved for Future Issuance

As of December 31, 2021, the Company had shares of common stock reserved for future issuance as follows: 

Options outstanding	5,373,203
Common stock available for issuance under the 2010 Plan	4,161,189
Redeemable convertible preferred stock	2,457,143
Non-redeemable convertible preferred stock	3,209,835
Total	15,201,370