Warrants (Tables)

6 Months Ended

Jun. 30, 2022

Proceeds from Issuance of Preferred Stock, Preference Stock, and Warrants [Abstract]

Summary of Outstanding Warrants

The following table shows the common stock warrants outstanding as of June 30, 2022:

Warrant Issuance Date	Shares of Common Stock Underlying Warrants		Exercise Price/Share		Expiration Date
August 2014		1,914	$	352.65	2024
March 2016		3,021		41.40	2026
March 2018		1,208		115.95	2028
June 2020		42,894	11.6565		2030
March 2022		3,244,987		2.062	2024
March 2022		3,244,987		2.062	2027