Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail)

v3.22.2.2
Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail) - shares
Sep. 30, 2022
Dec. 31, 2021
Class of Stock [Line Items]    
Common shares reserved for future issuance 42,158,758 14,367,493
Stock options    
Class of Stock [Line Items]    
Common shares reserved for future issuance 2,125,002 1,542,126
Restricted Stock Units    
Class of Stock [Line Items]    
Common shares reserved for future issuance 990,015 133,834
Warrant | March 2018 Public Offering    
Class of Stock [Line Items]    
Common shares reserved for future issuance 798,810 798,810
Warrant | December 2020 Public Offering Series 2    
Class of Stock [Line Items]    
Common shares reserved for future issuance 6,800,000 6,800,000
Warrant | Prefunded Warrants to Purchase Common Stock Associated with December 2020 Public Offering    
Class of Stock [Line Items]    
Common shares reserved for future issuance 3,200,000 3,200,000
Warrant | Warrants to Purchase Common Stock Associated With April 2022 Public Offering    
Class of Stock [Line Items]    
Common shares reserved for future issuance 15,000,000 0
Warrant | April 2022 Public Offering    
Class of Stock [Line Items]    
Common shares reserved for future issuance 11,666,667 0
Warrant | Warrant to purchase common stock associated with Danforth    
Class of Stock [Line Items]    
Common shares reserved for future issuance 50,000 50,000
Warrant | Warrants to purchase common stock associated with Loan Agreement    
Class of Stock [Line Items]    
Common shares reserved for future issuance 198,819 170,410
March 2019 Notes    
Class of Stock [Line Items]    
Common shares reserved for future issuance 1,138,200 1,138,200
2014 Employee Stock Purchase Plan    
Class of Stock [Line Items]    
Common shares reserved for future issuance 0 3,893
2014 Plan    
Class of Stock [Line Items]    
Common shares reserved for future issuance 62,995 295,220
2015 Plan    
Class of Stock [Line Items]    
Common shares reserved for future issuance 128,250 235,000