Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Common Stock Shares Activity (Detail)

v3.22.2.2
Stockholders' Equity - Summary of Common Stock Shares Activity (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Common Stock Outstanding Roll Forward [Roll Forward]        
Beginning balance $ 45,480,000 $ 32,320,000 $ 41,258,000 $ 22,758,000
Beginning balance (in shares)     28,705,334  
Net loss (29,584,000) (605,000) $ (48,380,000) (3,623,000)
Stock-based compensation expense 1,210,000 588,000 323,200 1,528,000
Common stock issued through employee stock purchase plan 8,000 13,000 18,000 22,000
Common stock issued, net of expenses 95,000 5,301,000 21,010,000 8,713,000
Common stock issued for vested restricted stock units 0 (3,000) 0 (3,000)
Vested Loan Agreement warrants     71,000 766,000
Ending balance $ 17,209,000 37,614,000 $ 17,209,000 37,614,000
Ending balance (in shares) 32,656,242   32,656,242  
April 2020 Notes        
Common Stock Outstanding Roll Forward [Roll Forward]        
Common stock issued for conversion of Notes       7,453,000
Common Stock        
Common Stock Outstanding Roll Forward [Roll Forward]        
Beginning balance $ 36,000 $ 26,000 $ 32,000 $ 20,000
Beginning balance (in shares) 32,596,403 23,147,552 28,705,334 19,663,698
Net loss $ 0 $ 0 $ 0 $ 0
Stock-based compensation expense   0   0
Common stock issued through employee stock purchase plan   $ 0   $ 0
Common stock issued through employee stock purchase (in shares) 3,714 2,759 6,834 4,943
Common stock issued, net of expenses $ 0 $ 1,000 $ 4,000 $ 6,000
Common stock issued, net of expenses (in shares) 50,000 733,937 3,895,943 3,250,739
Common stock issued for vested restricted stock units $ 0 $ 0 $ 0 $ 0
Common stock issued for vested restricted stock units (in shares) 6,125 1,322 48,131 7,110
Vested Loan Agreement warrants     $ 0 $ 0
Ending balance $ 36,000 $ 27,000 $ 36,000 $ 27,000
Ending balance (in shares) 32,656,242 23,885,570 32,656,242 23,885,570
Common Stock | April 2020 Notes        
Common Stock Outstanding Roll Forward [Roll Forward]        
Common stock issued for conversion of Notes       $ 1,000
Common stock issued for conversion of Notes (in shares)       959,080
Additional Paid-in Capital        
Common Stock Outstanding Roll Forward [Roll Forward]        
Beginning balance $ 423,719,000 $ 361,925,000 $ 400,705,000 $ 349,351,000
Net loss 0 0 0 0
Stock-based compensation expense 1,210,000 588,000 3,232,000 1,528,000
Common stock issued through employee stock purchase plan 8,000 13,000 18,000 22,000
Common stock issued, net of expenses 95,000 5,300,000 21,006,000 8,707,000
Common stock issued for vested restricted stock units 0 (3,000) 0 (3,000)
Vested Loan Agreement warrants     71,000 766,000
Ending balance 425,032,000 367,823,000 425,032,000 367,823,000
Additional Paid-in Capital | April 2020 Notes        
Common Stock Outstanding Roll Forward [Roll Forward]        
Common stock issued for conversion of Notes       7,452,000
Accumulated Deficit        
Common Stock Outstanding Roll Forward [Roll Forward]        
Beginning balance (378,275,000) (329,631,000) (359,479,000) (326,613,000)
Net loss (29,584,000) (605,000) (48,380,000) (3,623,000)
Stock-based compensation expense   0   0
Common stock issued through employee stock purchase plan   0   0
Common stock issued, net of expenses 0 0 0 0
Common stock issued for vested restricted stock units 0 0 0 0
Vested Loan Agreement warrants     0 0
Ending balance $ (407,859,000) $ (330,236,000) $ (407,859,000) (330,236,000)
Accumulated Deficit | April 2020 Notes        
Common Stock Outstanding Roll Forward [Roll Forward]        
Common stock issued for conversion of Notes       $ 0