XML 88 R68.htm IDEA: XBRL DOCUMENT v3.20.1
Common Stock - Additional Information (Detail) - USD ($)
 1 Months Ended 2 Months Ended 12 Months Ended
Nov. 03, 2017
Aug. 31, 2019
Mar. 11, 2020
Dec. 31, 2019
Dec. 31, 2017
Aug. 12, 2019
Dec. 31, 2018
Class Of Stock [Line Items]              
Common stock, shares outstanding       83,871,119     62,862,000
Issuance of common stock and preferred stock (in shares)   18,525,000          
Common stock, par value   $ 0.001   $ 0.001     $ 0.001
Preferred stock, par value       $ 0.001     $ 0.001
Net cash proceeds received       $ 65,948,000 $ 185,936,000    
Preferred stock deemed dividend       3,267,000      
Increase in estimated fair value as loss on warrant liability       7,500,000      
Common Stock              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)         22,588,000    
Warrants              
Class Of Stock [Line Items]              
Fair value of derivative liability       14,900,000   $ 7,400,000  
Warrants | Other Income, Net              
Class Of Stock [Line Items]              
Increase in estimated fair value as loss on warrant liability       $ 7,500,000      
Bain Life Sciences              
Class Of Stock [Line Items]              
Net cash proceeds received from issuance or sale of equity   $ 35,000,000.0          
Bain Capital Life Sciences Fund, L.P              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)   6,826,266          
Number of common stock allowed to purchase   2,645,566          
Net cash proceeds received from issuance or sale of equity   $ 31,700,000          
BCIP Life Sciences Associates, L.P              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)   698,734          
Number of common stock allowed to purchase   270,684          
Net cash proceeds received from issuance or sale of equity   $ 3,200,000          
Offering              
Class Of Stock [Line Items]              
Number of common stock allowed to purchase   0.25          
Combined price of common stock and warrant   $ 3.00          
Net cash proceeds received from issuance or sale of equity   $ 65,600,000          
Payment of issuance costs   $ 4,500,000          
Offering | Common Stock              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)       19,912,000      
2017 ATM Agreement              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)       1,386,906      
Net cash proceeds received       $ 13,900,000      
Remaining proceeds from common stock, under sales agreement       $ 118,600,000      
2017 ATM Agreement | Subsequent Event              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)     2,180,266        
Net cash proceeds received     $ 11,700,000        
Series B Convertible Preferred Stock              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)   4,840          
Preferred stock, par value   $ 0.001          
Preferred stock, shares outstanding       4,840     0
Preferred stock deemed dividend       $ 3,300,000      
Series B Convertible Preferred Stock | Common Stock              
Class Of Stock [Line Items]              
Number of common stock allowed to purchase       1,000      
Series B Convertible Preferred Stock | Bain Capital Life Sciences Fund, L.P              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)   3,756          
Series B Convertible Preferred Stock | BCIP Life Sciences Associates, L.P              
Class Of Stock [Line Items]              
Issuance of common stock and preferred stock (in shares)   384          
Series B Convertible Preferred Stock | Offering              
Class Of Stock [Line Items]              
Number of common stock allowed to purchase   250          
Combined price of preferred stock and warrant   $ 3,000          
Maximum | Warrants              
Class Of Stock [Line Items]              
Percentage of common stock held not to exceed for warrant exercises       19.99%      
Maximum | Offering              
Class Of Stock [Line Items]              
Warrant issued   5,841,250          
Maximum | 2017 ATM Agreement              
Class Of Stock [Line Items]              
Common stock sales agreement aggregate sales proceeds $ 150,000,000            
Commission on gross sales proceeds of common stock 3.00%            
Maximum | Series B Convertible Preferred Stock              
Class Of Stock [Line Items]              
Percentage of common stock held not to exceed for warrant exercises       19.99%      
Minimum | Warrants              
Class Of Stock [Line Items]              
Percentage of common stock to be held for exercise of warrants       4.99%      
Minimum | Series B Convertible Preferred Stock              
Class Of Stock [Line Items]              
Percentage of common stock to be held for conversion       4.99%