Annual report pursuant to Section 13 and 15(d)

Organization and Summary of Significant Accounting Policies (Detail)

v3.24.1
Organization and Summary of Significant Accounting Policies (Detail)
$ in Thousands
 12 Months Ended
Aug. 11, 2023
Dec. 31, 2023
USD ($)
segment
Institution
Dec. 31, 2022
USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]      
Reverse stock split ratio 0.067    
Accumulated deficit   $ (452,892) $ (444,768)
Unrestricted cash and cash equivalents   11,523 32,190
Restricted cash included in Other assets   $ 1,315 $ 2,489
Restricted Cash and Cash Equivalents, Noncurrent, Statement of Financial Position [Extensible Enumeration]   Other assets Other assets
Number Of Financial Institutions | Institution   2  
Number of Reportable Segments | segment   1  
Minimum      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Property, plant and equipment, useful Life   3 years  
Maximum      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Property, plant and equipment, useful Life   5 years  
Patents      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Amortization expense   $ 100 $ 100
Estimated amortization expense - year one   100  
Estimated amortization expense - year two   100  
Estimated amortization expense - year three   100  
Estimated amortization expense - year four   100  
Estimated amortization expense - year five   100  
Impairment of patents   $ 0 $ 400
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]   General And Administrative Expense General And Administrative Expense
Patents | Other Assets      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Finite-Lived Patents, Gross   $ 600 $ 700
Revenue | Concentration of Credit Risk and Other Risks and Uncertainties | Takeda Pharmaceuticals Inc      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Percentage of total revenues   0.00% 13.00%
Revenue | Concentration of Credit Risk and Other Risks and Uncertainties | Bristol Myers Squibb      
Organization And Summary Of Significant Accounting Policies [Line Items]      
Percentage of total revenues   92.00% 87.00%