v3.25.1
Nature of the Business - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 12 Months Ended
Oct. 31, 2024
Aug. 31, 2023
Dec. 31, 2020
Mar. 31, 2025
Jan. 10, 2025
Dec. 31, 2024
Nature Of Business [Line Items]            
Percentage of workforce eliminated   40.00%        
Accumulated deficit       $ 3,032,539   $ 2,970,325
Net income from up-front     $ 606,100      
Biogen Inc [Member]            
Nature Of Business [Line Items]            
Acquisition outstanding share per share Price         $ 7.22  
Research and Development Workforce [Member]            
Nature Of Business [Line Items]            
Percentage of workforce eliminated 55.00%          
Total Workforce [Member]            
Nature Of Business [Line Items]            
Percentage of workforce eliminated 33.00%          
Redeemable Convertible Preferred Stock [Member] | Convertible Notes [Member] | Initial Public Offering [Member]            
Nature Of Business [Line Items]            
Accumulated deficit       $ 3,000,000