v3.26.1
Organization and Nature of the Business (Details)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Mar. 18, 2026
USD ($)
Jan. 09, 2026
USD ($)
Jan. 07, 2026
$ / shares
shares
May 21, 2025
USD ($)
shares
Jun. 30, 2026
USD ($)
subsidiary
Mar. 31, 2026
USD ($)
Jun. 30, 2025
USD ($)
Mar. 31, 2025
USD ($)
Jun. 30, 2026
USD ($)
subsidiary
shares
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Organization and Nature of the Business                      
Number of wholly owned subsidiaries | subsidiary         2       2    
Issuance of common stock and equity awards in connection with the ACELYRIN Merger             $ 238,077        
Net proceeds                 $ 323,797    
Net Income (Loss)         $ (142,221) $ (93,053) $ 59,321 $ (98,963) (235,274) $ (39,642)  
Cash used in operating activities                 168,582 $ 186,707  
Accumulated deficit         1,137,150       1,137,150   $ 901,876
Cash, cash equivalents and marketable securities         $ 502,300       $ 502,300    
ACELYRIN                      
Organization and Nature of the Business                      
Purchase consideration       $ 238,077              
Issuance of common stock and equity awards in connection with the ACELYRIN Merger (in shares) | shares       48,653,549              
Fair value of net assets       $ 425,984              
Public Offering                      
Organization and Nature of the Business                      
Number of shares issued and sold | shares     17,650,000                
Issue price per share | $ / shares     $ 17                
Underwriters option period     30 days                
Maximum number of common stock for an option to purchase | shares     2,647,500                
Net proceeds   $ 324,400                  
ATM shares                      
Organization and Nature of the Business                      
Aggregate offering price $ 300,000                    
Percentage of commission to be paid 3.00%                    
Number of shares issued and sold | shares                 0