v3.26.3
Commitments and Contingencies (Details)
$ in Thousands
1 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Mar. 01, 2026
USD ($)
Jul. 31, 2026
USD ($)
Jun. 30, 2026
USD ($)
Feb. 28, 2026
USD ($)
candidate
Dec. 31, 2025
USD ($)
asset
Oct. 31, 2025
USD ($)
May 31, 2025
USD ($)
Mar. 31, 2024
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
May 31, 2026
USD ($)
Aug. 31, 2025
USD ($)
Jul. 31, 2025
USD ($)
May 31, 2023
amendment
Commitments and Contingencies                                      
Purchase obligation                 $ 305,900   $ 305,900 $ 305,900              
Research and development                 71,755 $ 174,004   271,625 $ 272,257            
Prepaid expenses and other current assets         $ 47,804       75,372   75,372 75,372              
Number of office lease amendment | amendment                                     4
Obtaining an operating lease right-of-use asset in exchange for an operating lease liability $ 1,400           $ 4,000         8,566 $ 3,982 $ 1,300 $ 1,600        
Operating lease right-of-use assets         4,939       12,847   12,847 12,847              
Lessee, operating lease, term of contract (in days) 24 months                                    
West Conshohocken, Pennsylvania                                      
Commitments and Contingencies                                      
Operating lease right-of-use assets                 4,000   4,000 4,000              
Operating lease, liability                 4,600   4,600 4,600              
Waltham, Massachusetts                                      
Commitments and Contingencies                                      
Operating lease right-of-use assets   $ 8,100                                  
Operating lease, liability   6,800                                  
Operating lease prepayment amount   $ 1,300                                  
Faroe License                                      
Commitments and Contingencies                                      
Upfront payment     $ 25,000                                
Arrowhead License                                      
Commitments and Contingencies                                      
Collaborative arrangement, milestone payment, eligible to receive                               $ 975,000      
Hoffmann-La Roche ("Roche") | Research, Development and Commercialization Agreement                                      
Commitments and Contingencies                                      
Milestone payment due               $ 5,000                      
Remainder of future milestone payments                                 $ 3,000    
CSPC                                      
Commitments and Contingencies                                      
Upfront payment           $ 120,000                          
Maximum of eligible milestone payments                                   $ 2,000,000  
Pfizer                                      
Commitments and Contingencies                                      
Upfront payment         50,000                            
Maximum of eligible milestone payments         $ 70,000                            
Number of additional early stage MASH assets | asset         2                            
Suzhou Ribo Life Science Co. Ltd. And Ribocure Pharmaceuticals AB                                      
Commitments and Contingencies                                      
Milestone payment due                 4,000                    
Upfront payment       $ 60,000                              
Maximum of eligible milestone payments       $ 4,400,000                              
Number of siRNA candidates | candidate       6                              
Research and development                     49,800                
Prepaid expenses and other current assets                 $ 10,200   $ 10,200 $ 10,200