v3.26.1
Segment Information - Summary of Results of Operations Provided to Company's CODM (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Revenues [Abstract]            
Total collaboration revenue $ (257)   $ 8,513   $ 991 $ 12,640
Operating expenses:            
Stock-based compensation expense         4,820 6,149
Total operating expenses 28,516   29,500   54,351 61,447
Operating loss (28,773)   (20,987)   (53,360) (48,807)
Other income (expense):            
Change in fair value of long-term investments 0   1,292   0 1,292
Net loss (27,482) $ (23,059) (19,908) $ (25,039) (50,541) (44,947)
Ionis            
Revenues [Abstract]            
Total collaboration revenue (300)   8,200   1,000 12,200
Other            
Revenues [Abstract]            
Total collaboration revenue     25     25
Operating Segments            
Revenues [Abstract]            
Total collaboration revenue (257)   8,513   991 12,640
Operating expenses:            
Employee-related expenses 7,419   10,119   15,294 21,783
Facilities and overhead costs 6,975   7,667   13,366 15,036
Professional services and consulting 2,465   2,549   5,137 5,094
Research and development supplies and services 9,389   5,944   15,734 13,385
Stock-based compensation expense 2,268   3,221   4,820 6,149
Total operating expenses 28,516   29,500   54,351 61,447
Operating loss (28,773)   (20,987)   (53,360) (48,807)
Other income (expense):            
Interest and other 1,291   2,415   2,829 5,294
Change in fair value of long-term investments     (1,292)     (1,292)
Provision for income taxes 0   (44)   (10) (142)
Net loss (27,482)   (19,908)   (50,541) (44,947)
Operating Segments | Ionis            
Revenues [Abstract]            
Total collaboration revenue $ (257)   8,202   $ 991 12,176
Operating Segments | Affini-T            
Revenues [Abstract]            
Total collaboration revenue     $ 286     $ 439