v3.26.1
Segment Reporting - Summary of Segment Loss Including Significant Segment Expenses (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Research and development compensation and benefits [1] $ 18,505 $ 14,801 $ 32,293 $ 22,450
Research and development - other 12,732 7,521 21,097 13,037
Total Research and development expense 56,365 35,839 101,432 54,613
General and administrative expense compensation and benefits [1] 13,516 16,995 21,420 20,949
General and administrative expense - other 5,351 4,291 11,090 7,641
Total general and administrative expense 18,867 21,286 32,510 28,590
Change in fair value of contingent milestone liabilities 43,529 0 43,529 0
Operating Expenses 118,761 57,125 177,471 83,203
Other income/expense [2] (2,525) 320 (5,164) (3,572)
Loss before income taxes 116,236 57,445 172,307 79,631
Danicamtiv        
Segment Reporting [Line Items]        
Program expenses 13,228 884 23,555 884
Ataciguat        
Segment Reporting [Line Items]        
Program expenses 7,975 7,889 16,617 9,834
Tonlamarsen        
Segment Reporting [Line Items]        
Program expenses $ 3,925 $ 4,744 $ 7,870 $ 8,408
[1] Includes stock-based compensation expense
[2] Other income (expense) for the three and six months ended June 30, 2026 primarily includes interest income. Other income (expense) for the six months ended June 30, 2025 primarily includes bargain purchase gain, change in fair value of Series A Preferred Stock tranche obligations and interest income.