v3.26.1
Segment Reporting - Summary of Segment Loss and Significant Expenses (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
Operating expenses:            
Total R&D $ 25,644   $ 39,272   $ 59,599 $ 80,737
Total G&A 9,293   6,626   28,149 16,441
Total operating expenses 34,937   45,898   87,748 97,178
(Loss) income from operations (34,937)   (45,898)   (87,748) (97,178)
Interest income 1,564   3,466   3,892 7,557
Other expense, net (1)   (13)   (2) (20)
Total other income (expense), net 1,563   3,453   3,890 7,537
Net loss (33,374) $ (50,484) (42,445) $ (47,196) (83,858) (89,641)
Operating Segments [Member]            
Operating expenses:            
External R&D [1] 15,197   26,143   33,839 53,921
Total R&D 25,644   39,272   59,599 80,737
Total G&A 9,293   6,626   28,149 16,441
Total operating expenses 34,937   45,898   87,748 97,178
(Loss) income from operations (34,937)   (45,898)   (87,748) (97,178)
Interest income 1,564   3,466   3,892 7,557
Other expense, net (1)   (13)   (2) (20)
Total other income (expense), net 1,563   3,453   3,890 7,537
Net loss (33,374)   (42,445)   (83,858) (89,641)
Total Internal R&D | Operating Segments [Member]            
Operating expenses:            
Total Internal R&D [2] 10,447   13,129   25,760 26,816
External G&A | Operating Segments [Member]            
Operating expenses:            
Total G&A [3] (459)   1,453   8,262 5,301
Internal G&A | Operating Segments [Member]            
Operating expenses:            
Total G&A [2] 9,752   5,173   19,887 11,140
Rosnilimab | Operating Segments [Member]            
Operating expenses:            
External R&D 1,217   15,613   5,811 30,639
ANB033 | Operating Segments [Member]            
Operating expenses:            
External R&D 8,837   3,926   18,136 7,729
ANB101 | Operating Segments [Member]            
Operating expenses:            
External R&D 687   2,040   2,171 3,521
ANB032 | Operating Segments [Member]            
Operating expenses:            
External R&D 5   108   (26) 3,644
Preclinical and other unallocated costs | Operating Segments [Member]            
Operating expenses:            
External R&D $ 4,451   $ 4,456   $ 7,747 $ 8,388
[1] External R&D consists of costs associated with our research and development activities, including drug discovery efforts, preclinical and clinical development of our programs, manufacturing, and allocated facility-related costs.
[2] Internal R&D and G&A consist of salaries and wages, stock-based compensation, recruiting and other employee benefits.
[3] External G&A consists of general and administrative expenses including legal services, insurance, professional fees for auditing, tax, and market research, and allocated facility-related costs not otherwise included in research and development expenses.