Budoprutug Delivers >90% B-Cell Depletion and 111,000/µL Platelet Rise in ITP
CLYM•Climb Bio’s Phase 1b data in primary immune thrombocytopenia show budoprutug achieved over 90% B-cell depletion by Week 4 and a 111,000/µL platelet increase at Week 24 in the 250 mg cohort, with durable responses in four of six pretreated patients. Safety was acceptable, and 1000 mg enrollment remains ongoing.
1. Study Design and Enrollment
The Phase 1b portion of the budoprutug trial in adults with primary immune thrombocytopenia enrolled 15 heavily pretreated patients across 250 mg (n=6) and 500 mg (n=9) cohorts, with two IV doses 14 days apart. Median follow-up was 38 weeks for 250 mg and 12 weeks for 500 mg cohorts.
2. Safety Profile
Budoprutug at both 250 mg and 500 mg doses was generally well tolerated, with all adverse events limited to Grade 1–2 and no serious events, infusion reactions or treatment discontinuations reported.
3. Efficacy Results
In the 250 mg cohort, B-cell counts were depleted by over 90% by Week 4 and mean platelet counts rose by 111,000/µL at Week 24, with durable platelet responses in four of six patients. Three of four patients previously treated with rituximab achieved responses, including two complete responses over 24 weeks.
4. Next Steps
Enrollment continues in the 1000 mg cohort, with additional safety and efficacy data expected by year-end 2026 to inform dose selection and potential Phase 2a expansion.
