Budoprutug (TNT119)

June 11, 2026: Climb Bio, Inc. (NASDAQ: CLYM) reported initial data from the ongoing Phase 1b portion of its Phase 1b/2a trial (NCT07043946) of budoprutug (anti-CD19 monoclonal antibody) in adults with primary immune thrombocytopenia (ITP), presented at the European Hematology Association (EHA) Congress 2026 (June 11–14, 2026).

As of June 1, 2026, 15 heavily pretreated patients (median 6–7.5 prior lines; disease duration 0.5–40 years) were enrolled across the 250 mg (n=6) and 500 mg (n=9) cohorts; median follow-up was 38 weeks (250 mg) and 12 weeks (500 mg). Budoprutug was generally well tolerated at 250 mg and 500 mg, with no serious adverse events, no discontinuations due to adverse events, and no infusion-related reactions; all adverse events were Grade 1–2.

In the 250 mg cohort, B-cell levels were depleted by an average of >90% by Week 4, and mean platelet count increased by 111,000/µL at Week 24. Durable platelet responses occurred in 4/6 patients; 2/6 maintained platelets >100×10^3/µL for >24 weeks. Among 4 prior rituximab-treated patients, 3 responded (2 durable complete responses). Enrollment is ongoing in the 1000 mg cohort, with additional data anticipated by year-end 2026.