Phase I CaDAnCe-101 trial update: Tacabrutideg for R/R CLL/SLL

Updated results from the Part 1 dose-findings cohorts of the phase I CaDAnCe-101 trial (NCT05006716), evaluating oral tacabrutideg (BGB-16673), a Bruton’s tyrosine kinase (BTK) degrader, in adults with relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; N = 67), were presented by Stephan Stilgenbauer at the European Hematology Association (EHA) 2026 Congress, June 11–14, 2026, Stockholm, SE. The primary objectives were safety and tolerability, the maximum tolerated dose (MTD), and the recommended dose for expansion (RDFE).

Key data: Patients had a median of four prior lines of therapy. Any grade treatment-emergent adverse event (TEAE) occurred in 97.0% of patients; Grade ≥3 TEAEs occurred in 62.7%, including Grade ≥3 infections in 35.8% and Grade ≥3 neutropenia in 25.4%. Grade ≥3 treatment-related TEAEs occurred in 34.3% of patients, while treatment-related TEAEs led to discontinuation in 6.0%; no treatment-related deaths occurred. The overall response rate (ORR) was 85.1% across doses and 94.1% in patients receiving the RDFE (200 mg tacabrutideg; n = 17), with a median duration of response (DoR) of 20.7 and 20.6 months, respectively. Response rates remained high across high-risk subgroups. Baseline cytopenic patients with treatment response experienced rapid and sustained improvements in platelet count, neutrophil count, and hemoglobin level. In the overall cohort, after a median follow-up of 25.4 months, median progression-free survival (PFS) was 24.4 months, and overall survival (OS) was favorable.

Key learning: Tacabrutideg demonstrated durable antitumor activity with a manageable safety profile in heavily pretreated R/R CLL/SLL, supporting continued evaluation of tacabrutideg in ongoing phase II and phase III studies.