Key clinical point: The noncovalent Bruton’s tyrosine kinase inhibitor (BTKi) pirtobrutinib was efficacious in patients with relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who had previously received BTKi therapy.
Major finding: An overall response was achieved by 73.3% (95% CI 67.3%-78.7%) of patients previously treated with BTKi therapy and by 82.2% (95% CI 76.8%-86.7%) of patients when partial response with lymphocytosis was included. At a 19.4-month median follow-up, the median progression-free survival was 19.6 (95% CI 16.9-22.1) months. Only 2.8% of patients discontinued pirtobrutinib permanently due to treatment-related adverse events.
Study details: Findings are from the phase 1-2 BRUIN trial including 317 patients with relapsed or refractory CLL or SLL who received pirtobrutinib, of which 247 had previously received ≥1 BTK inhibitor.
Disclosures: This study was supported by Loxo Oncology, a subsidiary of Eli Lilly. Some authors, including the lead author, declared serving as consultants or speakers for or receiving advisory board honoraria, travel support, or research funding from Loxo/Lilly. Seven authors declared being employees or stockholders of Loxo/Lilly.
Source: Mato AR et al. Pirtobrutinib after a covalent BTK inhibitor in chronic lymphocytic leukemia. N Engl J Med. 2023;389:33-44 (Jul 6). Doi: 10.1056/NEJMoa2300696