Eli Lilly’s Jaypirca improves progression-free survival in lymphoma trial

Eli Lilly (LLY) announced results from the Phase 3 BRUIN CLL-313 clinical trial of Jaypirca – pirtobrutinib -, a non-covalent Bruton tyrosine kinase, or BTK, inhibitor, vs. bendamustine plus rituximab, or BR, in treatment-naive patients with chronic lymphocytic leukemia or small lymphocytic lymphoma, or CLL/SLL without 17p deletions. Pirtobrutinib met its primary endpoint demonstrating a reduction in the risk of disease progression or death by 80%. BRUIN CLL-313 is the first Phase 3 study examining the efficacy and safety of a non-covalent BTK inhibitor, pirtobrutinib, exclusively in patients with treatment-naive CLL/SLL. At a median follow-up of 28.1 months, the primary endpoint of IRC-assessed progression-free survival, or PFS, was significantly improved with pirtobrutinib compared to BR. PFS results favored pirtobrutinib across all pre-specified subgroups, and was consistently observed among investigator assessments. Overall survival, or OS, a key secondary endpoint, remains immature, but a trend favoring pirtobrutinib was observed despite over half of patients treated with BR crossing over to receive pirtobrutinib after IRC-confirmed disease progression. Final testing of OS superiority is planned at a future date. The overall safety profile of patients treated with pirtobrutinib in BRUIN CLL-313 was similar to previously reported trials. Grade greater than or equal to 3 treatment-emergent adverse events occurred in 40.0% of patients who received pirtobrutinib versus 67.4% with BR. Fewer adverse event-related dose reductions – 3.6% versus 31.1% – and TEAE-related discontinuations – 4.3% versus 15.2% – were seen with pirtobrutinib versus BR.