Medicine company Eli Lilly and Company (NYSE: LLY) reported on Monday that it has recorded positive topline results from the Phase 3 BRUIN CLL-313 trial of Jaypirca (pirtobrutinib) in treatment-naïve patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) without 17p deletions.

Pirtobrutinib, the first and only approved non-covalent Bruton tyrosine kinase (BTK) inhibitor, achieved a highly statistically significant and clinically meaningful improvement in progression-free survival versus chemoimmunotherapy with bendamustine plus rituximab. The company described the effect size as among the most compelling ever observed for a single-agent BTK inhibitor in a front-line CLL study.

Overall survival, a key secondary endpoint, was not yet mature but trended in favour of pirtobrutinib. Data will be tested for statistical significance at the primary analysis, expected in 2026. Safety results were consistent with previous trials.

Findings from BRUIN CLL-313, together with the head-to-head Phase 3 BRUIN CLL-314 trial against ibrutinib, will support regulatory submissions later in 2025 to expand Jaypirca's use into earlier lines of therapy. Detailed results will be presented at an upcoming medical congress and submitted for peer-reviewed publication.