Eli Lilly Reports Positive Phase 3 Results for Jaypirca in CLL/SLL Treatment

Eli Lilly reported positive topline results from the Phase 3 BRUIN CLL-313 clinical trial of Jaypirca, a non-covalent BTK inhibitor, in treatment-naïve patients with CLL/SLL without 17p deletions. The study met its primary endpoint, demonstrating a highly statistically significant improvement in progression-free survival compared to chemoimmunotherapy. The overall safety profile of Jaypirca was consistent with previously reported trials. These results build on previous positive trial outcomes and will be tested for statistical significance at the time of the primary OS analysis in 2026.

Eli Lilly and Company (LLY) reported positive topline results from the Phase 3 BRUIN CLL-313 clinical trial of Jaypirca (pirtobrutinib), a non-covalent Bruton tyrosine kinase (BTK) inhibitor, in treatment-naïve patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) without 17p deletions. The study met its primary endpoint, demonstrating a highly statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to chemoimmunotherapy, as assessed by an independent review committee (IRC). This is one of the most compelling effect sizes ever observed for a single agent BTK inhibitor in a front-line CLL study [1].

The overall safety profile of Jaypirca in the BRUIN CLL-313 trial was generally consistent with previously reported trials across treatment settings. Overall survival (OS), a key secondary endpoint, was not yet mature at this analysis but was trending strongly in favor of pirtobrutinib and will be tested for statistical significance at the time of the primary OS analysis, which is anticipated to occur in 2026 [2].

These results build on the previously reported positive outcomes from the BRUIN Phase 1/2 trial, the Phase 3 BRUIN CLL-321 trial, and the Phase 3 BRUIN CLL-314 trial, which included treatment-naïve patients. The data from these studies will form the basis for seeking label expansions in earlier lines of therapy, with global regulatory submissions beginning later this year [2].

The results from the BRUIN CLL-313 and BRUIN CLL-314 studies will be presented at upcoming medical meetings and submitted to peer-reviewed journals. Jacob Van Naarden, executive vice president and president of Lilly Oncology, commented that "The results from BRUIN CLL-313 are striking and provocative, across both PFS and OS endpoints, further demonstrating the potential of pirtobrutinib to be a meaningful treatment option for people with untreated CLL/SLL" [2].

References:
[1] https://www.nasdaq.com/articles/eli-lilly-reports-positive-topline-results-phase-3-bruin-cll-313-clinical-trial-jaypirca
[2] https://www.morningstar.com/news/pr-newswire/20250908de67317/lillys-jaypirca-pirtobrutinib-the-first-and-only-approved-non-covalent-reversible-btk-inhibitor-significantly-improved-progression-free-survival-in-patients-with-treatment-nave-cllsll