On Monday, Eli Lilly And Co (NYSE:LLY) announced results from the Phase 3 BRUIN CLL-321 trial evaluating pirtobrutinib in adult patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) previously treated with a covalent BTK inhibitor.

The study's primary endpoint of progression-free survival (PFS) was met at primary analysis, demonstrating pirtobrutinib was superior to the investigator's choice of idelalisib plus rituximab (IdelaR) or bendamustine plus rituximab (BR).

The updated results corresponding to the final prespecified analysis demonstrate consistent improvement in PFS for patients treated with pirtobrutinib, with a reduction in risk of relapse, disease, or death by 46% compared to IdelaR or BR.

These data will be presented at the American Society of Hematology Annual Meeting and Exposition.

BRUIN CLL-321 enrolled 238 randomized patients to receive pirtobrutinib monotherapy (n=119) or the investigator's choice of IdelaR or BR (n=119).

Pirtobrutinib also demonstrated clinically meaningful improvements in other secondary endpoints such as investigator-assessed PFS (median PFS: 15.3 vs. 9.2 months), event-free survival (EFS) (median EFS: 14.1 vs. 7.6 months), and time to next treatment (TTNT) or death (median TTNT: 23.9 vs. 10.9 months).

Specifically, among patients in the control arm who were eligible for crossover, 76% (n=50/66) crossed over to receive pirtobrutinib. Multiple analyses that adjust for the crossover effect demonstrate trends favoring pirtobrutinib.

The overall safety profile for patients treated with pirtobrutinib in BRUIN CLL-321 was consistent with safety data from the Phase 1/2 BRUIN study, including adverse events of special interest.

Pirtobrutinib is approved as Jaypirca under the FDA's Accelerated Approval pathway for adult patients with CLL/SLL who have received at least two prior lines of therapy and adult patients with relapsed or refractory mantle cell lymphoma after at least two lines of systemic therapy.

Price Action: LLY stock is down by 0.14% at $802.42 at the last check Tuesday.