Eli Lilly and Company has announced positive topline results from its phase 3 BRUIN CLL-314 trial of Jaypirca (pirtobrutinib) in patients with chronic lymphocytic leukaemia or small lymphocytic lymphoma.
The study compared pirtobrutinib, a non-covalent BTK inhibitor, with Imbruvica (ibrutinib), a covalent BTK inhibitor, in treatment-naïve and previously treated BTK inhibitor-naïve patients.
Pirtobrutinib met the primary endpoint of overall response rate non-inferiority, as assessed by an independent review committee. The response rate favoured pirtobrutinib, with a nominal P-value for superiority below 0.05.
Progression-free survival data were immature at the time of analysis but showed a trend in favour of pirtobrutinib. No detriment was observed for overall survival.
BRUIN CLL-314 is the first head-to-head phase 3 trial in CLL to include treatment-naïve patients. This subgroup showed a particularly pronounced progression-free survival effect size.
The safety profile of pirtobrutinib was consistent with previous studies. Full results will be presented at a medical congress later in 2025.
Jacob Van Naarden, executive vice president and president of Lilly Oncology said: “These data mark the second positive phase 3 study in the programme, as we continue to build evidence supporting the potential role of pirtobrutinib in treating people with CLL/SLL.”
The results build on earlier data from the BRUIN phase 1/2 and phase 3 CLL-321 trials. A further phase 3 study, BRUIN CLL-313, is expected to report later in 2025 and, together with CLL-314, will support global regulatory submissions.
