THURSDAY, July 2, 2026 (HealthDay News) -- For patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), adding pirtobrutinib to venetoclax-rituximab (PVR) yields improved progression-free survival (PFS) compared to venetoclax-rituximab (VR), according to a study presented at the annual congress of the European Hematology Association, held from June 11 to 14 in Stockholm.
Matthew S. Davids, M.D., from Dana-Farber Cancer Institute in Boston, and colleagues compared the efficacy and safety of fixed-duration PVR versus VR in patients with R/R CLL. Patients were randomly assigned to receive PVR or VR (321 and 318, respectively), stratified by del(17p) status and previous exposure to covalent Bruton tyrosine kinase inhibitors (cBTKi). Both arms received 25 cycles of venetoclax and six cycles of rituximab; the PVR arm also received 28 cycles of pirtobrutinib, with a three-cycle lead-in of pirtobrutinib-rituximab before initiation of venetoclax.
The researchers found that for the primary end point of independent review committee-PFS, PVR demonstrated superiority versus VR in the intention-to-treat analysis population (hazard ratio, 0.547) at a median follow-up of 27.3 months. Twenty-four month PFS was 86.9 and 71.8 percent with PVR and VR, respectively. Across prespecified subgroups, including patients with prior cBTKi exposure, those who discontinued cBTKi due to progressive disease, and patients with del(17p)/TP53 mutation, the PFS benefit with PVR was consistent. Overall survival data were immature. The rates of any grade adverse events and grade 3 or higher adverse events were similar between the arms.
"Patients are getting this added progression-free survival benefit without much added toxicity, suggesting that this triplet therapy can benefit a wide range of patients, including older patients with other medical co-morbidities," Davids said in a statement.
Several authors disclosed ties to Eli Lilly, which manufactures pirtobrutinib and funded the study.
