Efficacy of Pirtobrutinib Monotherapy in Treatment-Naïve Chronic Lymphocytic Leukemia: A Bayesian Network Meta-Analysis of Randomized Controlled Trials

TL;DR

Pirtobrutinib, a new type of drug for chronic lymphocytic leukemia, shows better survival outcomes than some existing treatments in early studies.

Contribution

This study uses Bayesian network meta-analysis to compare pirtobrutinib with other first-line therapies for CLL, highlighting its potential as a superior treatment.

Findings

Pirtobrutinib has better progression-free survival outcomes than ibrutinib.

Pirtobrutinib's progression-free survival is comparable to second-generation covalent BTK inhibitors.

Wide credible intervals suggest uncertainty in interpreting treatment effects.

Abstract

There are multiple treatments available for chronic lymphocytic leukemia (CLL). This network meta-analysis compared NCCN-recommended therapies in the first-line setting for patients with CLL, with a focus on Bruton tyrosine kinase inhibitor (BTKi) therapy. The results show that pirtobrutinib, a non-covalent BTK inhibitor, has a high probability of being the optimally ranked BTKi therapy in the first-line setting. The findings demonstrate that pirtobrutinib has better progression-free survival (PFS) outcomes than ibrutinib. While PFS outcomes suggest that pirtobrutinib is comparable to second-generation covalent BTKi monotherapies, uncertainty exists in the interpretation of the treatment effect, as evidenced by wide credible intervals. These findings suggest the value of pirtobrutinib as a future treatment option for patients in the first-line setting.

Background: There are multiple effective treatment options for patients diagnosed with chronic lymphocytic leukemia and small lymphocytic lymphoma (hereafter, simply CLL). In 2025, two phase 3 randomized clinical trials of pirtobrutinib, a non-covalent BTK inhibitor, were reported, demonstrating improved outcomes versus comparator therapies in the treatment-naïve setting (NCT05254743 and NCT05023980). Methods: A systematic literature review was conducted to identify RCTs in the first-line setting for CLL. A Bayesian NMA was performed to compare overall response rate (ORR) and progression-free survival (PFS) of pirtobrutinib versus treatments recommended by the National Comprehensive Cancer Network in the first-line setting, with a focus on BTKi monotherapy. Results: Eight unique trials were identified for comparison versus pirtobrutinib. Eligible RCTs formed two disconnected networks (pirtobrutinib, ibrutinib and zanubrutinib were in Network 1; acalabrutinib was in Network 2). Results from Network 1 for ORR showed an odds ratio (OR) = 0.56 (95% credible interval [CrI], 0.28, 1.12) for ibrutinib versus pirtobrutinib and OR = 0.50 (95% CrI, 0.20, 1.27) for zanubrutinib versus pirtobrutinib. The PFS of ibrutinib was inferior to pirtobrutinib (hazard ratio (HR) = 1.89, 95% CrI, 1.13, 3.19); the PFS HR comparing zanubrutinib with pirtobrutinib was 1.51 (95% CrI, 0.84, 2.72). Conclusions: This NMA shows that pirtobrutinib has better PFS outcomes than ibrutinib. While PFS outcomes suggest that pirtobrutinib is comparable to second-generation covalent BTKi monotherapies, uncertainty exists in the interpretation of the treatment effect, as evidenced by wide credible intervals. These findings suggest the value of pirtobrutinib as a future treatment option for patients in the first-line setting.

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