BTK Inhibitor Regimens: Comparing Outcomes in Real-World Patients With R/R CLL

A real-world analysis of patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) found significantly better efficacy and tolerability with ibrutinib compared with idelalisib plus rituximab. Researchers published their findings in the British Journal of Haematology.

“Idelalisib, a phosphatidylinositol 3-kinase inhibitor, and ibrutinib, a Bruton tyrosine kinase inhibitor, were the first oral targeted agents approved for R/R CLL,” wrote a research team from the Czech Republic. “However, no randomised trials of idelalisib plus rituximab versus ibrutinib have been conducted.”

To compare the treatments, researchers conducted a retrospective analysis of 244 patients treated with ibrutinib and 171 patients treated with idelalisib plus rituximab. Patients had R/R CLL with a median of 2 previous lines. 

Median progression-free survival was 40.5 months with ibrutinib compared with 22 months with idelalisib plus rituximab, according to the study. Median overall survival was 54.4 with ibrutinib compared with 37.7 months with idelalisib plus rituximab. However, only progression-free survival remained significantly different between the treatments in multivariate analysis. 

Toxicity and CLL progression were the most common reasons for discontinuation, the study found. Toxicity was 22.5% with ibrutinib and 39.8% with idelalisib plus rituximab. Progression was 11.1% with ibrutinib and 27.5% with idelalisib plus rituximab.

“The idelalisib plus rituximab regimen may still be considered a reasonable option in highly selected patients without a suitable treatment alternative,” researchers wrote.

Reference:
Špaček M, Smolej L, Šimkovič M, et al. Idelalisib plus rituximab versus ibrutinib in the treatment of relapsed/refractory chronic lymphocytic leukaemia: a real-world analysis from the Chronic Lymphocytic Leukemia Patients Registry (CLLEAR). Br J Haematol. Published online March 27, 2023. doi:10.1111/bjh.18736