Comparable Efficacy of Idelalisib Plus Rituximab and Ibrutinib in Relapsed/refractory Chronic Lymphocytic Leukemia: A Retrospective Case Matched Study of the Polish Adult Leukemia Group (PALG)

Anticancer Res. 2018 May;38(5):3025-3030. doi: 10.21873/anticanres.12557.

Abstract

Background/aim: There is limited amount of data available on the comparative efficacy of ibrutinib and idelalisib, the B-cell receptor inhibitors (BCRi) newly approved for relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (r/r CLL/SLL) treatment. The aim of our study was to analyze and compare the outcomes of real-world r/r CLL/SLL patients treated with these two BCRi in outside clinical trials.

Patients and methods: A comparative case matched 1:2 analysis was performed on idelalisib combined with rituximab and ibrutinib efficacy in 102 patients with r/r CLL/SLL from two observational studies of the Polish Adult Leukemia Group (PALG).

Results: Both therapies produced similar overall response rates (idelalisib plus rituximab 76.4% and ibrutinib 72.1%). Median progression-free survival (PFS) and overall survival (OS) in both groups were not reached. Furthermore, no significant difference was observed between both BCRi regimens in regard to PFS (HR=0.75, 95% CI=0.30-1.86, p=0.55) and OS (HR=0.65, 95%CI=0.26-1.68, p=0.39).

Conclusion: In summary, the results of this retrospective analysis suggest that idelalisib combined with rituximab and ibrutinib therapies have comparable activity in r/r CLL/SLL in daily clinical practice.

Keywords: B-cell receptor inhibitors; Idelalisib; chronic lymphocytic leukemia; ibrutinib; rituximab.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Adenine / analogs & derivatives
  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / therapeutic use*
  • Case-Control Studies
  • Disease-Free Survival
  • Female
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell / drug therapy*
  • Leukemia, Lymphocytic, Chronic, B-Cell / mortality
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / drug therapy*
  • Piperidines
  • Polen
  • Purines / therapeutic use
  • Pyrazoles / therapeutic use*
  • Pyrimidines / therapeutic use*
  • Quinazolinones / therapeutic use
  • Retrospective Studies
  • Rituximab / therapeutic use

Substances

  • Antineoplastic Agents
  • Piperidines
  • Purines
  • Pyrazoles
  • Pyrimidines
  • Quinazolinones
  • ibrutinib
  • Rituximab
  • Adenine
  • idelalisib