Treatment with ibrutinib is associated with a high overall response rate in patients with relapsed or refractory chronic lymphocytic leukemia (CLL) and 17p deletion, according to a study published in the journal The Lancet Oncology.1
Patients with 17p deletion CLL have particularly poorer responses and survival after chemoimmunotherapy. Therefore, researchers sought to evaluate the activity and safety of the oral Bruton’s tyrosine kinase inhibitor, ibrutinib, in patients with relapsed or refractory CLL or small lymphocytic lymphoma (SLL) and 17p deletion.
For the international, open-label, phase 2 study (A Multicenter Phase 2 Study of PCI-32765 (Ibrutinib) in Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL) or Small Lymphocytic Lymphoma (SLL) With 17p Deletion; ClinicalTrials.gov Identifier: NCT01744691), investigators enrolled 145 patients, of which 144 received at least 1 dose of ibrutinib.
After a median follow-up of 11.5 months, results showed that 64% (95% CI, 56-71) achieved an overall response according to investigator assessment. The investigator-assessed overall response rate was 83% (95% CI, 76-89).
The 24-month progression-free survival and overall survival rates were 63% (95% CI, 54-70) and 75% (95% CI, 67-81), respectively. In addition, 79% of patients with any baseline cytopenia achieved sustained hematologic improvement.
In terms of safety, 8% of patients reported grade 3 to 4 major bleeding and 30% experienced grade 3 or worse infections, including pneumonia in 13%; however, 18 patients died as a result of adverse events.
Ibrutinib is already approved for the treatment of patients with 17p deletion CLL due to positive findings from a phase 3 trial that compared ibrutinib with ofatumumab in previously treated patients with CLL or SLL.
1. O’Brien S, Jones JA, Coutre SE, et al. Ibrutinib for patients with relapsed or refractory chronic lymphocytic leukaemia with 17p deletion (RESONATE-17): a phase 2, open-label, multicentre study. Lancet Oncol. 2016 Sep 13. doi: 10.1016/S1470-2045(16)30212-1. [Epub ahead of print]