Ibrutinib Versus Idelalisib Plus Rituximab in Resistant CLL
Posted: Thursday, February 25, 2021
According to research presented in the European Journal of Haematology, patients with chronic lymphocytic leukemia (CLL) who receive ibrutinib treatment may experience superior outcomes versus those who receive the combination therapy of idelalisib plus rituximab. Massimo Gentile, MD, of Azienda Ospedaliera di Cosenza, Italy, and colleagues sought to determine the most appropriate B-cell receptor pathway inhibitor treatment for patients with relapsed or refractory disease.
The study evaluated the records of 675 patients found in Campus CLL, a multicenter Italian working group database. Patients were categorized by treatment type, with 563 receiving ibrutinib and 112 receiving idelalisib plus rituximab.
Following an unadjusted univariate analysis, the ibrutinib group was associated with a significantly superior overall survival (hazard ratio [HR] = 0.5, 95% confidence interval [CI] = 0.36–0.71). A Cox univariate analysis followed this finding to avoid inadvertent confounding by indication. The relationship between treatment type and mortality rates, updated for all variables, was found to have been meaningfully associated with overall survival. On a third analysis, using the multivariate Cox regression model in which all identified variables were introduced, ibrutinib's efficacy was confirmed (HR = 0.67, 95% CI = 0.45–0.98, P = .04).
Cases considered to be high risk due to factors such as advanced age or previous treatment were more common in the idelalisib-plus-rituximab group. In the ibrutinib group, 119 patients (21.1%) discontinued treatment due to toxicity, 67 (11.9%) discontinued treatment due to disease progression, and 26 (4.6%) discontinued treatment due to Richter transformation versus 50 (44.6%), 16 (14.3%), and 2 (1.8%), respectively, in the combination-therapy group.
The authors acknowledged study limitations, such as the lack of randomization, the retrospective design, and the lack of access to additional possible confounders.
Disclosure: The study authors reported no conflicts of interest.