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Jennifer R. Brown, MD, PhD


RESONATE-2: Long-Term Follow-up on Use of Ibrutinib in CLL

By: Jenna Carter, PhD
Posted: Thursday, August 4, 2022

An article published in Blood Advances reported findings from a phase III study investigating the long-term effects of ibrutinib treatment in patients with chronic lymphocytic leukemia (CLL). Paul M. Barr, MD, of the University of Rochester Medical Center, New York, and colleagues conducted the RESONATE-2 open-label study to compare the efficacy and safety of ibrutinib versus chlorambucil in first-line CLL in patients 65 years and older. After 8 years of follow-up, there was a significant progression-free survival benefit with ibrutinib. They also found that ibrutinib treatment led to an 85% reduction in the risk of progressive disease or death compared with the standard chlorambucil chemotherapy.

“We report long-term follow-up from the RESONATE-2 phase III study of the once-daily Bruton’s tyrosine kinase inhibitor ibrutinib…, reporting extended follow-up data on patient outcomes, and safety is essential to inform clinical decision-making,” stated Dr. Barr and colleagues.

A total of 269 patients were randomly assigned to receive ibrutinib (n = 136) or chlorambucil (n = 133). Study endpoints included progression-free survival, overall response rate, improvement in hematologic parameters, and safety. Progression-free survival was analyzed according to the Kaplan-Meier method, and hazard ratios were estimated using a stratified Cox regression model, with treatment as the sole covariate.

After 8 years of follow-up, median progression-free survival was not yet reached for the ibrutinib group (95% confidence interval [CI] = 82.1 months to not estimable) compared with the chlorambucil group, which was 15 months (95% CI = 10.2–19.4 months). Additionally, the 7-year median survival rate for ibrutinib was 78% (hazard ratio [HR] = 0.453; 95% CI = 0.276–0.743). Moreover, there was an 85% reduction in the risk of progressive disease or death following treatment with ibrutinib versus chlorambucil (HR = 0.154; 95% CI = 0.108–0.220).

Disclosure: For full disclosures of the study authors, visit

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