Long-Term Study Confirms Benefit of Idelalisib in Relapsed CLL
Posted: Monday, August 12, 2019
The addition of idelalisib to rituximab increases both progression-free and overall survival in patients with relapsed chronic lymphocytic leukemia (CLL), the final results of a phase III study indicate. Jeff P. Sharman, MD, of Willamette Valley Cancer Institute and Research Center in Eugene, Oregon, and colleagues reported their long-term findings in the Journal of Clinical Oncology.
The randomized primary study originally included 110 patients each in the rituximab-plus-idelalisib (150 mg, twice daily) and rituximab-plus-placebo arms. The study was terminated early because of the superior efficacy of the idelalisib arm. “Patients in either arm could then enroll in an extension study to receive idelalisib monotherapy,” the authors recounted, and “no new idelalisib-related adverse events were identified with longer exposure.”
Ultimately, the team assessed the long-term efficacy and safety of treatment with idelalisib in the 110 patients who received at least a single dose of idelalisib in the primary study, 75 of whom enrolled in the extension study. The median progression-free survival was 20.3 months after a median follow-up of 18 months, and the overall response rate was 85.5% (94 of 110 patients, with 1 complete response).
“The median overall survival was 40.6 months and 34.6 months for patients randomly assigned to the idelalisib-plus-rituximab and placebo-plus-rituximab groups, respectively,” reported Dr. Sharman and co-investigators. “The longer-term data presented here confirm the previously reported efficacy of targeting PI3K with idelalisib in patients with relapsed/refractory chronic lymphocytic leukemia.”
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.