In patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) eligible for bendamustine-rituximab chemo-immunotherapy, adding ibrutinib to this combination resulted in significant improvements in outcomes and a manageable safety profile, a new study published online ahead of print in the journal The Lancet Oncology has shown.1
The American Cancer Society estimates that there were 14 620 new cases of CLL in the United States in 2015 and about 4650 patients died for the disease. CLL accounts for about one-quarter of new leukemia cases.2
Although most patients with CLL or SLL relapse after initial therapy, bendamustine plus rituximab and ibrutinib alone have been shown to be effective in the relapsed or refractory setting.1,3 Therefore, researchers sought to evaluate the efficacy and safety of adding ibrutinib to bendamustine plus rituximab in patients with relapsed/refractory CLL/SLL.1
For the international, double-blind, placebo-controlled, phase 3 HELIOS trial, researchers enrolled 578 patients with active CLL or SLL with measurable lymph node disease who had relapsed or refractory disease following 1 or more previous lines of systemic therapy consisting of at least 1 cycle of a chemotherapy-containing regimen. Although ibrutinib is effective in patients with del(17p), patients with this gene mutation were excluded because of known poor response with bendamustine plus rituximab.1
“This is one of the largest studies in relapsed CLL patients and the only placebo control ibrutinib study that for the first time demonstrated the feasibility and benefit of adding ibrutinib to chemotherapy,” lead investigator Asher Chanan-Khan, MD, hematologist at Mayo Clinic in Jacksonville, FL, said in an interview with Cancer Therapy Advisor.
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Participants were randomly assigned 1:1 to receive bendamustine 70 mg/m2 intravenously on days 2 to 3 in cycle 1, and days 1 to 2 in cycles 2 to 6, plus rituximab 375 mg/m2 intravenously on day 1 cycle 1, and 500 mg/m2 on day 1 of cycles 2 to 6 with ibrutinib 420 mg orally daily or placebo until unacceptable toxicity or disease progression.1