Ibrutinib shows promise in CLL/SLL
medwireNews: The addition of ibrutinib to bendamustine and rituximab significantly prolongs progression-free survival (PFS) in patients with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL), according to the HELIOS trial.
The interim results from the double-blind, phase III trial were reported last week at the annual meeting of the American Society of Clinical Oncology (ASCO), held in Chicago, Illinois, USA.
“The data further support [ibrutinib] as an important treatment option for [patients] with previously treated CLL/SLL”, commented the researchers.
Indeed, as the primary endpoint was met during the prespecified interim analysis, the Independent Data Monitoring Committee recommended unblinding the study, permitting patients in the placebo arm to crossover to receive ibrutinib.
A total of 578 CLL/SLL patients were randomly assigned to receive bendamustine and rituximab with either ibrutinib (n=289) or placebo (n=289) , and were followed up for a median of 17.2 months.
Median PFS was not reached for patients treated with ibrutinib compared with 13.3 months for those given placebo, which equated to a significant hazard ratio for disease progression or death of 0.20.
The overall response rate also varied significantly between the two groups, at 82.7% versus 67.8% for ibrutinib- and placebo-treated patients, respectively.
For most adverse events, the incidence in the ibrutinib and placebo arms was “similar”, said Asher Chanan-Khan, from Mayo Clinic in Jacksonville, Florida, USA, and co-workers.
The most frequently observed adverse events of grade 3 or 4 were neutropenia and thrombocytopenia, with an incidence of 53.7% and 15.0%, respectively, in the ibrutinib group and 50.5% and 15.0% in the placebo group.
And grade 3 or 4 atrial fibrillation occurred in 2.8% and 0.7% of patients given ibrutinib and placebo, respectively, and major haemorrhage in 2.1% and 1.7%.
HELIOS co-investigator Simon Rule, from Derriford Hospital in Plymouth, UK said in a press statement: “We knew ibrutinib was an effective single-agent treatment option with an established safety profile and we now have additional evidence suggesting that ibrutinib improves outcomes when combined with existing treatment regimens.”
“The results from the HELIOS trial are very encouraging for previously-treated patients with CLL or SLL and suggest that the ibrutinib combination may be an option for these patients moving forward.”
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