Credit: Steven Harbour
The phase 3 RESONATE study has been stopped early due to positive results in patients receiving ibrutinib.
In this trial, researchers compared the BTK inhibitor ibrutinib to the CD20-directed antibody ofatumumab in patients with relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL).
The study has ended early because 2 key endpoints were met—namely, ibrutinib significantly improved progression-free and overall survival rates.
The RESONATE study enrolled 391 patients with relapsed or refractory CLL or SLL with measurable nodal disease who were not eligible for treatment with purine-analog-based therapy. Patients had received at least 1 prior therapy.
The researchers randomized patients to receive 420 mg of ibrutinib orally once daily or intravenous doses of ofatumumab over the course of 24 weeks until disease progression or unacceptable toxicity.
At the planned interim analysis, ibrutinib had significantly improved progression-free survival (the primary endpoint) and overall survival (a secondary endpoint).
And the safety profile of ibrutinib was acceptable, according to the companies developing the drug (Pharmacyclics, Inc. and Janssen Research and Development, LLC).
Based on these results, an independent data monitoring committee recommended that patients in the ofatumumab arm be given access to ibrutinib.
Pharmacyclics has informed the US Food and Drug Administration of this recommendation, and Janssen has informed the European Medicines Agency. Both companies are in talks with the health authorities to define the next regulatory steps.
Pharmacyclics has said detailed data from the RESONATE study will be presented at an upcoming oncology conference.
Ibrutinib was recently approved by the US Food and Drug Administration to treat mantle cell lymphoma.
