Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma that occurs primarily in older adults. The disease is typically managed in the initial treatment setting with a combination of chemotherapy and immunotherapy, which tends not to be curative and may impart toxic side effects in some patients.
In search of an effective, less toxic treatment option for those afflicted by MCL, Dr. Jia Ruan and colleagues explored an alternative regimen free of conventional chemotherapy – lenalidomide plus rituximab – to be used in the initial treatment setting. Their multi-center phase II clinical trial of the novel biological pairing was the first-ever study of a non-chemotherapy first-line MCL treatment approach.
Thirty-eight MCL patients enrolled in the trial from July 2011 to April 2014. They received lenalidomide on days 1-21 of a 28-day cycle, and rituximab was administered four times per week during the first cycle, then once every other cycle. The first 12-cycle treatment was considered induction, or initial therapy, and was followed by a maintenance phase, in which therapy is provided to prevent relapse. Treatment was continuous until disease progression, and patients had the option to cease therapy after three years if in remission.
At the 2017 American Society of Hematology Annual Meeting, the researchers examined the long-term outcomes of the trial in a 5-year follow-up analysis to reveal that the drug combination shows promise for effective management of MCL, with the majority of trial participants doing well and maintaining good quality of life. About 90 percent of patients responded to the therapy, and over 60 percent remain in remission.
The research team also measured minimal residual disease (MRD) in patients’ blood, the small number of cancer cells that may be left after treatment that have the potential to grow and cause the patient to relapse. In the small subset of patients with available tumor tissues for MRD analysis, about 80 percent of patients were found to be MRD negative, further demonstrating the novel treatment regimen’s activity and feasibility as an additional therapeutic option for people with MCL.
“We are encouraged by the quality and durability of the responses with the biologic doublet of lenalidomide plus rituximab as initial therapy for mantle cell lymphoma,” said Dr. Ruan. “We hope to bring this active combination to larger studies where it can be combined with other agents and compared to conventional chemotherapy.”