Yesterdays results presented at ASH 2014 provides the first demonstrated feasibility and efficacy of a chemotherapy-free, biologic approach using lenalidomide and rituximab as an initial therapy for mantle cell lymphoma (MCL). These findings present an important chemotherapy-free alternative initial treatment for MCL, as current conventional upfront chemoimmunotherapies are generally not curative.
During this multi-center phase II study patients were administered lenalidomide at 20 mg in days 1-21 of a 28-day cycle for a total of 12 cycles, with doses escalated to 25 mg when tolerated. Rituximab was administered weekly x 4 during first cycle and then once every other cycle for a total of 9 doses. The induction phase was followed by a maintenance phase, which at the 13th cycle, lenalidomide was administered at 15 mg on days 1-21 of a 28 day cycle, while rituximab maintenance was employed once every other cycle until disease progression.
Of the 38 patients with previously untreated MCL the median age was 65 years (range 42-86), with a male to female ratio of 2.5:1. Treatment was generally well tolerated with mild to moderate side effects. The overall response rate in patients was 84.2%, complete response rate was over 50%, with median time to objective response being 2.8 months. The median progression-free survival has not been reached, and the 2 year progression free survival rate is estimated to be 83.9%.
This study demonstrated that a high proportion of MCL patients can achieve durable remissions while maintaining a high quality of life. The data gathered from this trial justifies further evaluations of the lenalidomide and rituximab regimen both alone and in combination with other treatment approaches to MCL.
