Clinical data from a Phase I/II study evaluating the combination of lenalidomide (Revlimid?, Celgene) plus rituximab (Rituxan?, Genentech/Biogen IDEC) in relapsed/refractory mantle cell lymphoma (MCL), conducted by investigators at the MD Anderson Cancer Center in Houston, TX, were presented at the 11th International Conference on Malignant Lymphoma in Lugano (11-ICML), Switzerland.
Patients with mantle cell lymphoma who had received one to four prior therapies received lenalidomide daily on days one to 21 of each 28-day cycle, and rituximab weekly for four doses during cycle one. The maximum tolerated dose in the phase I portion was 20 mg of lenalidomide daily, and 375 mg/m2 of rituximab in accordance with the study schedule.
Forty-six patients were enrolled in the Phase II portion of the study. The overall response rate was 57% with a complete response rate of 33% and a median duration of response of 18.9 (range 17-NR) months. After a median follow-up of 23.1 months, the median progression free survival and median overall survival were 13 months (95% CI 8.3-20.8) and 25.1 months (95% CI 19.8-NR), respectively. The combination regimen induced complete responses in two patients with bulky MCL and induced responses in patients who were refractory to or who did not tolerate prior treatment with bortezomib. The investigators have hypothesized that lenalidomide may enhance the effects of rituximab on ADCC (antibody-dependent cellular mediated cytotoxicity), or the ability of the body to direct immune defense cells to attack lymphoma cells.
The combination lenalidomide plus rituximab was well tolerated. Primary grade 3-4 toxicities included neutropenia (17%), lymphopenia (7.2%), and thrombocytopenia (4.5%).
For more information:
Lenalidomide and Rituximab in the Treatment of Relapsed Mantle Cell Lymphoma (MCL) and Diffuse Large B-Cell Lymphoma.
Rituximab, Lenalidomide, and Bortezomib in Mantle Cell Lymphoma