Low-dose metronomic, multidrug therapy with the PEP-C oral combination chemotherapy regimen for mantle cell lymphoma

The prednisone, etoposide, procarbazine and cyclophosphamide (PEP-C) oral combination chemotherapy regimen (prednisone 20 mg, cyclophosphamide 50 mg, etoposide 50 mg, and procarbazine 50 mg with an oral anti-emetic) was employed at our center to treat 22 patients with heavily pretreated, recurrent mantle cell lymphoma (MCL). All medications were administered daily until leukocytes fell to <3.0 x 10(9)/L whereupon treatment was withheld until recovery from the nadir. Therapy was then reinstituted on a daily, alternate day, or fractionated basis (e.g. 5 of 7 days) depending on patient tolerance. Doses given per day were held constant. Eighty-two percent achieved an objective response with 46% complete responses and 36% partial responses. Median time on therapy was 17 months. The regimen was well tolerated. Our findings demonstrate that low-dose oral agents administered in combination for continuous, prolonged periods with minimal drug-free intervals (metronomic therapy) may represent a novel, effective, easily tolerated approach to MCL and that this treatment approach warrants further exploration.