Dose-escalated CHOEP for the treatment of young patients with aggressive non-Hodgkin's lymphoma: I. A randomized dose escalation and feasibility study with bi- and tri-weekly regimens.

BACKGROUND To determine the maximum tolerated dose of a bi- and tri-weekly combination chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone plus etoposide (CHOEP) regimen without stem-cell support. PATIENTS AND METHODS Randomized phase I/II multicenter four-level (cyclophosphamide: 1000-1200-1400-1600 mg/m2; doxorubicin: 55-60-65-70 mg/m2; etoposide: 375-450-525-600 mg/m2) dose escalation study with CHOEP-14 and CHOEP-21 in young patients (18-60 years) with newly diagnosed aggressive non-Hodgkin's lymphoma. Dose-limiting toxicity was defined as thrombocytopenia <80,000/mm3 and leukocytopenia <2500/mm3 on days 16 (CHOEP-14) and 23 (CHOEP-21) or prolonged (>4 days) leukocytopenia (<1000/mm3) or thrombocytopenia (<20,000/mm3). RESULTS One hundred and thirty-nine patients (high-CHOEP-14: 47, high-CHOEP-21: 92) were randomly allocated to the study. Maximal tolerated dose was level 2 for CHOEP-14 and level 4 for CHOEP-21. With a less favorable profile of patients in CHOEP-14, 4-year event-free survival was 47.9% after high-CHOEP-14 and 66.2% after high-CHOEP-21, 4-year overall survival 62.1% after high-CHOEP-14 and 73.4% after high-CHOEP-21, respectively. CONCLUSION Significant dose escalations of CHOEP are possible with granulocyte colony-stimulating factor support, with different chemotherapy models favoring the maximally escalated bi- or tri-weekly regimen, respectively. Because a higher total dose can be achieved with six cycles of the tri-weekly compared with the biweekly regimen, CHOEP-21 at dose escalation level 3 was chosen for a nationwide randomized comparison with baseline CHOEP-21 in a subsequent phase III trial.