HOUSTON—In patients 65 years or younger with untreated mantle cell lymphoma (MCL), adding rituximab (Rituxan) to the hyper-CVAD/methotrexate/cytarabine (Ara-C) regimen produced high complete remission rates and failure-free survival rates equivalent to those reported for hyper-CVAD followed by stem cell transplants.
Results of a trial testing rituximab plus hyperfractionated cyclophosphamide, doxorubicin, vincristine, and dexamethasone (R-HCVAD) without stem cell transplant were presented at the Annual Meeting of The American Society of Hematology by Jorge Romaguera, MD, of The University of Texas M. D. Anderson Cancer Center. Dr. Romaguera cautioned that the data for patients under 65, "while very encouraging, are preliminary, and longer follow-up is warranted to assure this promising therapeutic outcome is sustained."
R-HCVAD also produced high complete remission rates in patients older than 65 with untreated aggressive MCL. In those patients, "the rate of complete remission has improved significantly when compared with CHOP (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone)," Dr. Romaguera noted. "The complete remission rate in patients over 65 was also significantly better than that of 68% reported with hyper-CVAD without rituximab. The failure-free survival rate for this subgroup, however, has not improved comparably and new approaches are needed."
Modifying the Regimen
This trial built on a previous one using the hyper-CVAD regimen that included stem cell transplants in patients younger than 66. That trial produced a complete response rate of 100% and prolonged failure-free and overall survival. Eight patients that were eligible for stem cell transplant and did not receive it, but completed six to eight cycles of hyper-CVAD had comparable failure-free survival rates.
The new trial used the hyper-CVAD regimen with two modifications: (1) rituximab at 375 mg/m² was added on day 1 of each cycle; and (2) stem cell transplants were not done for patients achieving complete remission within six courses of treatment.
The study included only untreated patients with aggressive MCL. "Other criteria were standard, including adequate organ function, unless the abnormalities were due to lymphoma," Dr. Romaguera explained. "Patients who were pregnant, had positive HIV status, or presented central nervous system lymphoma were excluded." There was no age limit.