ATLANTAUse of intensive immunochemotherapy plus purged stem-cell support can result in long-term survival in patients with mantle cell lymphoma, suggesting that MCL could be considered as curable. Christian Geisler, MD, PhD, of Rigshospitalet, Copenhagen, Denmark, presented this provocative idea, based on final results of the MCL2 study, at ASH 2007 (abstract LB1), speaking on behalf of the Nordic Lymphoma Group.
"We believe that this is the beginning of a new era for the treatment of mantle cell lymphoma," Dr. Geisler said.
In small studies of patients with advanced-stage MCL in first remission, myeloablative induction chemotherapy using CHOP (cyclophosphamide, Adriamycin, vincristine, prednisone) followed by stem-cell transplantation significantly improved outcomes, compared with interferon maintenance therapy. This approach did not result in effective long-term control, however.
Since high-dose cytarabine and rituximab (Rituxan) have also been found effective in MCL, these agents were incorporated into a Nordic protocol (MCL1) that evaluated intensive induction immunochemotherapy prior to transplant.
The phase II nonrandomized MCL2 study involved 159 untreated MCL patients: 84% had stage IV disease; all were under age 66. Treatment consisted of one cycle of augmented CHOP (maxi-CHOP) alone, then six cycles of rituximab plus maxi-CHOP alternating with rituximab plus high-dose cytarabine. Responders underwent stem-cell harvest followed by BEAM/BEAC with in vivo purged (rituximab) stem cell transplant. Patients were evaluated for survival after a median follow-up of 3 years from study entry.
Of 159 patients, 153 (96%) responded to induction chemotherapy (55% CR, 41% PR). Intent-to-treat analysis showed 5-year event-free survival (EFS) of 63% and 5-year overall survival (OS) of 74% (see Figure). Of the 144 (91%) responders who completed treatment, 72% were alive and disease free at 5 years.