A phase II clinical trial of intensive chemotherapy followed by consolidative stem cell transplant: long-term follow-up in newly diagnosed mantle cell lymphoma

Abstract

Mantle cell lymphoma (MCL) is associated with high relapse rates and poor survival when treated with conventional chemotherapy, with or without rituximab. We report the long-term follow-up of a phase II clinical trial using a new intensive multiagent chemotherapeutic regimen [cyclophosphamide, teniposide, doxorubicin and prednisone (CTAP) alternating with vincristine and high-dose methotrexate and cytarabine (VMAC)] in newly diagnosed MCL. Following 4-6 cycles of CTAP/VMAC induction, patients aged < or =65 years proceeded to consolidative autologous haematopoietic stem cell transplantation (auto-HSCT), while patients < or =55 years who had a HLA-identical sibling received allogeneic-HSCT (busulfan/cyclophosphamide conditioning for both). Twenty-five untreated MCL patients enrolled on the protocol between 1997 and 2002. Among evaluable patients, overall response rate (ORR) was 74% following induction chemotherapy. Seventeen patients received HSCT (autologous-13/allogeneic-4). On intent-to-treat analysis, ORR for patients who received consolidative HSCT was 100% (complete remission 76%). Therapy was well-tolerated with 4% treatment-related mortality (including HSCT). The 5-year event-free-survival (EFS) and overall survival (OS) for all patients was 35% and 50% respectively. Furthermore, at 66-months median follow-up, the 5-year EFS and OS for patients who received consolidative auto-HSCT was 54% and 75% respectively. Patients who received auto-HSCT had improved outcomes compared to no auto-HSCT (EFS P = 0.001; OS P = 0.0002). CTAP/VMAC induction followed by consolidative auto-HSCT for newly diagnosed MCL is associated with high ORR and durable survival.