Update of a GITIL Cohort Study: Frontline High Dose Sequential Chemotherapy with Rituximab and Autologous Stem Cell Transplantation Induces a High Rate of Long-Term Remissions in Patients with Mantle Cell Lymphoma

We updated a cohort study with the aim of evaluating if an up-front Rituximab supplemented high-dose sequential chemotherapy (R-HDS), supported by autologous bone marrow transplantation (ASCT) can induce log-term remissions in Mantle Cell Lymphoma (MCL), with an acceptable toxic profile. From 1997 to 2005, 77 consecutive MCL patients, <61 year old, considered suitable for ASCT in 11 Italian cancer centres were enrolled in this study (Group 1). Their clinical outcome was compared with that of 79 age-matched historic controls treated between 1978 and 1999 with standard-dose anthracyclin or fludarabine containing regimens (group 2). The majority of both groups had an advanced stage, bone marrow infiltration and >1 IPI risk factors, while >1 extranodal sites prevailed in Group 1 and a poor ECOG-PS in Group 2. After 2–3 cycles of either doxorubicin- or cisplatin-containing chemotherapy, Group 1 received R-HDS including: HD-cyclophosphamide (CTX) 7 gr/sqm and HD-Ara-C (2 g/sqm every 12 hours for 6 days), followed by HDS HD-melphalan (180 mg/sqm) and/or HD-mitoxantrone plus melphalan (60 and 180 mg/sqm) and ASCT. Rituximab (375 mg /sqm) was given for a total of 6 doses, twice after HD-CTX and HD-Ara-C, as in vivo purging before CD34+ cells harvest and twice after ASCT. Sixty-nine patients (90%) in Group 1 completed the planned program and a median number of 6.3 x 10^6 cells CD34+/kg were transplanted. In Group 2, 85% of patients received the planned chemotherapy. The CR rate was 86% in Group 1 and 35% in Group 2 and the treatment-related mortality was 1.3% and 0.8%, respectively. Moreover, in Group 1, 4 patient developed sMDS, and 4 died of solid tumors (n=3), or septic shock (n=1). After a median follow-up of 50 months (range 3–111) in Group 1 and 37 months (range 1–141) in Group 2, the rate of 1^st CCR was 65% and 14%, respectively. The 5-year projected OS, EFS and DFS were 74%, 61% and 70%, in Group 1 and 31%, 14% and 25%, in Group 2, respectively. Cox multivariate analysis failed to identify within potential prognostic markers factors predictive for OS and EFS. In conclusion, R-HDS induces long-term remissions with a manageable toxicity in patients with newly diagnosed MCL. Studies comparing this program with other intensive regimens are needed for ascertaining the role of R-HDS in the treatment of this otherwise incurable disease.