Nordic MCL3 study: 90Y-ibritumomab-tiuxetan added to BEAM/C in non-CR patients before transplant in mantle cell lymphoma

Abstract

The main objective of theMCL3 study was to improve outcome for patients not in complete remission (CR) before transplant by adding 90Y- ibritumomab-tiuxetan (Zevalin) to the highdose regimen. One hundred sixty untreated, stage II-IV mantle cell lymphoma patients <66 years received rituximab (R)-maxi-CHOP (cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone) alternating with R-high-dose cytarabine (6 cycles total), followed by high-dose BEAM/C (bis-chloroethylnitrosourea, etoposide, cytarabine, and melphalan or cyclophosphamide) and autologous stem cell transplantation from 2005 to 2009. Zevalin (0.4 mCi/kg) was given to responders not in CR before transplant. Overall response rate pretransplant was 97%. The outcome did not differ from that of the historic control: theMCL2 trial with similar treatment except for Zevalin.Overall survival (OS), eventfree survival (EFS), and progression-free survival (PFS) at 4 yearswere 78%, 62%, and 71%, respectively.For responding non-CRpatients who received Zevalin, duration of response was shorter than for the CR group. Inferior PFS, EFS, and OS were predicted by positron emission tomography (PET) positivity pretransplant and detectable minimal residual disease (MRD) after transplant. In conclusion, positive PET andMRD were strong predictors of outcome. Intensificationwith Zevalin may be too late to improve the outcomeof patients not in CR before transplant. © 2014 by The American Society of Hematology.