Long-term Survival After Autologous Transplantation Among Patients With MCL

Study findings confirm the long-term efficacy of autologous hematopoietic stem cell transplantion (autoHSCT) for treating mantle cell lymphoma (MCL; Lancet Haematol. 2021;8[9]:e648-e657. doi:10.1016/S2352-3026[21]00195-2).

“[AutoHSCT] in first remission is the current standard treatment in fit patients with [MCL],” explained Anna-Katharina Zoellner, MD, Department of Medicine III, University Hospital, Ludwig Maximilian University of Munich, Germany, and colleagues.

This study aimed to evaluate the efficacy of autoHSCT vs interferon alfa maintenance after chemotherapy with or without rituximab in patients with primary advanced-stage MCL.

Researchers performed a post-hoc, long-term analysis of an open-label, randomized, phase 3 trial. Patients were randomized in a 1:1 ratio to receive either myeloablative radiochemotherapy followed by autoHSCT or interferon alfa maintenance after completion of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-like induction therapy with or without rituximab.

The primary outcome was progression-free survival (PFS) from end of induction until progression or death among patients who achieved remission. The secondary outcome was overall survival (OS) from end of induction until death from any cause.

Researchers compared PFS and OS according to the intention-to-treat (ITT) principle between both groups among responding patients and examined efficacy in subgroups according to induction treatment with or without rituximab (R). 

The study included 269 patients who were randomly assigned to autoHSCT or interferon alfa between September 30, 1996, and July 1, 2004. The median follow-up was 14 years.

The ITT population consisted of 174 patients who responded to induction therapy. Of these 174 patients, 93 (53%) were randomized to autoHSCT and 81 (47%) to interferon alfa maintenance. The median age of patients was 55 years and 68 (39%) received R-CHOP.

The median PFS was 3.3 years in the autoHSCT group vs 1.5 years in the interferon alfa maintenance group (log-rank P = .019; adjusted hazard ratio [HR] 0.66). The median OS was 7.5 years vs 4.8 years, respectively.

For patients treated without rituximab, the PFS adjusted HR for autoHSCT vs interferon alfa maintenance was .4 compared to .72 for those treated with rituximab. For overall survival, the adjusted HRs for autoHSCT vs interferon alfa were .52 for those treated without rituximab and 1.05 for those treated with rituximab.

“Our results confirm the long-term efficacy of autoHSCT to treat [MCL] established in the pre-rituximab era,” concluded Dr Zoellner and colleagues.

“The suggested reduced efficacy after immunochemotherapy supports the need for its re-evaluation now that antibody maintenance, high-dose cytarabine, and targeted treatments have changed the standard of care for patients with [MCL],” they added.