Short Progression Free Survival Post Non-Myeloablative Sibling Allogeneic Stem Cell Transplantion for Multiple Myeloma.

Song, Kevin; Sutherland, Heather J.; Shepherd, John D.; Abou Mourad, Yasser; Barnett, Michael J; Forrest, Donna L.; Hogge, Donna E.; Narayanan, Sujaatha; Nantel, Stephen H.; Power, Maryse M; Toze, Cynthia L.; Smith, Clayton; Nevill, Thomas J.

doi:10.1182/blood.V114.22.4323.4323

Abstract 4323

Introduction

Allogeneic stem cell transplant has been considered the only potentially curative treatment for patients with myeloma. Due to the high treatment related mortality associated with myeloablative allogeneic stem cell transplantation, non-myeloablative allogeneic stem cell transplantion is being investigated.

Methods

Between May 2003 and June 2008, 23 patients received a non-myeloablative allogeneic stem cell transplant (NMT) using a fully matched sibling as the donor. All had received a previous autologous stem cell transplant (ASCT). 17 received the NMT as a part of a planned tandem transplant post ASCT. Six received the NMT after relapse post ASCT. Conditioning chemotherapy was a combination of cyclophosphamide 1000 mg/m2 daily x 2 days and Fludarabine 25mg/m2 daily for 5 days. Survival was measured from the date of allogeneic stem cell infusion.

Results

Median age at NMT was 52 years. Eight were female. Immunoglobulin isotype was 13 IgG; 5 IgA; 1 IgD; 4 light chain. ISS stage was 10 – stage 1; 8 – stage 2; 3- stage 3; 2 – insufficient information. 9/21 had del 13q; 3/9 t (4;14); 1/7 del 17p. Disease status at the time of NMT were 5 CR/nCR, 11 PR, 1 SD, 3 relapse chemo-sensitive, 3 relapse chemo-resistant. Median follow-up is 29 months (7 – 65 months). Median event free survival (EFS) for all patients is 17 months (95 % CI 8-26 months). Median EFS for the 17 patients who received NMT as a part of a planned tandem procedure was 18 months. Median overall survival (OS) for all patients is 29 months (95% CI unable to calculate). At the time of analysis 17 patients remain alive. Five patients are alive in continuous remission at a median of 40.9 months from NMT (13.5-47.6 months). Twelve patients have active disease requiring treatment. Three patients have died of myeloma, one of graft-versus-host-disease (GVHD) and two of other causes. Nineteen patients (83%) developed GVHD at some time post-transplant. Of 14 patients who have relapsed, eleven patients had GVHD at the time of relapse. Of the 6 patient who received the NMT after relapse post ASCT, 5 have relapsed post NMT and one died of GVHD within 9 months.

Conclusion

Non-myeloablative sibling allogeneic stem cell transplantation for myeloma produces short progression free survival in-spite of the presence of graft-versus-host-disease and only a limited number of patients benefit. Patient who receive this treatment after relapse from prior autologous stem cell transplant do particularly poorly. Improved overall survival is primary due to improvements in post-relapse myeloma therapy.