Supportive Care Only Versus Allogeneic Hematopoietic Cell Transplantation in Patients ≥ 60 Years with De Novo High-Risk MDS.

Abstract 596

Myelodysplastic syndromes (MDS) occur primarily in older patients, and allogeneic hematopoietic cell transplantation (HCT) only infrequently is considered a therapeutic option. Until recently best supportive care (BSC), only including transfusion support, has been the standard of care for the majority of these patients (pts). Novel treatment modalities and innovations in transplant protocols have changed that approach and have led to increased frequency of allogeneic HCT in pts more than 60 or 65 years of age. However, no randomized trial comparing outcomes with BSC and allogeneic HCT has been conducted.

Therefore, we performed a matched pair analysis including 126 patients 60-77 (median 65) years old with de novo high-risk MDS by FAB classification (RAEB n=88, RAEB-t n=20, CMML n=18) who underwent allogeneic HCT at a median of 8.6 months from initial MDS diagnosis. Cytogenetics were availabel in 108 pts (good: n=63, intermediate: n=18, poor: n=27), allowing for IPSS scoring in 107 pts: 28 were INT-1, 45 INT-2, and 34 HIGH risk. Before HCT most pts had progressed to more advanced disease (RAEB n=45, RAEB-t n=10, CMML n=10, AML n=61). At the time of HCT the median blast count in the marrow was 12%. While 51 pts had received supportive care only prior to HCT the remaining had undergone chemotherapy of various intensities including methyltransferase-inhibitors (n=10). Patients were prepared for HCT with one of several reduced intensity (RIC, n=79) or more conventional intensity (CI, n=47) conditioning regimens and transplanted from related (n=50) or unrelated (n=76) donors. The outcome after HCT was compared to outcome with BSC only in a matched pair group from the Düsseldorf registry. Matching criteria were age, gender, marrow blast count, FAB and IPSS category. One prerequisite was that controls were still under supportive care at the time of HCT of the corresponding matched patient.

With a median follow-up of 60 months from MDS diagnosis the 5-year overall survival (OS) rate was 45% for the HCT and 25% for the BSC cohort (p=0.008). These retrospective data suggest, therefore, that allogeneic HCT from related or unrelated donors, using various conditioning approaches, compared to BSC only, offers a meaningful survival advantage and the potential of cure for patients with high-risk MDS, even in the 7^th decade of life. There is a need for prospective clinical trials in order to determine the place of allogeneic HCT within the growing therapeutic opportunities for pts with MDS.