Among patients with hematologic malignancies who remain disease free for 2 years after haploidentical stem cell transplantation (haplo-SCT), long-term survival rates are likely to be high, according to research presented at the Annual Meeting of the Society of Hematologic Oncology (SOHO).
SCT has been shown to have the potential for a cure among patients with hematologic cancers, including those with high-risk disease. The risk presented by acute or chronic graft vs host disease (GVHD), however, has remained a significant issue in this patient population.
Prophylaxis against GVHD using on cyclophosphamide has improved outcomes overall among patients undergoing haplo-SCT over the past decade. For this study, researchers evaluated long-term outcomes among patients with hematologic disease who undergo haplo-SCT.
All included patients had received an initial haplo-SCT procedure between 2009 and 2019. The study’s primary objectives were progression-free survival and overall survival (PFS and OS, respectively); secondary objectives included cumulative incidence of relapse and nonrelapse mortality.
Overall, data from 336 patients were evaluated. In this cohort, 196 patients had acute myeloid leukemia or a myelodysplastic syndrome, 55 patients had acute lymphoblastic leukemia, 48 patients had a lymphoid malignancy, and 37 patients had a myeloproliferative neoplasm.
Initial analysis showed that 144 patients were disease free at 2 years post-haplo-SCT; these patients were defined as the long-term survival group. In this group, the median age was 45 years and 88% of patients had received intensity conditioning. Grade 2 to 4 acute or chronic GVHD had previously occurred in 37% and 19% of patients, respectively.
In the overall cohort, the 4-years PFS and OS rates were 42% and 47%, respectively; the 4-year rates in the long-term survival group, however, were 92% and 96%, respectively. The 4-year rates of cumulative incidence of relapse and non-relapse mortality, furthermore, were 4% and 3%, respectively, in the long-term survival group.
Further analysis showed that age of at least 55 years was predictive of both worse PFS (hazard ratio [HR], 2.63; 95% CI, 1.01-6.84) and OS (HR, 3.33; 95% CI, 1.08-12.23). In the long-term survival group, 9% of patients died during the observation period, 2 cases of which were due to relapse.
Saengboon S, Ramdial J, Saini N, et al. Long-term outcomes after haploidentical stem cell transplantation (haplo-SCT) for hematologic malignancies. Presented at: Annual Meeting of the Society of Hematologic Oncology (SOHO); September 28-October 1, 2022. Abstract AML-528.