Sangmin Lee, MD
Human leukocyte antigen (HLA)-mismatched hematopoetic stem cell microtransplantation (MST) has previously been evaluated in AML in combination with chemotherapy and suggests potential improvement in outcomes. Li et al evaluated MST combined with decitabine in patients with intermediate or high risk MDS compared to decitabine alone. Out of 22 patients in the study, the cohort that received MST with decitabine had higher median OS (24 vs 14.2 months, p=0.04), although there was no statistical significant difference in overall response rate. There was no reported graft vs host disease, and adverse events were similar between the two groups. The main limitation of the study was the very small sample size; further prospective studies utilizing MST in MDS are needed to demonstrate benefit.
MDS patients often present with neutropenia and develop worsening neutropenia due to myelosuppression from HMA therapy, resulting in increased risk of infections including invasive fungal infection (IFI). Tey et al reported a retrospective analysis of the rate of IFI in patients with MDS or low blast count AML receiving azacitidine. Out of 117 patients, 61% received antifungal prophylaxis, either with posaconazole (n=70) or voriconazole (n=1). The IFI rate was 7.7% in the cohort with median time of onset of 74 days from start of azacitidine treatment (range 1-226); the IFI rate did not differ statistically between those receiving prophylaxis vs not (5.6% vs 10.9%, p=0.30). However, presence of neutropenia at three months of treatment was associated with increased IFI risk (HR 8.29, p=0.01), and IFI was associated with increased mortality in a multivariate analysis (HR 8.37, p<0.0001). Anti-fungal prophylaxis is currently standard practice for MDS patients who present or develop neutropenia; however, HMA treatment is associated with prolonged neutropenia due to myelosuppression and time to response. A more effective therapy with less myelosuppression is needed for treatment of MDS.