LAUSR

OBJECTIVES To evaluate hypomethylating agent (HMA) persistence in patients with myelodysplastic syndromes (MDS), and examine its association with healthcare resource utilization (HRU) and progression to acute myeloid leukemia (AML). METHODS A total of 2,400 adults diagnosed with MDS initiating HMAs were included from IBM MarketScan databases during 1/1/2011-3/31/2018. The index date was HMA initiation following MDS diagnosis. Patients were classified according to their persistence status by the end of a fixed 'landmark period' of 4 months post-index. RESULTS Median persistence to HMAs was 5.6 months (95% CI: 5.2, 6.1); HMA non-persistence increased with time. Non-persistent patients had a significantly higher non-HMA-related HRU burden than persistent patients [adjusted incidence rate ratios, outpatient visits: 1.12 (95% CI: 1.10, 1.14); inpatient visits: 1.48 (95% CI: 1.30, 1.69); emergency department visits 1.30 (95% CI: 1.12, 1.50); all p-values < 0.001]. All-cause and HMA-related outpatient visits were lower among non-persistent patients, likely because of fewer HMA administration-related visits. The incidence rate of AML was numerically, although not significantly, higher in non-persistent patients, when starting follow-up at the end of the landmark period. When follow-up began at the index date, non-persistent patients had a significantly higher rate of AML [adjusted hazard ratio, 1.88 (95% CI: 1.53, 2.32); p-value < 0.001]. CONCLUSIONS HMA non-persistence, which increased over time, was associated with significantly higher non-HMA-related HRU, and numerically higher AML progression in MDS patients initiating HMAs. Future studies should evaluate predictors of HMA non-persistence in this patient population.