Under-use of Hypomethylating Agents in Patients With Higher-risk Myelodysplastic Syndrome in the United States: A Large Population-based Analysis.

BACKGROUND

Recent data suggest significant underutilization of hypomethylating agents (HMAs) that are recommended treatments for patients with myelodysplastic syndromes (MDS) with refractory anemia with excess blasts (RAEB). The study objective was to assess the degree of HMA use and predictors of HMA underuse in this population.

PATIENTS AND METHODS

This was a retrospective study including patients diagnosed with the RAEB form of MDS between January 2011 and December 2015 using the Surveillance, Epidemiology, and End Results-Medicare linked database. Patients were excluded if they had < 1 year of continuous enrollment before diagnosis or received stem cell transplant or lenalidomide during the follow-up period. HMA non-peristence was defined as use of < 4 cycles (3-10 HMA days/28 days) of HMAs or a gap of ≥ 90 days between consecutive cycles. Patients were characterized as HMA never-users, HMA-persistent users, and HMA-non-persistent users. Descriptive statistics were used to summarize patient characteristics. Multivariable logistic regression was used to assess predictors of HMA underuse and persistence.

RESULTS

Of the 1190 patients, 526 (44%) were never-users, 295 (25%) were non-persistent users, and 369 (31%) were persistent users. Age at diagnosis (eg, 66-70 years vs. ≥ 80 years; odds ratio [OR], 2.36; 95% confidence interval [CI], 1.56-3.56), marital status (single vs. married; OR, 0.67; 95% CI, 0.51-0.89), National Cancer Institute comorbidity index (≥ 3 vs. 0-1; OR, 0.62; 95% CI, 0.46-0.83), and performance status (poor vs. good; OR, 0.67; 95% CI, 0.51-0.87) were significantly associated with HMA underuse.

CONCLUSION

Several demographic and clinical factors were associated with underuse of HMAs. There is need for a better understanding of suboptimal HMA use and its relationship with clinical response.