COMPARATIVE SAFETY, HEALTHCARE EXPENDITURES, AND COST-EFFECTIVENESS ASSOCIATED WITH BRANDED AND GENERIC IMATINIB FOR CHRONIC MYELOID LEUKEMIA IN THE UNITED STATES

Chronic myeloid leukemia (CML) is one of the prevalent types of leukemia in the United States. Since the approval of imatinib in 2001, the prognosis of the disease has significantly improved. Anecdotal concerns regarding the safety profiles of generic imatinib may influence the treatment choice between branded and generic imatinib. Additionally, the real-world healthcare expenditures and cost-effectiveness associated with potential safety events for generic imatinib remain unclear, as does the extent of price reduction for insurance payors and patients. The study objectives were to evaluate the comparative safety, healthcare expenditures, and cost-effectiveness of generic imatinib as frontline treatment for CML in the US. Using both MarketScan and SEER-Medicare databases, we examined the two-year hazard ratios of the first occurrence of safety outcomes using Cox proportional hazard regressions and stabilized inverse probability of treatment weighting. We assessed the monthly incidence rate ratio of any hospitalizations and the difference in hospital length of stay between the two cohorts. We then examined differences in healthcare expenditures, including insurance payouts and out-of-pocket responsibility, using quantile regressions at the median. Combining findings from both real-world safety and healthcare expenses, we conducted cost-effectiveness and cost-utility analyses over different time horizons. We observed no significant differences in the hazards for the first occurrence of any safety event. However, during the period of continued imatinib use, generic users were associated with a higher incidence rate in any hospitalizations. We also observed a significantly lower monthly healthcare expenditure among generic users, whereas the main driver of this cost difference was the insurance payouts. Additionally, we found that generic imatinib was cost-saving and cost-effective according to cost-utility and cost-effectiveness analyses.This study suggests that generic and branded imatinib may share similar short-term safety profiles, and that generic users may be associated with higher incidence of hospitalizations throughout their entire period of continued imatinib use. While generic users experienced lower monthly healthcare expenditures, these cost reductions predominantly benefited insurance plans, with little impact on patients. Overall, patients currently receiving branded imatinib can consider switching to generic imatinib when financial considerations play a significant role in their decision-making process.