Cost-Effectiveness of Adjuvant Abemaciclib and Ribociclib in High-Risk Hormone Receptor–Positive Early Breast Cancer: An Indian Perspective

PURPOSE Incorporating adjuvant cyclin-dependent kinase (CDK) 4/6 inhibitors abemaciclib and ribociclib along with endocrine therapy has been shown to improve invasive disease-free survival (iDFS) for hormone receptor–positive (HR+) human epidermal receptor 2–negative (HER2–) early breast cancer (EBC). This study assesses the cost-effectiveness of this strategy, along with adjuvant aromatase inhibitors from an Indian perspective. METHODS A Markov chain model evaluated the cost-effectiveness of abemaciclib and ribociclib with letrozole compared with letrozole alone for HR+/HER2– EBC from a payer perspective in India. Key measures included lifetime quality-adjusted life-years (QALY), life-years (LY), and total costs. This study explores two scenarios for effectiveness: a best-case (BC) scenario, where the benefit of CDK4/6 inhibitors in improving iDFS lasts a lifetime, and a worst-case (WC) scenario, where benefits disappear after 5 years. Probabilistic sensitivity analyses (PSA) were used to account for simulation uncertainty. RESULTS In the BC scenario, abemaciclib added 2. 17 QALY and 4. 96 LY, incurring ₹2, 317, 957. 7 (27, 756. 65 in US dollars USD) in additional costs. However, the incremental cost-effectiveness ratio (ICER) for abemaciclib exceeded India's willingness-to-pay threshold in the BC and WC scenarios. In the BC scenario, ribociclib added 0. 98 QALY and 2. 58 LY with added costs of ₹1, 711, 504. 32 (20, 494. 6 USD). The ICER for ribociclib also surpassed India's threshold in both scenarios. PSA showed that neither drug was cost-effective at the current market prices in either BC/WC scenario. The cost of abemaciclib and ribociclib needs to be reduced by at least 78. 61% and 87. 19%, respectively, to be cost-effective in the BC scenario. CONCLUSION The combination of adjuvant abemaciclib or ribociclib with letrozole is not cost-effective for HR+/HER2– EBC in India in either the BC or WC scenario.