Effect of the copayment reduction system on accessibility to orphan drugs in South Korea.

Objective: This study aims to analyze the effect of the copayment reduction system on accessibility to orphan drugs (ODs) in South Korea.

Methods: Data on approval and reimbursement for drugs designated as ODs for the last 10 years (2012-2021) in South Korea were extracted. Among them, with 136 approved products as of 31 December 2022, the reimbursement rates and lead time to reimbursement between drugs for rare diseases (DRDs) and nondrugs for rare diseases (non-DRDs) were analyzed. The pricing and reimbursement (P&R) pathways between drugs for only rare diseases (DORDs) and drugs for rare and cancerous diseases (DRCDs) were compared.

Results: The reimbursement rates for DRDs and non-DRDs were 54.8% and 33.3%, respectively, and the lead time to reimbursement for DRDs and non-DRDs were 16.1 months and 31.2 months, respectively. The P&R pathways for DORDs and DRCDs were pharmacoeconomic evaluation waivers (21.7% and 52.6%), weighted average price (52.2% and 13.2%), and risk-sharing agreement (30.4% and 81.6%).

Conclusion: The copayment reduction system may act as a driver and also barrier for the reimbursement of ODs. To expand treatment accessibility to ODs, it is necessary to consistently grants benefits in all processes from OD designation to market access.