Background: The addition of a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to statin therapy reduces the rate of cardiovascular events. This study examined the cost-effectiveness of PCSK9 inhibitor+statin compared with standard therapy (statin monotherapy) in the treatment of triple-vessel coronary artery disease (CAD) in Japan.

Methods and Results: A Markov model was applied to assess the costs and benefits associated with PCSK9 inhibitor+statin over a projected 30-year period from the perspective of a public healthcare payer in Japan. The incremental cost-effectiveness ratio (ICER), expressed as the quality-adjusted life-years (QALYs), was estimated. The effects on survival and numbers of events were based on the FOURIER trial and the CREDO Kyoto registry. The ICER of PCSK9 inhibitor+statin over standard therapy was 13.5 million (95% confidence interval 7.6–23.5 million) Japanese Yen (JPY) per QALY gained for triple-vessel CAD. The probability of the cost-effectiveness of PCSK9 inhibitor+statin vs. standard therapy was 0.0008% at a cost-effectiveness threshold of 5 million JPY. In patients with poorly controlled familial hypercholesterolemia (FH) with triple-vessel CAD, the ICER was 3.4 million JPY per QALY gained.

Conclusions: PCSK9 inhibitor plus statin did not show good cost-effectiveness for triple-vessel CAD; however, it showed good cost-effectiveness for patients with triple-vessel CAD and poorly controlled FH in Japan.