Efficacy, Safety, and Pharmacokinetics of Inclisiran in Japanese Patients: Results from ORION-15.

Aim: To evaluate the efficacy, safety, and pharmacokinetics (PK) of inclisiran in Japanese patients with high cardiovascular risk and elevated low-density lipoprotein cholesterol (LDL-C).

Methods: ORION-15 was a phase 2, double-blind, placebo-controlled randomized trial. Patients with hypercholesterolemia, including heterozygous familial hypercholesterolemia (HeFH), were randomized to inclisiran sodium 100, 200, or 300 mg, or placebo and dosed subcutaneously on Days 1, 90, and 270. The primary endpoint was the percentage change from baseline to Day 180 to demonstrate the superiority of inclisiran vs. placebo. Patients who consented to the PK substudy had additional study procedures for blood collection and safety assessment.

Results: Overall, 312 patients (mean age, 63.6 years; male, 74.4%; baseline LDL-C, 114.0 mg/dL) were randomized. Baseline characteristics were well balanced among the groups. At Day 180, inclisiran at all doses demonstrated significant LDL-C and proprotein convertase subtilisin/kexin type 9 (PCSK9) reductions (p＜0.0001 for both), which showed a dose-response relationship. The greatest reductions (LDL-C, 65.3%; PCSK9, 79.2%) were with inclisiran sodium 300 mg. At Day 180, ＞86% of the patients receiving inclisiran achieved the Japan Atherosclerosis Society 2017 lipid management targets compared to 8.9% for placebo. The mean (SD) plasma half-life for inclisiran was 6.8 (2.0)-7.6 (0.8) h. The incidence of adverse events with inclisiran was similar to that with placebo.

Conclusion: Inclisiran sodium 100, 200, and 300 mg demonstrated clinically meaningful and statistically significant LDL-C and PCSK9 reductions at Day 180, which were consistent over 12 months. Inclisiran was effective and well tolerated in Japanese patients with hypercholesterolemia, including HeFH.