Recaticimab in adult heterozygous familial hypercholesterolemia (REMAIN-3): A multicentre, randomised, double-blind, placebo-controlled phase 3 study

Aims Heterozygous familial hypercholesterolemia (HeFH) is a genetic disorder, characterised by high plasma concentrations of low-density lipoprotein cholesterol (LDL-C) from birth. This study aimed to assess the efficacy and safety of recaticimab, a new humanised anti-PCSK9 antibody capable of reducing LDL-C levels in patients with poorly controlled HeFH. Methods and Results REMAIN-3 was a multicentre, randomised, double-blind, placebo-controlled phase 3 study done at 25 sites in China. Patients with a genetic or clinical diagnosis of HeFH, who were on stable lipid-lowering therapy for ≥28 days, had fasting LDL-C ≥2.6 mmol/L (or ≥1.8 mmol/L for those with a history of atherosclerotic cardiovascular disease), and had fasting triglyceride ≤5.6 mmol/L, were randomly allocated in a 2:1 ratio to receive subcutaneous recaticimab at 150 mg or matching placebo every 4 weeks for 12 weeks. The primary endpoint was the percentage change in LDL-C from baseline to week 12. Overall, 143 patients underwent randomisation and received recaticimab (n = 95) or placebo (n = 48). At week 12, the mean percentage change in LDL-C from baseline was -54.4% (95% CI, -57.9% to -50.8%) in the recaticimab group and -4.5% (95% CI, -9.4% to 0.3%) in the placebo group, with a treatment difference of -49.8% (95% CI, -55.8% to -43.9%; p < 0.0001). Recaticimab was superior to placebo in improving other lipid variables, including non-high-density lipoprotein cholesterol, apolipoprotein B, and lipoprotein a. Treatment-related adverse events (TRAEs) were comparable between groups (27.4% with recaticimab vs. 25.0% with placebo). The most common TRAEs occurring more frequently with recaticimab than placebo were injection site reaction (8.4% vs. 0%) and increased blood creatine phosphokinase (5.3% vs. 2.1%). Conclusions Recaticimab significantly lowered the LDL-C level compared with placebo, with an acceptable safety profile, providing a new effective treatment option for patients with inadequately controlled HeFH. ClinicalTrials.gov Identifier NCT04844125