Efficacy and Safety of Evolocumab and Alirocumab as PCSK9 Inhibitors in Pediatric Patients with Familial Hypercholesterolemia: A Systematic Review and Meta-Analysis

Background and Objectives: The proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors evolocumab and alirocumab are recently developed promising drugs used for treatment of familial hypercholesterolemia (FH). This systematic review and meta-analysis aimed to thoroughly evaluate the efficacy and safety of evolocumab and alirocumab among pediatric patients with FH. Materials and Methods: A comprehensive search was conducted in PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and ClinicalTrials.gov from inception through July 2024 to identify primary interventional studies among pediatric patients with FH. Meta-analyses were performed if appropriate. Statistics were analyzed using Review Manager version 5.4 and Stata version 16.0. Results: Fourteen articles reporting nine unique studies were included. There were three randomized controlled trials (RCTs) assessing evolocumab or alirocumab involving a total of 320 pediatric patients, one cross-over trial and five single-arm or observational studies. Pooled results showed significant efficacy of evolocumab/alirocumab in reducing low-density lipoprotein cholesterol (LDL-C) (weighted mean difference [WMD]: -37.92%, 95% confidence interval [CI]: -43.06% to -32.78%; I2 = 0.0%, p = 0.60), apolipoprotein B (WMD: -33.67%, 95% CI: -38.12% to -29.22%; I2 = 0.0%, p = 0.71), and also lipoprotein(a) (WMD: -16.94%, 95% CI: -26.20% to -7.69%; I2 = 0.0%, p = 0.71) among pediatric patients with FH. The efficacies of evolocumab/alirocumab on LDL-C reduction within pediatric patients with heterozygous FH (HeFH) were consistent between studies, whereas in patients with homozygous FH (HoFH), it varied dramatically. Pediatric patients with the null/null variant may respond to the treatment. PCSK9 inhibitors were generally well tolerated within most pediatric patients, in line with previous studies among adult populations. Conclusions: The PCSK9 inhibitors evolocumab/alirocumab significantly reduced LDL-C and some other lipid parameters, such as apolipoprotein B, in pediatric patients with HeFH. These drugs may be appropriate as a potential therapy for pediatric patients with HoFH who cannot achieve LDL-C targets with other treatments. Evolocumab/alirocumab was generally well tolerated in the pediatric population.