Alirocumab (Praluent®), a proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitor that has been co-developed by Regeneron Pharmaceuticals, Inc. and Sanofi (formerly sanofi-aventis), is approved globally for use in adults with established cardiovascular disease, primary hyperlipidemia [including heterozygous familial hypercholesterolemia (HeFH) or homozygous familial hypercholesterolemia (HoFH)]. In November 2023, based on clinical data in patients aged 8–17 years, alirocumab received its first pediatric approval in the EU as an adjunct to diet alone, or in combination with a statin and/or other low-density lipoprotein cholesterol (LDL-C)-lowering therapies, in pediatric patients aged ≥ 8 years with HeFH. Alirocumab was approved a few months later in the US for use as an adjunct to diet and other LDL-C-lowering therapies in pediatric patients aged ≥ 8 years with HeFH to reduce LDL-C. This article summarizes the milestones in the development of alirocumab leading to this first pediatric approval for HeFH.