Background and Aims: Homozygous familial hypercholesterolemia (HoFH) is a hereditary lipid metabolism disorder characterized by severe elevation of low-density lipoprotein cholesterol (LDL-C) and heightened risk of premature atherosclerotic cardiovascular disease (ASCVD). Lomitapide, an inhibitor of microsomal triglyceride transfer protein, has shown promise in reducing LDL-C levels, albeit with variable response in real-world settings. Sex-based differences in treatment efficacy and safety remain unclear., Methods and Results: This post-hoc analysis of the Pan-European Lomitapide Study investigated sex-specific disparities in the efficacy and safety of lomitapide in HoFH patients (N=38 women and N=37 men). Data were collected from HoFH patients receiving lomitapide across Europe. Clinical characteristics, lipid profile, and adverse events were compared between women and men. Results indicate comparable baseline characteristics and cardiovascular risk factors between sexes. While LDL-C reduction was comparable at each time point between the two groups, women exhibited a trend towards greater reduction compared to men, particularly evident at 6 months (-53.0% vs -32.9% p=0.051). Annual LDL-C reduction did not differ between sexes (-4.83% ± 7.02 vs -4.03% ± 9.74 p=0.526). No differences in the median lomitapide dose or the intensity of concomitant lipid lowering therapies were observed between sexes. Notably, gastrointestinal disturbances were more prevalent in women (78 events in women vs 32 in men, p=0.0002), although most adverse events were manageable. Event-free survival curves for ASCVD did not significantly differ between sexes (p=0.363)., Conclusions: Lomitapide demonstrates comparable efficacy in reducing LDL-C levels in men and women with HoFH, with potential sex-specific variations in tolerability., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Daniele Tramontano received speaking fees from SOBI; Marcello Arca received research grant support and lecturing fees from Alfasigma, Amgen, Amryt, Daiichi Sankyo, Ionis Pharmaceuticals/Akcea Therapeutics, Novartis, Pfizer, Regeneron Pharmaceuticals, Sanofi, Sobi, Viatris, and Ultragenyx; Laura D'Erasmo received fees or grants from Amryt Pharmaceutical, Akcea Therapeutics, SOBI, Aurora Biofarma, Novartis, Amarin, Daiichi-Sankyo, Bayer, and Sandoz; Ilenia Calcaterra received honoraria for advisory board from SOBI, Bayer e Sanofi; Sergio D'Addato received honoraria for advisory board from Amryt; Livia Pisciotta has participated as PI in clinical trials with Amryt; Genovefa Kolovou has given talks and participated in trials sponsored by Amgen, Lilly, MSD, Novartis, Sanofi, Vianex and nonfinancial support from Amryt; Evangelos Liberopoulos has participated in educational, research and advisory activities sponsored by AstraZeneca, MSD, Lilly, Bayer, Amgen, Sanofi, Boehringer-Ingelheim, Novartis, Novo Nordisk, Viatris and Servier. Anja Vogt received honoraria or travel support from Aegerion, Akcea, Amgen, Amryt, Daiichi-Sankyo, MSD, Novartis, Regeneron/Sanofi; Jaimini Cegla has received speaker/consultancy fees or research grants from: Amgen, Sanofi, Pfizer, Amryt, Ultragenyx, Verve Therapeutics, Sobi, Novartis, Akcea, Silence Therapeutics; Meral Kayikcioglu has received honoraria from Abbott, Abdi Ibrahim, Chiesi, LIB Therapeutics, Novartis, NovoNordisk, TR-pharma, and Ultragenix; research funding from Amryt Pharma, and has participated in clinical trials with Amgen, Ionis, LIB Therapeutics, Novartis, Novo Nordisk; Sergio Martinez-Hervas received fees for speaker or advisory work from Amarin, Amgen, Amryt, Daiichi-Sankyo, Sanofi and Ultragenyx. The other authors have no conflicts of interest to declare., (Crown Copyright © 2024. Published by Elsevier B.V. All rights reserved.)