The effect of lomitapide on cardiovascular outcome measures in homozygous familial hypercholesterolemia: A modelling analysis.

Background Patients with homozygous familial hypercholesterolemia are at high risk of cardiovascular disease due to high low-density lipoprotein (LDL)-cholesterol levels. Cardiovascular disease outcome studies are impossible to conduct, due to the rarity of homozygous familial hypercholesterolemia. We modelled the potential efficacy of lomitapide, a microsomal transfer protein inhibitor, on major adverse cardiovascular events (MACEs) and survival. Design We calculated the effect on cardiovascular outcomes of a 38% plasma LDL-cholesterol reduction induced by lomitapide. Methods Age-dependent hazards and treatment-dependent hazard ratios for mortality and time to first MACE were calculated from an observational study of 149 South African homozygous familial hypercholesterolemia patients. Cardiovascular-related mortality hazards were derived by adjusting for general population non-cardiovascular-related mortality. For every mmol/L LDL-cholesterol reduction, a relative risk reductions of 23% (mortality) and 15% (major adverse cardiovascular events) were observed. Results For the most robust model, baseline median survival with current treatments (LDL-cholesterol 8.7 mmol/L) was 48 years. In the survival benefit analysis, starting lomitapide at age 18 years and reducing LDL-cholesterol by 3.3 mmol/L from baseline would increase life expectancy by 11.2 years and delay the time to first MACE by 5.7 years. Analysis suggested lifetime lomitapide treatment could increase median life expectancy by 11.7 years and time to first MACE by 6.7 years. Conclusion Our modelling analyses show that additional LDL-cholesterol lowering by lomitapide may increase life expectancy in patients with homozygous familial hypercholesterolemia. Further clinical studies are warranted to determine the cardiovascular morbidity and mortality benefits of lomitapide.