Usefulness of Gemcabene in Homozygous Familial Hypercholesterolemia (from COBALT-1)

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by severely elevated plasma low-density lipoprotein-cholesterol (LDL-C), and premature atherosclerotic cardiovascular disease. Depending on residual LDL receptor (LDLR) function, most HoFH patients respond modestly to statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. However, LDL-C typically remains markedly elevated necessitating additional therapies, including apheresis. Gemcabene is a novel lipid-lowering agent with a mechanism of action independent of the LDLR, which has previously demonstrated the ability to reduce levels of LDL-C on top of maximally tolerated statins. The present study (COBALT-1) assessed efficacy, tolerability, and safety of gemcabene as an adjunctive therapy to current lipid-lowering treatment for familial hypercholesterolemia patients. Eight patients with either a clinical or genetic diagnosis of HoFH on stable standard of care, including statins, ezetimibe, and PCSK9 inhibitors, were treated with gemcabene in an open-label study for 12 weeks. DNA analysis for mutations in the LDLR, apolipoprotein B, and PCSK9 genes was performed. Patients received 300 mg gemcabene for the first 4 weeks, 600 mg for the next 4 weeks, and 900 mg for the final 4 weeks. All patients completed the 12-week study. Mean change from baseline in LDL-C was -26% (p = 0.004) at Week 4 (300 mg), -30% (p = 0.001) at Week 8 (600 mg), and -29% (p = 0.001) at Week 12 (900 mg). In conclusion, the COBALT-1 study demonstrates gemcabene has potential to significantly reduce LDL-C levels when used as an adjunctive therapy to current lipid-lowering treatment for familial hypercholesterolemia patients.