Efficacy and safety of ezetimibe 40 mg vs. ezetimibe 10 mg in the treatment of patients with homozygous sitosterolaemia.

OBJECTIVE

To assess the effect of ezetimibe (EZE) 40 mg/day on non-cholesterol sterol plasma concentrations in patients with homozygous sitosterolaemia (HoS).

METHODS

This was a multi-centre, randomised, double-blind, placebo-controlled parallel group study. Twenty-seven patients (> or = 18 years) with HoS and plasma sitosterol levels > 5 mg/dl who had been taking EZE 10 mg/day for > or = 6 months prior to enrolment received open-label EZE 10 mg/day for the duration of the study and were randomised 1 : 1 to blinded EZE 30 mg/day (4 x EZE 10 mg tablets; n = 13) or placebo (1 x EZE 10 mg tablet and 3 x matching placebo tablets; n = 14) for 26 weeks. Patients were permitted to remain on other ongoing treatments (e.g. bile salt-binding resin, statin and/or low sterol diet). End-points included median per cent between-group changes from baseline in plasma sitosterol, campesterol, lathosterol, low-density lipoprotein (LDL) sterols, LDL cholesterol (LDL-C) measured by gas-liquid chromatography, and Achilles tendon thickness size measured radiographically.

RESULTS

Ezetimibe 40 mg/day resulted in median per cent changes from baseline in plasma sitosterol levels of 3.3% vs. -10% in the EZE 10 mg/day group, in plasma campesterol of -0.5% vs. -9.7% in the EZE 10 mg/day group, and in plasma lathosterol of 0.8% vs. 1.1% in the EZE 10 mg/day group (p = ns for all between-group differences). Median per cent changes in the EZE 40 mg/day and EZE 10 mg/day groups, respectively, were 1.3% and 0% for LDL sterols and 2.5% and 4.4% for LDL-C (p = ns for both between-group differences). At study end-point, Achilles tendon thickness remained unchanged in the EZE 40 mg/day group and increased slightly in the EZE 10 mg/day group (2.2%), yielding a non-significant between-group difference of -2.2%. EZE 40 mg/day was generally well tolerated.

CONCLUSIONS

In patients with HoS, treatment with EZE 40 mg/day for 26 weeks was no more effective at reducing plasma plant sterol concentrations vs. EZE 10 mg/day. EZE 40 mg/day had a safety and tolerability profile similar to EZE 10 mg/day.