Effect of mipomersen on LDL-cholesterol in patients with severe LDL-hypercholesterolaemia and atherosclerosis treated by lipoprotein apheresis (The MICA-Study).

BACKGROUND AND AIMS: In this study, we evaluated the effect of mipomersen in patients with severe LDL-hypercholesterolaemia and atherosclerosis, treated by lipid lowering drugs and regular lipoprotein apheresis.

METHODS: This prospective, randomized, controlled phase II single center trial enrolled 15 patients (9 males, 6 females; 59 ± 9 y, BMI 27 ± 4 kg/m2 ) with established atherosclerosis, LDL-cholesterol ≥130 mg/dL (3.4 mmol/L) despite maximal possible drug therapy, and fulfilling German criteria for regular lipoprotein apheresis. All patients were on stable lipid lowering drug therapy and regular apheresis for >3 months. Patients randomized to treatment (n = 11) self-injected mipomersen 200 mg sc weekly, at day 4 after apheresis, for 26 weeks. Patients randomized to control (n = 4) continued apheresis without injection. The primary endpoint was the change in pre-apheresis LDL-cholesterol.

RESULTS: Of the patients randomized to mipomersen, 3 discontinued the drug early (<12 weeks therapy) for side effects. For these, another 3 were recruited and randomized. Further, 4 patients discontinued mipomersen between 12 and 26 weeks for side effects (moderate to severe injection site reactions n = 3 and elevated liver enzymes n = 1). In those treated for >12 weeks, mipomersen reduced pre-apheresis LDL-cholesterol significantly by 22.6 ± 17.0%, from a baseline of 4.8 ± 1.2 mmol/L to 3.7 ± 0.9 mmol/L, while there was no significant change in the control group (+1.6 ± 9.3%), with the difference between the groups being significant (p=0.02). Mipomersen also decreased pre-apheresis lipoprotein(a) (Lp(a)) concentration from a median baseline of 40.2 mg/dL (32.5,71) by 16% (-19.4,13.6), though without significance (p=0.21).

CONCLUSIONS: Mipomersen reduces LDL-cholesterol (significantly) and Lp(a) (non-significantly) in patients on maximal lipid-lowering drug therapy and regular apheresis, but is often associated with side effects.