In familial hypercholesterolemia (FH) patients exposed to mipomersen for as long as 16 months, the safety profile of the drug continues to be encouraging. Reductions in low-density lipoprotein (LDL)-cholesterol were also maintained in patients who had responded to treatment in their initial study and continued on treatment.
In this open-label extension (OLE) study, patients with FH who were initially enrolled in one of two Phase II efficacy studies of mipomersen were allowed to enter the OLE study. All patients in the study were being treated with maximum-tolerated lipid-lowering therapy before and during the study. Most patients received 200mg/week of mipomersen in addition to maximum-tolerated lipid-lowering therapy. The median duration of continuous exposure in these patients was 38 weeks. The maximum continuous exposure was 64 weeks.
All patients in the study had the opportunity to self-administer mipomersen. Although the study was not designed to measure efficacy, the activity of mipomersen was clearly demonstrated and appeared to be well maintained with longer-term dosing. With respect to safety, the drug was well tolerated in longer-term treatment.