Aim: The alirocumab open-label extension study ODYSSEY OLE (NCT01954394) included patients diagnosed with heterozygous familial hypercholesterolaemia (HeFH) who had completed previous Phase 3 parent studies. Alirocumab is a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) and is administered subcutaneously in two dosages (75 mg or 150 mg every 2 weeks [75Q2W and 150Q2W, respectively]). This post-hoc analysis examined regional differences in physician dosing decisions.
Methods: Patients received a starting dose of alirocumab 75Q2W (patients from FH I, FH II and LONG TERM parent studies). LDL cholesterol (LDL-C) levels were blinded to the patient and physician until Week 8; subsequently, LDL-C values were communicated to physicians. From Week 12, dose adjustment from 75Q2W to 150Q2W, or vice versa, was possible based on the physician’s judgment.
Results: Mean LDL-C values used by physicians for the decision to increase the dose from 75Q2W to 150Q2W were higher in Eastern Europe and the rest of the world (ROW) compared with Western Europe and North America (Table); the differences in LDL-C between groups may be reflective of the regional variation between guidelines and clinical practices. Conversely, irrespective of region, the mean LDL-C at the time of decision to maintain at 75Q2W was approximately 1.8 mmol/L.
Conclusions: In this open-label extension study, we observed regional differences in the pattern of physicians’ decisions to adjust alirocumab dose in HeFH patients. This interesting finding suggests that physicians may perceive the severity of HeFH and/or the treatment thereof differently depending on their region.

01 - REGIONAL VARIATIONS IN ALIROCUMAB DOSING PATTERNS DURING AN OPEN-LABEL EXTENSION STUDY IN PATIENTS WITH HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLAEMIA