An audit of the effectiveness of PCSK9 inhibition in reducing cholesterol in patients attending lipid clinics

Abstract

Introduction: Evolocumab and alirocumab are monoclonal antibodies that inhibit PCSK-9 and reduce LDl-C. This audit assessed the effectiveness of PCSK9 inhibitor administration in patients attending lipid clinics at regional and local centres. Methods: Data from patients in treated in accord with NICE Technology Appraisals TA394 and TA396 was obtained from the lipid clinics at Guy's & St. Thomas' Hospitals and Queen's Hospital, Burton-on-Trent. All patients had undergone a cardiovascular assessment and lipid measurements. Results: The 75 patients were aged 61.1+/-12.1 (average+/-SD) years and 33% were female. The indications for prescription were Familial Hypercholesterolaemia (75%); intolerance to >3 statins (67%), coronary heart disease with LDL-C>4 mmol/L (33%); multivascular disease and LDL-C>3.50 mmol/L (26%) and other (9%). Scripts were issued for Evolocumab (140mg; n=52) and Alirocumab (n=17; 12 receiving 150 mg and 5 75 mg respectively). Data was available for 43 patients who had completed more than 3 months treatment. Pre-treatment total cholesterol (TC) was 7.94+/-2.37 mmol/L, LDL-cholesterol (LDLC) 5.44+/-1.90 mmol/L, triglycerides (TG) median 1.89 (range 0.5-34.8) mmol/l and HDL-C 1.39+/-0.38 mmol/L. Post-treatment levels were TC 5.91+/-2.45 mmol/l, LDL-C 3.30+/-1.63 mmol/L, TG 1.67 (0.63-27.8) mmol/l and HDLC 1.42+/-0.4 mmol/L. The average reductions in lipids were a median 41 (range 90 to-35) %; (2.07+/-1.17 mmol/L) for LDL-C, and 27 (range 52 to-19)% (2.10+/-1.48 mmol/L) for TC respectively. Discontinuations were reported in 7 patients and 3 reported adverse effects (myalgia). A <25% LDL-C response was seen in 19% of patients. Conclusion: Treatment with PCSK9 inhibitor therapy is associated with a 41% reduction in LDL-C in qualifying patients who tolerate the medication but 19% fail to respond.