Effectiveness and safety of PCSK9 inhibitors in real-world clinical practice. An observational multicentre study. The IRIS-PCSK9I study

BACKGROUND AND AIMS: The benefits of the PCSK9 inhibitors, alirocumab and evolocumab, in lowering LDL-cholesterol and preventing major adverse cardiac events (MACE) have been demonstrated in pivotal clinical trials. However, few studies of routine clinical practice have been conducted to analyse and compare the efficacy and safety of the two drugs. METHODS: Retrospective observational study of patients treated with a PCSK9 inhibitor in five hospitals in Andalusia (southern Spain). Baseline demographic and clinical data, LDL-cholesterol levels and the occurrence of MACEs during the follow-up period were recorded. RESULTS: A total of 141 patients were included in the study: 90 were treated with alirocumab and 51 with evolocumab. The patients’ mean age (IQR) was 58 (11) years and 58 (41%) were women. The most frequent concomitant medications were statins, 94 (66.7%), followed by antiplatelet therapy (66%) and ezetimibe (65.2%). The median (IQR) follow-up period was 18 (18) months, with 18 (24) for alirocumab and 11 (18) for evolocumab. At the six-month follow-up visit, LDL-cholesterol values had decreased to pre-treatment levels and remained significantly decreased (p < 0.05) over time, for both drugs, and a greater reduction was achieved in patients with established cardiovascular disease and concomitant treatment with statins. With respect to adverse effects, there were nine MACEs (6.4%), of which seven were with alirocumab (7.8%) and two with evolocumab (3.9%) (p NS). Other adverse effects (9.2%) included local erythema (3.5%), muscle cramps (2.1%), respiratory symptoms (2.1%) and asthaenia (1.4%). CONCLUSIONS: The efficacy and safety of alirocumab and evolocumab in routine clinical practice are consistent with the findings of the pivotal clinical trials.