Safety of Monoclonal Antibodies Inhibiting PCSK9 in Pregnancy: Disproportionality Analysis in VigiBase®

Safety data on the use of monoclonal antibodies inhibiting proprotein convertase subtilisin/kexin type 9 in pregnancy are scarce. This study queried VigiBase®, the World Health Organization global pharmacovigilance database, to search for signals of disproportionate reporting for pregnancy outcomes with alirocumab and evolocumab. As of November 22, 2023, there were 45 safety reports of exposure to evolocumab (N = 31) and alirocumab (N = 14) in pregnancy. Most of them originated from Europe (N = 25, 55.6%) and were more frequently reported by healthcare professionals (N = 35, 77.8%). Median patient age was 37 years (25th-75th percentiles; 32-41 years). Drug exposure occurred during pregnancy in 36 (80.0%) safety reports, via paternal exposure during pregnancy in four (8.9%), during lactation in three (6.7%), and in two safety reports the time of drug exposure remained unknown. Twenty safety reports (57.8%) merely reported drug exposure, while 19 (42.2%) also reported pregnancy outcomes, however, without specific maternal toxicities or patterns of birth defects. Spontaneous abortion was reported in eight safety reports without representing a signal of disproportionate reporting compared with either the full database (reporting odds ratio, ROR, 0.06 95% confidence interval, CI 0.03-0.12) or statins (ROR 0.16, 95% CI 0.08-0.32). In conclusion, this study showed that, currently, there are no signals of increased reporting of spontaneous abortion with alirocumab and evolocumab compared with the full database and statins in VigiBase®. Notwithstanding, lack of disproportionality is not synonymous with safety and, as disproportionality analyses depend on the number of safety reports that progressively accumulate in VigiBase®, they should be repeated at regular intervals to confirm the results of the present study.