Formulation-Specific Safety Issues of HIV Pre-exposure Prophylaxis Drugs: A Disproportionality Analysis of the FAERS Database.

BACKGROUND AND

OBJECTIVE

As human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) use expands, real-world post-marketing safety evidence remains limited, particularly regarding potential formulation-specific adverse-event patterns across oral and long-acting agents. We aimed to characterise the post-marketing safety profiles of FDA-approved PrEP drugs using the FDA Adverse Event Reporting System (FAERS).

METHODS

We conducted a disproportionality analysis using the FDA Adverse Event Reporting System (FAERS) data from 2012 to 2024. Individual Case Safety Reports (ICSRs) listing emtricitabine/tenofovir disoproxil fumarate (FTC/TDF), emtricitabine/tenofovir alafenamide (FTC/TAF) or cabotegravir (CAB) as suspected PrEP drugs were included. Two comparator groups were used: all non-PrEP ICSRs and ICSRs involving non-PrEP HIV drugs. Disproportionality was evaluated at the MedDRA high-level term (HLT) level using reporting odds ratios and 95% confidence intervals (CIs), identifying signals of disproportionate reporting (SDRs) with a lower bound of the 95%CIs > 1. Sensitivity analyses explored sex, reporter type, and indication.

RESULTS

We identified 3201 PrEP-related ICSRs (FTC/TDF: 2688; FTC/TAF: 463; CAB: 50), predominantly involving young adult males. FTC/TDF exhibited a broad pattern of SDRs-including renal/metabolic abnormalities, muscular signals, mucosal disorders and some previously under-characterised signals-many of which attenuated when using HIV-treated comparators. FTC/TAF showed a narrower, highly consistent pattern dominated by hepatobiliary and metabolic monitoring procedures, renal function evaluations and neurosensory disturbances. CAB showed specific, reproducible signals for injection-site, dermatologic and procedure-related events.

CONCLUSIONS

PrEP agents display distinct, formulation-specific and reproducible safety patterns in FAERS. Comparator choice substantially influences the detection and interpretation of SDRs and can help distinguish reproducible formulation-related reporting patterns from findings that may be driven by the clinical and reporting context. These insights highlight priority areas for future research.