Assessing the Safety of a Novel Monoclonal Antibody Cocktail for Postexposure Prophylaxis in Category III Animal Exposures.

Background: TwinRab™ is a novel life-saving biological containing two monoclonal antibodies (docaravimab and miromavimab) essential for all age victims of category III animal exposures. It effectively neutralizes rabies and similar viruses at the exposure site until the body generates vaccine-induced antibodies. This postmarketing surveillance study assesses the safety of TwinRab™ in current postexposure prophylaxis (PEP) use and aims to reinforce its safety data for future applications.

Methods: The prospective, open-label observational study was conducted on patients with the World Health Organization category III animal exposures at a government hospital in a northern region of India, by a suspected rabid animal. The study protocol included administering TwinRab™ (40 IU/kg) and a full course of anti-rabies vaccination as PEP.

Results: Out of 405 participants, 404 completed the study as per the protocol. Adverse events (AEs) occurred in 12.35% of cases, with 9.88% local AEs (primarily pain and tenderness) and 2.47% systemic AEs (fever, malaise, and myalgia). All AEs were mild and resolved without complications. Most participants (88.9%) and investigators (89.1%) rated TwinRab™'s tolerability as excellent.

Conclusion: The present study demonstrates the evidence of a satisfactory safety profile along with better tolerability of TwinRab™ (40 IU/kg) for category III animal exposures and supports its continued usage.