A Clinical Study Investigating the Safety and Immune Responses After Immunization With Investigational Monkeypox Vaccines

Summary

This is a dose-escalation, Phase I/II study evaluating the safety, tolerability, reactogenicity and immunogenicity of the investigational RNA-based multivalent vaccine candidate BNT166a for active immunization against monkeypox (mpox). This study started with substudy A (SSA) and substudy B (SSB) for which recruitment has been completed. A Substudy C (SSC) was planned, but the sponsor decided not to conduct it. This study will therefore continue with substudy D (SSD). In SSA and SSB, dosing started with an initial sentinel group, followed by the expansion cohort. This study was initially planned to investigate two vaccine candidates (the quadrivalent BNT166a and the trivalent BNT166c). The sponsor decided to not activate the groups with BNT166c.

Timeline

Start

2023-09-21

Primary completion

2025-08-25

Completion

2026-03-04

Publications

• Bahner F, Faust SN, Davies LRL, Blokhina O, Brandon DM, Smith WB, Chatterjee VKK, Hassanin H, Babu TM, Zuiani A, Steinhauser S, Poran A, Brittain C, Mucker E, Hooper JW, van der Most RG, Alonso PL, Tureci O, Mensa FJ, Sahin U. Safety and immunogenicity of mRNA-based mpox vaccine candidate BNT166a: an open-label, dose-escalation, first-in-human trial. Lancet Infect Dis. 2026 Jun 3:S1473-3099(26)00177-5. doi: 10.1016/S1473-3099(26)00177-5. Online ahead of print.
• Zuiani A, Dulberger CL, De Silva NS, Marquette M, Lu YJ, Palowitch GM, Dokic A, Sanchez-Velazquez R, Schlatterer K, Sarkar S, Kar S, Chawla B, Galeev A, Lindemann C, Rothenberg DA, Diao H, Walls AC, Addona TA, Mensa F, Vogel AB, Stuart LM, van der Most R, Srouji JR, Tureci O, Gaynor RB, Sahin U, Poran A. A multivalent mRNA monkeypox virus vaccine (BNT166) protects mice and macaques from orthopoxvirus disease. Cell. 2024 Mar 14;187(6):1363-1373.e12. doi: 10.1016/j.cell.2024.01.017. Epub 2024 Feb 15.

Drugs

Indications