Last updated on 05 November 2025

The essential

UNITY is a phase III, multi-country, randomized, placebo-controlled, double-blinded trial to assess the efficacy and safety of tecovirimat antiviral treatment for patients with mpox virus disease

ANRS 0576s UNITY is an international trial (Argentina, Brazil and Switzerland) aiming to assess the efficacy and safety of tecovirimat as an antiviral treatment in adults and adolescents (14 years old and older) with a confirmed mpox virus infection. The study includes one arm where participants are randomised to receive either the active drug or placebo, and an open-label arm to provide tecovirimat to participants with severe manifestation of the diseases or at risk of severe complications.
Detailed analyses will also enable to establish the relationship between the concentration of tecovirimat in blood and tissues and its efficacy, and to study potential resistance of the virus to tecovirimat.

Main objectives of UNITY

The primary objective is to evaluate the clinical efficacy, assessed as time to all visible lesion(s) resolution, of tecovirimat treatment + Standard of Care (SOC) compared to placebo + SOC for patients with mpox infection.

The UNITY trial is part of the MPX-RESPONSE project, which aims to improve knowledge about mpox, evaluate potential treatments, and strengthen Europe’s overall preparedness for emerging infectious disease outbreaks.

MPX-Response

Scientific publications

Telford E, Grinsztejn B, Olsen IC, Pulik N, Mentré F, Haviari S, Hentzien M, Ségéral O, Ekkelenkamp MB, Ogoina D, Strub-Wourgaft N, Diallo A, Yazdanpanah Y, Calmy A. The international Unity study for antivirals against mpox is a blueprint for future epidemics. Nat Med. 2023 Aug;29(8):1894-1895. doi: 10.1038/s41591-023-02393-6. PMID: 37391664.