Antivirals and therapeutic monoclonal antibodies (AvATher) Workgroup

Last updated on 27 November 2025

In brief

AvATher is an expert advisory group that provides evidence-based advice on antiviral compounds and monoclonal antibodies targeting Covid-19, as well as other respiratory viruses, in late preclinical or clinical development.

Objective

Initially designed to evaluate antiviral drugs against Covid-19, AvATher is extending its scope to other respiratory viruses (Coronavirus, influenza, RSV, other viruses considered to be priority pathogens). The group  works with the agency’s other facilitation groups, in particular the Coordinated Action on Respiratory Viruses and the GEPC Preclinical Studies Group.

In the event of an epidemic crisis caused by other pathogens (viral haemorrhagic fever, Arbovirus, etc.), the group may exceptionally be asked to issue opinions and/or recommendations, or to appraise clinical trials concerning new antiviral candidates potentially active against the pathogen.

Activities

In particular, the AvATher group is responsible for :

  • issuing advisory opinions for health authorities and/or clinicians on antiviral drugs in advanced clinical development. This especially applies to Covid-19, which can still cause severe forms of the virus in at-risk populations, such as immunocompromised individuals.
  • maintaining an active scientific watch on the literature concerning antivirals (available or under development) within the Group’s scope.
  • evaluating the therapeutic potential and prioritising antiviral candidates in order to promote/facilitate their clinical evaluation within one of the national or European clinical research platforms.
  • advising decision-making bodies on the relevance of considering the clinical evaluation or inclusion in the French therapeutic arsenal of a specific antiviral in a given indication.

Chair and Co-Chair


Lionel Piroth
Dijon University Hospital


Laurence Weiss
Paris Cité University

Members

Claire Andrejak (Amiens University Hospital)
Yvanie Caillé (Association Renaloo)
Alban Dhanani (ANSM)
Alexandre Duvignaud (Bordeaux University Hospital)
Slim Fourati (APHP-Hospital Henri-Mondor)
François Goehringer (Nancy Hospital – Hôpitaux de Brabois)
Jérémie Guedj (Inserm)
Thomas Maitre (APHP, Paris)

Robert Manfredi (French Ministry of Health and Prevention /Population Health Division)
Guillaume Martin-Blondel (Toulouse University Hospital)
Mathieu Molimard (Bordeaux University)
Meena Murmu (ANRS MIE)
Delphine Planas (Pasteur Institute, Paris)
Franck Touret (Aix-Marseille University)
Astrid Vabret (Caen University Hospital)
Hervé Watier (Tours University)

Discover the Assessment of the Potential Role of Ensitrelvir in COVID-19 Prevention and Treatment by the AvATher WG

The AvATher expert group met on 13 November 2025 following a mandate from the Directorate General for Health (DGS) to assess the potential role of ensitrelvir in the prevention and treatment of COVID-19. This opinion reviews the available clinical evidence, the current epidemiological situation in France, and the relevance of integrating this antiviral into national strategies. The conclusions presented here reflect the collective analysis and consensus of the AvATher group.

 

SARS-CoV-2: opinion of the AvATher Group on KAVIGALE® (sipavibart)

This document is the response to the request from HAS for a complementary opinion regarding the coverage of KAVIGALE® (sipavibart) under the standard reimbursement framework. It presents the opinion of the AvATher group, particularly on the product’s efficacy in light of the current epidemiological context of circulating SARS-CoV-2 variants and on the relevance of its use in the COVID-19 prophylaxis strategy.

Discover the report from the AvATher group on Onradivir

This document presents scientific exchanges between AvATher and Guangdong Raynovent Biotech Co., Ltd. (China) that took place on March 13, 2025, on Onradivir, a novel antiviral treatment for Influenza.

This meeting report details:

  • Preclinical assessments of Onradivir’s efficacy
  • Key clinical trial findings
  • Published safety and effectiveness data

A central focus is AvATher’s expert perspective on Onradivir’s therapeutic potential, especially in combination therapies pairing a PB2 inhibitor with a neuraminidase inhibitor for enhanced antiviral strategies.

Influenza A: opinion from the AvATher group on Xofluza® (baloxavir marboxil)

This document presents the opinion of the AvATher group issued on February 18, 2025, regarding baloxavir marboxil (Xofluza®), a cap-dependent endonuclease inhibitor, in the context of the increasing outbreaks of highly pathogenic avian influenza (HPAI) H5N1 and the emergence of human cases of influenza A (H5N1).

The opinion outlines the antivirals currently authorized in the European Union and analyzes the available data on the virological and pharmacological efficacy of Xofluza®, particularly in comparison with other existing treatments. It also examines aspects related to virus transmission, administration protocols, and resistance management. Additionally, the document discusses relevant clinical studies and potential public health implications, particularly in comparison with oseltamivir.

Covid-19: Opinions issued by the AvATher group