The European Medicines Agency (EMA), through its Committee for Medicinal Products for Human Use (CHMP), has recommended that Tecovirimat SIGA should no longer be used for the treatment of mpox, following a comprehensive review of clinical data. The decision, however, does not impact the medicine’s approved use for treating smallpox, cowpox and complications arising from smallpox vaccines.

Mpox is a viral infection characterised by fever, swollen lymph nodes, muscle aches and a distinctive rash with fluid-filled lesions. While most cases are mild, the disease can lead to severe complications in vulnerable populations, including children, pregnant individuals and immunocompromised patients.

The CHMP’s recommendation is based on findings from four clinical studies—PALM007, STOMP, UNITY and PLATINUM-UK—which consistently showed that Tecovirimat SIGA did not significantly improve outcomes in patients with active mpox lesions. The studies found no meaningful difference between the antiviral and placebo in terms of faster lesion healing, pain relief or viral clearance.

Originally authorised under exceptional circumstances, Tecovirimat SIGA’s approval for mpox was based on animal model data due to limited human cases at the time. However, subsequent outbreaks enabled human clinical trials, which failed to confirm its efficacy when administered to patients with established symptoms.

Despite the lack of effectiveness in mpox treatment, the EMA noted that no new safety concerns were identified during the review. The recommendation also takes into account additional data from global access programmes, epidemiological studies, and laboratory research.

The restriction is limited specifically to mpox treatment, as the clinical context and disease progression differ from other orthopoxvirus infections such as smallpox and cowpox. The EMA emphasised that existing authorisations for these conditions remain valid.

There are currently no other medicines authorised in the European Union specifically for the treatment of mpox. Patients who have already started treatment with Tecovirimat SIGA may continue their course, while new patients are advised not to initiate therapy for mpox.

The CHMP’s opinion will now be forwarded to the European Commission for a final decision, after which updated guidance will be communicated to healthcare professionals across EU member states.