Xervyteg (Allogeneic faecal microbiota, pooled)

Where it stands

Xervyteg (allogeneic faecal microbiota, pooled), developed by MaaT PHARMA, received a negative opinion from the EMA's Committee for Medicinal Products for Human Use (CHMP) on 17 September 2026. The record is classed as official. The proposed indication was treatment of adult patients with acute graft-versus-host disease (aGvHD).

No approval date is recorded. On the records, the product has no EU marketing authorisation. A CHMP opinion is a scientific recommendation to the European Commission, which issues the legally binding decision. A negative opinion, if it stands, leads to refusal of the marketing authorisation.

The records do not give the grounds for the negative opinion, the vote, or any company response. This analysis does not speculate on the reasons.

Regulatory pathway and designations

The records show no designations for this product. That means no orphan, PRIME or other special status is recorded. It does not establish that none exist elsewhere. The records also do not say which procedure or legal basis was used, or whether accelerated assessment or conditional approval was sought.

After a negative CHMP opinion, an applicant can generally request a re-examination. Under the standard EU process it must notify the EMA within 15 days of receiving the opinion, then submit detailed grounds within 60 days. The CHMP then re-examines the opinion, typically with a different rapporteur and co-rapporteur, and adopts a final opinion. The records do not say whether MaaT PHARMA has taken, or intends to take, this step.

If the negative opinion is confirmed or not challenged, the Commission would be expected to adopt a decision refusing the authorisation. The EMA usually publishes a public assessment report explaining the refusal, and that report would be the first reliable source for the committee's reasoning.

Safety and pharmacovigilance

The records contain no safety data, risk management plan details, or pharmacovigilance commitments for Xervyteg, so no safety conclusions can be drawn here.

What to watch

The first item is whether MaaT PHARMA notifies the EMA of a re-examination request within the standard timelines. The second is the publication of the CHMP meeting highlights and the assessment report, which should set out the grounds for the negative opinion. Those grounds would show whether the concerns relate to efficacy, safety, quality or a combination.

If a re-examination goes ahead, the final CHMP opinion and the subsequent European Commission decision are the next formal milestones. The records contain no dates for either.

Company communications on its regulatory strategy and on any effect on other markets or programmes are also worth tracking. None of this is covered in the records provided.