Regarding the CHMP Opinion on Trofinetide

The European Medicines Agency (EMA) has announced that its Committee for Medicinal Products for Human Use (CHMP) has recommended not granting marketing authorisation for Trofinetide for the treatment of Rett syndrome in Europe.

According to EMA, the CHMP concluded that the treatment effects observed after 12 weeks were not sufficient at this stage to be considered “clinically meaningful” for people living with Rett syndrome.

We recognise how difficult and disappointing this news may be for many families across Europe who have followed this process with hope. Rett syndrome remains a severe, lifelong condition, and Europe still has no approved disease-specific treatment.

At the same time, the European regulatory process includes mechanisms designed to allow further scientific clarification and dialogue, and that process is continuing.

🔹 Re-examination and next steps

Acadia Pharmaceuticals has indicated that it intends to request a re-examination of the CHMP opinion within the allowed timeframe.

Rett Syndrome Europe welcomes this step. Re-examination is an important part of the European regulatory system and provides an opportunity for further scientific discussion and for additional analyses or data to be considered in evaluating the treatment’s potential benefits for people living with Rett syndrome.

RSE will follow this process closely and will provide clear updates to our member associations so that families receive consistent and reliable information.

🔹 Respect for the regulatory process

RSE fully respects EMA’s scientific independence and its responsibility to evaluate medicines based on evidence, safety and demonstrated clinical benefit.

At the same time, we recognise the considerable effort required to develop new treatments for rare diseases. RSE acknowledges the commitment and investment made by Acadia Pharmaceuticals, the clinical investigators, and the families who participated in the clinical trials that made this research possible.

Progress in rare diseases depends on continued collaboration between families, clinicians, researchers, industry partners and regulators, and this shared effort remains essential for the Rett community.

🔹 For families and caregivers

We understand that this announcement may bring feelings of grief, frustration, uncertainty or confusion. These reactions are entirely valid.

For questions regarding individual care or treatment options, families should consult their clinical teams, who know each patient’s situation best. RSE does not provide medical advice, but we remain committed to supporting balanced, evidence-based communication.

🔹 The importance of the patient perspective

This moment also highlights an important broader challenge. For complex neurodevelopmental conditions such as Rett syndrome, defining what constitutes a clinically meaningful benefit can be particularly difficult.

Small improvements in areas such as communication, breathing patterns, comfort, engagement or daily functioning may represent meaningful changes for families and caregivers, even when they are difficult to capture within short-term clinical trial endpoints.

RSE therefore continues to advocate for strong and structured patient involvement throughout medicine development and regulatory evaluation, so that the lived experience of people with Rett syndrome and their families is appropriately reflected in how treatment benefits are assessed.

We will continue strengthening our dialogue with regulators, researchers and industry partners to ensure that the perspective of the Rett community is heard constructively and early in these processes.

Rett Syndrome Europe remains committed to working collaboratively with EMA, industry partners, clinicians, researchers and national associations to advance the development of safe and effective treatments for Rett syndrome.

We remain hopeful that the ongoing regulatory process will help further clarify the potential of new therapies for people living with Rett syndrome.