On 15th July 2025, Astellas Pharmaceuticals Inc. announced that they have received approval from the US Drug Regulator, the FDA, to move forward with a Phase 1/2 clinical trial of their gene therapy product ASP2957. The trial – which will be called VALOR – will initially be in the United States for children aged 3 years and under, who have x-linked myotubular myopathy (XLMTM) and meet other inclusion criteria. The full trial details can be found here on ClinicalTrials.gov
“Astellas has received Investigational New Drug (IND) clearance from the Food and Drug Administration (FDA) for ASP2957, the Astellas development compound number for KT430, an investigational gene therapy aimed at treating XLMTM. This clearance allows us to move forward with a Phase 1/2 interventional clinical trial in the United States. Currently, we are in discussions with various sites to initiate the trial and are awaiting ethics approval to move forward.
This milestone is a significant step forward, and we want to take a moment to acknowledge the invaluable role the XLMTM community has played in guiding our work. Your collaboration and support have been crucial, and we sincerely thank you for your continued engagement.
We will share more information about the clinical trial in the next couple of weeks. Please reach out to agt_patientadvocacy@astellas.com if you have any questions in the meantime.
With very best wishes,
Chelsea Moran (Patient Partnerships Lead) and Rahul Gentyala (Medical Lead) on behalf of the XLMTM team.”
Astellas Pharma Inc. have released two new infographics in PDF format to help provide our XLMTM patient community with clear information about the EXCEL Study and VALOR clinical trial.
You can open and download the infographic on VALOR here:-
Astellas_XLMTM Community Information – VALOR clinical trial overview_FINAL
Webinar with Astellas – your opportunity to hear more and ask questions
MTM-CNM Family Connection and the Myotubular Trust are jointly hosting a webinar on Thursday 24th at 6.30pm-8.00pm (UK time) with Astellas. Astellas will present their plans for both this clinical trial (VALOR) and the liver natural history study (EXCEL), and will also take questions from the community.
If you would like to register for this webinar, or if you would like us to ask questions on your behalf, please do so here.
A positive step forward
This news is a very positive step forward for the myotubular myopathy community. We are very grateful to Astellas Therapeutics for their commitment to gene therapy. We recognise this will open up so many questions for patients, parents and families everywhere, and please do know you can always contact us with questions or to discuss.
