Gene therapy trial for rare muscle disease halted after severe side effects

NCT ID NCT03199469

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This trial tested a gene therapy called AT132 for X-linked myotubular myopathy (XLMTM), a rare muscle disease present at birth that causes severe breathing problems. The therapy aimed to deliver a healthy copy of the MTM1 gene to improve muscle function. However, the study was stopped early because of serious complications and deaths. Children who received the therapy are being monitored for long-term safety and muscle function.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance
AT132 (resamirigene bilparvovec) gene therapy
What this could lead to
If successful, this gene therapy could improve muscle function and reduce breathing support needs in children with XLMTM.
What could go wrong
The study was stopped early due to severe complications and deaths. The therapy may worsen liver problems and has not shown adequate safety.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Ann & Robert H Lurie Children's Hospital of Chicago

    Chicago, Illinois, 60611, United States

  • Hopital Armad Trousseau

    Paris, 75012, France

  • Hospital for Sick Children

    Toronto, Ontario, M5G0A4, Canada

  • Kinderklinik und Kinderpoliklinik im Dr. Von Haunerschen Kinderspital Klinikum der Universitat Munchen

    München, 80337, Germany

  • National Institute of Neurological Disorders and Stroke/NIH Porter

    Bethesda, Maryland, 208892, United States

  • UCLA Medical Center

    Los Angeles, California, 90095, United States

More trials for these conditions

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