After gene therapy deaths, Astellas tries potentially safer approach

Astellas Pharma said Thursday it will license and develop a new gene therapy for a devastating muscle disorder, after four boys died in a clinical trial testing an earlier treatment.

The hope is that the new therapy will allow researchers to treat the disease, known as X-linked myotubular myopathy, or XLMTM, with much lower doses of the viruses used to shuttle genes into patients’ cells. In theory that should minimize the risk of severe side effects.

“The lower the dose we give, the lower the risk is going to be,” said Alan Beggs, the Boston Children’s Hospital researcher who helped develop the earlier treatment and is a scientific co-founder of the startup behind the new drug.