After gene therapy deaths, Astellas is trying a 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 deliver genes to patients’ cells. In theory, that should minimize the risk of serious side effects.

“The lower the dose we give, the lower the risk will 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 medicine.