Patient deaths in Audentes gene therapy study increase worry over high-dose treatments

Two patients in an Audentes Therapeutics gene therapy trial have died, STAT’s Matthew Herper reports — heightening safety concerns over high-dose forms of these medicines.

The company told patient groups in a June 23 letter, obtained by STAT, that the patients died after having serious liver problems that appeared related to the company’s experimental treatment for X-linked myotubular myopathy, a rare condition that causes muscle weakness. Most patients with the disease don’t survive childhood.

Although previous data from the study showed that the gene therapy improved patients’ ability to breathe, CEO Natalie Holles told STAT that the company has stopped enrolling patients in the study because of the deaths. The FDA then placed a clinical hold on the trial a few weeks ago.

“This unfortunate event may be a wake-up call to do the basic studies to support clinical development as higher and higher doses of [gene therapy] are administered,” one gene therapy consultant told STAT.