Angelman trial pause for antisense oligo comes with efficacy data that lift Ultragenyx shares

GeneTx and Ultragenyx will look to adjust dosing and administration in their Phase I/II trial of GTX-102 to treat Angelman syndrome after patients experienced a serious adverse event thought to be tied to local inflammation due to the therapy.

GeneTx Biotherapeutics LLC and Ultragenyx Pharmaceutical Inc. (NASDAQ:RARE), which partnered a little over a year ago to develop the antisense oligonucleotide, have paused dosing and enrollment in the study after all five patients in the trial experienced mildly or moderately severe adverse lower extremity weakness that have improved over a few weeks...