Af­ter pump­ing the brakes on their An­gel­man syn­drome study, Ul­tragenyx and GeneTx are back in the race

Eleven months af­ter high dos­es of Ul­tragenyx and GeneTx’s An­gel­man syn­drome can­di­date tem­porar­i­ly caused some pa­tients to lose their abil­i­ty to walk, the FDA is al­low­ing the part­ners to restart the tri­al — but with a much low­er dose reg­i­men.

Reg­u­la­tors have re­moved a clin­i­cal hold on Ul­tragenyx and GeneTx’s an­ti­sense oligonu­cleotide GTX-102, open­ing the door for more pe­di­atric pa­tients to en­roll in a Phase I/II tri­al. The part­ners halt­ed the tri­al in Oc­to­ber af­ter all five pa­tients in the study ex­pe­ri­enced “low­er ex­trem­i­ty weak­ness” re­ceiv­ing the two high­est dos­es dur­ing an es­ca­la­tion pe­ri­od. Two of them lost their abil­i­ty to walk or bear weight.

Unlock this article instantly by becoming a free subscriber.

You’ll get access to free articles each month, plus you can customize what newsletters get delivered to your inbox each week, including breaking news.

SIGN UP LOG IN BECOME A PREMIUM SUBSCRIBER