Ultragenyx Wilson Disease Update April 2024

As Ultragenyx continues to advance its research for Wilson disease, please find a status update on the CYPRUS2+ study.

The CYPRUS2+ study is designed with three stages. We are currently in Stage 1 where we are evaluating the safety and efficacy of three dose levels of UX701, an investigational gene therapy for the treatment of Wilson disease. UX701 is delivered by a one-time infusion directly into the bloodstream through a vein (IV). All 15 patients in Stage 1 have received UX701 and are being followed over the course of 52 weeks. Once initial dose finding data are evaluated, a Stage 2 dose will be selected for further evaluation in the randomized, placebo-controlled portion of this study.

For Stage 2 of the CYPRUS2+ study, we plan to enroll an additional 63 patients randomized 2:1 to receive UX701 or placebo. Two thirds of the patients will be randomly selected to receive a single IV infusion of UX701 and one third will receive placebo, they will be carefully monitored by the study team over 52 weeks. Patients will then crossover to receive a second infusion of either study drug or placebo. After the initial 52-week period, all study participants will receive long-term follow up in Stage 3.

Ultragenyx is sponsoring this global study of UX701, which aims to correct the ATP7B gene with the goal of restoring the body’s ability to transport copper so that it does not collect inside the organs. We expect to have a better understanding of the associated benefits of UX701 on liver function and neurological symptoms as the study progresses. The safety and effectiveness of UX701 has yet to be established. This type of research takes time, so it will be a while before we know whether and when UX701 will receive regulatory approval.

As requested, we will continue to share updates as new information becomes available. For questions, please email PatientAdvocacy@Ultragenyx.com.