In November of last year, we shared a letter from Ultragenyx about their UX055 Gene Therapy Program for CDKL5 Deficiency Disorder in which it was stated, “Pending the outcome of additional non-clinical studies, we expect to submit an Investigational New Drug (IND) application to the US Food and Drug Administration (FDA) in 2023.”

Today, we would like to share an update on the timing of the IND filing – found here. This update notifies the community of a delay in the filing that will push it beyond Q4 of 2023. Please note that Ultragenyx is urgently working towards a future regulatory submission and will provide you with an update by March 2024 when new information becomes available.

The IFCR team is here to answer any questions you might have. If we can not, we will find someone that can.

“Developing new treatments for rare diseases is hard, and we will all be in this together. Many
unforeseen challenges will occur that we must solve to advance research and getting to a safe and
effective drug will take time, fortitude, and collaboration with the community.” -Dr. Emil Kakkis