Pegzilarginase Clinical Trial Update (January 2023)

As Aeglea previously announced, we are in the process of concluding our ongoing pegzilarginase Phase 1 and Phase 3 clinical trials and transitioning those patients to a new study. All patients in our two pegzilarginase clinical trials received their last dose before the end of December, and final study visits with their study physician are planned to be completed before the end of January. Aeglea has begun the process of initiating a new open-label extension (OLE) safety study for those trial patients who wish to continue on pegzilarginase therapy.

We are committed to working with our study physicians and their sites to start up this new OLE study as efficiently as possible. We have provided all sites with the required regulatory documentation so they can work internally, with their institutional review board/ethics committee (IRB/EC), and with local health authorities to open the trial and resume dosing patients with pegzilarginase. Each institution has its own process and timelines, and Aeglea is committed to working quickly with each of them to minimize the treatment gap. If your family member was a participant in one of our previous trials, please contact your investigator or study coordinator with any questions regarding timing or next steps at your respective institution.

In parallel, please know that Aeglea is in continued dialogue with the US FDA on a potential path to resubmission with the goal of approval, and the marketing authorization application (MAA) in Europe is currently under review by the European regulatory authorities.

– Linda Neuman, MD, MBA, Chief Medical Officer, Aeglea BioTherapeutics