Aeglea BioTherapeutics presents 20-dose data from pegzilarginase trials at SSIEM
Aeglea BioTherapeutics presented 20-dose data on 14 patients from the company's completed Phase 1/2 trial and ongoing Phase 2 open-label extension, or OLE, trial for pegzilarginase in patients with Arginase 1 Deficiency, or ARG1-D, at the Symposium of the Society for the Study of Inborn Errors of Metabolism, or SSIEM. Data from all patients following 20 doses of pegzilarginase continued to demonstrate marked and sustained reductions in plasma arginine. Overall, 79% of patients were clinical responders, using mobility assessment components that correspond with the pivotal PEACE trial secondary endpoint. Pegzilarginase was well tolerated and the rates of treatment-related adverse events decreased over time. Serious adverse events included hypersensitivity and hyperammonemia, which were infrequent, managed with standard treatment and did not lead to any patient discontinuations. The company believes the improvements in arginine control and evidence of clinical benefit following pegzilarginase treatment provide further validation of the key endpoints and design elements of the pivotal Phase 3 PEACE trial and that the Phase 1/2 and OLE trials demonstrate the value of utilizing only three mobility assessment tools to capture the clinical benefit of pegzilarginase. Additionally, Aeglea announced that 10 patients have been dosed subcutaneously with pegzilarginase in the ongoing OLE trial in patients with ARG1-D. Subcutaneous administration of pegzilarginase controls plasma arginine similarly to IV administration, providing potential additional advantages such as improving compliance and/or convenience. Pegzilarginase was well tolerated subcutaneously, with only four mild injection site reactions related to pegzilarginase in more than 200 injections to date. All 10 eligible patients switched to, and remain on, pegzilarginase subcutaneous, with no patient discontinuations In June, Aeglea announced the dosing of the first patient in its pivotal PEACE trial, which is intended to further evaluate the efficacy and safety of pegzilarginase. The company expects to continue discussions with the FDA on the pegzilarginase program and our next steps in Q4 or Q1 of 2020. The company also expects to report topline data from the pivotal PEACE trial in Q1 of 2021.