PTC Therapeutics, Inc. (NASDAQ: PTCT) announced that 17 abstracts and presentations on Sephience (sepiapterin) are scheduled for the 2026 Society for the Study of Inborn Errors of Metabolism Annual Symposium in Helsinki, Finland, from Aug. 25-28.

The presentations include data from clinical trials and real-world studies on Sephience, which is approved in the United States, the European Union, Japan, and other countries for the treatment of phenylketonuria (PKU) in patients one month of age and older.

Key data highlights from a company press release include findings from the AMPLIPHY study showing that participants who switched to Sephience from sapropterin achieved a 100% greater reduction in blood phenylalanine (Phe) levels. In a separate analysis of participants with high baseline Phe levels of 900 µmol/L or above, Sephience produced clinically meaningful reductions in blood Phe within 14 days, with response rates described as comparable to the overall study population.

Real-world data presented by an independent researcher showed that Sephience enabled dietary liberalization in adolescents with PKU while maintaining metabolic control within recommended targets. The results were observed in patients with both BH4-responsive and classical, non-BH4-responsive PKU.

"The SSIEM presentations further demonstrate the broad clinical benefits of Sephience across the full spectrum of individuals living with PKU," said Matthew B. Klein, M.D., Chief Executive Officer of PTC Therapeutics.

Sephience carries warnings related to increased bleeding risk, hypophenylalaninemia in pediatric patients, and potential interactions with levodopa and PDE-5 inhibitors. The most common adverse reactions reported in trials included diarrhea, headache, abdominal pain, and feces discoloration.