PTC Therapeutics, Inc. announced the submission of the sepiapterin MAA to the European Medicines Agency. The MAA submission is for the treatment of pediatric and adult patients with PKU, including the full spectrum of disease subtypes. The sepiapterin MAA includes the results of the phase 3 APHENITY trial in which sepiapterin had a statistically significant and clinically meaningful reduction in blood phenylalanine levels in pediatric and adult PKU patients.

Sepiapterin treatment resulted in a mean reduction in Phe levels of 63% in the overall treated population and 69% in the subgroup of subjects with classical PKU. The vast majority of subjects (84%) achieved Phe control in accordance with treatment guidelines, and 22% of subjects had normalization of Phe levels. Data from the ongoing APHENITY open-label extension study demonstrates that these sepiapterin treatment effects are durable.

In addition, data from the Phe tolerance sub study demonstrate that subjects are liberalizing their diet, beyond the recommended daily allowance of protein, and maintaining control of Phe within target levels from guidelines. The ability to enable patients to liberalize their highly restrictive diets and still maintain Phe control, is a very meaningful sepiapterin treatment benefit for physicians, payers and patients. PTC expects to submit the sepiapterin NDA to the FDA no later than the third quarter of 2024.

Submissions in 2024 are planned in a number of additional key countries where PTC has existing rare disease commercial infrastructure including Brazil and Japan.