The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to APR-OD031, an investigational treatment for people with phenylketonuria (PKU).

This designation is intended to promote the development of treatments for serious diseases with fewer than 200,000 cases in the U.S. Among its incentives are exemption from FDA fees, the agency’s assistance in clinical trial design, tax credits, and seven years of market exclusivity upon approval.

This is the second orphan drug designation for APR Applied Pharma Research, the company developing APR-OD031. APR-TD011 also received the same designation as a potential treatment for epidermolysis bullosa.

“The Orphan Drug Designation for our drug candidate APR-OD031 is a huge achievement for a small company like APR, which is focusing its efforts on the improvement of PKU standard of care,” Paolo Galfetti, CEO of APR, said in a press release. “Together with the other orphan drug designation granted 6 months ago, APR is strengthening its position as a patient centric company dedicated to major unmet needs in the rare disease space.”

APR-OD031 is an oral, extended release formulation that uses a specialized system developed by APR to deliver amino acids (the building blocks of proteins) to cells. The system, called Physiomimic Technology, captures the amino acids in small granules to allow for gradual absorption by cells in the gut. According to APR, the system’s special coating masks undesirable characteristics of the formulation, such as smell and taste, which in turn may improve compliance to treatment.

The goal is to mimic normal absorption of dietary protein. In doing so, the treatment is designed to reduce fluctuations in the levels of the amino acid phenylalanine and ease protein breakdown in muscles, which is common in PKU patients not responding to treatment with Kuvan (sapropterin dihydrochloride, by BioMarin).

“As father of a PKU boy and as professional in this industry, I feel the privilege and the honor for leading a group of passionate people, all sharing the same vision to improve the quality of life of patients and families living with rare diseases,” said Galfetti. “We will work closely with the FDA to complete the development and bring to the patients this new drug as soon as possible for the benefit of the PKU community still in the need of innovative and meaningful medications.”