The European Commission (EC) has granted orphan drug designation (ODD) to PTI-428 for the treatment of cystic fibrosis, according to Proteostasis Therapeutics Inc.

PTI-428 is the company’s proprietary cystic fibrosis transmembrane conductance regulator (CFTR) amplifier that is currently in clinical development. In addition to ODD from the EC, PTI-428 has ODD, Breakthrough Therapy Designation and Fast Track Designation from the US FDA.

PTI-428 is an investigational CFTR amplifier in development for the treatment of CF in patients with at least one F508del mutation in the CFTR gene, as part of PTI’s proprietary triple combination regimen that includes PTI-808, a novel potentiator, and PTI-801, a third-generation corrector. PTI-428 has been shown to work early during CFTR biogenesis to increase levels of newly synthesized CFTR protein, suggesting potential therapeutic benefits in combination with CFTR correctors and potentiators.

ODD in the EU is based upon a positive opinion from the European Medicines Agency’s (EMA) Committee for Orphan Medicinal Products (COMP) and provides regulatory and financial incentives for companies to develop and market therapies to treat serious disorders affecting no more than five in 10,000 persons in the EU. Companies that obtain ODD benefit from a number of incentives, including ten-year marketing exclusivity in the EU upon approval, as well as eligibility for protocol assistance, reduced fees and access to the EU’s centralized marketing authorization procedure. Currently, over half of the global CF population lives in Europe with limited access to approved CFTR modulator therapies.

“This designation by the EC is further validation of both PTI-428’s potential and PTI’s mission to offer additional disease modifying treatment options for CF,” said Meenu Chhabra, President and Chief Executive Officer of Proteostasis Therapeutics.  “Orphan drug status is granted to development-stage drugs that make a major contribution to patients’ care, either by demonstrating a significant clinical benefit over existing therapies or by providing a treatment for patients for whom existing therapies do not work. We look forward to advancing PTI-428 in the clinic later this year, as part of the planned 28-day Phase 2 studies of our proprietary combination CFTR modulator treatments.”