Red blood cells
The US Food and Drug Administration (FDA) has granted orphan drug designation to RA101495 for the treatment of paroxysmal nocturnal hemoglobinuria (PNH).
RA101495 is a synthetic, macrocyclic peptide being developed by Ra Pharmaceuticals.
The peptide binds complement component 5 (C5) with sub-nanomolar affinity and allosterically inhibits its cleavage into C5a and C5b upon activation of the classical, alternative, or lectin pathways.
By binding to a region of C5 corresponding to C5b, RA101495 also disrupts the interaction between C5b and C6 and prevents assembly of the membrane attack complex.
In phase 1 studies, dosing of RA101495 was well tolerated in healthy volunteers and demonstrated sustained and near complete suppression of hemolysis and complement activity.
The phase 1 results were presented at the 21st Congress of the European Hematology Association in June 2016 (abstracts LB2249 and P632).
RA101495 is currently under investigation in a phase 2 trial of patients with PNH.
“There is an urgent need for new treatment options for patients suffering from PNH,” said Doug Treco, PhD, president and chief executive officer of Ra Pharmaceuticals.
“The current standard of care requires biweekly intravenous infusions, a dosing regimen that imposes a severe burden on patients, providers, and caregivers. We have designed RA101495 for once-daily, subcutaneous self-administration, an approach which has the potential to ease this burden, improve convenience, and provide much-needed dosing flexibility.”
“We are encouraged by our initial phase 2 data in PNH patients, which showed near-complete inhibition of hemolysis and a favorable safety and tolerability profile. We look forward to advancing our PNH program and providing additional data updates around year-end.”
About orphan designation
The FDA grants orphan designation to drugs and biologics intended to treat, diagnose, or prevent diseases/disorders that affect fewer than 200,000 people in the US.
The designation provides incentives for sponsors to develop products for rare diseases. This may include tax credits toward the cost of clinical trials, prescription drug user fee waivers, and 7 years of market exclusivity if the product is approved.
