Reviva is now planning to launch Phase 2 studies testing RP5063 in both IPF and pulmonary arterial hypertension (PAH) patients. The FDA granted orphan drug designation to the therapy in 2016 for the treatment of PAH.
“Obtaining the orphan drug designation is a significant regulatory milestone as well as a notable achievement for Reviva, since it validates the significant therapeutic potential of RP5063 for the treatment of IPF,” Laxminarayan Bhat, PhD, founder, president and CEO of Reviva, said in a press release.
RP5063 is a new chemical entity with a novel mechanism that regulates serotonin and dopamine signaling pathways. In the brain, dysfunctional serotonin signaling contributes to neurological diseases, but in the lungs, it is associated with pulmonary fibrosis (PF) and PAH.
Serotonin signaling involving the 5-HT receptors of the lungs has been reported to cause vasoconstriction, vascular remodeling and vascular inflammation, fibrosis, and other hallmarks of PF and PAH. RP5063 was designed to inhibit the 5-HT receptors, reducing these changes.
According to Reviva, RP5063 was effective in animal models designed to mimick PF in humans. It significantly improved survival rate and reduced inflammatory cytokines and tissue scarring (fibrosis) in the lungs of PF animal models, suggesting its potential to improve and stabilize lung function.
“IPF is a devastating disease with limited treatment options and no cure. RP5063, however, provides a novel mechanism of action that has the potential to impact multiple aspects of this disease and, combined with convenient delivery options, RP5063 affords hope to many patients suffering from this debilitating disease,” Bhat said.
Orphan drug status is granted to candidates for the treatment of rare diseases — diseases that affect fewer than 200,000 people in the United States. The designation provides incentives including assistance in clinical trial design, tax cuts for trial costs, and up to seven years of market exclusivity in the U.S. if the drug is approved.
Reviva has also successfully completed a Phase 2 trial testing RP5063 in patients with schizophrenia and schizoaffective disorders.