Repurposed receptor

VANCOUVER, British Columbia—Idiopathic pulmonary fibrosis (IPF) is a chronic lung condition involving progressive, irreversible lung function decline and scarring (fibrosis) with no cure and no options for removing the scarring from the lungs. GlobalData, a research and consulting firm, projects that the IPF market will grow from just over $900 million in 2015 to $3.2 billion by 2025, a compound annual growth rate of 13.6 percent.

Algernon Pharmaceuticals Inc., a clinical-stage pharmaceutical company focused on the areas of nonalcoholic steatohepatitis, chronic kidney disease, inflammatory bowel disease and IPF, has announced that ifenprodil (NP-120), an NDMA receptor antagonist and its lead compound in drug in an IPF research program, reduced fibrosis by 56 percent in a recent study. The drug, an orally delivered small molecule, was originally developed by Sanofi in the 1990s with the brand name Cerocal to treat peripheral circulatory disorders.

Algernon conducted two independent studies showing that NP-120 outperformed the world’s leading two treatments for IPF—nintedanib and pirfenidone—in a recent preclinical in-vivo animal study.

Drug repurposing, the process of discovering new therapeutic uses for existing drugs, offers several benefits over traditional drug development, including reduction in investment and risk, shorter research periods and a longer active patent life. According to Algernon’s website, a drug repurposing strategy can save as much as eight years of preclinical research and millions in R&D costs.

Because NP-120 is already approved with an established safety history, Algernon anticipates moving the drug directly into a Phase 2 human trial. Algernon’s business model is to repurpose safe, approved, genericized drugs that are not available in the U.S. or Europe, screen them in globally accepted animal models for new diseases, file new intellectual property rights, and then move them into an off-label Phase 2 trial in the country where they were originally approved. Once a signal is established in a human trial, the company will begin to advance the repurposed drug through a U.S. FDA registration.

Christopher J. Moreau, CEO of Algernon Pharmaceuticals, said, “We are very pleased to announce NP-120 (ifenprodil) as part of a class of compounds that could be beneficial for patients with IPF, a very serious disease. We plan to move NP-120 (ifenprodil) into a Phase 2 clinical trial as quickly as possible to establish human efficacy. We also intend to pursue partnering discussions specific to our IPF program and to seek an orphan designation with regulatory authorities.”

Ifenprodil is an N-methyl-d-aspartate (NDMA) receptor glutamate receptor antagonist specifically targeting the NMDA-type subunit 2B (Glu2NB). It also exhibits agonist activity for the Sigma-1 receptor, a chaperone protein up-regulated during endoplasmic reticulum stress.

Data from this recent study demonstrated a statistically significant improvement in established fibrosis in a 21-day bleomycin mouse model, with treatment beginning on day 7. Pirfenidone (100 mg/kg, BID), both a positive control and comparator arm in the study, showed a 44-percent reduction in fibrosis vs. untreated controls (not statistically significant) as measured by Trichrome staining and modified Ashcroft scoring. Nintedanib (40 mg/kg, QD), a second positive control and comparator arm, and NP-251 (30 mg/kg, TID) both showed a 51-percent reduction in fibrosis vs. untreated controls (p<0.05). NP-120 (20 mg/kg, TID) showed a 56.0-percent reduction in fibrosis vs. untreated controls (p=0.015).

Algernon also tested NP-121 (radiprodil), which possess a similar phenylethanolamine pharmacophore as NP-120, in its initial IPF in-vivo animal study. In the study, both compounds at the same dose reduced fibrosis to a similar extent. This data established an early indication that this could be a potential drug class effect and not unique to NP-120 alone. NP-121 was originally developed by Gideon Richter and Forest Labs, and reached Phase 3 trials for the treatment of diabetic nephropathy. The French pharmaceutical firm UCB has recently tested NP-121 for the treatment of drug-resistant infantile spasms.

Algernon has filed several patent applications protecting their intellectual property rights with respect to both NP-120 and NP-121 and other derivatives. The company has protected its lead compounds with both method of use and new composition of matter patents for their derivatives and analogues.