Omeros Corporation reported that it has identified compounds that interact selectively with each of four additional orphan G protein-coupled receptors (GPCRs) - GPR15, GPR39, GPR78 and GPR161. Omeros has now announced that it has unlocked 14 of the 80 Class A orphan GPCRs. GPCRs represent the premier family of drug targets, with more than 30 per cent of currently marketed drugs targeting only 46 GPCRs. There are approximately 120 orphan GPCRs, and Omeros, which expects to unlock a large percentage of these for drug development, is initially targeting Class A orphan GPCRs.
The four unlocked orphan receptors announced are linked to a wide range of indications and present multiple new opportunities for drug development by the pharmaceutical industry. GPR15 has been associated with rheumatoid arthritis and HIV-mediated enteropathy, a chronic intestinal illness in HIV-infected patients. GPR39 has been implicated in the pathogenesis of obesity-related type-2 diabetes and esophageal squamous cell carcinoma, the most prevalent esophageal cancer worldwide. GPR78 has been linked to bipolar affective disorder and schizophrenia, and GPR161 has been tied to congenital cataracts and birth defects of the brain and spinal cord.
“These discoveries further validate our proprietary technology and underscore our unique ability to open to the pharmaceutical industry previously inaccessible targets for drug development,” said Gregory A Demopulos, MD, chairman and chief executive officer of Omeros. “Each of these receptors is linked to severe medical disorders, and our success enables the design of novel compounds that could result in new and more effective therapies for patients that need them.”
Omeros has begun screening orphan GPCRs against its small-molecule chemical libraries using its proprietary, high-throughput Cellular Redistribution Assay (CRA). Omeros has announced that it has identified and confirmed sets of compounds that interact selectively with 14 orphan receptors linked to esophageal squamous cell carcinoma and obesity-related type-2 diabetes (GPR39), squamous cell carcinoma (GPR87), pancreatic cancer (GPR182), acute lymphoblastic leukaemia (P2Y8/P2RY8), sleep disorders (OPN4), cognitive disorders (GPR12), bipolar disorder and schizophrenia (GPR78), psychotic and metabolic disorders (GPR27, GPR85, GPR173), appetite control (GPR101), rheumatoid arthritis and HIV-mediated enteropathy (GPR15), motor control (GPR139) and congenital cataracts and birth defects of the brain and spinal cord (GPR161). The CRA detects receptor antagonists and agonists. Antagonists comprise the majority of marketed drugs, and all of the compounds characterized so far by Omeros are antagonists.
GPCRs, which mediate key physiological processes in the body, are one of the most valuable families of drug targets. According to Insight Pharma Reports, GPCR-targeting drugs represent 30 to 40 percent of marketed pharmaceuticals. Examples include Claritin (allergy), Zantac (ulcers and reflux), OxyContin (pain), Lopressor (high blood pressure), Imitrex (migraine headache), Reglan (nausea) and Abilify (schizophrenia, bipolar disease and depression) as well as all other antihistamines, opioids, alpha and beta blockers, serotonergics and dopaminergics.
The industry focuses its GPCR drug discovery efforts mostly on non-sensory GPCRs. Of the 363 total non-sensory GPCRs, approximately 240 have known ligands (molecules that bind the receptors) with nearly half of those targeted either by marketed drugs (46 GPCRs) or by drugs in development (about 70 GPCRs). There are approximately 120 GPCRs with no known ligands, which are termed “orphan GPCRs.” Without a known ligand, drug development for a given receptor is extremely difficult.
Omeros uses its proprietary high-throughput CRA to identify small-molecule agonists and antagonists for orphan GPCRs, unlocking them to drug development. Omeros believes that it is the first to possess the capability to unlock orphan GPCRs in high-throughput, and that currently there is no other comparable technology. Unlocking these receptors could lead to the development of drugs that act at these new targets. There is a broad range of indications linked to orphan GPCRs including cardiovascular disease, asthma, diabetes, pain, obesity, Alzheimer's disease, Parkinson's disease, multiple sclerosis, schizophrenia, learning and cognitive disorders, autism, osteoporosis, osteoarthritis and several forms of cancer.
Omeros is a clinical-stage biopharmaceutical company committed to discovering, developing and commercializing products targeting inflammation, coagulopathies and disorders of the central nervous system.