We have scientific expertise in the field of G protein-coupled receptors (GPCRs) and members of our scientific team were the first to identify and characterize all non-sensory GPCRs common to mice and humans. Our work was published in a peer-reviewed article titled "The G protein-coupled receptor repertoires of human and mouse" that appeared in the April 2003 issue of Proceedings of the National Academy of Sciences (Vol. 100, No. 8: pp. 4903-4908). Non-sensory GPCRs are involved in metabolism, behavior, reproduction, development, hormonal homeostasis and regulation of the central nervous system and comprise one of the largest families of proteins in the genomes of multicellular organisms.

According to Insight Pharma Reports, 30% to 40% of all drugs sold worldwide target GPCRs. However, based on available data, we believe that there are 363 non-sensory GPCRs of which there are 243 non-orphans and 120 orphans. A non-orphan GPCR is one for which there is a known naturally occurring or synthetic molecule, or ligand, that binds the receptor, while an orphan GPCR has no known ligand. Without a known ligand, there is no template from which medicinal chemistry efforts can be readily initiated nor a means to identify the GPCR's signaling pathway and, therefore, drugs cannot easily be developed against orphan GPCRs.

We hold an exclusive option to acquire all patent and other intellectual property rights to a cellular redistribution assay, or CRA, which we have tested and optimized and that we believe can be used in a high-throughput manner to identify synthetic molecules, including antagonists, agonists and inverse agonists, that bind to orphan GPCRs. We recently announced that we, using the CRA, successfully identified compounds that interact with, and modulate the signaling of, three orphan GPCRs linked to cancer, metabolic disorders and appetite control.

We also have developed a proprietary rapid mouse gene knock-out platform technology, which is described in a peer-reviewed article titled "Large-scale, saturating insertional mutagenesis of the mouse genome" that appeared in the September 2007 issue of Proceedings of the National Academy of Sciences (Vol. 104, No. 36: pp. 14406-14411). We have used this platform to create 61 different GPCR-specific strains of knock-out mice, and we have established a battery of behavioral tests that allows us to characterize these knock-out mice and identify candidate drug targets.

Using our expertise and these assets, we believe that we are the first to possess the capability to conduct high-throughput de-orphanization of orphan GPCRs, and that there is no other existing high-throughput technology able to "unlock" orphan GPCRs. Based on available data, we believe that there may be greater than 65 new druggable targets among the orphan GPCRs, including the three that we have unlocked. "Unlocking" these orphan GPCRs could lead to the development of drugs that act at these new targets.

Patent Position

Omeros owns one issued U.S. patent, three pending U.S. patent applications and an additional two issued patents and two pending patent applications in key foreign markets, which are directed to previously unknown links between specific molecular targets in the brain and a series of CNS disorders, and to research tools that are used in the GPCR program.