Omeros To Present Results From Dose-Ranging Stage Of OMS721 Clinical Trial In Atypical Hemolytic Uremic Syndrome At World Congress Of Nephrology

SEATTLE, Wash.--(BUSINESS WIRE)--Omeros Corporation (NASDAQ: OMER) today announced that data from the dose-ranging stage of the Phase 2 clinical trial evaluating OMS721 in the treatment of atypical hemolytic uremic syndrome (aHUS) will be presented next month at the International Society of Nephrology’s World Congress of Nephrology in Mexico City. The poster presentation, “Dose-Finding Clinical Trial of OMS721 for the Treatment of Atypical Hemolytic Uremic Syndrome (aHUS) – Stage 1 Results,” summarizes early clinical data from three different doses of OMS721 administered for up to four weeks in patients with aHUS. The poster (Number SAT-218) will be presented by Professor Michal Nowicki, an OMS721 clinical trial investigator and President of the Polish Society of Nephrology, during a moderated poster session scheduled for Saturday, April 22nd, 12:00 - 13:15 PDT, Hall A (Exhibition). OMS721 is Omeros’ lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2), the effector enzyme of the lectin pathway of the complement system.

“Not only was platelet count increased with just four weeks of dosing in these patients, renal failure was reversed and dialysis was able to be stopped. Assuming that similar data are seen in the ongoing Phase 3 trial, OMS721 would represent an important and welcome treatment for patients with aHUS.”

Recently published on the International Society of Nephrology website, an abstract of the poster summarizes the data to be presented. The data are from Stage 1 of the open-label trial evaluating the use of OMS721 in patients with thrombotic microangiopathies, including aHUS, across multiple doses. To be enrolled in the trial, patients with aHUS must either (1) have demonstrated thrombocytopenia, evidence of microangiopathic hemolytic anemia, and elevated creatinine despite at least four plasma therapy (PT) treatments (PT-resistant patients); or (2) have required at least weekly PT and had elevated creatinine (PT-responsive patients). Patients received OMS721 in one of three dosing groups (low, middle, high) by intravenous administration weekly for up to four weeks. Patients in each cohort could receive additional OMS721 half-doses after PT, if administered.

Seven patients with aHUS were enrolled in Stage 1: three patients in the low-dose group, two patients in the mid-dose group and two patients in the high-dose group. One patient in the high-dose group was PT-responsive and the remaining six patients were PT-resistant. The data demonstrate a dose response in platelet count assessed as change from baseline. The mean change from baseline in platelet count was statistically significant (p < 0.05) as measured by area under the curve (AUC). Renal replacement therapy (RRT) was able to be discontinued in one patient during OMS721 treatment and renal function remained stable following completion of treatment. Another patient, who was on chronic RRT and considered ineligible for kidney transplantation, stabilized on OMS721 treatment and was deemed eligible for transplantation.

“These data demonstrate a clear dose response with significant and clinically meaningful improvement in aHUS patients treated with OMS721,” stated Professor Nowicki. “Not only was platelet count increased with just four weeks of dosing in these patients, renal failure was reversed and dialysis was able to be stopped. Assuming that similar data are seen in the ongoing Phase 3 trial, OMS721 would represent an important and welcome treatment for patients with aHUS.”

OMS721 was well tolerated in this trial. Five serious adverse events (SAEs) were reported. A case of granulomatous orchitis in a patient with a prior history of M. haemophilum infection was considered by the investigator to be possibly a relapse and treatment-related; all cultures were subsequently found to be negative and the patient recovered. No other SAEs were considered treatment-related.

“Our Phase 3 trial evaluating OMS721 in aHUS patients is underway,” stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. “OMS721 has been shown to ablate activity in the lectin pathway of complement, believed to be the trigger for aHUS, and we expect that patients will find subcutaneous dosing of OMS721 both convenient and comfortable. In addition to our Phase 3 program in aHUS, we are planning to initiate Phase 3 programs this year in IgA nephropathy and in stem cell transplant-associated thrombotic microangiopathy, and the breadth of potential indications for OMS721 continues to grow.”

About Omeros’ MASP Programs
Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2, a novel pro-inflammatory protein target involved in activation of the complement system, which is an important component of the immune system. The complement system plays a role in the inflammatory response and becomes activated as a result of tissue damage or microbial infection. MASP-2 is the effector enzyme of the lectin pathway, one of the principal complement activation pathways. Importantly, inhibition of MASP-2 does not appear to interfere with the antibody-dependent classical complement activation pathway, which is a critical component of the acquired immune response to infection, and its abnormal function is associated with a wide range of autoimmune disorders. MASP-2 is generated by the liver and is then released into circulation. Adult humans who are genetically deficient in one of the proteins that activate MASP-2 do not appear to be detrimentally affected by the deficiency. OMS721 is Omeros’ lead human MASP-2 antibody. Following discussions with both the FDA and the European Medicines Agency, a Phase 3 program for OMS721 in atypical hemolytic uremic syndrome (aHUS) is in progress. Also, two Phase 2 trials are ongoing. One is evaluating OMS721 in glomerulonephropathies, which has generated positive data in patients with immunoglobulin A (IgA) nephropathy; the other has reported positive data both in patients with hematopoietic stem cell transplant-associated thrombotic microangiopathy (TMA) and in those with aHUS. In addition to potential intravenous administration, Omeros plans to commercialize OMS721 for one or more therapeutic indications as a subcutaneous injection and is also developing small-molecule inhibitors of MASP-2. Based on requests from treating physicians, Omeros has established a compassionate-use program for OMS721, which is active in both the U.S. and Europe. The FDA has granted OMS721 both orphan drug status for the prevention (inhibition) of complement-mediated TMAs and fast track designation for the treatment of patients with aHUS.

Omeros also has identified MASP-3 as the critical activator of the human complement system’s alternative pathway, which is linked to a wide range of immune-related disorders. In addition to its lectin pathway inhibitors, the company is advancing its development of antibodies and small-molecule inhibitors against MASP-3 to block activation of the alternative pathway.

About Omeros Corporation
Omeros is a biopharmaceutical company committed to discovering, developing and commercializing both small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system. Part of its proprietary PharmacoSurgery^® platform, the company’s first drug product, OMIDRIA^® (phenylephrine and ketorolac injection) 1% / 0.3%, was broadly launched in the U.S. in April 2015. OMIDRIA is the first and only FDA-approved drug (1) for use during cataract surgery or intraocular lens (IOL) replacement to maintain pupil size by preventing intraoperative miosis (pupil constriction) and to reduce postoperative ocular pain and (2) that contains an NSAID for intraocular use. In the European Union, the European Commission has approved OMIDRIA for use in cataract surgery and lens replacement procedures to maintain mydriasis (pupil dilation), prevent miosis (pupil constriction), and to reduce postoperative eye pain. Omeros has clinical-stage development programs focused on: complement-associated thrombotic microangiopathies; complement-mediated glomerulonephropathies; Huntington’s disease and cognitive impairment; and addictive and compulsive disorders. In addition, Omeros has a proprietary G protein-coupled receptor (GPCR) platform, which is making available an unprecedented number of new GPCR drug targets and corresponding compounds to the pharmaceutical industry for drug development, and a platform used to generate antibodies.

Forward-Looking Statements
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