Rolling Submission of the Remaining BLA Sections Continues On Track for Scheduled Completion 1H 2020

SEATTLE, WA, USA I October 28, 2019 I Omeros Corporation (Nasdaq: OMER) has submitted the first sections of the rolling submission of its Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for narsoplimab for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA), a far-too-often deadly complication of stem-cell transplantation.

Narsoplimab, also known as “OMS721,” is Omeros’ lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2). There currently is no approved product for the treatment or prevention of HSCT-TMA, and narsoplimab is the only drug in development for the treatment of HSCT-TMA with FDA’s breakthrough therapy designation. Narsoplimab also has been granted FDA’s orphan drug designation for this indication.

Last month, Omeros announced that FDA had agreed with the company’s proposed schedule for the rolling review of its BLA for narsoplimab in the treatment of HSCT-TMA. Rolling submission enables Omeros to submit sections of the BLA as they are completed, which can accelerate the time to approval by allowing FDA to review the sections as they are submitted rather than waiting to begin its review until the entire BLA has been submitted. Because narsoplimab has orphan drug designation for HSCT-TMA, FDA has waived the approximately $3 million prescription drug user fee that would normally be due when BLA submission is initiated.

“This is an important milestone for Omeros, our shareholders and, most importantly, those patients who will undergo stem-cell transplantation,” said Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. “We look forward to continuing to work closely with FDA and European regulators to make narsoplimab commercially available as soon as possible to patients who need it. Until that time, we remain committed to making the drug readily accessible to stem cell-transplant TMA patients and their physicians through our expanding compassionate-use program.”

Included in today’s announced submission are all of the nonclinical (i.e., pharmacology, pharmacokinetics and toxicology) data, study reports, overview and summaries of the BLA. Once all clinical data collection, dataset compilation and data analysis are complete, the clinical parts of the BLA are scheduled for submission to be followed by the quality (i.e., chemistry, manufacturing and controls) section. Serial submission of the clinical and quality sections remains on track for scheduled completion in the first half of next year. Omeros anticipates that FDA will grant the BLA submission for narsoplimab a priority review which, under the Prescription Drug User Fee Act (PDUFA), further shortens FDA’s overall review time.

There are approximately 25,000 to 30,000 allogeneic stem-cell transplantations in the U.S. and Europe annually. TMA has been reported to occur in approximately 40 percent of them, with an estimated 80 percent of those having high-risk features. The mortality rate in severe HSCT-TMA can exceed 90 percent.

About Omeros Corporation

Omeros is an innovative biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting complement-mediated diseases, disorders of the central nervous system and immune-related diseases, including cancers. Fueled by the successful commercialization of OMIDRIA® (phenylephrine and ketorolac intraocular solution) 1%/0.3%, Omeros has multiple clinical-stage development programs focused on complement-mediated diseases and substance abuse. In addition, the company has a diverse group of preclinical programs including GPR174, a novel target in immuno-oncology that modulates a new cancer immunity axis recently discovered by Omeros. Small-molecule inhibitors of GPR174 are part of Omeros’ proprietary G protein-coupled receptor (GPCR) platform through which it controls 54 new GPCR drug targets and their corresponding compounds. The company also exclusively possesses a novel antibody-generating platform.

About Omeros’ Complement 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.

Phase 3 clinical programs are in progress for narsoplimab, Omeros’ lead MASP-2 inhibitor also known as “OMS721,” in hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA), in immunoglobulin A (IgA) nephropathy, and in atypical hemolytic uremic syndrome (aHUS). The FDA has granted narsoplimab breakthrough therapy designations for HSCT-TMA and for IgA nephropathy; orphan drug status for the prevention (inhibition) of complement-mediated thrombotic microangiopathies, for the treatment of HSCT-TMA and for the treatment of IgA nephropathy; and fast track designation for the treatment of patients with aHUS. The European Medicines Agency has granted orphan drug designation to narsoplimab for treatment in HSCT and for treatment of primary IgA nephropathy. In addition to narsoplimab, Omeros is developing small-molecule inhibitors and second-generation antibodies against MASP-2.

Omeros also has identified MASP-3 as the key activator of the complement system’s alternative pathway and as the enzyme responsible for the conversion of pro-factor D to factor D. The alternative pathway 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. Omeros is scaling up the manufacturing of its MASP-3 antibodies in preparation for clinical trials slated for the first half of next year.

SOURCE: Omeros