MedImmune starts phase 2 trial of antibody targeting IL-5 receptor

MedImmune has announced that it has initiated a Phase 2 clinical trial in patients with chronic asthma to determine the safety of subcutaneous dosing of a humanized monoclonal antibody (MAb) that targets the interleukin-5 receptor (IL-5R).

Preclinical data suggest that inhibiting the IL-5R pathway may lead to a targeted approach for treating patients with asthma, supporting continued study of this antibody.

"Asthma can be a very debilitating disease, and despite current therapies, patients are in need of novel treatment options," said Nestor Molfino, M.D., vice president, clinical development, pulmonary disease. "Some asthmatics may show an increased circulation of eosinophils in blood -- a certain type of white blood cell believed to play a critical role in the severity and disease pathway of asthma; therefore administration of this antibody may increase asthma control."

MEDI-563, which was generated using BioWa's POTELLIGENT(TM) Technology platform, has previously been investigated in a Phase 1 open-label dose-escalating study to evaluate the safety and tolerability of a single intravenous infusion in adults with mild-to-moderate asthma. Data from the completed Phase 1 study demonstrated that the antibody was well-tolerated with biologic activity producing substantial and prolonged depletion of blood eosinophils, thus supporting its continued development. Published literature suggests that reduction of eosinophils in sputum was associated with better asthma control and increases in sputum eosinophilia were associated with exacerbations of asthma. The antibody is also currently being evaluated in a double-blind, placebo-controlled Phase 1 study to evaluate the safety and tolerability and effects of the antibody on airway eosinophils in adults with asthma.

About Interleukin-5 Receptor (IL-5R)

Interleukin-5 is a cytokine secreted predominantly by T-lymphocytes, mast cells, and eosinophils involved in regulating the differentiation, proliferation, and activation of eosinophils via the IL-5 receptor, known as IL-5R. The IL-5R consists of an alpha chain and a beta chain. Expression of the IL-5R alpha chain is restricted largely to eosinophils, basophils, and some mast cells in humans. The alpha-chain exclusively binds IL-5 and the intracellular portion of IL-5Ralpha is involved in cellular activation. Thus, the IL-5R alpha.chain may be a good target for a therapeutic antibody in the management of asthma. Eosinophils, and perhaps basophils and some mast cells, can be preferentially targeted for antibody-dependent cell cytotoxicity through IL-5R alpha chain depleting cells thought to be key in disease pathogenesis and severity. In addition, blocking of IL-5R alpha could provide benefit by neutralizing effects of IL-5.

MedImmune's Clinical Development in Asthma

MedImmune has multiple approaches in development targeting asthma. Currently, in human testing, the company has antibodies targeting IL-9 and IL-13, in addition to the anti-IL-5R that is the subject of this press release.

Asthma is a chronic disease of the airways that may cause wheezing, breathlessness, chest tightness and coughing. According to the U.S. Centers for Disease Control and Prevention, more than 30 million Americans reported having a history of asthma in 2003, including nine million children. About 20 million said they currently had asthma. In 2000, the CDC reported that there were more than 10 million asthma-related outpatient visits to private physician offices and hospital clinics. The National Institutes of Health have estimated asthma-related healthcare costs in the U.S. at $14 billion annually.