ACAAI: Expect More Generic Corticosteroids in the Future

PHILADELPHIA, Nov. 16 -- With the first generic version of a nasal corticosteroid approved this year, more can be expected, according to a presentation here.

The FDA approved a generic version of Flonase (fluticasone propionate) last February 2006, said Faud M. Baroody, M.D., of the Pritzker School of Medicine in Chicago at a symposium presented in conjunction with the American College of Asthma, Allergy & Immunology meeting here.

The generic drug is manufactured by Roxane Laboratories in Columbus, Ohio. A check by Dr. Baroody at his local pharmacy found that a one-month supply of brand-name Flonase cost .99, compared with .99 for the generic version.

Dr. Baroody outlined some of the specifications a generic drug must meet to be approved by the FDA:

• >The generic must have the same active ingredient and strength as the original as well as come in the same form (tablet, pill, etc.).
• The manufacturer must show bioequivalence to the original drug.
• The generic drug's labeling must be the same as the approved drugs. There can be no additional indications.
• The generic drug's manufacturing process and quality control measures must be fully documented.

We can also expect to see more improved corticosteroid formulations such as Omnaris (ciclesonide), Dr. Baroody said. This nasal spray was approved in October by the FDA for treating allergic rhinitis in adults and children 12 and older.

The spray contains a prodrug which is converted to an active compound in nasal and bronchial epithelial cells, Dr. Baroody said. In one allergen challenge study, Omnaris significantly improved measures of nasal airflow, as assessed by rhinomanometry, as well as subjective symptoms of obstruction an itching, he said.

Although he did not mention Omnaris specifically, Jonathan Corren, M.D., of the University of California Los Angeles School of Medicine, noted that nasal corticosteroids used to treat rhinitis have been shown to improve asthma as well.

About 25% of patients with rhinitis will also have some degree of asthma, Dr. Corren said. While oral or topical antihistamines are a chief rhinitis treatment, they have little effect on asthma. But nasal corticosteroids are a different story, he said.

Recent studies demonstrated that that in rhinitis patients who also have asthma, nasal corticosteroids for treating the rhinitis improved measures of lung function, bronchial hyperresponsiveness, pulmonary nitric oxide, and rates of asthma exacerbations, he said.

Finally, recent studies are revealing more about the mechanism of corticosteroid action in the airway, said Robert Schleimer, Ph.D., of Northwestern University in Chicago.

Corticosteroids inhibit cytokines, such as IL-4 and IL-13 during the late phase of allergic inflammation. This, in turn, inhibits the recruitment of inflammatory cells, most notably eosinophils and basophils, Dr. Schleimer said.

However, studies also suggest that corticosteroids inhibit B cell activating factors produced by epithelial cells. Despite having a dampening effect on the immune system, corticosteroids "also seem to spare the host defense response and even enhance the anti-microbial response," Dr. Schleimer said.

For example, corticosteroids appear to increase the presence of neutrophils, and important host defense cell, he said. Further research will be necessary to understand all the facets of corticosteroids' mechanism of action in the airway, he concluded.