NEW YORK (Reuters Health) – Omalizumab may improve symptoms in people with severe allergic asthma that is not controlled by corticosteroids and beta-agonists, suggests a new study supported by the drug’s makers.

The researchers, led by Dr. Nicola Hanania of the Baylor College of Medicine in Houston, note that about one third of patients taking inhaled corticosteroids (ICS) and long-acting β2-agonists (LABAs) for asthma still don’t get better, which leaves them with limited options.

They sought to determine if omalizumab, marketed as Xolair, could provide a better option to those patients by randomizing 850 adolescents and adults with treatment-resistant allergic asthma to omalizumab or a placebo on top of high-dose ICS and LABAs (salmeterol or formoterol).

Those patients continued to be woken up by asthma symptoms and to need rescue medication multiple times per week, despite at least 8 weeks of treatment with both types of drugs.

The study, published Monday in Annals of Internal Medicine, was conducted at 197 research sites in the U.S. and Canada. It was funded by Genentech and Novartis, and the drugmakers were also involved in designing the research, interpreting the results, and writing the manuscript.

The treatment group was given a minimum dose of 0.008 mg/kg of body weight per 1 IU/mL IgE every two weeks, or a doubled dose every four weeks subcutaneously. No dose modifications of omalizumab, ICS, or LABAs were allowed during the 48-week study.

All but two patients took at least one dose of omalizumab or the placebo and were included in primary analysis, and 673 completed the study, a similar proportion in both groups.

There were fewer asthma exacerbations requiring steroid therapy in patients taking omalizumab than those in the placebo group (0.66 vs. 0.88 per patient, P = 0.006), and the time to first asthma exacerbation was increased in those taking omalizumab.

More participants in the treatment group also had an improvement on the Asthma Quality of Life Questionnaire that was greater than the minimal clinically important difference than in the placebo group (67.8% vs. 61.0%, P = 0.42).

Mean asthma symptom score and daily albuterol puffs also improved in the omalizumab group compared to the placebo group, but neither measure improved above a minimal clinically important difference.

Rates of adverse events were similar in both groups (80.4% for omalizumab vs. 79.5% for placebo), as were rates of serious adverse events (9.3% for omalizumab vs. 10.5% for placebo).

However, researchers note that the study was too small to compare rare adverse events, such as anaphylaxis and cancer, in the two groups.

Omalizumab is approved by the FDA to treat severe allergic asthma that isn’t controlled by corticosteroids, but the standard of care – including a combination of ICS and LABAs – has evolved since data were last reviewed, Dr. Hanania and colleagues note.

Based on this new evidence, they conclude that “The combined effect of omalizumab on asthma exacerbations, quality of life, asthma symptoms, and short-acting β2-agonist use comprises a meaningful clinical benefit for patients with severe asthma.”

Ann Int Med 2011.