Genentech Inc.'s anti-IgE recombinant humanized monoclonal antibody continues to generate positive clinical data in treating seasonal allergic rhinitis and ultimately could serve to validate the approach of targeting IgE to treat a variety of IgE-mediated indications. On Friday, the company announced statistically significant results in a Phase III trial. GNE and partners Novartis Pharma AG and Tanox Inc. (Houston, Texas) hope that similar efficacy will be seen in an ongoing Phase III study to treat allergic asthma.

The concept behind rhuMAb-E25 is that the antibody will bind to IgE circulating in the blood, thereby preventing it from binding to mast cells. This serves to block the release of inflammatory mediators and attenuate allergic response.

In the Phase III seasonal allergic rhinitis study, 251 patients received either subcutaneous injections of 300 mg anti-IgE or placebo. There was a significant reduction in patient nasal symptoms (the primary end point), ocular symptoms and use of antihistamine tablets for the anti-IgE group (see B9).

According to Robert Fick, senior clinical scientist and anti-IgE project team leader at GNE, the importance of the trial is two-fold. "On one hand we have confirmatory Phase III data that effectively substantiates our Phase II/III trial," he said. "But on a broader scale, we have confirmation of the concept that blocking IgE should curtail allergic disease."

Patients in the Phase II/III study also showed significant improvement over placebo on measures of nasal and ocular symptom severity and on the amount of rescue medication required (see BioCentury, Nov. 16, 1998).

In light of these two trials, "people are beginning to think that anti-IgE is for real in treating IgE-mediated diseases," said Fick.

Anti-IgE is also in Phase III testing in 1000 patients to treat allergic asthma. GNE (South San Francisco, Calif.) expects data from the study by year end. Fick told BioCentury that GNE and partner Novartis (Basel, Switzerland) hope to file a single BLA for both indications in May 2000. - Steve Edelson

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