Sublingual Grass Pollen Tablets Show Promise as Immunotherapy

Barbara Boughton

April 05, 2011

April 5, 2011 (San Francisco, California) — Sublingual grass pollen tablets have the potential to significantly reduce allergic rhinitis symptoms, and current dosages produce minimal adverse effects, according to 2 studies presented here at the American Academy of Allergy, Asthma and Immunology 2011 Annual Meeting.

In a randomized placebo-controlled phase 3 study, 473 patients were randomized to receive either sublingual grass pollen tablets or placebo. Those who received the grass pollen tablets experienced a 28% reduction in symptoms, compared with those who received placebo, said David Bernstein, MD, professor of medicine and environmental health at the University of Cincinnati, Ohio.

Patients experienced significant decreases in sneezing, rhinorrhea, nasal congestion, and itchy and watery eyes, Dr. Bernstein reported.

"At the same time, the safety profile was very good," he added. Most reactions to the grass pollen tablets were localized to the mouth and did not persist beyond several days or weeks, he noted. There were no serious or anaphylactic reactions to the tablets, and the most common adverse effects were throat irritation, oral pruritis, ear pruritis, and oral paresthesia. The grass pollen tablet used in the study was composed of a mixture of 5 different pasture grasses common to most of the United States (300 index of reactivity sublingual immunotherapy). A similar tablet has shown clinical efficacy and has been well tolerated in European trials, Dr. Bernstein said. Both Stallergenes and ALK America have sublingual grass pollen and dust mite tablets in development. None of these products has yet been approved in the United States.

"Tablets with other allergens are actively being studied — they're in the works because they've shown promise," said Linda Cox, MD, another researcher from the trial. Dr. Cox is associate clinical professor at Nova Southeastern in Fort Lauderdale, Florida.

Another study unveiled at the meeting used a sublingual immunotherapy tablet containing Timothy grass pollen in a randomized double-blind study of 438 patients with allergic rhinitis. Participants underwent treatment for a median of 16 weeks. During peak grass pollen season, patients who received the sublingual tablets experienced 21% to 22% fewer symptoms than those who received placebo, and their quality of life during standard activities improved by 27%. The treatment was well tolerated and there were no systemic allergic reactions or anaphylaxis, Dr. Bernstein said.

"Sublingual immunotherapy is a treatment that's effective and is more amenable to pediatric patients, who would rather not get regular allergy shots," said Kari Nadeau, MD, PhD, a pediatrician and director of immunotherapy trials at Stanford University School of Medicine in California. Dr. Nadeau has tested a sublingual immunotherapy that combines dust mites and Timothy grass pollen. "So far, the therapy looks very safe. The challenge is in getting the dose right and figuring out compliance, since patients give the therapy to themselves [at home]," she said.

The most recent trials with grass pollen tablets have been successful, and current dosages appear be both effective and safe, Dr. Nadeau noted. Whether or not the tablets get approved by the US Food and Drug Administration (FDA) in the next year or 2 depends on how quickly the agency is willing to act, she said.

"I hope the FDA does approve these therapies. If you can use them in children, then potentially you can stop the allergic march," Dr. Nadeau said. "It starts with eczema, and progresses to allergic rhinitis and then asthma," she explained. But a therapy that would be more easily accepted than current subcutaneous allergy shots could make a dent in the number of patients who suffer from these allergic diseases, she said.

The 300IR grass pollen study was funded by Stallergenes, which manufactures sublingual grass pollen tablets. Dr. Cox is a consultant to Stallergenes. Dr. Bernstein is a consultant for Merck and ALK America, another manufacturer of grass pollen tablets. Dr. Nadeau has disclosed no relevant financial relationships.

American Academy of Allergy, Asthma and Immunology (AAAAI) 2011 Annual Meeting: Abstracts 277 and 279. Presented March 19, 2011.


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