The study is the first Phase III clinical trial to demonstrate the efficacy of liquid sublingual therapy for ragweed allergy, North America’s dominant seasonal allergy.
Deborah Gentile, MD, Director of Research in the Division of Allergy, Asthma and Immunology at Allegheny General Hospital (AGH) and one of the lead authors on the study, said the results are great news for allergy patients, who could soon find weekly visits to the doctor’s office for allergy shots becoming a thing of the past.
“With sublingual immunotherapy, allergy patients can administer their own medication at their convenience, without leaving their homes,” Dr. Gentile said. “We also expect more patients will adhere to their medication regimen when no injections are involved.”
Dr. Gentile collaborated in the study with Peter S. Creticos, MD of Creticos Research Group, Crownsville, Maryland and Allergy and Asthma Specialists of Greater Washington, Warrenton, Va.; Robert Esch, Ph.D., and Brad Whitlow, BS, of Greer Laboratories, Lenoir, NC; Peter Couroux, MD, Topstone Research, Toronto, Ont; Pina D’Angelo, M.Sc., PRACS Institute, Mississauga, Ont., and Michael Alexander, MD of Niagara Clinical Research, Niagara Falls, Ont.
A successful Phase 3 clinical trial marks the final step before submitting a treatment for FDA approval, Dr. Gentile said. Phase III trials take a new treatment that has shown promising results in earlier studies of relatively small numbers of patients and compare it with the current standard of care for that disease in a larger sampling of patients.
The study looked at 429 patients ages 18-55 with ragweed-related allergic rhinoconjunctivitis who were randomly selected to receive either the maximum tolerable dose of standardized glycerinated short ragweed sublingual allergen immunotherapy liquid (RW-SAIL), or a placebo identical in taste and texture. They did not receive allergy shots, the current standard of care.
They self-administered the treatment for approximately 8-16 weeks before and through the end of the ragweed pollen season and recorded in an electronic diary their daily symptoms of rhinoconjunctivitis (nasal congestion, runny nose, post-nasal drip, sneezing, red eyes.)
RW-SAIL significantly improved allergy management, as patients reported a 43 percent decrease in symptoms compared with those who got the placebo. None of the subjects experienced anaphylaxis, a life-threatening allergic reaction, or needed to use epinephrine, an emergency treatment for severe allergic reactions.
Subcutaneous immunotherapy (SCIT), or injections, is the conventional mode of therapy for patients suffering from ragweed allergy. The treatment is complicated by the prolonged injection schedule, which often leads to patient noncompliance due to the frequent doctor’s office visits required, as well as discomfort and the risk of anaphylaxis.
Sublingual immunotherapy (SLIT), under the tongue drops or tablets, is widely used in Europe but not yet approved by the U.S. Food and Drug Administration. Some physicians prescribe the drug off-label to patients who are willing to pay out of pocket for the more convenient therapy.
The current study is the first prospective, confirmatory Phase III trial to demonstrate the clinical effectiveness of SLIT with liquid drops in treating ragweed allergy. The clinical improvement of 43 percent well exceeded the 20 percent that is the World Allergy Organization’s accepted norm for clinically meaningful improvement, Dr. Gentile said.
Dr. Gentile and AGH colleague David Skoner, MD, Director of AGH’s Division of Allergy, Asthma and Immunology, have been pioneers in the development of oral immunotherapy for allergy sufferers. Their studies have paved the way for this significant Phase III trial.
At this year’s AAAAI conference, Dr. Skoner also presented the results of a nationwide survey showing that educational efforts are needed to improve patient expectations and knowledge about specific immunotherapy (SIT), which desensitizes patients to their allergens. It is one of the most effective therapies available for allergic rhinoconjunctivitis, which is one of the most common chronic diseases in the U.S.
A telephone survey of 2,765 people showed that only 32 percent had heard of SIT, and of those aware of it 65 percent had discussed it with their health care providers.
For more information, contact:
The West Penn Allegheny Health System
The West Penn Allegheny Health System