Instead of enduring years of allergy shots that may only marginally reduce their symptoms, "hayfever" victims may soon be closer to getting substantially more effective control of their allergic problems with just six shots in six weeks.
The results of a new clinical study by Johns Hopkins researchers show that an experimental immunotherapy for severe ragweed allergy dramatically reduces allergic symptoms such as a runny nose, sneezing, nasal congestion and itchy, watery eyes. The new treatment nearly eliminates the need for relief medications such as antihistamines and decongestants and is substantially safer than conventional allergy shots, the scientists report.
"Our studies represent a major advance in the development of new treatments for allergic disease," says Peter Creticos, associate professor of medicine at Hopkins and principal investigator of the study using a drug produced by Dynavax Technologies Corporation of Berkeley, Calif.
In an abstract scheduled for presentation March 2 at a special session at the American Academy of Allergy, Asthma and Immunology meetings in New York, Creticos described experiments of the drug on 25 adults with chronic, severe ragweed allergy.
Current immunotherapy for ragweed allergies typically requires a tedious six-month build-up phase of shots, with subsequent maintenance injection therapy over three to five more years. "This study demonstrates that we can induce a clear clinical response in ragweed-allergic patients with a brief six-week, six-injection regimen," Creticos says.
There is also the risk of developing a serious allergic reaction to allergy injections, but the new drug was well tolerated by patients and caused no systemic allergic reactions, according to Creticos.
The new immunotherapeutic drug, called AIC, is created by attaching immune-boosting molecules, or oligonucleotides, to the major ragweed protein responsible for allergic reactions. Preliminary results show a several-fold reduction in hayfever symptoms and a similar reduction in allergy medication requirements during peak ragweed season compared to patients who received a placebo.
"The immunotherapy drug reduces the severity of symptoms and the need for other medications, while improving the quality of life for allergy sufferers," Creticos says.
In the study, a phase II trial, researchers recruited adults with seasonal ragweed allergies who had positive skin-test reactions to ragweed pollen. Each study participant received six injections of the Dynavax drug. The scientists measured the response to inhaled ragweed before and after injections, and tested immune response and clinical symptoms during an entire ragweed season, including antibody measurements and T cell studies.
The results of this study affirm the value of the immunotherapuetic approach, Creticos says, which could prove useful in a variety of inflammatory conditions besides allergy, including asthma, gastrointestinal disorders and rheumatoid arthritis.
Additional clinical trials are planned for the upcoming ragweed season. FDA approval must be obtained before the drug is available to the general public, a process that usually takes several years to complete.
Other investigators in the study are Joseph Eiden, David Broide, Susan Balcer-Whaley, John Schroeder, Arouna Khattignavong, Huamin Li, Philip Norman and Robert Hamilton.
This research was performed as part of the Immune Tolerance Network, with support from the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Juvenile Diabetes Research Foundation.