Johns Hopkins researchers last year reported that an experimental treatment for severe ragweed allergy consisting of just six shots in six weeks dramatically reduced allergic symptoms such as runny nose, nasal congestion and sneezing and nearly eliminated the need for relief medications like antihistamines and decongestants. Now, follow-up of patients who continued in the study for a second year shows that the initial six-injection course of this treatment appears to be effective--and safe--for more than one allergy season.
"We are particularly pleased that this brief, six-week, six-injection regimen can have lasting positive effects for more than one season of ragweed exposure," said Peter Creticos, associate professor of medicine at Johns Hopkins and principal investigator of the study. "These studies represent a major advance in the development of new treatments for allergic disease, especially when compared with conventional allergy treatments, which can take years to be effective," he said.
The new treatment is an allergy vaccine created by attaching immune system-boosting molecules, or oligonucleotides, to Amb 1 a, the major ragweed protein responsible for allergic reactions.
Creticos presented the new findings of the study on March 11 at a special symposium on allergy therapeutics at the 60th annual meeting of the American Academy of Allergy, Asthma and Immunology.
The observer-blinded, placebo-controlled Phase II study evaluated adult volunteers who had a history of fall seasonal hayfever and had skin test reactions to ragweed pollen. Using a vaccine developed by scientists at the University of California, San Diego and produced by Dynavax Technologies Corp. of Berkeley, Calif., Johns Hopkins investigators gave patients the new treatment before the 2001 ragweed season. These patients were followed for their clinical improvement throughout the 2001 and 2002 ragweed seasons, without additional injections of the vaccine.
The follow-up phase of the study showed that patients given the vaccine had improved hayfever symptoms and quality of life measurements and less need for relief medications during the second ragweed season, and these changes were similar to those observed during the initial ragweed season.
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.