Previous research has demonstrated that immunotherapy is effective in reducing symptoms of patients with severe allergic rhinitis. However, findings from a new study have shown that for these benefits to last, treatment should continue for three years.
As part of the GRASS Randomised Clinical Trial, the authors set out to examine whether two years of treatment with grass pollen sublingual immunotherapy provides improved nasal response to allergen challenge at three-year follow-up. A total of 106 patients were recruited for the double blind, placebo-controlled trial, and randomised to one of three treatment groups: subcutaneous immunotherapy, sublingual immunotherapy, or placebo.
After a two-year course of treatment, the results showed that both therapies were effective at tackling symptoms, with patients reporting a dramatic improvement in quality of life. However, the authors found one year after finishing treatment, sublingual grass pollen immunotherapy was not significantly different from placebo in improving nasal response to allergen challenge among patients with moderate to severe seasonal allergic rhinitis.
Commenting on the findings, co-author Professor Stephen Durham said: “We have reconfirmed that both treatments are effective but that in order to get the long-term clinical benefits after stopping the treatment, you have to take it for three years.”