Long-term Immunotherapy Effective Against Allergic Rhinitis

Three-year treatment with immunotherapy effectively controlled symptoms of allergic rhinitis.

Results from a new study suggest that shorter term immunotherapy may not improve allergic rhinitis symptoms in the long-term.

When patients with moderate-to-severe seasonal allergic rhinitis were treated with immunotherapy tablets for only 2 years, investigators did not see much difference in symptoms compared with placebo, according to a study published by JAMA.

Allergic rhinitis, also known as hay fever, is fairly common in the United States, with 15% to 30% of the population reporting a diagnosis or nasal symptoms.

This condition can impact quality of life, sleep, and performance at work or in school, especially in the summer time when pollen is the most prevalent.

“Hay fever causes major impairment of sleep, work and school performance and leisure activities during what for most of us is the best time of the year,” said lead researcher Stephen Durham. “Most people respond to the usual antihistamines and nasal sprays, although there is a portion who do not respond adequately or who have unacceptable side effects to the treatment.”

Similar immunotherapy techniques have been successful in treating patients with food allergies. For these treatments, patients are exposed to the allergen at increasing amounts to build up resistance in hopes of eliminating unnecessary immune response.

Treatment with subcutaneous and sublingual immunotherapy for 3 years was shown to improve symptoms for at least 2 years after treatment cessation, according to the study. However, it was previously unknown whether a shorter course of drugs would elicit the same long-term benefits, while reducing costs, patient inconvenience, and adverse events related to long-term treatment.

In the new study, the investigators randomized 106 patients with moderate-to-severe seasonal allergic rhinitis to receive 2 years of sublingual immunotherapy (n=36), subcutaneous immunotherapy (n=36), or placebo (n=34) for 15 weeks.

After 2 years, the investigators discovered that both treatments effectively suppressed rhinitis symptoms, with nearly all reporting a dramatic improvement in quality of life, according to the study.

However, patients who were treated with immunotherapy had symptoms similar to those treated with placebo only 1 year after treatment was stopped, suggesting that the longer treatment is ideal for these patients.

“This study shows that whereas both immunotherapy treatments were highly effective, two years of treatment was insufficient for long-term benefits,” Durham said. “Clinicians and patients should continue to follow international guidelines that recommend a minimum of 3 years’ treatment.”

Since their previous findings indicate that 3 years of immunotherapy treatment improved symptoms, the authors do not suggest that patients are treated for less than that amount of time.

“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 3 years,” Dr Durham concluded.