Continued symptom relief 2 years after grass peptide immunotherapy treatment
Published online: September 27, 2019
Patients with allergic rhinoconjunctivitis (ARC) often experience both nasal and eye symptoms when exposed to common environmental allergens such as tree and grass pollens. Although treatments that provide symptom relief are available (antihistamines and corticosteroids), they do not cure the allergy itself with some patients still reporting symptoms after taking their medication. Peptide immunotherapy modifies the underlying allergic disease by providing small doses of short synthetic peptides derived from a specific allergen to achieve desensitization. In a previous randomized, placebo-controlled clinical trial, treatment with grass allergen peptides was superior to placebo in improving ARC symptoms in grass-allergic adult patients when exposed to grass in the Environmental Exposure Unit (EEU).
In a recent article published in The Journal of Allergy & Clinical Immunology (JACI), Ellis and colleagues evaluated the long-term efficacy of immunotherapy with grass allergen peptides 1 and 2 years after treatment was completed. Participants who completed the original clinical trial were invited to attend both the 1- and 2-year follow-up studies. These participants had a documented history of ARC when exposed to grass pollen and were previously randomized to placebo or one of three 14-week peptide treatment regimen: 8 x 6 nmol (one 6 nmol intradermal injection every 2 weeks), 4 x 12 nmol (one 12 nmol intradermal injection every 4 weeks), 8 x 12 nmol (one 12 nmol intradermal injection every 2 weeks). For both follow-up assessments, ARC symptoms were assessed after the natural grass pollen season. Study participants attended four consecutive 3-hour rye grass pollen challenges (one per day) in the EEU. ARC symptoms included both nasal (sneezing, itchy nose, blocked nose, runny nose) and non-nasal symptoms (red/burning eyes, itchy eyes, watery eyes, itching of ears, palate or throat).
A total of 118 and 84 study participants completed the 1-year and 2-year follow-up studies respectively. At the 1-year follow-up, participants who received the 8 x 6 nmol peptide treatment regimen showed a 67% improvement in ARC symptoms over placebo when challenged with rye grass in the EEU. The 4 x 12 nmol group showed a 42% symptom improvement while the 8 x 12 nmol group showed no improvement when compared to placebo. At the 2-year follow-up, similar findings were observed in the 8 x 6 nmol (72% improvement over placebo) and 4 x 12 nmol group (78% improvement over placebo). All post-treatment adverse events were considered unrelated to treatment across both follow-up assessments.
In patients with a clear history of ARC triggered by grass pollen, a short 14-week treatment regimen with grass allergen peptides provided ARC symptom relief for up to 2 years after treatment. The peptide injections were tolerable with both studies providing preliminary support for future clinical trials to evaluate grass allergen peptides in larger patient groups in a natural outdoor setting.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.
Graphical Abstract