HOUSTON -- Ragweed sublingual immunotherapy (SLIT) was associated with improved allergy symptoms and was generally well tolerated in pediatric patients, according to results of a phase III study.
The trial of over 1,000 children met its primary endpoint. During peak ragweed season, those treated with the daily ragweed SLIT tablet (Ragwitek) had a 38.3% relative reduction versus the placebo group in their total combined score (TCS), the sum of their daily rhinoconjunctivitis symptom and medication use scores (least square mean difference 2.73, P<0.001), reported Hendrik Nolte, MD, PhD, of Ragwitek's developer ALK in Bedminster, New Jersey.
Across the entire ragweed season, patients on the study drug experienced a 32.4% reduction in TCS compared with the placebo group (least square mean difference 1.40, P<0.001), the authors explained during a poster session here at the American Academy of Allergy, Asthma, & Immunology annual meeting.
Children treated with the SLIT drug also showed highly significant improvement over placebo-treated patients in ragweed symptoms and declines in medication use, they reported.
Ragwitek was approved by the FDA for use in adults with ragweed allergies in 2014, but there is currently no approved ragweed SLIT for use in children. ALK noted in a press release that, based on the strength of this phase III trial, it plans to seek FDA approval of the ragweed SLIT for pediatric use.
The randomized, placebo-controlled trial included 1,022 children with ragweed allergic rhinitis -- with or without either conjunctivitis or asthma -- that went on to receive treatment. A total of 952 completed the study. Patients had an average age of 12 years (range 5 to 17), and the majority were boys (62.9%) and white (93%).
Co-author David Bernstein, MD, of the University of Cincinnati College of Medicine, told MedPage Today that one of the most interesting findings from the trial involved children with concurrent asthma (although asthma symptoms were not a primary outcome in the trial, they were recorded).
"What they found ... was that asthma daily symptom scores [with ragweed SLIT] decreased by 30% over placebo," he said, adding that improvement in asthma symptoms has been reported in children and adults on subcutaneous immunotherapy.
Children in the trial had a history of significant seasonal allergic rhinitis. They underwent skin and blood testing to document sensitization.
Compared with placebo patients, ragweed SLIT-treated children saw their rhinoconjunctivitis daily symptom score reduced by a relative 35.4% during peak season (least square mean difference 1.40, P<0.001) and their daily medication score reduced by 47.7% (least square mean difference 1.84, P<0.001).
Researchers reported no anaphylaxis events, severe treatment-related systemic allergic events, or events of compromised airways associated with the SLIT treatment. However, discontinuation rates due to adverse events (throat irritation, oral pruritus, and ear pruritus) were higher with SLIT than with placebo (3.9% vs 1.0%).
Disclosures
The study was funded by ALK and Nolte works for the company. A co-author is an employee of Merck.
Bernstein disclosed relevant relationships with GlaxoSmithKline, ALK, Aimmune, Amgen, AstraZeneca, BioCryst, Genentech, Merck, Novartis, Regeneron, Sanofi, Shire, and Teva.
Primary Source
American College of Allergy, Asthma, & Immunology
Source Reference: Nolte H, et al "Efficacy and safety of ragweed SLIT-tablet from a large trial in children with allergic rhinoconjunctivitis" ACAAI 2019; Abstract P450.