Sustained effect of SQ-standardized grass allergy immunotherapy tablet on rhinoconjunctivitis quality of life

The prevalence of allergic rhinoconjunctivitis has increased significantly over the past decades with grass pollen being a common trigger. The impact of allergy on patient's quality of life is substantial.

To investigate the sustained effect on quality of life during the grass pollen season 1 year after 3 years of treatment with the SQ-standardized grass allergy immunotherapy tablet (AIT), Graza (Phleum pratense 75,000 SQ-T/2800 BAU; ALK, Denmark).

The trial was a randomized, parallel-group, double-blind, placebo-controlled trial in adult subjects with a history of moderate-severe grass pollen induced rhinoconjunctivitis inadequately controlled by symptomatic medications. Subjects received 3 years of grass AIT (n = 157) or placebo (n = 126), followed by 1 year of follow-up. Quality of life assessments were based on the standardized rhinoconjunctivitis quality of life questionnaire (RQLQ(S)); completed weekly during the entire grass pollen season.

During follow-up, the overall RQLQ(S) score for the entire grass pollen season was significantly improved in the active group (relative difference to placebo: 23%, P = 0.004). The improvement was higher during the peak pollen season (28%, P = 0.001). The treatment effect of grass AIT during the follow-up year and the previous three treatment years was similar. Improvements were found in all seven RQLQ(S) domains. The RQLQ(S) as a function of the weekly average pollen counts showed a clear separation between the treatment groups (P < 0.001).

In subjects inadequately controlled by symptomatic medications, grass AIT provided sustained and clinically relevant improvements in rhinoconjunctivitis quality of life compared to placebo. The effect increased with increasing grass pollen exposure.