Objective: A double-blind, placebo-controlled study was performed with 37 patients to assess the efficacy as well as the safety of short-term pre-seasonal subcutaneous immunotherapy (SCIT) with a six-grass pollen allergoid for one year.
Results: After one pre-seasonal treatment cycle there are significant differences between the groups in favour of active treatment. On a "1-10" visual rating scale patients' condition is improved in the active group by a median of 2.5 points, whereas no change is found in the placebo treated group (p = 0.024). Thirteen of 20 (65%) actively treated patients in comparison to 6 of 17 (35%) placebo treated patients improved for at least two points which was defined as clinically relevant. The efficacy of SCIT is further demonstrated by significantly reduced skin test reactivity and significant increases in immunological parameters like allergen-specific IgG1 and IgG4 in actively treated patients. Injections are well tolerated and only mild to moderate systemic reactions occurred.
Conclusion: The high-dose hypoallergenic grass pollen preparation was shown to be safe and clinically efficacious. One pre-seasonal course of 7 SCIT injections was sufficient to reach significant and clinically relevant efficacy with good safety.