Method: Out of 160 patients recruited, 131 adult patients with ARC induced by HDMs were randomized for this dbpc phase II study (EudraCT No 2013-000617-20) conducted in Germany. Treatment consisted of either 300 UA/d; 1,000 UA/d; 2,000 UA/d; 3,000 UA/d or placebo over a course of 12 weeks. Efficacy was assessed by the improvement of reactions to a titrated conjunctival allergen challenge. Safety was assessed by frequency, type and severity of treatment-related adverse events (TRAE).
Results: After a 12-week course of immunotherapy, 88.5% and 76.0% of the patients treated with 2,000 UA/d and 1,000 UA/d, respectively, showed a tenfold improvement in the threshold of allergen concentration compared to 64.2% under placebo (p<0,05 and p=0.358). Neither treatment related SAEs nor cases of anaphylaxis were reported, so there was no need for the use of epinephrine. In total, of all patients under active treatment 4.95% experienced local TRAEs while 6.93% had systemic TRAEs.
Conclusions: The treatment with mite monomeric allergoids is a well-tolerated and safe treatment for patients suffering from HDM induced ARC. The highest proportion of patients with improvement in the CPT threshold of allergen concentration was found in patients treated with 2.000 UA/d corresponding to approximately 168.000 UA cumulative dose during the course of the trial.