Randomized Dose–Response Study of Subcutaneous Immunotherapy with a Dermatophagoides pteronyssinus Extract in Patients with Respiratory Allergy

AIM: To evaluate the efficacy of Dermatophagoides pteronyssinus (DPT) subcutaneous immunotherapy in allergic rhinoconjunctivitis patients. PATIENTS & METHODS: This 17-week double-blind study randomized 136 patients (95 evaluable) to five dose groups of DPT depot extract (0.0625-0.75 skin prick test [SPT] units) or placebo, administered in a six updosing schedule. RESULTS: A dose-response was observed for clinical efficacy (allergen concentration needed to induce a positive nasal provocation test response from baseline to final visit) and safety (adverse reactions). Local and systemic reactions occurred with 14.8 and 6.4% of administered doses, respectively; a single anaphylactic reaction occurred in each of Groups 3, 4 and 5 (0.3% of doses). CONCLUSION: The risk-benefit profile appeared most favorable with a DPT dose of 0.125 SPT units.