Phase II/III clinical trial to assess the tolerability and immunological effect of a new updosing phase of Dermatophagoides mix-based immunotherapy.

BACKGROUND

Immunologically enhanced subcutaneous specific immunotherapy (SCIT) has been developed with a fast and simplified updosing phase containing equal parts of the house dust mites (HDM) Dermatophagoides pteronyssinus and Dermatophagoides farinae (Dermatophagoides mix) adsorbed on aluminum hydroxide.

OBJECTIVE

To evaluate the tolerability and immunological impact of the updosing phase of this new allergen extract formulation.

MATERIAL AND METHODS

We performed a multicenter, open-label, single-arm, phase II/III clinical trial. The inclusion criteria were a clinical history of rhinitis/conjunctivitis due to HDM (with/without asthma) and sensitization to HDM (positive specific IgE and skin prick test). Five updosing injections of Dermatophagoides mix (300, 600, 3000, 6000, and 15000 SQ+) were administered at weekly intervals with 1 maintenance injection (15000 SQ+) 2 weeks after the last updosing injection. Two days after each visit, patients were contacted by telephone to follow up on any adverse events. IgE-blocking factor, IgG4, and immediate skin reactivity were evaluated.

RESULTS

The sample comprised 102 patients (mean [SD] age, 29.3 [7.7] years; male, 52.9%). There were 117 adverse drug reactions (ADR): 101 were local, regardless of reaction size, in 48 (47.1%) patients and 7 were systemic (all grade I) in 5 (4.9%) patients. All ADRs were mild, except for 1, which was moderate. Six weeks of treatment led to statistically significant increases in IgE-blocking factor and IgG4, as well as a significant reduction in immediate skin reactivity.

CONCLUSION

This new updosing phase of Dermatophagoides mix-based immunotherapy had a good tolerability profile and induced a significant immunological effect.