Allergen-specific immunotherapy is the only method of treating allergic asthma with long-term effectiveness and potentially, able to change the disease course. The development of a new therapeutic vaccine for allergic asthma associated to mite sensitization and effective with few administrations would be a very advantageous alternative. The objective of this research was to evaluate the immunogenicity in humans of a Dermatophagoides siboney allergy therapeutic vaccine, adjuvanted with Neisseria meningitidis proteoliposome B (PROLINEM-DS).
This was an open, uncontrolled, non-randomized Phase I Clinical Trial in 20 adult asthmatic patients sensitized to Dermatophagoides siboney. The vaccine was administered subcutaneously, in a dose-escalation scheme with three effective doses with a 2 week interval (days 1-28). Allergen-specific cellular response of PBMC was determined by cytokines in culture supernatant, IL-4, IL-5 (Th2 pathological response), IFNg (Th1) and IL-10 (Tr1).
Allergen specific IgE levels decreased (p=0.002) and IgG4 levels (p=0.015) increased at the end of the following period (day 84) as compared to baseline. The IgE/IgG4 ratio (p<0.001) was significantly reduced, with 85% of the patients having more than 20% reduction relatedto baseline values. IgG specific to N. meningitidis showed a significant increase (p=0.0001). An increased secretion of IL10 and INFgin PBMC culture supernatant was also foundwith respect to baseline values (p<0.001).
The IgE/IgG4, IL10 and INFg ratios constitute promising efficacy biomarkers. The preexisting response to N. meningitidis was not negatively affected. The scheme of only three doses of the vaccine caused favorable immunological changes as an immunotherapy intervention.