Double-blind, placebo-controlled, dose-ranging study of new recombinant hypoallergenic Bet v 1 in an environmental exposure chamber.

BACKGROUND: Recombinant allergens offer a tool for improving specific immunotherapy (SIT). OBJECTIVE: To find the optimal dose of a new hypoallergenic folding variant of recombinant Bet v 1 (rBet v 1-FV) as SIT for patients with birch pollen allergy. METHODS: Before SIT, thirty-seven adult patients were exposed for eight hours in an environmental exposure chamber (EEC) to birch pollen at an average concentration of 3500 ± 500 grains/m(3) , then randomized to four maintenance dose groups of rBet v 1-FV and one placebo group: 20 µg (n = 7), 80 µg (n = 8), 160 µg (n = 7), 320 µg (n = 8), and placebo (n = 7). Patients were treated for 10 weeks with weekly injections and then re-exposed in the EEC. The optimal dose for SIT was assessed using efficacy results from the EEC, IgG responses, and tolerability. RESULTS: Thirty-six patients were evaluable for efficacy assessment. The total symptom score significantly decreased in all active groups compared with placebo (-18.8% for placebo patients; -71.9%, P = 0.0022 for 20 µg; -75.6%, P = 0.0007 for 80 µg; -81.8%, P = 0.0009 for 160 µg; -78.3%, P = 0.0003 for 320 µg). IgG1 increased significantly in all active groups compared to placebo. All four active doses were well tolerated, no serious adverse event occurred; two Grade II reactions, according to EAACI classification, were observed, one in each of the 160- and 320-µg groups. CONCLUSIONS: Considering efficacy, immunological response, and tolerability, a maintenance dose of 80 µg of rBet v 1-FV appears to be the ideal dose for allergen immunotherapy in birch pollen allergic patients.

Prospective validation of 'Allergy-Control-SCORE(TM)': a novel symptom-medication score for clinical trials.

BACKGROUND: Combined symptom and medication scores (SMS) are recommended as primary endpoints in clinical trials. Several SMS have been created, but none has been formally validated. OBJECTIVE: To evaluate the validity of the 'Allergy-Control-SCORE© (ACS)', a novel instrument to assess patient's allergy severity by recording symptoms and rescue medication. METHODS: One hundred and twenty-one consenting subjects (age 18-65 year), including 81 patients with allergic rhino-conjunctivitis and/or asthma and 40 healthy controls, participated in the study. They recorded daily nasal, eye, and lung symptoms using a 4-point scale (none, mild, moderate, and severe) and use of anti-symptomatic medication. Pollen counts were monitored during the study period. Symptom and medication scores values were compared to global allergy severity, quality of life, and allergy-related medical consultations. Feasibility was tested through a questionnaire on comprehensibility, easiness of use, and completeness. Retest reliability was assessed by testing consistency, in relation to pollen exposure, and for values recorded during each of 2 consecutive weeks. RESULTS: Convergent reliability analysis indicated a highly significant correlation between ACS© and global allergy severity (P < 0.0001), quality of life (P < 0.0001), and allergy-related medical consultations (P < 0.0001). Scores were highly related to pollen counts. Allergy-Control-SCORE© showed a good retest reliability (r = 0.81; P < 0.0001) and discriminated extremely well between patients with allergy and healthy controls (6.1 ± 4.8 vs 0.2 ± 0.5; t = 10.82; P < 0.0001) with a sensitivity of 97% and a specificity of 87%. Study participants evaluated the feasibility of the SMS as excellent. CONCLUSIONS: Allergy-Control-SCORE© is a valid and reliable instrument to assess allergy severity in clinical trials and observational studies of respiratory allergic diseases.

Clinical effects of specific immunotherapy: a two-year double-blind, placebo-controlled study with a one year follow-up.

BACKGROUND: A new depot allergoid of house dust mite (Dermatophagoides pteronyssinus - D.pt) has been created in line with the principles and methodology established in the successful development of pollen allergoids. A two-year double-blind placebo-controlled clinical trial, with one further follow-up year of active treatment, has been conducted to assess clinical efficacy and tolerance. METHODS: 40 patients (20 verum and 20 placebo) with IgE-mediated mite allergy and a history of moderate to severe perennial symptoms of rhinoconjunctivitis with or without asthma participated in a 2-year randomized, double-blind, placebo-controlled trial. Actively treated patients were included in a follow-up year. Active treatment was performed with an aluminium hydroxide adsorbed house dust mite allergoid. Parameters for baseline data and clinical efficacy: nasal challenge, quantitative skin prick testing, Visual Analog Scale (VAS), patients' diaries, physician's assessment of patients? health condition, symptoms and use of anti-allergic medication as well as adverse reactions and changes in specific IgG4 and IgE antibodies. RESULTS: The trial detected superiority (p < 0.05) of mite depot allergoid versus placebo with regard to VAS and symptom intensity sum score in patients who needed anti-allergic medication in the baseline period. Significant differences (p < 0.05) between verum and placebo groups were also seen for patients' reactivities to nasal challenges and prick tests with allergen. The blinded assessment by the physician documented a significant difference (p < 0.05) between the groups in favour of active treatment. After reaching the maximum dose as well as after 12 and 24 months, specific IgG4 antibody concentrations were significantly elevated in the verum group (p < 0.05) by comparison with placebo. Local reactions were less frequent in the verum group and no systemic adverse reactions occurred. A third year of active treatment resulted in further improvement and documented the advantage of booster therapy to stabilize the clinical success. CONCLUSION: Specific immunotherapy with a mite depot allergoid induced significant clinical improvements versus placebo. Safety was assessed as excellent, and no systemic adverse reactions occurred.

Efficacy and safety of preseasonal-specific immunotherapy with an aluminium-adsorbed six-grass pollen allergoid.

BACKGROUND: The clinical efficacy and safety of a six-grass pollen allergoid has been studied. The advent of more exacting clinical guidelines and a better appreciation of the possible mechanisms of treatment prompted this reappraisal. METHODS: A 2-year double-blind multicentre placebo-controlled phase 3 clinical trial was undertaken in 154 patients suffering symptoms of rhinoconjunctivitis with or without asthma (GINA I or II). Therapy comprised two consecutive preseasonal short-courses of subcutaneous injections using a grass pollen allergoid adsorbed to aluminium hydroxide. RESULTS: A combined symptom and medication score (SMS) was used as the primary end-point for clinical efficacy. SMS from the first year showed a significant difference of 26.6% between the two study groups (P=0.026) and this was improved after the second year when there was a 48.4% difference in SMS between active and placebo treatment in favour of the allergoid (P = 0.018). Highly significant increases in grass pollen allergen-specific IgG1 and IgG4 antibody concentrations were measured in association with active treatment. Allergen tolerance was increased as judged by a conjunctival provocation test and significant improvements in quality of life were documented using a standardized questionnaire. The allergoid was well tolerated. CONCLUSIONS: The grass pollen allergoid was shown to be safe and clinically efficacious in the management of hay fever with or without asthma (GINA I or II).