Abstract
Background:
Maintenance doses for AIT have been recommended for at least 3 years but
little data on long-term efficacy is available depending on AIT
duration.
To show sustained efficacy 10 years after completion of treatment with
depigmented-polymerized house dust mite (dpg-pol HDM) allergen extract
in adults with asthma and/or rhinoconjunctivitis.
Methods:
Patients included in a double-blind placebo-controlled AIT study with
dpg-pol HDM allergen extract were reviewed at completion of the
perennial treatment and 10 years later (10y-FU). Change in symptom and
rescue medication score was the primary objective. Visual analogue
scale, asthma control test (ACT) and degree of disease control were the
secondary objectives. A comparative analysis between patients who
underwent AIT treatment for < 3 years and ≥ 3 years was
performed.
Results:
Data from 31 patients (mean age 38 years) were available at 10y-FU. All
had asthma and 29 had rhinoconjunctivitis at baseline. Twenty-three
patients were treated ≥ 3y and 8 for < 3y. Seventeen (55%)
patients were asymptomatic at completion of AIT, with significant
differences for nasal, conjunctival and bronchial symptoms
(p<0.0001) compared to baseline only in those patients treated
≥3y. Nine (52.9%) patients remained completely asymptomatic at 10yFU ,
all were treated for ≥ 3 years. Moreover, significant reduction in the
number of patients with rhinitis (p=0.0117), conjunctivitis
(p<0.0001) and bronchial (p=0.0005) symptoms was observed at
10y-FU compared to baseline only in the ≥3y treated. Ten (32.3%)
patients didn´t require any rescue medication at 10y-FU, all had been
treated for ≥ 3y. ACT at 10y-FU showed a good control of asthma (median
23.5; 95% IC[22.0, 25.0]). No significant differences were observed
between VAS at end of treatment compared to VAS at 10y-FU.
Conclusions:
Sustained clinical efficacy is achieved 10 years after completion of
depigmented-polymerized HDM, however these findings were observed only
if patients are treated for at least 3 years.