Treating allergic rhinitis with SLIT-liquid found to significantly reduce asthma onset or worsening

2nd May 2024

Patients with allergic rhinitis who take a liquid sublingual allergen immunotherapy (SLIT-liquid) have a significant reduction in the risk of asthma onset or worsening for up to eight years compared with patients taking symptomatic allergic rhinitis therapies alone, a large real-world study has found.

Allergic rhinitis affects 400 million people worldwide, with one third of these patients also having allergic asthma, the French researchers wrote in The Lancet Regional Health – Europe.

Current allergic rhinitis management strategies aim to control symptoms and reduce inflammation, with oral or nasal antihistamines or intranasal corticosteroids the recommended first-line treatments.

Allergen immunotherapy (AIT) – currently the only causal treatment option for allergic disease – might be indicated in combination with pharmacotherapy if the response to first-line therapies was inadequate or absent, researchers said.

AIT is recommended to be administered for at least three years, either subcutaneously or sublingually, with tablets or liquid formulations.

Randomised controlled trials and observational studies have confirmed the efficacy and safety of AIT in allergic rhinitis, with or without asthma, but data has been limited on the impact of AIT on asthma onset and worsening.

For the national EfficAPSI real-world study, researchers analysed a cohort of 112,492 people with allergic rhinitis who initiated personalised SLIT-liquid (brand name Staloral) and 333,082 controls who were dispensed allergic rhinitis symptomatic medication but had no history of receiving allergen immunotherapy.

Data on the control patients were taken from the French national health data system SNDS, with data on the exposed patients taken from the database of SLIT-liquid manufacturer Stallergenes Greer, which also funded the EfficAPSI study.

One third of patients in both groups had a history of mild-to-moderate asthma, the study authors noted.

Among the exposed patients, two thirds were treated for a single allergen, mainly house dust mites and grass pollen.

The median follow-up was 6.9 years for exposed patients and 8.2 years for the control group.

First author Professor Pascal Demoly, professor of pulmonology and head of department at the University Hospital of Montpellier, France, and co-authors said that they found a 36% reduction overall in the risk of new asthma events in patients treated with SLIT-liquid compared with controls.

SLIT-liquid exposure was associated with a significantly lower risk of asthma onset according to three definitions: combined: HR 0.64, sensitive: HR 0.76, and specific: HR 0.66.

The sensitive definition of asthma events considered the first asthma drug dispensation, hospitalisation or long-term disease for severe asthma, the researchers explained.

The specific definition omitted drug dispensation and the combined one considered the dispensations of specific asthma medications, hospitalisation or long-term disease for severe asthma.

Professor Demoly and colleagues said: ‘Of note, our results showed a greater reduction in younger patients which highlights the interest of starting AIT as early as possible.’

In patients with pre-existing asthma, the Global Initiative for Asthma (GINA) treatment step-up evolution was also analysed, with researchers finding SLIT-liquid exposure was associated with a one-third reduction in GINA step-up regardless of baseline treatment step.

‘Our findings support the long-term effectiveness of personalised SLIT-liquid in real-life for the treatment of [allergic rhinitis] patients with and without pre-existing asthma and substantiate its evidence as a relevant causal treatment option for patients with respiratory allergies, for all ages and allergens considered, with abilities to prevent both disease onset and progression,’ the researchers concluded.

This follows similar research from Germany in 2021, which found allergen immunotherapy for allergic rhinitis and/or asthma remained effective over a nine-year follow-up period.

Allergen immunotherapy effectiveness confirmed in long-term real-world study

3rd December 2021

Allergen immunotherapy in patients with allergic rhinitis and/or asthma was effective over a nine-year period in a real-world study.

The effectiveness of allergen immunotherapy (AIT) in allergic rhinitis (AR) patients both with and without asthma has been confirmed in a nine-year retrospective analysis by researchers from the Paediatric Pulmonology and Allergy, Children’s Doctor Service, Heidelberg, Germany.

Allergies represent an abnormal immune system reaction to otherwise harmless allergens and in the UK, AR is estimated to affect 10-15% of children and 26% of adults. In addition, patients with AR can also suffer with asthma as a co-morbidity, with studies suggesting that 10% to 40% of AR patients have asthma.

Furthermore, the presence of AR is associated with an incremental adverse impact on the disease-specific quality of life in patients with asthma and the level of asthma control.

Allergen immunotherapy (or desensitisation treatment) involves exposure to increasing doses of an allergen such as grass pollen, dust mites or cat dander. AIT can be given via the subcutaneous or sublingual route, both of which have been shown to be effective treatment for patients with AR. Nevertheless, there is a recognised recognised lack of information from studies on the effectiveness of AIT in real-world studies and over the longer term.

In order to address this gap in the evidence, the German researchers undertook the Real World effectiveness in allergy immunotherapy (REACT) study, primarily to assess the efficacy of AIT over a period of years.

Using a retrospective, observational, propensity score matched cohort study, the team analysed health insurance claims from 2007 to 2017 and included AR patients with and without asthma and who had received an AIT prescription. These individuals were then propensity-score matched with AR individuals (also with or without asthma) but who had not been prescribed AIT.

The primary outcome of the study was set as AR prescriptions in each follow-up year and secondary outcomes included asthma prescriptions, severe asthma exacerbations and any changes in the individual’s asthma treatment steps.

AIT findings

Between 2007 and 2017, 115,098 individuals had at least one AIT prescription, of whom, 46,024 with a mean age of 29.5 years (53% male) were propensity score matched. In addition, 14,614 AR patients with AR and co-existing asthma (mean age, 28.3 years, 54% male) were also matched with controls. However, over the 9 years, the study population declined, leaving 3692 individuals in the main cohort and 1142 with co-existent asthma.

When compared to control patients, AIT use was consistently associated with greater reductions in both AR and asthma prescriptions. In addition, there was a significantly greater likelihood that patients using AIT would have an asthma treatment step-down (p < 0.0001) and a reduction in severe asthma exacerbations (p < 0.05).

The authors concluded that their study had confirmed the real-world effectiveness of AIT as evidenced by sustained reductions in AR and asthma prescriptions, prevention of asthma exacerbations, and improved and sustained long-term asthma control.

Citation
Fritzching B et al. Long-term real-world effectiveness of allergy immunotherapy in patients with allergic rhinitis and asthma: Results from the REACT study, a retrospective cohort study. Lancet Regional Health Europe 2021.