Combination Therapy in Asthma Management: A Systematic Review of Allergen Immunotherapies and Biological Therapies

Abstract

Asthma, a prevalent respiratory condition, often requires comprehensive management strategies to control symptoms effectively. This systematic review aims to evaluate the efficacy of combining Allergen Immunotherapy (AIT) with biological therapies in reducing respiratory symptoms and medication use among adult asthmatic patients. A narrative synthesis approach was employed to conduct this systematic review. The literature search, spanning from 2000 to 2024, was conducted using PubMed, MEDLINE, and Embase, yielding 1,220 records. After removing duplicates and screening titles and abstracts, 1,124 studies were evaluated, with five Randomized Controlled Trials (RCTs) meeting the inclusion criteria. Studies were selected based on stringent eligibility criteria, including adult participants and interventions combining AIT and biological therapies. Quality assessment was conducted using the Critical Appraisal Skills Programme (CASP) framework, and data were extracted and synthesised using narrative summary and thematic analysis. The review synthesised data from five RCTs, encompassing a total of 703 participants aged 11 to 65 years. The studies varied in geographic location, including Europe and the United States, and targeted a range of allergens such as house dust mites, grass pollen, and animal dander. The primary outcome, a reduction in respiratory symptoms, was consistently met across all studies. Combination therapies showed significant improvements in symptom control, as measured by tools such as the Asthma Control Questionnaire (ACQ) and Total Asthma Symptom Score (TASS). Additionally, the studies demonstrated a substantial reduction in the use of medications, including inhaled corticosteroids (ICS) and rescue medications, highlighting the effectiveness of the combined treatment approach. This systematic review demonstrates that combining AIT with biological therapies is highly effective in managing asthma and related allergic conditions, such as rhinitis. The findings underscore significant improvements in both symptom control and medication reduction, suggesting that these combination therapies could play a crucial role in advancing asthma treatment strategies. However, the review also highlights challenges such as patient adherence and cost considerations, which need to be addressed to fully integrate these therapies into clinical practice. Future research should focus on standardising protocols, assessing long-term effects, and exploring cost-effective strategies to overcome barriers to implementation, ensuring broader access to these advanced treatments.