Roles of real-world evidence in severe asthma treatment: challenges and opportunities

Recent advances in asthma research have led to the development of novel biologics that hinder the pathologic actions of key molecules in severe asthma (SA). Traditional randomised controlled studies (RCTs), the gold standard for evaluating the efficacy and safety of medical interventions with excellent internal validity, have proven the clinical benefits and favourable safety profiles of type 2-biologics in SA. However, RCTs are not always ideal because of shortcomings such as limited external validity and practical issues in the management of SA that could not be solved through strictly designed clinical trials. Thus, the applicability of their findings may be questioned for asthmatic patients because treatment adherence is frequently poor in the real world. Real-world evidence (RWE) includes a wide range of real-world data (RWD) collected from multiple sources in clinical practice, such as electronic medical records, healthcare insurance claims, and retrospective or prospective patient registries. It may help clinicians make decisions about the management of patients with SA. RWE is also gaining attention to address clinical questions not answered by traditional RCTs. Since there are various types of RWD with different possibilities and limitations, and thus it is important to decide which type of RWD could be “fit for purpose” to address a specific question. This narrative review is to discuss the challenges and opportunities of RWD for evaluating the effectiveness and clinical outcomes of biological treatments for SA.