Individual clinical and demographic baseline characteristics significantly impact outcomes in moderate-to-severe asthma, influencing symptom control, reliever use, and exacerbation risk, according to a new study. The research highlights the importance of personalized management approaches to optimize therapy and prevent further airway damage.
The study employed parametric drug–disease models using pooled patient data from clinical trials to estimate patient/disease-related factors and drug-specific properties. This approach allowed researchers to evaluate the effect of interindividual differences in baseline characteristics on treatment performance, disentangling it from the pharmacological effect itself.
Impact of Baseline Characteristics
The analysis revealed that patients with higher ACQ-5 scores at baseline experienced less asthma symptom control, higher reliever use, and a greater risk of exacerbations within the first year (p < 0.01). Male non-smokers with a BMI < 25 kg/m² and no exacerbation history had a lower risk of exacerbation compared to female smokers with a BMI ≥ 25 kg/m² and prior exacerbation history (p < 0.01). Smokers, on average, used 75.4% more reliever medication compared to never-smokers.
ACQ-5, BMI, and smoking status at baseline influenced both immediate symptoms and exacerbation risk, irrespective of treatment choice. The model-based approach distinguished patient-/disease-specific features from drug-specific properties, providing insight into the interplay between reliever use and varying symptom control status.
Treatment Differences and Simulation Scenarios
Patients treated with fluticasone furoate/vilanterol (FF/VI) had a lower risk of exacerbation than those treated with fluticasone propionate (FF) or budesonide/formoterol (BUD/FOR) (p < 0.001). Stabilization of symptom scores requires time, with maximum treatment response potentially not reached within 12 weeks. While BUD/FOR shows a faster initial decrease in ACQ-5, FF/VI produces a larger shift in final ACQ-5 scores after 12 months. Combination therapy (FF/VI and BUD/FOR) significantly reduced reliever use compared to inhaled corticosteroid (ICS) monotherapy.
Simulation scenarios indicated that stepping up patients uncontrolled on fluticasone propionate (FP) 250 μg to combination therapy with FF/VI may offer a significantly greater reduction in exacerbation risk than FP 500 μg (+4.9%, p < 0.01) or BUD/FOR (+8.9%, p < 0.01). The long-term benefits observed with FF/VI may be attributed to higher adherence to once-daily dosing and differences between the molecules within these formulations.
Implications for Clinical Management
The study suggests that the effects of ICS-containing treatments on long-term outcomes are influenced by patients’ individual characteristics, highlighting the potential role for personalized interventions. Identifying patient groups most likely to benefit from early dual ICS/LABA therapy is crucial to prevent further airway damage and remodeling. Factors such as high BMI, low FEV1, exacerbation history, and female sex have been identified as independent predictors of future asthma exacerbation.
Considering the heterogeneity of disease status and treatment effects longitudinally is essential. For patients at increased risk of exacerbation, continuing with ICS monotherapy may lead to more exacerbations compared to earlier treatment step-up to once-daily ICS/LABA therapy. However, the potential benefit of step-up would be less impactful if the patient continues to smoke.
The study's strengths include individual patient-level data from a large pool of patients following different interventions and a modeling strategy that enables the analysis of how immediate treatment effects and longer-term exacerbation risk interact longitudinally at an individual patient level. Limitations include potential selection bias in clinical trials, which may not fully reflect clinical practice.
