Understanding the Clinical Implications of Individual Patient Characteristics and Treatment Choice on the Risk of Exacerbation in Asthma Patients with Moderate-Severe Symptoms

Plain Language SummaryThe goal of this project was to demonstrate that individual baseline characteristics can affect the risk of exacerbation as well as the overall treatment response in patients receiving regular maintenance doses of inhaled corticosteroids, given as monotherapy or in combination with long-acting beta-agonists. Using computer simulations based on a drug-disease model previously developed from a large pool of patients with moderate-severe asthma symptoms (N = 16,282), we describe how demographic and clinical baseline patient characteristics at the time of treatment start correlate with the risk of exacerbation. Our results indicate that poor symptom control, limited lung function, obesity, smoking and sex are associated with significant increase in the incidence of asthma attacks. Such an effect is augmented in winter because of the contribution of seasonal variation. This analysis also allowed us to assess how different treatments modify or reduce the annual incidence of moderate to severe attacks. In addition, simulated scenarios showed that combination therapy with fluticasone propionate/salmeterol results in 10% fewer asthma attacks relative to budesonide/formoterol combination therapy. Such a difference may be associated with corticosteroid-specific properties, which vary between inhaled corticosteroids. Consequently, even though comparable level of immediate relief and symptom control may be achieved whilst on treatment, these effects do not imply the same long-term reduction in the risk of exacerbation. These factors should be considered as a basis for personalised clinical management of patients with moderate-severe asthma. IntroductionThe assessment of future risk has become an important feature in the management of patients with asthma. However, the contribution of patient-specific characteristics and treatment choices to the risk of exacerbation is poorly understood. Here we evaluated the effect of interindividual baseline differences on the risk of exacerbation and treatment performance in patients receiving regular maintenance doses of inhaled corticosteroids (ICS) or ICS/long-acting beta-agonists (LABA) combination therapy.MethodsExacerbations and changes to asthma symptoms 5-item Asthma Control Questionnaire (ACQ-5) were simulated over a 12-month period using a time-to-event and a longitudinal model developed from phase III/IV studies in patients with moderate-severe asthma (N = 16,282). Simulations were implemented to explore treatment performance across different scenarios, including randomised designs and real-world settings. Treatment options included regular dosing with ICS monotherapy [fluticasone propionate (FP)] and combination therapy [fluticasone propionate/salmeterol (FP/SAL) or budesonide/formoterol (BUD/FOR)]. Exacerbation rate was analysed using the log-rank test. The cumulative incidence of events was summarised stratified by treatment.ResultsBeing a woman, smoker, having higher baseline ACQ-5 and body mass index (BMI) and lower forced expiratory volume in the first second (FEV1) are associated with increased exacerbation risk (p < 0.01). This risk is bigger in winter because of the seasonal variation effect. Across the different scenarios, the use of FP/SAL resulted in a 10% lower annual incidence of exacerbations relative to FP or regular dosing BUD/FOR, independently of baseline characteristics. Similar differences in the annual incidence of exacerbations were also observed between treatments in obese patients (BMI & GE; 25-35 kg/m(2)) (p < 0.01) and in patients who do not achieve symptom control on FP monotherapy.ConclusionsIndividual baseline characteristics and treatment choices affect future risk. Achieving comparable levels of symptom control whilst on treatment does not imply comparable risk reduction, as shown by the lower exacerbation rates in FP/SAL vs. BUD/FOR-treated patients. These factors should be considered as a basis for personalised clinical management of patients with moderate-severe asthma.