Genotype‐Guided Asthma Treatment Reduces Exacerbations in Children: Meta‐Analysis of Two RCTs

Background Long‐acting beta2‐agonists (LABA) in combination with inhaled corticosteroids (ICS) are commonly used to treat asthma, however, some children lack response to the addition of LABA. This might be partially due to the presence of the Arg16Gly polymorphism, encoded by rs1042713 G>A in the ADRB2 gene. Carrying the A allele (Arg16) at this variant has been associated with an increased risk of exacerbations despite LABA treatment. We investigated whether genotype‐guided treatment improved asthma‐related outcomes. Methods We conducted an individual participant data meta‐analysis of two randomised controlled trials: PUFFIN (Dutch and Swiss 6–18 year‐olds) and PACT (English and Scottish 12–18 year‐olds). Children with uncontrolled asthma despite ICS who required a step‐up in treatment were included. Participants were randomised to genotype‐guided treatment or the control group with a follow‐up of at least 6 months. Genotype‐guided treatment consisted of adding LABA for children with ADRB2 Gly16/Gly16, whilst children with ADRB2 Arg16/Arg16 or Arg16/Gly16 were treated with double dose ICS (PUFFIN) or add‐on montelukast (PACT). The primary outcome was a change in asthma control; secondary outcomes included exacerbation rate and time to exacerbation. Repeated measures mixed models and Cox regression were used. Results Fifty‐nine out of 102 (PUFFIN) and 59 out of 91 (PACT) children had at least one Arg (A allele). Amongst all 193 children, no difference was observed in asthma control between the study groups. However, genotype‐guided treatment resulted in lower asthma exacerbation rates (−0.08 (95%CI −0.16 to −0.00, p = 0.04)) compared to the control group. Conclusion Genotype‐guided step‐up treatment for children with uncontrolled asthma on ICS may lower asthma exacerbation rates and may be useful for personalising asthma care.