The past clinical trials have found that the use of short-acting beta-agonists, such as albuterol, were linked to worse outcomes in patients with asthma with the Arg/Arg genotype of the beta-2 adrenergic receptor gene. In the presented data, those patients with the Arg/Arg profile responded to Advair (the combination of an inhaled corticosteroid and a long-acting beta-agonist) or Serevent (a long-acting beta-agonist) treatment as well as those patients with the two other forms of the gene (Arg/Gly and Gly/Gly).
The 544-patient trial evaluated three groups of patients: those with the Arg/Arg genotype, those with the Arg/Gly genotype and those with the Gly/Gly genotype. Patients were treated for 16 weeks with either Advair or Serevent.
That trial looked at 11 different genetic polymorphisms or haplotypes on that gene and found that no single variation was associated with a differential response to Advair or Serevent.
The results showed that there was no significant difference between any of the three genotype groups for the primary endpoint, morning peak expiratory flow rate, and all genotype groups showed sustained improvement on treatment with Advair or Serevent. There was also no difference between the improvement recorded for each of the three groups on the secondary endpoints of forced expiratory volume in one second, symptom-free days or use of a rescue inhaler.