Omalizumab treatment and exercise capacity in severe asthmatics - results from a pilot study

In patients with moderate to severe allergic asthma, clinical effectiveness of omalizumab, an approved anti-IgE-reacting substance, is usually assessed by pulmonary function testing (PFT), symptom scores and physicians judgement.

We postulate that cardiopulmonary exercise testing (CPET) may provide an additional option to verify symptomatic changes in patients with allergic asthma.

Ten consecutive patients with allergic asthma were treated with omalizumab. Prior to and after 16 weeks of treatment all patients underwent PFT and symptom-limited CPET. Results were compared to 10 asthmatic controls without omalizumab medication. Symptoms were assessed according to investigators judgement (IGETE).

All 20 patients showed a significantly impaired exercise capacity at baseline [peak oxygen uptake (VO(2)) 71 ± 16% predicted]. In patients with omalizumab, peakVO(2) increased from 13.8 (8.4-21.4) to 16.8 (11.2-23.9) ml/kg/min (p < 0.05), VO(2) at anaerobic threshold increased by 22% [9.8 (3.3-15.2) to 12.3 (6.7-14.4) ml/kg/min (p < 0.05)]. There was no improvement in the controls. The increase in VO(2) was significantly correlated to the improvement in symptoms. All patients revealed dynamic hyperinflation under exercise with a decreasing extent with omalizumab treatment.

This study suggests that CPET may provide additional and useful tools to assess and verify the individual clinical response to omalizumab treatment. An improvement in exercise capacity can reliably mirror changes in quality of life and IGETE. Patients with omalizumab experience significant improvements in their initially impaired exercise capacity. CPET can be safely accomplished in patients with severe asthma.