DUAL study extension 2nd season: Benefit of Omalizumab and SIT over SIT alone maintained for GETE evaluation but not for symptom load

Background:

Previous study data generated in patients with grass- and rye pollen seasonal allergic asthma in 2006 have demonstrated a statistically significant and clinically relevant superiority of the combination of Xolair® (Omalizumab, OMA) plus a depigmented allergenic extract (Depigoid®) versus SIT monotherapy. There are now data available on the follow-up season in 2007 in which both arms have been treated with SIT only after the core study in 2006 was finished. The purpose of this extension study was to assess the possible long-term effects of a single pre- and co-seasonal treatment period with OMA+SIT versus SIT alone in the subsequent pollen seasons.

Methods:

After both study arms have completed the 20 weeks treatment of the core study (OMA+SIT vs. Placebo+SIT) in 2006, 128 patients have been switched to maintenance treatment with SIT alone. Symptom load during grass pollen season 2007 was determined. Global evaluation of treatment effectiveness (GETE) was performed by patients and physicians at the end of grass pollen season using a 5-point scale which evaluates changes in asthma control/symptoms.

Results:

No statistically significant difference in symptom load between former treatment arms during grass pollen season in 2007 was observed. However, GETE performed by the physicians was significantly improved at the end of the second pollen season in patients who received combination therapy with OMA and SIT in 2006. Both treatments were well tolerated.

Conclusion:

The positive effect of a combination therapy with SIT and OMA in terms of symptom load within the first season was not longer observed in 2007 after treatment with OMA has been stopped. However, add-on OMA to SIT in 2006 improves GETE in patients with seasonal allergic asthma in the second grass pollen season.