Biologics effective for severe asthma, confirms real-world study

Consistent with clinical trial data, the use of biologic therapies significantly reduced asthma exacerbations in addition to having steroid-sparing effects in patients with severe, refractory asthma who were dependent on oral steroids, according to a real-world study presented at the annual CHEST Meeting 2019 held in New Orleans, Louisiana, US.

The average number of exacerbations significantly dropped from four times in the year before switching to the biologics mepolizumab or benralizumab to one event during the year after initiating biologic therapy (p=0.002). [CHEST 2019;doi:10.1016/j.chest.2019.08.128]  

Similarly, the patients required a significantly lower dose of prednisone in the 6 months after vs before initiating biologics (median dose, 5 vs 20 mg; p=0.001), reported Dr Dayne Voelker from the Mayo Clinic in Rochester, Minnesota.

“We are able to demonstrate significant effectiveness of these agents in reducing asthma exacerbations as well as oral steroid dosages in this difficult patient population,” said Voelker and co-authors.

The findings came from a retrospective analysis of electronic medical records of 50 patients (29 female, median age at treatment initiation=54 years) with severe asthma who initiated on mepolizumab (n=42) or benralizumab (n=8) for at least 6 months. They were followed up for a median duration of 9 months after initiating biologics.

Lung function, based on forced expiratory volume in 1 second (FEV1) did not changed significantly from baseline at 6 and 12 months of initiating biologic therapy, which according to Voelker, was consistent with clinical trial data.

Biologics that are currently approved for the treatment of severe asthma include the interleukin (IL)-5 receptor antagonists benralizumab, the IL-5 inhibitors mepolizumab and reslizumab, and the IL-4 and IL-13 inhibitor dupilumab. 

However, most of the data on biologics were from phase III clinical trials whereby the patient population were carefully selected based on strict inclusion and exclusion criteria. There is still a lack of data on real-world experience and long-term use of the drugs, Voelker pointed out.

“This study confirms the long-term benefit of extended biologic therapy use in severe, refractory oral steroid-dependent asthma [in the real world],” said the researchers.

Similar findings have also been found in the real-world REALITI-A study of mepolizumab, which showed that mepolizumab significantly reduced exacerbation rate by 69 percent (p<0.001) and the dose of maintenance oral corticosteroids required by 50 percent (from 10 to 5 mg/day). Also, there were 77 percent fewer exacerbations leading to ED visits or hospitalization in the year after vs before using mepolizumab (p<0.001). [ERS 2019, abstract OA2104]

In particular, biologic therapies seem to benefit the most for patients with disease associated with eosinophil-mediated Th2 inflammation, Voelker noted. While biologic therapies can be expensive, they may turn out to be cost effective in the long run given that long-term steroid use comes with detrimental side effects, he added.