|AstraZeneca's headquarters in London--Courtesy of AstraZeneca|
It's one step back, one step forward for AstraZeneca's key respiratory drug benralizumab. After acknowledging a midstage setback for the drug in COPD last month, AstraZeneca's big MedImmune division has come back with positive, though somewhat mixed, Phase IIb data underscoring the effectiveness of knocking down eosinophils--white blood cells--in preventing asthma attacks.
Benralizumab--an IL-5 antibody--reduced the rate of asthma exacerbations, hitting the primary endpoint in the trial, says AstraZeneca ($AZN). But the study flagged weak results for the low end of the doses used in the trial, with the top dose doing better in patient groups which could be identified with higher levels of eosinophils, which are widely considered a trigger for asthma as well as COPD. In its statement, MedImmune noted a treatment response ranging from 40% to 70%, depending on the dose and subpopulation treated.
AstraZeneca is using the results to help guide the late-stage studies now underway. The pharma giant pushed ahead with a Phase III trial of benralizumab in COPD, jumping off ahead of a Phase IIa failure. In that study with 101 patients, benralizumab failed to improve the rate of acute exacerbations. And there was also a higher rate of severe treatment-emergent adverse events in the drug arm.
Eosinophils, though, may point to a future for this drug in asthma and COPD, which spurred AstraZeneca to assign a peak potential sales figure of $2 billion to the therapy as it wrestled out of Pfizer's ($PFE) embrace earlier this year. The current data was published in The Lancet.
But it's a crowded field in which GlaxoSmithKline ($GSK), Teva ($TEVA) and Novartis ($NVS) play a big role. GlaxoSmithKline started a Phase III study for mepolizumab in COPD patients last April as it wrapped a successful late-stage effort in asthma. And Teva's reslizumab also did well in Phase III for asthma.
"Asthma is a highly heterogeneous disease and these data advance our understanding of patient subtypes, potential biomarkers and targeted therapies to achieve the best outcomes for patients," said Bing Yao, the head of MedImmune's Respiratory, Inflammation and Autoimmunity Innovative Medicines Unit. "The insights from this Phase II trial played a key role in the design of our Phase III asthma programme. We are encouraged by the development prospects for benralizumab as a potential innovative medicine for patients with severe asthma and COPD."
- here's the summary from The Lancet
- here's the release