AstraZeneca relies on biomarkers for Phase 3 asthma studies
- AstraZeneca on Wednesday announced its anti-interleukin-13 (IL-13) antibody tralokinumab failed to meet a primary endpoint of a significant reduction in the annual asthma exacerbation rate (AAER) in the Phase 3 STRATOS 1 study.
- The British pharma’s other Phase 3 STRATOS 2 study is still ongoing and data is expected in the second half of 2017.
- Due to the failure in STRATOS 1, the second study will be changed to focus on a sub-group that has elevated biomarkers associated with IL-13.
While STRATOS 1 was technically a failure, the trial did its job in another respect — it used a biomarker to identify the high-responding population.
The STRATOS studies are meant to evaluate patients with severe asthma, inadequately controlled despite receiving inhaled corticosteroids plus a long-acting beta 2-agonist (LABA).
STRATOS 1 was designed to use biomarkers to identify patients that had an enhanced response to tralokinumab, while STRATOS 2 was designed to validate those biomarkers findings.
A planned analysis of a sub-population with elevated biomarker levels showed a "clinically relevant" reduction in AAER. AstraZeneca will focus on that group in STRATOS 2, but the phrasing used by the drugmaker suggests the sub-group's response did not separate from placebo in a statistically significant way.
The use of biomarkers to identify high-responding patients is an evolving area of drug development. While more often used in cancer, companies are also using the tool in other therapeutic areas.
But the science isn’t exact. There is no regulatory framework around biomarkers and companies usually develop their own — which often leads to different biomarker tests that have different thresholds of a biomarker for similar drugs.
Despite the challenges of working with biomarkers, they can offer companies a clearer picture of what population a drug will work best in.
- AstraZeneca Press release
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