Treatment using tezepelumab did not meet the primary endpoint of statistically significant reduction in the daily OCS dose, versus placebo


Tezepelumab fails in Phase 3 study. (Credit: kalhh from Pixabay.)

AstraZeneca and Amgen announced that their investigational asthma drug tezepelumab has failed in Phase 3 SOURCE trial, when compared to placebo.

The 48-week multicentre, randomised, double-blinded, parallel-group, placebo-controlled trial study evaluated the efficacy and safety of the drug in 150 severe asthma patients, who needed corticosteroids (OCS) as maintenance, in addition to standard of care (SoC).

In the trial, the treatment using tezepelumab did not meet the primary endpoint of a statistically significant reduction in the daily OCS dose, without loss of asthma control, compared to placebo.

The drug demonstrated a similar effect on other efficacy parameters to those observed in previous clinical studies, including the Phase 3 NAVIGATOR trial.

Phase 3 NAVIGATOR study met the primary endpoint, demonstrating a statistically significant and clinically meaningful reduction in the AAER, compared to placebo plus SoC.

AstraZeneca BioPharmaceuticals R&D executive vice president Mene Pangalos said: “Based on the totality of evidence, including the compelling exacerbation reduction results seen in the registrational NAVIGATOR Phase III trial and the PATHWAY Phase IIb trial, we remain confident that tezepelumab has the potential to improve care for a broad population of severe asthma patients.

“Our initial analysis of SOURCE in oral corticosteroid-dependent asthma indicates that the trial design may have contributed to the result of the primary endpoint. We are in the process of further analysing the data from SOURCE and look forward to sharing these results with the medical community.”

Tezepelumab is an advanced human monoclonal antibody, designed to inhibit the action of TSLP, an epithelial cytokine responsible for allergic, eosinophilic and other types of airway inflammation related to severe asthma.

TSLP is released in response to multiple triggers related to asthma exacerbations, including allergens, viruses and other airborne particles. Elevated levels of TSLP is expressed in patients with asthma and is linked with disease severity.

In the clinical study, tezepelumab showed a consistent safety profile with previous trials.

Tezepelumab is developed by AstraZeneca, in collaboration with Amgen. The companies extended their 2012 collaboration agreement earlier this year.