Amgen and AstraZeneca have announced that the experimental monoclonal antibody tezepelumab demonstrated a clinically meaningful reduction in annualized asthma exacerbation rate (AAER) in severe, uncontrolled asthma patients. In the NAVIGATOR Phase 3 trial, the drug led to a 56% reduction in AAER versus placebo over 52 weeks when used as part of the standard of…