AstraZeneca and Amgen restructured their existing collaboration for tezepelumab (Tezspire), an anti-TSLP antibody for severe asthma. Under the updated terms, AstraZeneca made a $575M payment to Amgen to increase its share of tezepelumab economics (moving from 50/50 US split to AZ-favorable terms). Total consideration to Amgen across the original and restructured deals is approximately $2.3B including royalties. AZ gained global commercialization lead.