By Colin Kellaher

AstraZeneca PLC on Friday said the U.S. Food and Drug Administration granted orphan-drug designation to tezepelumab for the treatment of the rare inflammatory disease eosinophilic esophagitis.

The U.K. pharmaceutical giant, which is developing tezepelumab with Amgen Inc., said there are currently no approved treatments in the U.S. for eosinophilic esophagitis, which can make eating difficult or uncomfortable, potentially leading to chronic pain, difficulty swallowing, poor growth, malnutrition and weight loss.

The FDA's orphan-drug program gives special status to drugs and biologics for diseases and disorders that affect fewer than 200,000 people in the U.S. and provides for an extended marketing-exclusivity period against competition.

AstraZeneca and Amgen, a Thousand Oaks, Calif., biotechnology company, agreed in 2012 to collaborate on tezepelumab, which is currently under FDA priority review for patients with asthma, with a decision expected early next year.

Under an update earlier this year to their collaboration, Amgen and AstraZeneca will continue to share costs and profits equally after payment by AstraZeneca of a mid-single-digit royalty to Amgen. AstraZeneca continues to lead development of the drug, while Amgen leads manufacturing.

Write to Colin Kellaher at colin.kellaher@wsj.com

(END) Dow Jones Newswires

10-08-21 0737ET