AstraZeneca PLC said the U.S. Food and Drug Administration granted orphan-drug status to its drug Lynparza for pancreatic cancer drug.

Cambridge, U.K.-based AstraZeneca is evaluating Lynparza against placebo in a late-stage pancreatic cancer study, called Polo, with results expected in the first half of 2019.

The drug, which AstraZeneca is developing with Merck & Co. Inc., was previously designated an orphan drug for treatment of ovarian cancer, fallopian tube cancer and primary peritoneal cancer.

Lynparza, also known as olaparib, is already approved to treat adults with recurrent epithelial ovarian, fallopian tube or primary peritoneal cancer, who have had their tumor shrink at least 50% through chemotherapy.

The U.S. FDA's orphan-drug program encourages the development of rare disease therapies through incentives, such as market exclusivity and relief from certain regulatory fees.

Pancreatic cancer accounts for about 3% of all cancers in the U.S., with five-year survival rates at 8.5%. AstraZeneca Chief Medical Officer Sean Bohen said pancreatic cancer is an area of significant unmet clinical need.