The enrollment pause could affect at least one ongoing Phase 3 study of Novartis’ pill, which is approved for use in advanced and metastatic disease. That clearance is limited to people whose tumor can be treated with hormone drugs but not with a therapy like Herceptin that targets a protein called HER2. This type of tumor, referred in shorthand as HR+ and HER2-, accounts for roughly 70% of all breast cancer cases in the U.S.
