Bayer AG's promises of soaring sales for its experimental pipeline of drugs -- hinging in large part on an unproven treatment for an uncommon cancer -- are being met with skepticism. The German conglomerate is relying on positive signs in early human trials to predict more than 2 billion euros in annual sales for anetumab ravtansine should it win regulatory clearance for using the medicine in treating multiple cancers, its oncology chief Robert LaCaze said in an interview this month.