FRANKFURT, May 7 (Reuters) - Germany’s Bayer (BAYGn.DE) has started testing a contested sister compound to its potential blockbuster Nexavar in the third and last phase, raising the stakes in a legal tussle with development partner Onyx (ONXX.O). Germany’s Bayer said on Friday it has started to enroll patients in a Phase III trial to test the drug, dubbed regorafenib or BAY 73-4506 by Bayer, to fight advanced bowel cancer after other treatments have failed.
