Regeneron Pharmaceuticals Inc. and its partner Sanofi voluntarily withdrew their application with the U.S. drug regulator for the expanded use of their anti-cancer drug Libtayo in patients with advanced cervical cancer.

The application for the monoclonal antibody as the second-line of treatment in the patients was withdrawn "after the companies and the U.S. Food and Drug Administration were not able to align on certain post-marketing studies," the companies said on Friday.

The FDA had accepted the supplemental application for priority review in September.

Regeneron and Sanofi are still discussing marketing applications with regulatory authorities outside the United States, they said.

The drug is already approved for some types of skin and lung cancer.

Regeneron recorded $78 million in sales of Libtayo in the third quarter, while Sanofi garnered 35 million euros ($38.98 million). ($1 = 0.8978 euros)