British biotechnology BTG Plc said it could receive up to $307 million in milestone payments, plus royalties, after licensing a preclinical cancer drug to U.S.-based Onyx Pharmaceuticals, the company that developed kidney cancer drug Nexavar.

Under the terms of the agreement, BTG will receive an upfront payment of $13 million dollars and has the potential to receive development milestone payments of up to $ 72 million plus additional payments of up to $ 235 million relating to product approval and achievement of commercial milestones. BTG will also receive a royalty on any future sales worldwide.

BGC 945 progressed into late-stage preclinical development through BTG´s collaboration with The Institute of Cancer Research  where the compound was discovered.

BTG will share approximately 10 percent of the upfront and milestone revenues relating to BGC 945 with ICR, plus a pass-through royalty.

BGC 945 is a novel compound that inhibits thymidylate synthase (TS), an enzyme involved in cell growth and division. Unlike traditional TS inhibitors, BGC 945 enters tumour cells via the alpha-folate receptor, which is over-expressed in certain tumor types, including ovarian, lung, endometrial and mesothelioma cells, but has a restricted expression profile in normal tissues.