In 2003, Aventis entered into a collaboration with Regeneron Pharmaceuticals, a New York biotechnology company, to develop Regeneron's VEGF-inhibiting drug, aflibercept, in the field of cancer, which was then in Phase I clinical trials. Aventis invested $45 million in Regeneron and made an upfront payment of $80 million in cash. Regeneron partnered the drug with Bayer Healthcare in the field of proliferative eye diseases, and under the name Eylea it was approved by the U.S. Food and Drug Administration (FDA) in 2011; after several setbacks in clinical trials, Regeneron and Sanofi got the drug approved in metastatic colorectal cancer in combination with other agents, under the brand name Zaltrap in 2012.