The approval follows a recommendation from the European Medicines Agency in November based on a late-stage study of the drug that showed significant improvement in survival among patients with colon cancer.

Zaltrap, approved in the US in August 2012, is among the new products Sanofi is relying on to restore growth after the loss of several blockbuster drugs to generic competitition.

But CM-CIC analyst Arsene Guekam expects the drug, co-developed with US biotechnology company Regeneron, will remain a niche product for Sanofi.

Guekam is forecasting peak sales of 300 million euros ($406 million) a year since Zaltrap will compete against established medicines like Roche's Avastin and Erbitux, sold by German drugmaker Merck, as a second-line treatment for advanced bowel cancer.

Zaltrap is also unlikely to be used to treat other types of tumours, after it failed studies in prostate, lung and pancreatic cancer.

Sanofi shares, which have risen around 26 percent in the last twelve months, were trading 1.7 percent at 70.85 euros at 1016 GMT, and were the leading gainer on the benchmark CAC40 index, up 0.5 percent.