Ombrabulin was an experimental drug candidate discovered by Ajinomoto and further developed by Sanofi-Aventis.

[1] Ombrabulin is a combretastatin A-4 derivative that exerts its antitumor effect by disrupting the formation of blood vessels needed for tumor growth.

[2][3] It was granted orphan drug status by the European Medicines Agency in April 2011.

[4] In January 2013, Sanofi said it discontinued development of ombrabulin after disappointing results from phase III clinical trials.

[5]