'''Ombrabulin''' is an experimental drug candidate discovered by [[Ajinomoto]] and under development by [[Sanofi-Aventis]].<ref name=sanofi>{{cite web | url = http://www.sanofi-aventisoncology.com/wps/portal/oncology/pipeline/ombrabulin | title = Ombrabulin (AVE8062) | publisher = Sanofi-Aventis Oncology}}</ref> Ombrabulin is a [[combretastatin A-4]] [[derivative (chemistry)|derivative]] that exerts its antitumor effect by disrupting the formation of blood vessels needed for tumor growth.<ref>{{Cite journal | pmid = 10551334 | year = 1999 | last1 = Hori | first1 = K | last2 = Saito | first2 = S | last3 = Nihei | first3 = Y | last4 = Suzuki | first4 = M | last5 = Sato | first5 = Y | title = Antitumor effects due to irreversible stoppage of tumor tissue blood flow: evaluation of a novel combretastatin A-4 derivative, AC7700 | volume = 90 | issue = 9 | pages = 1026–38 | journal = Japanese journal of cancer research : Gann | doi=10.1111/j.1349-7006.1999.tb00851.x}}</ref><ref>{{Cite journal | pmid = 12085211 | year = 2002 | last1 = Hori | first1 = K | last2 = Saito | first2 = S | last3 = Kubota | first3 = K | title = A novel combretastatin A-4 derivative, AC7700, strongly stanches tumour blood flow and inhibits growth of tumours developing in various tissues and organs | volume = 86 | issue = 10 | pages = 1604–14 | doi = 10.1038/sj.bjc.6600296 | pmc = 2746587 | journal = British journal of cancer}}</ref> It was granted [[orphan drug]] status by the [[European Medicines Agency]] in April 2011.<ref>{{cite web | url = http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/orphans/2011/04/human_orphan_000912.jsp&mid=WC0b01ac058001d12b&murl=menus/medicines/medicines.jsp&jsenabled=true | title = Orphan Designation EU/3/11/853 | publisher = European Medicines Agency | date = 15 April 2011}}</ref> In January 2013, Sanofi said it has discontinued development of ombrabulin after disappointing results from phase III clinical trials.<ref>{{Cite news|url = http://www.pmlive.com/pharma_news/sanofi_r_and_d_chief_updates_on_pipeline_457999|title = Sanofi has 65 new compounds in development, says R&D chief|last = |first = |date = |work = |access-date = |via = }}</ref>