Sanofi-Aventis has filed suit against W.C. Heraeus GmbH for infringement of US5338874 which covers oxaliplatin as product. Eloxatin is covered by following patents
US5338874 (Expiry Apr 07,2013)
US5420319 (Expiry Aug 08,2016)
US5716988 (Expiry Aug 07,2015)
US5290961 (Expiry Jan 12, 2013)
Sanofi-Aventis alleged Infringement of US5338874 ("Cis oxalato (trans 1-1,2-cyclohexanediamine) PT(II) Having Optically High Purity," issued August 16, 1994) based on Heraeus' filing of a DMF (drug master file) with the FDA for the manufacture of Eloxatin® (oxaliplatin for injection, used to treat colorectal cancer).
Oxaliplatin is a platinum-based chemotherapy drug in the same family as cisplatin and carboplatin. It is typically administered in combination with fluorouracil and leucovorin in a combination known as FOLFOX for the treatment of colorectal cancer. Compared to cisplatin the two ammine groups are replaced by cyclohexyldiamine for improved antitumour activity. The chlorine ligands are replaced by the oxalato bidentate derived from oxalic acid in order to improve water solubility.
Oxaliplatin was discovered in 1976 at Nagoya City University in Japan by Professor Yoshinori Kidani, who was granted U.S. Patent 4,169,846 over the drug in 1979. Oxaliplatin was subsequently in-licensed by Debiopharm, a Swiss drug company headquartered in Lausanne and developed as an advanced colorectal cancer treatment. Debio licensed the drug to Sanofi-Aventis in 1994. Eloxatin gained European approval in 1999 and USFDA approval in 2004.
