Sales of Sanofi-Aventis’ Eloxatin, already hit by the loss of patent protection in Europe, are about to be hammered even further after US regulators approved a host of generic injectable versions of the chemotherapy drug.

Teva Pharmaceutical Industries said it has received approval from the US Food and Drug Administration and already launched 50mg and 100mg versions of Eloxatin (oxaliplatin) injection for adjuvant treatment of stage III colon cancer in patients who have undergone complete resection of the primary tumour and for advanced colorectal cancer. The Israeli company noted that in June, a court in New Jersey found in its favour in a patent infringement case with Debiopharm which licensed the drug to Sanofi but both of these companies have appealed the decision.

Sanofi has also sued the FDA seeking to rescind all approvals granted to date for oxaliplatin, pending resolution of the outstanding appeal. Nevertheless the agency has also just approved copycat versions of the drug made by Fresenius, Novartis’ Ebewe and Sandoz units and India’s Sun Pharma. Tentative approvals have been granted to Turkey’s MN Pharmaceuticals and Hospira,, which is also involved in a legal dispute with Sanofi.

The companies who have started shipping oxaliplatin seem to have different views on what US sales of the branded drug are. Teva said that 2008 turnover reached $1.3 billion, Hospira claims it was $1.4 billion, while Sun Pharma believes that annual sales in the USA are worth $2.3 billion.

Last month Sanofi revealed that second-quarter sales of Eloxatin declined 4.3% to 353 million euros, due to generic competition in Europe.