Hospira has won approval for the first U.S. generic version of Sanofi-aventis’ Taxotere cancer drug, according to a Reuters report.

U.S. sales of Taxotere, an infused chemotherapy known generically as docetaxel, were $1.2 billion last year, according to Hospira. JPMorgan analyst Chris Schott said recently that U.S. approval of generic Taxotere was the most important near-term catalyst for Hospira's shares.

Taxotere lost U.S. patent protection in November, but the FDA wanted changes to the packaging and labeling of Hospira's product before granting approval, a Hospira spokesman said.

Sanofi said it has braced for the arrival of generic rivals to Taxotere and included the impact in its 2011 earnings forecast. The French drugmaker's U.S. Taxotere sales slumped 28% in the fourth quarter because wholesalers were anticipating the arrival of a generic.

Hospira, in its 2011 financial forecast, assumed it would be starting U.S. sales of its generic. The company, a maker of injectable drugs, already markets docetaxel in Europe and Australia.