Drug manufacturer Mylan has revealed it has been given permission to make a generic version of breast cancer drug Arimidex.
The company said the US Food and Drug Administration has granted it approval for the one milligram tablet of anastrozole.
Anastrozole is the active ingredient in Arimidex, which is made by UK drug manufacturer AstraZeneca.
Figures show that US sales of Arimidex, which is used to treat some types of breast cancer in postmenopausal women, were around $917 million (£608 million) for the year ending on March 31.
The FDA has already granted permission to Teva Pharmaceutical Industries to make a generic version of the drug.
Copyright Press Association 2010