A federal judge in the District of Columbia ruled against Astellas Pharma, a Japanese drugmaker that wants to ban generic versions of its transplant drug, Prograf.

Tokyo-based Astellas Pharma sued the day after Sandoz won approval from the Food and Drug Administration this month to make a generic version of the drug.

Astellas sought stricter regulations for generic rivals, arguing that sufficient tests had not been done to ensure the public safety. It wanted manufacturing of generic versions stopped while its appeal was heard.

Although additional testing may reveal more about the drug, the FDA testing methodology was adequate, US District Judge Robert Urbina ruled.