Pfizer has lost a Beijing court case over the rights to a popular Chinese translation of its drug Viagra.
Pfizer has been working hard to protect its Viagra brand in China
A court ruled Pfizer can no longer use the name Wei Ge, or mighty brother, to market Viagra as China's Guangzhou Welman had registered the brand.
While Pfizer markets the anti-impotence pill as Wan Ai Ke in China, it is commonly called Wei Ge by the public.
The US firm has challenged firms in China for copying the look or using variations on the name of its key drug.
In a separate ruling in December, the same court ordered two other Chinese companies to stop selling anti-impotence drugs under the name Wei Ge.
In the latest case, the Beijing Court ruled that Guangzhou Welman had registered the Wei Ge brand correctly and should be allowed to use it.
The court ruled that the fact that "Wei Ge" is a commonly used translation for Viagra does not automatically give Pfizer any right to the name.