More challenges
Under US law, Pfizer could have launched its own lawsuit against Dr Reddy’s to try to halt the generic drug, but it has not done so.
Pfizer is the world’s biggest drugs company. It has said its profits target this year assumes that none of its drugs will face cheap generic competition.
But anti-convulsant Neurontin, hypertension drug Norvasc and Zoloft are all the subject of court battles over copycat or altered versions.