Pfizer and Astellas Pharma have reached a settlement over a dispute concerning rights to sell the blockbuster cholesterol drug Lipitor (atorvastatin) in Japan with the latter firm emerging victorious and retaining the rights to market the treatment until July 2016.

Astellas filed a lawsuit in November after the New York-based behemoth asserted that the Japanese firm’s licence only ran until 2011, when the substance patent on atorvastatin in Japan expires. Astellas licensed Lipitor from Warner-Lambert, before it merged with Pfizer, and launched the product onto the Japanese market in 2000.

The problem has now been cleared up and the firms issued a statement saying that they are “pleased with the prompt resolution of this issue, and are committed to the marketing and promotion of Lipitor in Japan with a renewed focus.” The settlement involved no payments.

Keeping hold of the world’s best-selling drug is obviously good news for Astellas and the pact probably suits Pfizer at the moment as well. Takumi Yamagishi, senior drugs analyst at Shinko Securities, told Reuters that "I think Pfizer probably decided that with all this restructuring, it was not the time to be fighting a lawsuit and alienating a business partner."