AstraZeneca has entered into an agreement with Actavis and Egis Pharmaceuticals to settle US patent lawsuits concerning its cholesterol blockbuster Crestor.

The deal, which settles uncertainty about the status of the Anglo-Swedish drugmaker's biggest-earner in the USA, sees Actavis and Egis concede that the Crestor (rosuvastatin) substance patent is valid, enforceable and would be infringed by their proposed generic products.

The settlement permits Actasvis to begin selling its copycat version of Crestor and its rosuvastatin zinc product beginning May 2, 2016, while paying AstraZeneca 39% of net sales until the end of paediatric exclusivity on July 8 of that year. The entry date could be earlier and the fees eliminated in certain circumstances.

The agreement also means that Actavis will not carry on with its appeal of a decision by the US Court of Appeals for the Federal Circuit in December that upheld the validity and enforceability of the Crestor substance patent. No financial details of the settlement, which also involves Shionogi (which discovered the drug) have not been disclosed.

Actavis chief executive Paul Bisano noted that the agreement "ensures that consumers will benefit from an earlier launch of a rosuvastatin calcium product and eliminates ongoing litigation and uncertainty of marketplace acceptance of a non-generically substitutable product if Actavis had proceeded to launch the alternate product,” ie the rosuvastatin zinc version.

The settlement will allow AstraZeneca to focus on the major restructuring it unveiled last week and progress the pipeline so that the loss of Crestor  in three years' time will be softened. While headlines last week highlighted the 4,000 job cuts planned over the next three years, the firm also made an upfront payment of $240 million to Moderna Therapeutics as part of their messenger RNA pact and announced the creation of a translational research centre for cardiovascular and metabolic disease and regenerative medicine with Karolinska Instituet.