The substance patent for Crestor expires on January 8, 2016, but AstraZeneca won a six-month extension under the US paediatric trials incentive programme.Sales of Actavis' generic before the extension expires on July 8 will incur a 39 per cent royalty fee to AstraZeneca.The victory in the US overshadows some bad news for AstraZeneca earlier this month when it lost a lawsuit defending Crestor's intellectual property in Australia.he company said it has entered into a settlement agreement with Actavis and Egis Pharmaceuticals over their plan to launch generic Crestor (rosuvastatin calcium), blocking competition for the product until May 2016.