AstraZeneca has announced that it has reached an agreement with Teva Pharmaceutical Industries to settle patent litigation over Teva’s proposed generic version of Nexium, used to prevent gastro-oesophageal reflux disease.

The agreement will protect AstraZeneca’s esomeprazole capsules from immediate generic competition, but will allow Teva to market its generic esomeprazole on 27 May 2014, subject to regulatory approval.

Teva conceded that all Teva’s US Nexium patent litigations are valid and enforceable and that six Nexium patents would be infringed by the manufacture or sale of their generic esomeprazole.

This is the second time that AstraZeneca has reached a settlement with generics companies seeking to produce their own version of Nexium after the company reached an agreement with India’s Ranbaxy In April 2008. Under this agreement Ranbaxy will also start producing a generic in May 2014.

In a separate agreement, AstraZeneca and Teva have agreed to settle patent litigation related to Prilosec (omeprazole). Under this agreement, Teva will make a one-time payment to AstraZeneca for past infringing sales.