The European Patent Office (EPO) rejected a patent for Nexium, AstraZeneca’s best-selling heartburn drug, the company said today.
German generic manufacturer Ratiopharm International had challenged the patent, and the Munich-based EPO upheld its appeal, leading to the decision. Europe accounted for $1.1 billion of Nexium’s $4.6 billion in global sales in 2005.
The revoked patent specifically covered the magnesium salt of esomeprazole (Nexium's active ingredient) and was set to expire in 2014. The loss means generic competitors potentially can get on the market sooner. Nexium, however, has data exclusivity until 2010 in major European markets, a legal device that bars generic firms from obtaining marketing approval.
"AstraZeneca has a slew of other patents that they will assert against generics to try to delay their market entry, but this patent which covered the drug by itself was the best tool for keeping generics off the market,” Jay Lessler, a pharmaceutical patent attorney with the New York firm of Darby & Darby, told MM&M.
Other patents protecting the drug include process, method of use and additional substance patents with expiration dates ranging from 2009 through to 2019, AstraZeneca said.
In a statement, the company said it’s disappointed with the EPO decision but will defend and enforce its intellectual property rights. Another EPO hearing is scheduled for March concerning the Nexium process patent.
Setbacks with its pipeline have forced AstraZeneca to cut costs and look to older medicines such as Nexium for growth. Last month the firm announced a delay in the development of sepsis treatment Cytofab. And earlier this year, trials of blood thinner Exanta and Type II diabetes drug Galida were halted due to safety issues.