US court invalidates key patent on J&J's Zytiga

US generic competition for Johnson & Johnson’s (J&J) Zytiga (abiraterone) prostate cancer drug has moved a step closer after a court invalidated a key patent.

J&J has said it will appeal against the decision of the Inter Partes review, where the US Patent & Trademark Office (USPTO) decides whether patents can be contested.

The USPTO’s Patent Trial and Appeal Board was ruling on a J&J patent that is protecting the drug from generic competition until 2027.

It ruled that the patent describing a method of administering Zytiga should not have been granted because the process it described was obvious.

US generic company Argentum had asked the board to invalidate the patent so that it can market its cut-price copy.

Zytiga has been approved in advanced prostate cancer since 2011 and is the top-selling cancer drug from J&J's pharma unit Janssen, generating US revenues of $352 million in the third quarter, and $669 million worldwide.

As well as the threat from generics, Zytiga is competing with Pfizer/Astellas’ Xtandi (enzalutamide), which is also approved in advanced prostate cancer.

J&J said in a statement that it was “disappointed” by the USPTO’s decision.

The company statement said: “We are evaluating our options with respect to a request for rehearing and/or appeal to the Court of Appeals for the Federal Circuit. We believe the '438 patent is valid and will continue to vigorously defend it."

Argentum’s CEO, Jeffrey Gardner, said: “We believe that the PTO's decision will be upheld if appealed by Janssen , and will save the US healthcare system billions of dollars over the next decade. Those savings will inure to the benefit of American patients by improving their access to the high quality, safe, and effective FDA-approved generic alternatives that they deserve."

Inter Partes Review decisions by the USPTO do not result in termination of a 30-month stay triggered  by an originator company's patent infringement lawsuit against a potential generic competitor.