- A U.S. administrative court on Wednesday invalidated a key patent protecting Johnson & Johnson's prostate cancer drug Zytiga, potentially exposing the blockbuster product to generic competition sooner than expected.
- In a final written decision, the Patent Trial and Appeal Board (PTAB) ruled the claims underpinning J&J's last unexpired Orange Book patent on Zytiga were obvious and therefore unpatentable. J&J plans to defend the patent in question, saying it may ask a federal appeals court to consider the case.
- As it stands, the decision is a win for generic maker Argentum Pharmaceuticals LLC, which challenged J&J's patent. Earlier copycat competition to Zytiga, if it comes, could also change the market balance for Pfizer Inc. and Astellas Pharma Inc.'s rival treatment Xtandi.
While J&J's blood cancer business has grown rapidly, Zytiga (abiraterone acetate) remains the pharma giant's top-selling cancer drug by sales.
Currently, Zytiga's sole unexpired Orange Book patent is set to expire in 2027. Wednesday's decision from the PTAB could change that, potentially ushering in earlier generic competition and dealing J&J a financial blow. J&J contends the patent in question — referred to as the '438 patent — remains valid and will fight the ruling.
"We are disappointed in and strongly disagree with the U.S. Patent and Trademark Office's (USPTO) decisions relating to Zytiga as part of the inter partes reviews," the company said in a Jan. 17 statement. "We are evaluating our options with respect to a request for rehearing and/or appeal to the Court of Appeals for the Federal Circuit."
Twelve generic drugmakers have submitted applications for U.S. approval of Zytiga copies, but are currently tied up in a patent litigation with J&J in U.S. district court. A trial scheduled for October 2017 has been postponed pending continued pretrial activities, according to a regulatory filing from J&J.
J&J seeks to block the competitors from marketing a copycat version of its drug until after the '438 patent expires in 2027.
Separately, Argentum and several others filed for inter partes review through the U.S. Patent Office, leading to Wednesday's ruling.
Argentum's statement mentions no plans for next steps, likely reflecting the potential for J&J to request a rehearing or appeal.
If generic rivals do enter in the near future, J&J could be caught in a precarious position. Pfizer and Astellas' rival Xtandi (enzalutamide) has gained some ground commercially, although Zytiga still commands a 60% market share according to data compiled by Cowen & Co.
Both drugs are approved to treat metastatic castration-resistant prostate cancer, although Zytiga is only approved in conjunction with the steroid prednisone. Xtandi can also be taken with or without food, while Zytiga must only be taken on an empty stomach.
A recent success by Xtandi in a late-stage trial testing the drug in patients with earlier-stage disease could further strengthen Pfizer and Astellas' position. The results were obtained two years earlier than had originally been expected, due to a change in trial protocol and reduction in patient enrollment.
For its part, J&J does have a successor to Zytiga waiting in the wings and expects to secure approval of the drug, called apalutamide, sometime this year for pre-metastatic castration-resistant prostate cancer.
A key part of J&J's strategy in metastatic prostate cancer, however, is combining apalutamide with Zytiga in chemotherapy naive patients. Generic versions of Zytiga on the market could make that prospect less lucrative.