USPTO invalidates J&J’s patent on prostate cancer drug Zytiga

Argentum Pharmaceuticals brought the challenge to the patent, in a proceeding called inter partes review.

Argentum disputed all claims of Janssen's U.S. Patent No. 8,822,438, which will expire on 24 August 2027.

The US PTO concluded that Argentum "satisfied its burden of demonstrating, by a preponderance of the evidence, that the subject matter of claims 1–20 would have been obvious.”

Zytiga is a prescription medicine used in combination with prednisone for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC), a type of advanced prostate cancer that is resistant to medical or surgical treatments that lower testosterone.

It blocks CYP17-mediated androgen production, which expands prostate cancer growth at three sources, including the testes, adrenals and the prostate tumor tissue.

Zytiga is said to decrease androgen production in the testes and do not affect the adrenal glands or prostate tumor tissue.

Argentum Pharmaceuticals CEO Jeffrey Gardner said: “The inter partes review process is an important tool by which generic and biosimilar companies can create prescription drug savings by ensuring that non-innovative patents do not block competition.

“Argentum's core mission is to lower the cost of prescription drugs by challenging patents that are not innovative and which artificially support high drug prices.”

Johnson & Johnson stated: "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.”