Amerigen loses patent case against UCB at Federal Circuit

US-based Amerigen Pharmaceuticals has lost in its bid to prove that claims in a patent owned by biopharmaceutical company UCB were covered by a prior invention.

In a precedential ruling on Friday, January 11, the US Court of Appeals for the Federal Circuit upheld a decision by the US Patent Trial and Appeal Board (PTAB) that all the challenged claims would not have been obvious given the prior art and that UCB’s patent was not unpatentable.

The decision concerned UCB’s ‘650 patent (number 6,858,650) for “stable salts of novel derivatives of 3,3-diphenylpropylamines”. The patent covers a drug called Toviaz (fesoterodine), which is used to treat urinary incontinence.

In December 2016, Amerigen sought inter partes review of nine claims of the ‘650 patent. The patent has 24 claims in total.

In its petition, Amerigen alleged that the nine claims would have been obvious because of the prior art.

Toviaz is metabolite of an older drug named Detrol, which is used to treat an overactive bladder. Unlike Detrol, Toviaz is a “prodrug”, which is typically used to improve drug delivery. This means that when it enters the body, Toviaz is an inactive molecule and requires transformation within the body into its active therapeutic form.

The court ruled that a person of ordinary skill would not have been motivated to improve Detrol’s bioavailability.

In its reason for its judgment, the court said that Detrol “did not have a bioavailability problem” and therefore a person of ordinary skill “would not have modified the drug to solve a problem that did not exist”.

In its conclusion the court said that “any compound may look obvious once someone has made it”, but “working backwards from that compound, with the benefit of hindsight, once one is aware of it does not render it obvious”.

It concluded that Amerigen’s arguments were not persuasive and affirmed the PTAB’s decision.

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