Federal Circuit revives Orexo’s opiate patent suit against Teva
The US Court of Appeals for the Federal Circuit yesterday revived a patent infringement lawsuit against Teva Pharmaceuticals, in a win for Sweden-based Orexo.
Last year, drug developer Orexo accused the Israeli company of infringing its patents (US numbers 9,259,421 and 8,940,330) covering Zubsolv (buprenorphine and naloxone), a treatment for opiate addiction.
The ‘330 patent was the only one involved in the proceedings at the Federal Circuit yesterday.
In its complaint, filed at the US District Court for the District of Delaware, Orexo said that generic manufacturer Actavis submitted an amendment to an Abbreviated New Drug Application (ANDA) in an attempt to bring a generic of Zubsolv to market.
Teva allegedly participated in activities surrounding the ANDA, and acquired Actavis in 2016.
Orexo, which claimed that its Zobsolv patents are valid until 2032, sought to prevent the ANDA progressing.
In response to the complaint, Teva claimed that Orexo’s ‘330 patent is invalid in light of prior art.
Teva relied on a combination of prior art, including US patent number 8,475,832 for Suboxone (buprenorphine and naloxone), another method of treating opiate addiction.
The Delaware court agreed with Teva and determined that claims of the asserted ‘330 patent were invalid on the ground of obviousness.
It held that all the ingredients in the ‘330 patent’s claims were “generally known” and the new combination claimed by the ‘330 patent would have been obvious.
Orexo appealed against the decision.
Yesterday, the Federal Circuit noted that all parties agree that Zubsolv improves the treatment of opiate dependence and minimises its abuse, compared with prior art, as it allows patients to reduce dosages and lower their dependency on the drug.
However, Teva argued that improved function and use are irrelevant if the formulation itself is obvious.
The Federal Circuit disagreed with Teva.
“This theory is flawed, for an unobvious improvement in properties or use is highly relevant to patentability of a new product,” the court said.
Although it contains the same active ingredients, the earlier ‘832 patent does not reduce the amount of buprenorphine needed to provide an effective substitution therapy dose, which the ‘330 patent does, the Federal Circuit said.
The ‘832 patent contains “no suggestion of the different structure of the Zubsolv tablet and its advantage in deterring abuse”, the court added.
Clarifying the correct assessment of obviousness, the Federal Circuit said: “The question is not whether the various references separately taught components of the ‘330 patent formulation, but whether the prior art suggested the selection and combination achieved by the ‘330 inventors.”
The Federal Circuit held that the prior art neither shows nor suggests the combination claimed in the ‘330 patent, nor that such a combination would achieve the enhanced therapeutic effect.
As Teva failed to provide “clear and convincing evidence” of obviousness, the Federal Circuit reversed the Delaware court’s determination of invalidity and remanded the matter for further proceedings.
Stephen McNeeney, partner at Potter Clarkson, represented Orexo in the dispute. Speaking to LSIPR, he said that the decision is a "hugely significant and business-critical verdict" for Orexo.
"The way is now clear for Zubsolv to play a significant role in helping healthcare providers tackle the growing opioid addiction challenge across the US and beyond," he added.
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