US biotech wins review of rival’s endocrine patents after Vidal intervention
USPTO director remanded case back to PTAB after it denied post-grant review of Spruce patents | Judges determined likelihood of claims being unpatentable due to prior art and lack of written description.
Neurocrine Biosciences has won a post-grant review of two patents belonging to rival Spruce Biosciences, which was initially denied by the US Patent Trial and Appeal Board ( PTAB) but revived following a sua sponte review by Patent and Trademark Office director Kathi Vidal.
The board’s decision to review the patents, which relate to treatments for a rare group of genetic disorders known as congenital adrenal hyperplasia (CAH), was published on Friday (December 1).
CAH affects the adrenal glands and involves a deficiency of enzymes needed to make certain hormones.
It was “more than likely” that Neurocrine would prevail in showing that the patents were unpatentable on the grounds of prior art and lacking written description support, the PTAB said in its decision issued last week.
Neurocrine was denied post-grant review of the patents—US patent numbers 10,849,908 and 11,007,201—in 2021 and 2022 respectively.
However in August this year, Vidal vacated the board’s decision citing errors in its determination of whether the patents were anticipated by prior art and supported by adequate written description.
‘More than likely’ anticipated
Spruce’s ‘908 patent is directed to the administration of a compound known as a CRF1 receptor antagonist, to reduce the level of a certain hormone in a patient by at least 10% from baseline.
In her director’s decision supporting post-grant review, Vidal found that Neurocrine had sufficiently shown that there was a prior art reference that disclosed a method of treating CAH by administering a species of CRF1 receptor antagonist within the claimed genus.
San Franciso-based Spruce contested that this prior art was “extensively considered and applied by the examiner during prosecution of the ’908 patent”, and yet the claims were allowed.
However, the three-judge PTAB panel disagreed with Spruce that in allowing the claims of the ’908 patent, the examiner recognised its argument concerning the patentable distinction between the placebo described in the prior art and the baseline required by the claims of the ’908 patent.
In an article published in September following Vidal’s decision, Karina Moy (associate), Jason Weil (counsel) and Rubén Muñoz (partner) at Akin wrote: “A genus claim is anticipated by an earlier disclosure of a species within that genus.
“Because the reference disclosed administering a species (crinecerfont) within the claimed genus (CRF1 receptor antagonists), the reference anticipates the claimed method as long as it discloses the remaining limitations expressly or inherently.”
The PTAB panel also found that the prior art reference “more than likely” anticipated the '201 patent, comprised of method claims for treating CAH, and that it could also be shown to lack written description.
“If any claim limitations are not expressly disclosed in a prior art reference, patent challengers should consider whether they may be an inherent property of that disclosure and whether any later, non-prior art reference could help establish the inherent existence of those limitations in the art,” wrote Moy, Weil and Muñoz.
Post-grant review has been granted for both patents.
The case is Neurocrine Biosciences v Spruce Biosciences, with Neurocrine represented by Fish & Richardson and Spruce by Wilson Sonsini.
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