The Patent Trial and Appeal Board has received 37 petitions for post grant review of patents issuing from examination conducted by the Patent Office’s Group Art Unit 1600. The Board has issued four final written decisions thus far. We discussed the first final written decision here, where all claims were upheld in the face of a challenge based on obviousness grounds only. Three of the four final written decisions issued so far on biotech/pharma subject matter dealt only with art-based challenges. Grünenthal GmbH v. Antecip Bioventures II LLC, Case PGR2017-00008 (June 22, 2018) marks the first PGR final written decision addressing written description of a patent arising from Art Unit 1600; all claims were held to be unpatentable under Section 112.

The petitioner requested PGR of claims 1-17 of U.S. Patent No. 9,283,239, which recite methods of treating complex regional pain syndrome via a specific dosing regimen of zoledronic acid. The petitioner challenged the claims based on anticipation, obviousness, lack of enablement, and lack of written description. The PTAB initially denied institution only on the written description grounds, but later modified the institution decision to institute on all of the challenged claims and all of the grounds presented in the petition in view of the Supreme Court’s decision in SAS Institute, Inc. v. Iancu, 138 S. Ct. 1348 (2018). The parties jointly and successfully moved the Board to limit the review to Petitioner’s challenge based on written description.

Petitioner asserted that the patent specification failed to sufficiently disclose the dosing regimen recited in the claims: “about 80 to about 500 mg of zoledronic acid within a period of six months.” Petitioner argued that the specification listed “dozens of dosage amounts, frequencies and durations of treatment, and conditions to be treated,” but did not expressly disclose the claimed dosage range and timing recited in claim 1, and did not reasonably convey that the inventors considered the claimed range to be part of their invention. Patent Owner pointed to the disclosure of ranges in the specification that encompass the claimed range; use of the term “about” which, according to the Patent Owner, signaled that ends of the ranges are estimates; and argued that one of ordinary skill could derive the dosage regimen from various disclosures in the specification when taken together.

The Board agreed with the petitioner that the specification did not clearly allow one of ordinary skill to recognize the “about 80 mg” endpoint recited in the claims: “There is no disclosure of ‘about 80 mg’ as a preferred endpoint, no disclosure of a specific embodiment including a dose of 80 mg, nor any other description suggesting the importance or criticality of the ‘about 80 mg’ endpoint.” Further, the disclosure the Patent Owner cited as enabling one of ordinary skill to derive the claimed regimen was insufficient, according to the Board, to satisfy the written description requirement. The Board again pointed to the specification’s silence as to any significance of using about 80 mg of zoledronic acid, analogizing the facts of the case to those of Purdue Pharma L.P. v. Faulding Inc., 230 F.3d 1320 (Fed. Cir. 2000), where the Federal Circuit held that claims reciting an extended-release drug formulation requiring a certain ratio relating to pharmacokinetics could not be derived from the specification.

However, none of the cases concluding that … a person of ordinary skill in the art could derive a claimed range from a specification are factually equivalent to the present case, where… a non-original claim recites a dosage regimen range with endpoints derived from an inordinate amount of picking and choosing from disparate disclosures of various embodiments reciting broader ranges.

The “six month” time feature also was not explicitly disclosed in the application, “further complicating the process necessary to derive the recited dosing regimen from the ’239 patent specification.” The Board ultimately held that all of the challenged claims failed to comply with the written description requirement of Section 112.

Given the limited availability of PGRs, Petitioners challenging dosing regimen patents have mainly relied upon IPRs rather than PGRs. The wider range of potential grounds for challenge offered by PGRs make them an attractive option for challengers of biotech/pharma patents, including those based on dosage regimens.