Provisional Patent Applications Must Provide Written Description Support to Afford Provisional Filing Date

Takeaway: The Patent Trial and Appeal Board (“PTAB”) denied instituting an inter  partes review based on the patent owner’s challenge that the prior art used for asserting obviousness could not afford the provisional filing date because there was insufficient written description support and therefore should not qualify as prior art. Provisional Patent applications must sufficiently disclose the invention. 

In Forty Seven, Inc. v. Stichting Sanquin Bloedvoorziening, IPR2016-01529, Paper 13 (P.TA.B., Feb. 9, 2017), the PTAB agreed with the patent owner that the prior art reference used for an obviousness challenge should not be afforded the provisional patent application filing date because there was not enough written description support.

The petitioner of the inter partes review (“IPR”) of U.S. Patent No. 9,352,037 (“the ’037 patent”) asserted the IPR based on obviousness grounds, relying on WO 2009/091547 to Majetti (“Majetti”) as a primary reference. However in order for Majetti to be considered prior art, its effective filing date must be based on its priority application, U.S. Provisional Application No. 61/011,324, which predated the ’037 patent.

However, the patent owner argued that claim 10 of the provisional application did not provide sufficient written description to support claim 10 of Majetti.  The patent owner contended that claim 10 of Majetti is directed to a broad genus of agents for treating acute myeloid leukemia cancer stem cells and the provisional application failed to provide a representative number of species to adequately describe the genus.  Therefore, under 35 U.S.C. § 112, the claims of Majetti were not fully supported by the disclosure of the provisional application.

The PTAB applied Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1350 (Fed. Cir. 2010), which states that a “sufficient description of a genus . . . requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the genus so that one of skill in the art can visualize or recognize the members of the genus.”  Therefore, Majetti was not entitled to the filing date of its provisional patent application and thus the PTAB denied the institution of the IPR.