PTAB: Open-Ended Markush Group Improper and Indefinite

Ex parte Kiely is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing whether a Markush group stating “selection from the group comprising” was indefinite.

In Ex parte Kiely the Appellant argued that the phrase “selection from the group comprising” was not improper because the Examiner allowed claims in another application with language and alleged that such phrasing was found proper in Multilayer Stretch Cling Film Holdings, Incorporated v. Berry Plastics Corporation, 831 F.3d 1350 (Fed. Cir. 2016). The PTAB disagreed.

First, the PTAB relied on Abbott Labs. v. Baxter Pharm. Products, Inc. for the proposition that “a proper Markush group is limited by the closed language term ‘consisting of.’” 334 F.3d 1274, 1281 (Fed. Cir. 2003). The PTAB also cited MPEP § 2173.05(h), which states “[i]f a Markush grouping requires a material selected from an open list of alternatives (e.g., selected from the group ‘comprising’ or ‘consisting essentially of’ the recited alternatives), the claim should generally be rejected under 35 U.S.C. 112(b) as indefinite because it is unclear what other alternatives are intended to be encompassed by the claim.”

With respect to Appellant’s reliance on Multilayer Stretch Cling, the PTAB noted that this case did not sanction the phrase “selected from the group comprising.” The claims at issue in Multilayer Stretch Cling did not even use this language. To the contrary, the court in Multilayer Stretch Cling stated:

[I]f a patent claim recites ‘a member selected from the group consisting of A, B, and C,’ the ‘member’ is presumed to be closed to alternative ingredients D, E, and F. By contrast, the alternative transitional term ‘comprising’ creates a presumption that the recited elements are only a part of the device, that the claim does not exclude additional, unrecited elements.

Finally, the PTAB rejected the Appellant’s argument that allowed claims in another application could cure the indefiniteness rejection because “compliance for each case with the statutory requirements is done on a case-by-case basis.” See In re Giolito, 530 F.2d 397, 400 (CCPA 1976)(“We reject appellants’ argument that the instant claims are allowable because similar claims have been allowed in a patent. It is immaterial whether similar claims have been allowed to others.”); see also In re Wertheim, 541 F.2d 257, 264 (CCPA 1976) (holding that “[i]t is immaterial in ex parte prosecution whether the same or similar claims have been allowed to others”).

Accordingly, the PTAB affirmed the Examiner’s indefiniteness rejection.

Takeaway: A Markush group is common when claiming alternative members for a particular purpose. The proper language for a Markush group is “selected from the group consisting of.” The PTAB in Ex parte Kiely was not open to an alternative format that bucked this convention. Thus, when claiming a Markush group it is best to use the standard phrasing. It is also important to remember that a Markush group carries a presumption that it is closed to unrecited alternatives and a presumption, albeit weaker, that it is closed to mixtures/blends of the recited alternatives. This latter presumption was overcome in Multilayer Stretch Cling, because the specification supported blends. Therefore, a Markush group should not be used when there is a clear intent for the claim to remain open to unrecited elements/members.

Judges: T. Owens, M. Colaianni, D. Praiss