Others have suggested that this holding raises the bar for showing support for negative limitations by requiring an explicit “reason to exclude” the limitation. My understanding in reading the opinion was just the opposite – that even when there is no literal support expressly excluding the element or operation at issue, support can be shown inferentially when the specification describes a reason to exclude the relevant limitation. The “reason to exclude,” in my reading of the case, is merely an alternative avenue to show support for a narrowing limitation (i.e., sufficient but not necessary). The opinion states that negative claim limitations are adequately supported “when” the specification describes a reason to exclude the relevant limitation, not “when and only when” or anything to that effect, and no dispositive precedent is cited in this regard.
Background / Facts: Plaintiff Santarus, Inc. is the exclusive licensee of patents on specified formulations of benzimidazole proton pump inhibitors (PPI) – a class of chemical compounds that inhibit gastric acid secretion and help prevent and treat stomach acid-related diseases and disorders. There were several issues that the court dispatched with fairly easily, but I found the most interesting to be the written description issue relating to the inclusion of the negative limitation “wherein the composition contains no sucralfate.”
Issue(s): Whether the clause “wherein the composition contains no sucralfate” is supported by the written description.
Holding(s): Yes. The claim limitation specifying that sucralfate is not administered in conjunction with the claimed formulation restricted the claims to this preferred use. This exclusion narrowed the claims, as the patentee is entitled to do. “Negative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation. Such written description support need not rise to the level of disclaimer. In fact, it is possible for the patentee to support both the inclusion and exclusion of the same material. The claim limitation that the Phillips formulations contain no sucralfate is adequately supported by statements in the specification expressly listing the disadvantages of using sucralfate.”