Four Points do not Make a Range
When patent attorneys draft patents, we include all kinds of details about the invention. All these details go into the written description, and one practice we sometimes use to ensure we fully describe an invention is to describe number ranges. For example, if an inventor indicates that a for a drug to be made, it must contain 7% of chemical 1 and 43% of chemical 2, the patent practitioner may, through dialog with the inventor, come to encompass those values by ranges, provided they are supported by the invention. (If the invention only functions as described when exactly 7% of chemical 1 and 43% of chemical 2 is used, claiming a range would not be appropriate.) For example, a patent practitioner might write, “the drug comprises chemical 1 and chemical 2, where chemical 1 can range from 4–11% (preferably 7%) and chemical 2 can range from 35%–50%. (preferably 43%).”
This brings us to Indivior UK v. Dr. Reddy’s Labs.
Indivior involves an IPR (inter partes review) proceeding. Ordinarily, IPRs are limited to prior art issues, though occasionally, Section 112(a) (requiring written description of the invention) issues come up when the challenged patent tries to claim priority back to one or more prior filings. In short, that is what happened here.
Indivior attempted to claim sublingual films that contained some drug treatment. The limitations at issue:
Claim 1 recited: “about 40 wt % to about 60 wt % of a watersoluble polymeric matrix”
Claims 7 & 12 recited: “about 48.2 wt % to about 58.6 wt %”
Claim 8 recited: “about 48.2 wt %”
But the original specification failed to directly describe any of these amounts or ranges. Instead, the specification included two tables that featured four examples. Those examples, when computed out, result in values that fall within the range of 48.2–58.6%. The process of carrying out those computations is not expressly described in the specification, and that specification also fails to give any reasons why those examples, computed out, should result in end points that form a range of values. On appeal, the Court wrote, “[f]or written description support of a claimed range, more clarity is required.”
The Court continued:
Here, one must select several components, add up the individual values, determine the aggregate percentages, and then couple those aggregate percentages with other examples in the ’571 application to create an otherwise unstated range.
Performing these calculations resulted on the four examples resulted in values that included the lower value of 48.2% and the higher values of 58.6%. These values, the Court asserted, are expressions of inventive values, not an invitation to undertake additional post-hoc inventing. Thus:
Indivior failed to provide persuasive evidence demonstrating that a person of ordinary skill would have understood from reading the ’571 application that it disclosed an invention with a range of 48.2 wt % to 58.6 wt %. A written description sufficient to satisfy the requirement of the law requires a statement of an invention, not an invitation to go on a hunting expedition to patch together after the fact a synthetic definition of an invention. “[A] patent is not a hunting license. It is not a reward for the search, but compensation for its successful conclusion.” Brenner v. Manson, 383 U.S. 519, 536 (1966).
So what lesson may be had from this?
It is often better to include too much than too little, and patent practitioners should not rely on unstated mathematics to flesh out our disclosures. If a range is intended, write that out explicitly. If you intend for a range to be created via example, then summarize the range at the end and explain how to perform the relevant computations. This case appears to showcase a patentee making an effort to expand on their written description by reading between the lines, so to speak, and the Court pushed back.