In an application brought before the Federal Court pursuant to the Patented Medicines (Notice of Compliance) Regulations1, Eli Lilly Canada Inc. (Eli Lilly) sought to prohibit the Minister of Health from issuing a Notice of Compliance (NOC) to Novopharm Ltd. (Novopharm) for a generic version of raloxifene hydrochloride until the expiry of Canadian Patent No. 2,250,191 (the ‘191 patent), which is the basis for Eli Lilly’s medicine marketed in Canada under the brand name EVISTA. In hearing the application, the Federal Court2 examined issues of validity and infringement of the ‘191 patent, which claims that well-chosen particle size of raloxifene and its salts benefits both bioavailability and control of the manufacturing process. Novopharm claims that the ‘191 patent is invalid on the basis of obviousness and lack of utility, and in any event, that the ‘191 patent is not infringed by Novopharm’s product.

The patent claims at issue were construed as relating to ranges of particle sizes where the particle size itself was claimed as essential to the invention of increasing bioavailability of raloxifene and its salts. The only pertinent data in the specification contained in the patent disclosed one point within the claimed range and a further comparative point outside the range.

In examining the information was disclosed under the ‘191 patent, Justice Hughes for the Federal Court reasoned that:

“A single point cannot define a range. There is no data at or near the limits of the range nor is there provided data as to a number of points within the stated range so as to establish that in the range there is surprising consistency. A single point within the range does not demonstrate consistency throughout the range.

Therefore the question becomes whether there is sufficient information provided in the ‘191 patent to enable a person skilled in the art to “soundly predict” consistency within the range…”3

In view of the above, Justice Hughes held that the claims at issue were invalid in that the description contained in the patent failed to establish that the claimed particle size range has the promised utility, namely, consistent in vivo absorption/bioavailability. Accordingly, Justice Hughes held that Novopharm’s allegation as to invalidity for lack of utility is justified. Having already found that Novopharm’s allegation of non-infringement was justified, the Federal Court dismissed Eli Lilly’s application to prohibit the Minister of Health to from issuing an NOC to Novopharm to market a generic version of raloxifene hydrochloride.

The case is of interest since the Federal Court revisited the AZT case where the Supreme Court of Canada4 outlined the indicia of sound prediction, which provides that if there was not a fulsome disclosure in the patent itself from which a person skilled in the art could conclude that there was utility, the disclosure could nonetheless be considered to be adequate for that purpose if a person skilled in the art could “soundly predict” that there would be utility. In this regard, the Supreme Court of Canada set out three components for sound prediction: (1) a factual basis; (2) an articulable and sound line of reasoning; and (3) proper disclosure.

In the chemical and biological arts, sound prediction reinforces the need for results that help to define the invention’s boundaries. This can be difficult, especially if there are many parameters defining the invention. For inventors, particularly those who have limited budgets and facilities, the requirement of fulsome disclosure on the basis of the indicia of sound prediction also presents practical issues since such inventors will often have to make a choice between obtaining seemingly obvious data to support a patent application versus abandoning the endeavour in favour of another. On the other hand, a subsequent inventor would have room to argue for claims relating to ranges even when there is a single prior art result within the range (“A single point cannot define a range.”), a proviso that would need to be added to exclude the single point as it is prior art.