The Federal Court of Appeal (FCA) has held that in order to determine whether a patent claims an unpatentable method of medical treatment (MMT), it is necessary to determine whether the use of the invention requires the exercise of professional skill and judgment. In the case of pharmaceutical dosing claims, the determination cannot be based solely on whether the claimed dosing and schedule is fixed or not.

Background

Janssen markets INVEGA SUSTENNA® (paliperidone palmitate) for the treatment of schizophrenia and related disorders. Janssen’s Canadian Patent No. 2,655,335 (335 Patent) teaches a dosing regimen. Patients are to receive a first and second loading dose followed by maintenance doses at specific concentrations on specific days.

Pharmascience Inc. (PMS) sought a Notice of Compliance to market a generic version of INVEGA SUSTENNA® (the PMS Product). Janssen commenced an infringement action under section 6 of the Patented Medicines (Notice of Compliance) Regulations. PMS defended the action on a number of grounds, including that claims of the 335 Patent are invalid for claiming unpatentable MMTs. The Federal Court (FC) found the claims of the 335 Patent valid. PMS appealed to the FCA.

Skill & judgment: the proper approach to identifying MMT claims

MMTs are not patentable because they do not fit within the Patent Act’s definition of “invention”. The FCA reviewed Supreme Court of Canada jurisprudence holding that MMTs are “unrelated to trade, industry or commerce” and concern non-economic professional skills. By contrast, a “commercial offering” may be patented.

In order to determine whether a claim covers an unpatentable MMT, it is necessary to determine whether use of the invention requires the exercise of skill and judgment. In this regard, the FCA distinguished between:

  • the exercise of skill and judgment in deciding how to use an invention, which is an unpatentable MMT; and
  • the exercise of skill and judgment in deciding whether to use an invention, which “does not indicate” an MMT.

The burden remains on the party challenging the patent to show that a claim covers an MMT.

The FC did not err in its MMT analysis

The FCA rejected each of PMS’s arguments concerning alleged MMT claims in the 335 Patent. In summary:

  • Product vs. dosing claims. The FC did not err in concluding that claims 1–16 and 33–63 were to a vendible product, not an MMT, and were therefore patentable subject matter.
  • Relevance of fixed dosing. The FC’s discussion of the law regarding fixed dosages and schedules was incomplete. The FCA held that, “[t]hough a fixed dosage and schedule may be a good indication that no [professional] skill and judgment would be required, evidence may indicate otherwise.” Nonetheless, the FC did not commit a reviewable error as its analysis properly focused on whether use of the claims required the exercise of skill and judgment.
  • Characterization of the fixed dosing claims. In finding that claims 17–32 do not interfere with a physician’s skill and judgment, the FC did not err. PMS argued that the invention in the 335 Patent is not limited to a fixed dosage regimen, focusing on instances of variability in dosing and scheduling (e.g., a window of days in which to administer the second loading dose and the maintenance doses). The FCA rejected PMS’s argument, finding that it was open to the FC to conclude that these sources of variability had “no clinical implications” and “do not interfere with a physician’s exercise of skill and judgment”.

Accordingly, the FCA dismissed the appeal.

Review of parallel litigation

As we recently reported, multiple generic companies have been unsuccessful in their attempts to market generic versions of INVEGA SUSTENNA®:

  • The FCA found that PMS would induce infringement of the 335 Patent with its proposed generic version of INVEGA SUSTENNA® (see here).
  • Apotex’s challenge to the validity of the 335 Patent was found by the FCA to be an abuse of process (see here). The FCA found that Apotex would induce infringement of the 335 Patent with its proposed generic version of INVEGA SUSTENNA® (see here).
  • Teva Canada Limited’s (Teva) proposed product was found by the FC to directly infringe certain claims of the 335 Patent; and the 335 Patent was valid (see here). Teva’s appeal to the FCA was unsuccessful (see here). Janssen’s appeal regarding induced infringement was successful.

Links to decisions:

Pharmascience Inc. v Janssen Inc., 2024 FCA 23