APPEAL WATCH: If You Can’t Patent the Drug, Patent the Dosage

The Supreme Court of Canada (“SCC”) is set to review the patentability of dosage regimens for medical treatments. Last month, the SCC granted leave to appeal [41209] the Federal Court of Appeal (“FCA”) decision in Pharmascience Inc v Janssen Inc and Janssen Pharmaceutica NV, 2024 FCA 23 [FCA].

Specifically, the SCC will revisit the prohibition against patenting “methods of medical treatment.” The Federal Court (“FC”) and the FCA both found that Janssen Inc and Janssen Pharmaceutica NV’s (“Janssen’s”) dosage regimen was not a method of medical treatment because it stipulated fixed amounts and schedules and therefore did not interfere with a physician’s exercise of skill and judgment.

Facts

In the 1990s, Janssen began researching a long-acting injectable treatment for symptoms of schizophrenia and related disorders (Janssen Inc and Janssen Pharmaceutica NV v Pharmascience Inc, 2022 FC 1218, para 13 [FC]). Janssen sought to create a treatment that patients could self-administer less frequently than oral medication to improve their adherence to the treatment regimen (FC, paras 11-12).

Janssen eventually developed a specific dosage regimen for paliperidone palmitate, an injectable antipsychotic. “Loading doses” of 150 and 100 milligram equivalent (“mg-eq”) are injected on days 1 and 8, followed by a 75-mg-eq “maintenance dose” every month thereafter (FC, para 25). The timing may be adjusted according to variable “dosing windows” of ± 2 or 7 days, and alternative dosage amounts are given for renally impaired patients (FC, para 26).

In 2008, Janssen filed a Canadian patent (the “335 Patent”) for its injectable paliperidone palmitate treatment under the brand name INVEGA SUSTENNA® (FC, paras 28-38). The patent teaches Janssen’s dosage regimen and describes pharmaceutical formulations, pre-filled syringes, and other means of delivery adapted for the regimen (FC, paras 94-111).

In 2020, Pharmascience Inc (“Pharmascience”) sought permission to market a generic version of INVEGA SUSTENNA® in Canada (FC, paras 42, 44). In response, Janssen commenced an infringement action against Pharmascience (FC, para 46).

Procedural History

Pharmascience alleged that the 335 Patent was invalid and would not be infringed by its generic alternative (FC, paras 44-45). Manson J of the FC addressed the issues of infringement and validity in separate hearings.

In his initial summary judgment, Manson J found that Pharmascience’s product would induce infringement of the 335 Patent (Janssen Inc and Janssen Pharmaceutica NV v Pharmascience Inc, 2022 FC 62, para 145 [FC MSJ]). Though Pharmascience’s product would not be sold in pre-filled syringes, prescribers would use it to implement Janssen’s patented dosage regimen (FC MSJ, para 120). Pharmascience would have knowingly induced this third-party infringement, as Pharmascience’s product monograph contained instructions to use the 335 Patent’s dosage regimen (FC MSJ, paras 133, 137, 144).

In the subsequent trial, Manson J ruled that the 335 Patent was valid. Janssen’s dosage regimen was not obvious, as there was not a finite number of predictable solutions to the problem of determining the appropriate dose, and extensive testing had been required to solve it (FC, para 143).

Further, the 335 Patent did not describe an unpatentable “method of medical treatment.” On this point, Manson J considered that dosage regimens with fixed amounts and schedules are patentable, while those indicating variable ranges within which a physician must exercise skill and judgment are not patentable (FC, para 164). The 335 Patent described fixed amounts and schedules, and the variations it permitted “d[id] not have clinical implications,” therefore the claims were patentable (FC, para 170).

Issues

Pharmascience appealed Manson J’s finding that the 335 Patent was valid. The FCA addressed two issues, the second of which was most relevant to its disposition (FCA, para 13):

1. Did Manson J err in law by excluding certain claims from the methods of medical treatment analysis on the basis that they concerned a vendible product?
2. Did Manson J err in law by determining that the claims were patentable? The FCA subdivided this issue into two aspects (FCA, para 44):
   1. Did Manson J incorrectly describe the relevance of the dichotomy between fixed and variable dosages to the test for methods of medical treatment?
   2. Did Manson J incorrectly characterize the claims as defining fixed dosages and schedules?

Decision

The FCA unanimously upheld Manson J’s finding that the 335 Patent was valid. Locke JA ruled that Manson J had made no legal error, but corrected Manson J’s reasoning on the test for methods of medical treatment under the second issue. Relying on a line of mostly trial-level decisions, Manson J had considered the distinction between fixed and variable dosages to be determinative (FC, para 164). However, Locke JA described this approach as “incomplete,” serving only as an “indication” of the underlying principle (FCA, 45). Instead, the true basis for finding that a claim describes a method of medical treatment must be its interference with a medical practitioner’s exercise of skill and judgment.

The FCA reviewed the SCC’s rulings on the prohibition against patenting methods of medical treatment. The prohibition is not found in the Patent Act, RSC 1985, c P-4 (FCA, para 17). Instead, it originated in Tennessee Eastman Co v Commissioner of Patents (1972), [1974] SCR 111 [Tennessee Eastman] and was later confirmed in Shell Oil Co v Commissioner of Patents, [1982] 2 SCR 536 and Apotex Inc v Wellcome Foundation Ltd, 2002 SCC 77 (FCA, paras 17-23). In those cases, the SCC explained that methods of medical treatment are unpatentable because they have no relation to trade, commerce, or industry and instead only relate to professional skills (FCA, paras 21-22). To qualify as an “invention” for the purposes of patentability, a patent’s subject matter must be a “vendible product” that “has economic value” and is “distinguishable from the skilled work of a physician” (FCA, para 26).

Thus, the FCA reasoned, an invention will be considered an unpatentable method of medical treatment if using it requires an exercise of skill and judgment (FCA, para 37). Courts are permitted to use the distinction between fixed and variable dosages as an indicator, but only if the analysis remains tied to the ultimate question of whether professional skill is applied (FCA, para 28).

There are also qualifications. The FCA declined to assert that any treatment that requires a physician to monitor a patient would be unpatentable, since such a rule would “cast too wide a net” (FCA, para 30). Additionally, the exercise of skill and judgment that would make an invention unpatentable must concern how to use the invention, not merely whether to use it or not (FCA, para 31).

The FCA acknowledged—but did not base its decision on—several instances of variability in the 335 Patent’s dosage regimen. For example, the fact that the dosage regimen was not “one size fits all,” potentially requiring different dosages for different patients, was not sufficient to make it unpatentable (FCA, para 50). Another example is the FCA’s response to the 335 Patent’s statement that doses may need to be titrated up or down (FCA, para 54). Previous decisions had cited titration to conclude that using an invention required skill and judgment (FCA, para 55). In the present case, however, the FCA ruled that titration could not ground such a conclusion about the 335 Patent as a whole (FCA, para 55).

Analysis

Who Cares What the Claims Say?

In his FC decision, Manson J noted that the starting point for analyzing the patentability of a dosage regimen is to ask, “what do the claims say?” (FC, para 161). He also noted that claim construction is a matter of law, not of fact or of mixed law and fact (FC, para 90). In light of the FCA’s decision, however, applying this characterization to the methods of medical treatment test could prove inappropriate or misleading in many cases.

Theoretically, emphasizing claim construction is easier to justify under Manson J’s fixed or variable dosages test than under the FCA’s professional skill test. If the decision maker’s only goal is to determine whether a dosage regimen contains fixed amounts and schedules, a dogged adherence to the meaning of the words in the claim should be sufficient, since it is unimaginable that a claim could disclose fixed amounts without stating them explicitly. However, if the question is whether a physician must exercise skill and judgment, the words alone are hardly enough. In that case, a decision maker must ascertain the factual matrix surrounding the treatment. This is especially pertinent given the FCA’s warning against a “rigid approach” to the test, as well as its admission that some exercises of skill and judgment will not be substantial enough to justify a finding of unpatentability (FCA, para 34).

In practice, the FCA did not exclude matters of fact from its analysis, even when it addressed the fixed or variable dosages test specifically. On the surface, the FCA appeared to approve of Manson J’s focus on “what the claims say” (FCA, paras 6, 28). Yet its decision regularly cites evidentiary findings to dismiss Pharmascience’s arguments. In his review of previous cases decided by the fixed or variable dosages test, Locke JA stated, “Clearly, this issue is factually suffused; it depends on the evidence and it concerns how the patented invention is intended to be used” (FCA, para 35).

From Pharmascience’s perspective, the FCA’s references to matters of fact—without overturning Manson J—could amount to an unfair bait and switch. Pharmascience asserted only errors of law in its argument on appeal, a strategy likely influenced by Manson J’s focus on claim construction in the FC trial (FCA, para 16). On certain points, however, the FCA noted that it would not consider the evidence before the FC, as Pharmascience had not asserted any errors of fact or of mixed law and fact (FCA, paras 52, 55). These statements suggest—contrary to the implication of Manson J’s decision—that the FCA would have had to find a palpable and overriding error to rule in Pharmascience’s favour. Pharmascience may have approached its appeal very differently had it known the decision could have turned on this standard.

Questionable Underpinnings

The FCA underlined that interference with professional skill is the true test for methods of medical treatment. However, it also confirmed the relevance of the fixed or variable dosages test both explicitly and in its substantive findings. As such, it only partially addressed Manson J’s complaint—based on previous comments by Locke JA himself—that the distinction between fixed and variable dosages has a “questionable underpinning” in the SCC jurisprudence (FC, paras 165-66).

Ultimately, the FCA gave a puzzling justification for accepting the fixed or variable dosages test. According to Locke JA, “the distinction [between fixed and variable dosages] makes sense if one bears in mind the guidance…that what matters is what the claims say; the product that the patentee puts on the market is incidental” (FCA, para 28). Aside from leaving the law in a state of some ambiguity, this explanation relies on claim construction in a way that, as discussed above, is neither theoretically nor practically appropriate for the FCA’s substantive approach. The SCC may wish to resolve some of this confusion on appeal.

But the SCC may also revisit its justification for the prohibition against patenting methods of medical treatment in general. Janssen’s invention story shows how developing a dosage regimen can blur the line between vendible product and professional skill. The SCC jurisprudence since Tennessee Eastman frames the prohibition as protecting individual physicians’ professional competencies from patent monopolization. Yet in Janssen’s case, Manson J justified the 335 Patent’s validity in large part by finding that no individual physician could have discovered an effective dosage regimen on their own (FC, paras 140-54). Far from threatening physicians’ freedom to practice professionally, Janssen’s research furnished the basis for their ability to provide treatment at all.

Nevertheless, it is also absurd to suggest that a dosage regimen like that of INVEGA SUSTENNA® could be administered without any exercise of skill and judgment whatsoever, particularly in the context of psychiatric illness. On appeal, the SCC should craft a rule that better reflects the realities of medical treatment while balancing the benefits to researchers, generic drug manufacturers, and patients.

This article was edited by Alexandre Cachon.