Tuesday, August 30, 2022

Fixed Dosage Regimen is Patentable Subject Matter

Janssen Inc v Pharmascience Inc 2022 FC 1218 Manson J

2,655,335 / paliperidone regimens / INVEGA SUSTENNA / NOC

In this action, Manson J found that Janssen’s 335 patent was not invalid for obviousness or as claiming an unpatentable method of medical treatment. The obviousness decision turned on the facts; the discussion of methods of medical treatment is of more general interest, though it does not break new ground.

This decision followed from Manson J’s prior decision in Janssen v Pharmascience 2022 FC 62, a motion for summary trial, in which he found that Pharmascience’s proposed paliperidone product would induce infringement of the 335 patent [48]: see here. The 335 patent has been the subject of a variety of other litigation, of which the most relevant is Teva Paliperidone 2020 FC 593, in which, as mentioned here, Manson J found that the 335 patent was not obvious, in a decision that turned on the facts.

Paliperidone is a second-generation anti-psychotic, known to be useful in treating schizophrenia. “[S]chizophrenia is incurable and requires life long management with antipsychotic medications. Adherence to a treatment regimen is critical. . . . A leading cause of relapse is non-adherence, where patients do no [sic] take their antipsychotic medication as prescribed, or at all” [11]. One strategy to improve adherence is the use of long-acting formulations. The 335 Patent relates to a long-acting formulation, in particular a dosing regimen for injectable paliperidone palmitate “depot” formulations, which releases from the injection site slowly [12].

Manson J’s analysis on obviousness followed similar lines to his decision in Teva Paliperidone 2020 FC 593: he found the same inventive concept [127] and his findings on the differences between the state of the art and the inventive concept were also consistent with Teva Paliperidone [134]. The key question was whether these differences were obvious. While Pharmascience argued that there were some crucial differences in the evidence on this point between this case and Teva Paliperidone [135], Manson J again concluded that the 335 patent was not obvious or obvious-to-try, in an analysis that turned on the facts [136]–[147]. The key point is that while there was a general motivation to develop a depot formulation of paliperidone to address compliance problems [155], there was not a specific motivation to develop the claimed dosing regimens [153]–[155]. Consequently, the claimed dosing regimens were not obvious [159].

The question of whether the 335 patent claimed unpatentable methods of medical treatment was of more general interest. Manson J noted that the Federal Court and FCA have acknowledged that the jurisprudence as to what constitutes an unpatentable method of medical treatment is inconsistent [161]. He noted, helpfully, “there appears to be no question in the case law that claims to a vendible product are patentable as not being methods of medical treatment” [163]. Many of the claims at issue were “product” claims, in particular claims to prefilled syringes (claims 1 to 16) and Swiss-type claims (claims 33 to 48), and consequently clearly do not constitute unpatentable methods of medical treatment [163]. It is worth noting that Manson J expressly stated that the Swiss-type claims are “product” claims [109]; his holding in Hoffmann-La Roche v Sandoz 2021 FC 384, [95]–[109], that the Swiss-type claims should be construed as use claims now appears to be an outlier: see also my recent post on Janssen v Apotex 2022 FC 996.

The question therefore only arose in respect of the “use”: claims [163]. The justification for the bar on patenting methods of medical treatment is that claims to a method of medical treatment should not constrain a medical professional in the exercise of their skill and judgment: [166], quoting Hospira 2020 FCA 30 [52]. Manson J summarized the law as being that use claims to dosing regimens that are “restricted to particular dosages and specific administration schedules” have been found to be patentable subject matter, “whereas claims to dosages or schedules with ranges within which the physician must exercise skill and judgment have been found to not be a vendible product and thus not patentable” [164]. This is a point Manson J has made before, in Hoffmann-La Roche v Sandoz 2021 FC 384. As discussed here, I’m not sure that distinction entirely reconciles the cases; and Manson J immediately went on to note that claims involving dosage ranges have been held unpatentable “at least in some cases” [165]. Moreover, Manson J evidently does not consider the distinction to be sound in principle, saying the distinction “seems to have a questionable underpinning in resulting judgments based on this dichotomy” but “nevertheless that is where we are under the current state of decisions up to and including decisions in the Federal Court of Appeal” [165]. In other words, we can all recognize that the current state of the jurisprudence is unsatisfactory, but it is what it is, at least for now.

Despite the very confused state of the law, this turned out to be a relatively easy case. The use claims were to a very specific dosing regimen, with “no choices in respect of possible ranges for the dosage amounts, which are fixed at loading doses of 150 mg-eq. on Day 1, 100 mg-eq. on Day 8, and 75 mg-eq thereafter as the maintenance dose” [168]. These are the types of claims that have consistently been held to be patentable subject-matter. Manson J noted that while there was some flexibility in dosing windows, “those choices do not have clinical implications,” as they were incorporated into the regimen to allow for a missed dose, or for convenience in the injection site [170].

Manson J made two observations of general interest. First, as the FCA pointed out in Hospira [52], quoted at [166], “It would seem that a medical professional will be constrained in their exercise of skill” whether the patent claims a fixed dosage or a range of dosages. That is, if a medical professional decides, in their professional judgment, that a certain dosage is required, and that dosage is claimed in a claim to a fixed dosage, their skill will be constrained as much as if it fell within a claimed range. Manson J noted that, in this case, the use claims “do not prevent physicians from practicing in a manner they had previously ‘because they weren’t doing anything before’ the 335 Patent with paliperidone palmitate to treat schizophrenia” [167]. Note the shift from asking whether the medical professional is constrained in the exercise of their skill and judgment, to asking whether they are constrained from practising in the manner they had previously. It seems to me that the medical professional will never be prevented from practising in the manner that they had previously in any case in which the claim is not invalid for anticipation. A valid patent does not constrain a physician’s choices as compared with what they were doing previously; on the contrary, it expands their choices by disclosing new information about how to best treat patients, which would not have been available but for the lure of the patent.

Manson J also noted that “A physician can choose to implement a claimed specific dosing regimen or not; however, skill and judgment are not required to implement the claimed dosing regimens” [171], and for that reason, the claimed subject-matter was not an unpatentable method of medical treatment. This observation also illustrates that the exercise of skill and judgment is always required in medical treatment, even in the administration of a fixed dosage regime. If the exercise of skill and judgment in deciding whether a particular regime is appropriate is not objectionable, I have difficulty seeing why it is any more objectionable if some skill and judgment must be exercised in deciding the exact dose within a claimed range.

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