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On May 5, 2020, Manson J. of the Federal Court issued the second decision on the merits under the amended Patented Medicines (Notice of Compliance Regulations). The Court upheld the validity of Janssen’s patent for paliperidone palmitate (Janssen’s INVEGA SUSTENNA) (Canadian Patent No. 2,655,335 (335 patent), and found infringement of certain claims: Janssen Inc. v Teva Canada Ltd., 2020 FC 593.

The 335 patent relates to dosing regimens for long-acting paliperidone palmitate depot formulations for treatment of schizophrenia. According to the decision, the goal of the invention was to develop a dosing regimen that ensures an optimum plasma concentration-time profile for treating patients with paliperidone. The 335 patent claims a “loading dose” regimen, in which paliperidone is administrated on day 1 and day 8 at certain doses into the deltoid muscle, followed by a “maintenance dose” comprising certain doses of paliperidone injected into the gluteal or deltoid muscle, administered monthly thereafter.

The Court examined two main issues, whether the 335 patent was invalid for obviousness and infringement.

Validity – Not obvious

Justice Manson found that the Asserted Claims of the 335 patent were not obvious. The Court found that the validity of the dependent claims “rises or falls with the inventiveness of the dosing regimens”.

The Court found that the inventive concept of these claims is a safe and effective dosing regimen using a depot formulation of paliperidone designed to quickly attain, and maintain, therapeutic plasma concentrations of paliperidone for treating patients with schizophrenia.

In construing the claims, the Court found that “continuous schedule” included multiple maintenance doses. The Court also held that to construe the terms otherwise would be inconsistent with the ordinary meaning of the words and a letter from Janssen to the Commissioner of Patents which was admitted pursuant to section 53.1 of the Patent Act.

The common general knowledge included that depot formulations were advantageous due to patient compliance and dosing flexibility, that dosing of depot formulations vary from drug to drug and that the risk of adverse events in testing depot formulations was a concern.

Teva asserted that the differences between the prior art and the invention could be bridged by routine testing to arrive at the dose amount, schedule and injection sites claimed in the 335 patent. The prior art disclosed target paliperidone plasma concentration ranges and depot formulations that are therapeutically effective for around one month.

The Federal Court, however, found that the necessary pharmacokinetic data to design a dosing regimen was not disclosed in the art and that to determine the rate of release of paliperidone in a depot formulation, testing in animal models followed by testing in humans was required. The skilled person would have to run clinical trials to evaluate the safety and efficacy of a large number of variables including various dosing and injection sites. Such testing, while finite, was not a finite number of “identified, predictable solutions”. It was not self-evident that some combination of the dose amount, schedule and injection sites would quickly and safely achieve therapeutic concentrations of paliperidone. Developing a depot formulation is a long and difficult enterprise, and the effort required to reach the claimed dosing regimen in light of the state of the art and common general knowledge was substantial. While there was general motivation to develop a depot formulation of paliperidone, there was not necessarily a specific motivation to develop the particular dosing regimens in the 335 patent, and known depot dosing regimens required oral starting periods, oral supplementation or dose titration.

Based on the above findings, the Court found that the combination of the elements in the claimed dosing regimen is inventive and the Asserted Claims of the 335 patent were not obvious.

Direct infringement 

The patent contained three broad types of “use” claims:

  • claims 1 to 16 relate to prefilled syringes adapted for administration according to the claimed dosing regimens (“prefilled syringes claims”);
  • claims 17 to 32 relate to “use of a dosage form” according to the claimed dosing regimens; and
  • claims 33 to 48 relate to use of paliperidone as paliperidone palmitate in the manufacture/preparation of a “medicament” adapted for administration according to the claimed dosing regimen (Swiss-style claims).

The Court held there would be direct infringement of the first and third claim sets.

The Court was satisfied that the Teva product incorporates all the formulation elements of the claims.

The parties agreed that the “use of a dosage form” claims would not be directly infringed by Teva, as Teva itself would not be “using” the paliperidone palmitate.

Teva argued that the Swiss-style claims should be read as “use of a dosage form” claims. However, the Court found that the Swiss-style claims are capable of infringement if the medicament is adapted for administration to a psychiatric patient in need of treatment according to the claimed dosing regimen.  The Federal Court found that Teva’s product would incorporate all essential elements of the prefilled syringes claims and Swiss-style claims and that, should Teva come to market and sell its paliperidone palimitate prefilled syringes, it will infringe. The capable, approved and intended use of the Teva Product in its product monograph incorporates all of the dosing and administration elements. Since Teva’s product monograph teaches that the product can be administered according to the claimed dosing regimen, this is sufficient to establish direct infringement of these two claim sets.

No induced infringement

The Federal Court found that the first prong of the inducement test (which requires direct infringement) was met, as the evidence (IMS data, pharmacists’ evidence that the Teva product will likely be interchangeable with INVEGA SUSTENNA, and expert evidence of prescribing physicians) showed that at least some patients will receive Teva’s product in accordance with the Asserted Claims.  However, the Court held that Janssen did not show that Teva would meet the second step of the inducement test, which requires that the acts of infringement be influenced by Teva. Even though Teva’s product monograph included direct references to infringing dosing regimen, the evidence showed that generally physicians do not look at generic product monographs when they are already familiar with the brand and will consider individual patient characteristics in determining a dosing regimen. Therefore, the Federal Court found that the acts of infringement would not be influenced by Teva to the point that, without the influence, direct infringement would not occur. Accordingly, the Court found that Teva would not induce infringement of any of the Asserted Claims.

Conclusion

In view of the above, the Federal Court granted a declaration of infringement of the Swiss-style and prefilled syringes claims and an injunction until expiry of the 335 patent. Teva has appealed.

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