On 23 August 2022, the Federal Court issued its public judgment and reasons in two actions under subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations (the Regulations) relating to paliperidone palmitate (Janssen's Invega Sustenna). The Court found that the claims of Canadian Patent No. 2,655,335 (the 335 patent) were not invalid for obviousness or lack of patentable subject matter (ie, as a method of medical treatment).(1)


The 335 patent relates to dosing regimens for paliperidone palmitate depot (long-acting) formulations for the treatment of schizophrenia. The claimed dosing regimens involve administering specified doses of paliperidone into a deltoid muscle on days one and eight and then into a deltoid or gluteal muscle monthly thereafter.

The 335 patent is the subject of prior Federal Court litigation resulting in three decisions on the merits:

The present decision addressed Pharmascience's patent invalidity defences raised in the above-noted action partially determined by summary trial and in a separate action brought by Janssen under subsection 6(1) of the Regulations in 2022.


In finding the 335 patent claims not obvious, the Court noted that the evidence in this case was consistent with the findings on non-obviousness in Teva Paliperidone. The state of the art did not set out safety, efficacy, pharmacokinetics or pharmacodynamics of paliperidone palmitate. At a minimum, pharmacokinetic information and results from clinical trials with paliperidone palmitate would be required to determine a suitable dosing regimen for paliperidone palmitate long-acting depot injection. The information described in an investors meeting transcript cited by Pharmascience (which was not at issue in Teva Paliperidone) was broad and did not disclose details of the 335 patent claims that would modify the Court's previous analysis of the prior art.

The Court also found that the 335 patent claims were not invalid as a method of medical treatment (which was not at issue in Teva Paliperidone). This analysis was relevant in respect of "use" claims but not "product" claims (which included claims to prefilled syringes and dosage forms as well as "Swiss-type" claims). The Court noted that, once a physician chooses to use the products for the purpose claimed, each of the claims teaches fixed dose amounts, intervals and injection sites. While select claim elements were held to involve choice (eg, injection site for the maintenance dose), the Court found that these choices do not have clinical implications. Professional skill and judgement would thus not be required to implement the claimed dosing regimens.

Pharmascience may appeal as of right.

For further information on this topic please contact Malcolm Harvey at Smart & Biggar by telephone (+1 416 593 5514) or email ([email protected]). The Smart & Biggar website can be accessed at www.smartbiggar.ca.


(1) Janssen Inc v Pharmascience Inc, 2022 FC 1218.