Canada implemented its patent term extension program, the Certificate of Supplementary Protection (CSP) framework, on September 21, 2017. The CSP regime is beneficial to qualifying pharmaceutical product developers because it can add up to two additional years of patent protection. Notably, CSP is not as beneficial as other major jurisdictions, which generally allow up to five years of patent term extension. The purpose of the CSP regime is, in part, to compensate pharmaceutical product innovators for patent term lost while waiting for regulatory approval in Canada in accordance with the Comprehensive Economic and Trade Agreement (CETA) with the European Union. Due to CSP’s strict timing requirements, multi-national pharmaceutical companies must pay particular attention to regulatory filing dates for new drug applications in Canada and in other jurisdictions, as well as deadlines for filing CSP applications in Canada.

To be eligible for a CSP, the applicant must obtain an eligible patent, obtain approval by Health Canada via a Notice of Compliance (NOC), follow strict timing requirements, meet various restrictions on claim scope, and pay an application fee.[1]

A patent is eligible if it includes at least one claim directed to a medicinal ingredient or combination of all the medicinal ingredients in a drug, a medicinal ingredient or combination of all the medicinal ingredients obtained by a specified process (product by process claim), or a use of the medicinal ingredient or combination of all the medicinal ingredients in a drug. Pure process claims or formulation claims are considered to not protect the medicinal ingredient or combination of medicinal ingredients per se, and are not considered eligible for a CSP. Thus, the CSP framework is also more restrictive in terms of the types of claims that are eligible for CSP compared to other major jurisdictions.[2]

The NOC must be the first authorization issued in Canada with respect to the medicinal ingredient or the combination of medicinal ingredients. To be considered the first authorization, the medicinal ingredient or combination must include more than “prescribed variations” from a prior authorization. Specifically, the medicinal ingredient cannot be: (1) esters, salts, complexes, chelates, clathrates, or other non-covalent derivatives; (2) enantiomers or mixtures of enantiomers; (3) solvates or polymorphs; (4) in vivo or in vitro post-translational modifications; or 5) any combination of (1)-(4), of a previously authorized medicinal ingredient. As such, the Canadian list of “prescribed variations” is more broadly defined than those in other major jurisdictions.

The prescribed variations list will be particularly restrictive for biosimilars and biobetters compared to other jurisdictions. For example, the human biologic product GAZYVA (obinutuzumab) received Patent Term Extension (“PTE”) of 946 days in the United States.[3] GAZYVA is a leukemia drug marketed by Roche which has a significantly better clinical efficacy than Roche’s earlier drug Rituxan. Although both drugs target the same protein, GAZYVA has a modified glycosylation pattern, making the antibody-tumor complex more recognizable by macrophages. In the United States, only salts and esters are expressly excluded variations.[4] However, GAZYVA would not be eligible for CSP because glycosylation modifications are an excluded variation under Canada’s list of prescribed variations.

For applicants seeking drug approval in the European Union, any member country of the European Union, the United States, Australia, Switzerland or Japan, the applicant must file for new drug approval with Health Canada no later than 12 months after filing in these countries.[5] While, the 12 month filing requirement for the new drug submission may incentivize pharmaceutical developers to file new drug applications in Canada sooner, the 12-month filing requirement will add new complexities and considerations for multi-national pharmaceutical companies. For example, filing for approval in another country too soon would cause an applicant to forfeit patent term extension in Canada. Additionally, the CSP application must be filed within 120 days following the issuance of the NOC or within 120 days of the patent’s grant date, whichever occurs later.

To date, 42 applicants have filed CSP applications. Of those, 29 have been issued a CSP, 7 have been refused, and 6 are pending.[6] Notably, application 900011 for Rebinyn® (Coagulation Factor IX (recombinant), glycoPEGylated) was rejected because it only varied from the authorized medicinal ingredient by post-translational modifications, namely pegylation and different glycosylation patterns. In Canada, the patent for Rebinyn® (CA 2,462,930) will expire August 2022, while U.S. patent 7,138,371 received 381 days PTE and is not expected to expire until November 2023. [7]

Overall, the CSP framework adds complex new variables for pharmaceutical companies to consider when developing and executing global regulatory strategies. It also creates new considerations when implementing patent strategies, e.g., targeted claim drafting and timing of patent prosecution procedures to ensure eligibility and maximization of patent term extension under the CSP framework. To take advantage of the new framework, multi-national pharmaceutical companies will need to update regulatory and patent filing procedures as well as increase communications between regulatory personnel, in house patent portfolio managers, and outside patent prosecution counsel.