Patents to Salts of Medicinal Ingredients to Become Listable on “Canada’s Orange Book”

The Canadian government has published proposed amendments to the PM(NOC) Regulations, which make patents with claims to a different salt form of an approved medicinal ingredient eligible for listing on Canada’s patent register (Canada’s version of the U.S. Orange Book). The rationale for the amendments is to align patent listing requirements with proposed changes to the Food and Drug Regulations (FDR) that permit generic manufacturers to use alternative salt forms as reference products when seeking approval under the administrative new drug submission (ANDS) pathway.

What you need to know

• These proposed amendments to the PM(NOC) Regulations are not law. Stakeholders are invited to provide feedback on the proposed amendments until May 24, 2021.
• If enacted, the proposed amendments would expand the definition of “claim for the medicinal ingredient” to include salts of an approved medicinal ingredient. This would permit patents containing a claim for a different salt form of an approved medicinal ingredient to be eligible for listing on Canada’s patent register.
• The current law is that a “claim for the medicinal ingredient” does not include different chemical forms of the medicinal ingredient, such as different salt forms, so patents containing such claims are not eligible for listing on Canada’s patent register (a claim to a hydrate or solvate of the medicinal ingredient is regarded as a claim for the medicinal ingredient).
• The proposed amendments provide a 30-day transitional period to enable the submission of patent lists that include these newly eligible patents, even if the deadline for filing a patent list has otherwise expired. Drug companies may wish to audit their patent portfolios before the proposed amendments come into force to assess whether any further patents should be listed during the transitional period.

Analysis

Definitional changes

If enacted, the proposed amendments would expand the definition of “claim for the medicinal ingredient” in section 2 of the PM(NOC) Regulations to include “a claim for a variation of the medicinal ingredient that, when compared to the medicinal ingredient, is identical, excluding those appended portions, if any, that cause either the variation or the medicinal ingredient to be a salt, hydrate or solvate”. The proposed amendment would replace the current phrase, “but does not include different chemical forms of the medicinal ingredient”.

Effect of the proposed change

According to the Regulatory Impact Analysis Statement (RIAS) published by Industry Canada with the proposed amendments, this proposed change would permit patents containing a claim related to a different salt form of an approved medicinal ingredient to be eligible for listing on the patent register. Specifically, the RIAS states that this definition would cover:

1. a claim for a salt form that is different from the approved medicinal ingredient (where the approved medicinal ingredient is a different salt form or is a base form), and
2. a claim for the base form of the medicinal ingredient (where the approved medicinal ingredient is a salt form).

The RIAS specifies that “other different chemical forms” of the medicinal ingredient would continue to fall outside the scope of the definition. For example, we expect that esters would continue to be considered a different chemical form. The RIAS notes that patents containing claims for hydrates and solvates of a medicinal ingredient were already listable as “different polymorphs of the medicinal ingredient”, and their specific mention in the proposed definition only makes this fact more explicit.

According to the RIAS, the objective of the proposed amendments to the PM(NOC) Regulations is to “restore the balance at the heart of the linkage regime” in view of proposed amendments to the FDR. Those proposed amendments to the FDR would make it easier for a generic drug manufacturer to bring a chemical variant of an existing innovator drug to market by allowing for a salt, hydrate or solvate of an approved medicinal ingredient to be used as the reference product in an ANDS¹. According to the RIAS, stakeholder feedback following publication of the proposed FDR amendments was taken into account in developing the proposed amendments to the PM(NOC) Regulations.

Transitional provisions

Within 30 days after the day on which the proposed PM(NOC) Regulations come into force, a patent list with a patent that meets the eligibility criteria prescribed in the transitional provision may be submitted to Health Canada, even if the deadline for filing the patent list has otherwise expired.

The transitional provision applies to patents that were ineligible to be added to the patent register during the period beginning on June 17, 2006 and ending on the day on which the proposed PM(NOC) Regulations come into force only because the patent related to a different salt form of an approved medicinal ingredient. Consistent with current practice, the transitional provision only applies to patents that have a filing date in Canada that precedes the filing date of the applicable regulatory submission. The 30-day transitional period is intended to provide sufficient time to submit a patent list without creating prolonged uncertainty for subsequent entry manufacturers who may be looking for clarity, in advance of filing their submissions, on what patents they will be required to address under the transitional provision. Drug companies may wish to audit their patent portfolios before the proposed PM(NOC) Regulations come into force to assess whether any further patents should be listed during the 30-day transitional period.

Coming into force

If enacted, the proposed PM(NOC) Regulations will come into force on the day on which the proposed FDR are registered, but if the PM(NOC) Regulations are registered after that day, they will come into force on the day on which they are registered. The RIAS states that the intent is for the proposed PM(NOC) Regulations to come into force before the proposed FDR, to provide time for a first person to submit or resubmit patent lists for eligible patents prior to the coming into force of the proposed FDR.

Next steps

Comment period

The proposed PM(NOC) Regulations are not law and may be amended further before they become law. The next step in the regulatory amendment process is for Industry Canada to collect and review comments. Interested persons may make representations until May 24, 2021. Following that, Industry Canada may request further feedback or publish the amendments (as previously published, or with minor revisions) in Part II of the Canada Gazette. Any amendments will only come into force after the final version has been published in Part II of the Canada Gazette.

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¹ See our bulletin from April 10, 2019 which provides more details regarding the proposed FDR amendments.