Canadian Drug Pricing Regulator Ordered to Reconsider Differin

Canadian Drug Pricing Regulator Ordered to Reconsider Differin

Woman rubs medicinal cream on her skin

Canada (Attorney General) v Galderma (2019 FCA 196)

When a pharmaceutical manufacturer owns a series of related patents, it is sometimes unclear which patents actually protect the marketed product. The Patented Medicine Prices Review Board (“PMPRB”) has the power to compel the disclosure of financial information but only for drugs under patent protection. In a June 28th ruling, the Federal Court of Appeal (“the FCA”) clarified the test for determining whether or not a patent pertains to a drug. The FCA’s ruling overturns a decision from the PMPRB to demand financial information from Galderma Canada Inc. (“Galderma”) regarding its acne treatment, Differin. The FCA found that the PMPRB unreasonably concluded that a patent for a more concentrated medication also pertained to Differin.


Differin, a formulation containing 0.1% adapalene, was originally put on the market under two patents that have since expired. Differin XP, a formulation containing 0.3% adapalene, is protected by Canadian Patent No. 2,478,237 (“the ‘237 Patent”), which will expire in 2023.

After the two Differin patents expired, the PMPRB requested information about the drug on the basis that the ‘237 Patent also applied to the 0.1% formulation. The PMPRB reached this conclusion by finding that, although the ‘237 Patent mentions the 0.3% formulation is in its abstract, “the patent does not, on its face relate exclusively to a 0.3% concentration adapalene.” [para 43] The PMPRB decided that a patent need only be connected to a medicine by “the merest slender thread.” [para 18]

The Federal Court later quashed the PMPRB’s decision and the Attorney General appealed to the FCA.

The “Face of the Patent”

The first issue was that the PMPRB considered only the abstract and introductory paragraphs of the patent. A previous FCA decision found that a rational connection can be drawn between a medicine and a patent without going beyond the face of a patent, but this does not mean that the PMPRB can skip integral parts of the patent including the claims section. [para 34] The term “face of a patent” merely indicates that the PMPRB is required to “take the language of the patent at face value” and does not need to conduct an in-depth analysis. [para 38]

What is the Invention of the ‘237 Patent?

The second issue was that the PMPRB failed to identify the invention claimed in the ‘237 Patent. According to the FCA, there is only one correct interpretation of the patent. [para 45] The ‘237 Patent claims a new 0.3% formulation of adapalene, which is more effective than compositions with a lower concentration. None of the claims cover a composition of adapalene of less than 0.3%. [para 49].

Does the ‘237 Patent “Pertain” to Differin?

Lastly, the FCA found that the PMPRB did not reasonably conclude that the ‘237 pertains to Differin. The PMPRB argued that the test for which patents pertain to a medicine should be interpreted broadly and that the “merest slender thread” can connect a patent to a marketed drug. However, the PMPRB’s jurisdiction is limited to patents where “the invention is intended or capable of being used for medicine or for the preparation or production of medicine.” [para 65] Since the PMPRB wrote in its reasons that the ‘237 Patent is not intended or capable of being used to produce 0.1% adapalene, it was unreasonable to conclude that the patent pertained to Differin. [para 41]

The FCA could only find that the PMPRB’s decision-making methods were wrong, but it could not determine what the correct decision ought to have been. The case has been returned to the PMPRB for re-determination.


This ruling appears to revise a previous decision of the FCA. In ICN Pharmaceuticals, Inc v Canada ([1997] 1 FC 32), the court had found that a patent pertains to a drug if there is a rational connection or nexus with the medicine, even if the connection is the merest slender thread. [para 62] The FCA now describes this test as merely a “metaphor” for the statutory provision that lays out the PMPRB’s true powers. [para 64] Going forward, the PMPRB’s jurisdiction will be restricted to drugs will a less tenuous connection to a patent. For more information, please contact a PCK IP professional.