On February 23, 2022, the Federal Court released its reasons for judgment in a patent infringement action under subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations regarding risedronate sodium (Allergan ACTONEL DR): Allergan Inc v Apotex Inc2022 FC 260. Kane J. held that Canadian Patent No. 2,602,188 (the ‘188 patent) was valid but not infringed.
The ‘188 patent relates to a dosage form of a bisphosphonate, particularly risedronate, which exhibits pharmaceutically effective absorption when taken with or without food. At the time of the priority filing date of the ‘188 patent, oral bisphosphonates used to treat osteoporosis, including risedronate, were known to be poorly absorbed, particularly when taken with food. Accordingly, these drugs should be taken on an empty stomach. The inventors of the ‘188 patent had sought to overcome this problem, called the food effect.
Allergan’s claims were all dependent on Claim 1, which states “[a]n oral dosage form of a bisphosphonate for use with or without food or drink”. Claim 1 further states that the oral dosage form comprises a pharmaceutical composition containing risedronate and EDTA in a specified molar ratio and an enteric coating to provide “pharmaceutically effective absorption of the bisphosphonate with or without food or drinks “.
The Court found that the 188 patent was not anticipated by a Brazilian patent application referenced in the description of the 188 patent (Brazilian patent application 0106601; BR 601). While BR 601 disclosed formulations that overlapped with those contained in the ‘188 patent, BR 601 did not provide sufficient guidance to direct the skilled artisan to the formulations of the ‘188 patent, address the dietary effect, or disclose that a Pharmaceutically effective absorption would be obtained with or without food. With respect to empowerment, the Court found that a person skilled in the art relying on BR 601 would not be able to exploit the invention of the 188 patent without trial and error and significant experimentation, including including human clinical trials.
The Court again considered BR 601 finding that the 188 patent was not obvious. As directed by the Federal Court of Appeal in Hospira Healthcare Corporation v Kennedy Trust for Rheumatology Research, 2020 FCA 30, Kane J. included BR 601 in the mosaic of prior art considered to determine obviousness, while the likelihood that a person skilled in the art would find BR 601 when a reasonably diligent search was declared relevant to whether a person skilled in the art would have thought to combine the document with other prior art. Based on all of the evidence, including expert evidence relating to BR 601 and the use of EDTA and enteric coatings, the Court concluded that a person skilled in the art would not not been brought directly and without difficulty to combine the elements of the claimed claims of the 188 patent. The Court also concluded that it would not have been obvious to attempt to obtain the claimed invention.
Apotex’s other challenges to the validity of the ‘188 patent – futility, insufficiency and overbreadth – were all dismissed.
The Court found that Apotex would not infringe the claimed claims of the 188 patent by making, constructing, using or selling its risedronate product, nor would Apotex induce the infringement of the claimed claims.
The Court’s conclusion of no infringement was based on its interpretation of the asserted claims. Allergan asserted that the claimed dosage form is a product that can be used with or without food, that is to say, a dosage form containing specific ingredients and a specific coating. However, the Court found that it was not necessary to read “suitable for use” in the claims and that an essential element of the claimed claims was that the oral dosage form can be taken with or without food as desired. of the patient. The claimed claims did not merely claim a product; rather, they claimed the use of an oral dosage form that can be taken in one of two ways depending on patient preference.
Since Apotex’s proposed product monograph – consistent with ACTONEL DR’s product monograph – stated that its risedronate product should be taken with food and may cause abdominal pain if taken without food , the Court found that Apotex’s product was not subject to the claimed claim. Similarly, considering both the expert testimony and Apotex’s proposed product monograph, the Court concluded that Apotex would not infringe the asserted claims.