Federal Court Finds Formulation Patent Relating To ACTONEL DR Valid But Not Infringed

• Published date: 31 March 2022
• Subject Matter: Intellectual Property, Food, Drugs, Healthcare, Life Sciences, Patent, Food and Drugs Law
• Law Firm: Smart & Biggar
• Author: Malcolm Harvey

On February 23, 2022, the Federal Court issued its public reasons for judgment in a patent infringement action pursuant to subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations relating to risedronate sodium (Allergan's ACTONEL DR): Allergan Inc v Apotex Inc, 2022 FC 260. Justice Kane found Canadian Patent No. 2,602,188 (the 188 patent) valid but not infringed.

The 188 patent relates to a dosage form of a bisphosphonate, specifically, risedronate, that displays 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, especially when taken with food. As a result, these drugs were required to be taken on an empty stomach. The inventors of the 188 patent had sought to overcome this issue, termed the food effect.

The claims asserted by Allergan were all dependent on claim 1, which recites "[a]n oral dosage form of a bisphosphonate for use with or without food or beverage intake". Claim 1 further recites that the oral dosage form comprises a pharmaceutical composition containing risedronate and EDTA in a specified molar ratio and an enteric coating to provide for "pharmaceutically effective absorption of the bisphosphonate with or without food or beverage intake".

Validity

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 overlap with those contained in the 188 patent, BR 601 did not provide sufficient guidance to direct the skilled person to the formulations of the 188 patent, address the food effect, or disclose that pharmaceutically effective absorption would be achieved with or without food. With respect to enablement, the Court found that a skilled person relying on BR 601 would not be able to work the invention of the 188 patent without trial and error and significant experimentation, including human clinical trials.

The Court addressed BR 601 again in finding that the 188 patent was not obvious. Per the Federal Court of Appeal's guidance in Hospira Healthcare Corporation v Kennedy Trust for Rheumatology Research, 2020 FCA 30, Justice Kane included BR 601 in the mosaic of the prior art considered to determine obviousness, while the likelihood of a skilled person locating BR 601 in...