Justice Kane of the Federal Court found Canadian Patent 2,602,188, listed on the Patent register for ACTONEL DR (used for the treatment of osteoporosis), to be valid but not infringed by APO-RISEDRONATE in an infringement action under the Patented Medicines (Notice of Compliance) Regulations.
The 188 Patent claims an oral dosage form of risedronate, EDTA (a chelating agent), and an enteric coating which “provide for pharmaceutically effective absorption of the [risedronate] with or without food or beverage intake,” and which thus avoid the “food effect” wherein food in the stomach attaches to risedronate and prevents its absorption. Oral bisphosphonates, such as risedronate, were known to be poorly absorbed in the gastrointestinal tract and patients had to take the medication on an empty stomach to overcome the food effect. Justice Kane therefore construed the claims to require that the risedronate dosage form could be taken with or without food because pharmaceutically effective absorption would be achieved either way. She rejected Allergen’s argument that “with or without food” was merely an option or a capability.
The 188 Patent was valid
Justice Kane held that the claims of the patent were not anticipated. While the closest prior art claimed multiple compositions of bisphosphonates, chelating agents, and coatings to increase the bioavailability of bisphosphonates, it did not enable the skilled person to make the invention claimed in the 188 Patent because the disclosure was broad and claimed a wide range of possible formulations and did not seek to solve the food effect problem.
Justice Kane held the claims were not obvious because the prior art did not disclose the use of EDTA to overcome the food effect for bisphosphonates. Justice Kane found the work required to solve the food effect would be considerable, require innovative thinking and creativity, and extensive experimentation with no guarantee of success. Curiously Justice Kane held that the key patent application for anticipation would not have turned up in a “reasonably diligent search.”
Apotex’s utility attack was discarded because there was no conclusive evidence that the formulations in the study supporting the patent would not achieve pharmaceutically effective absorption, while insufficiency failed because the skilled person could conduct non-inventive trial and error work to adjust the formulations.
Justice Kane agreed with Apotex’ argument that APO-RISEDRONATE DR did not infringe, including by inducement, because it was required to be taken with food and the Apotex product monograph stated that APO-RISEDRONATE DR was not suitable for use without food because it would cause abdominal pain. (Indeed, the ACTONEL DR product monograph directed the patient to take the product with food and not on an empty stomach).
The full decision can be found here.