Patent for once-daily anticoagulant dosing declared invalid as prior research made invention obvious

The High Court declared invalid a patent covering a once-daily dosing regimen for the anticoagulant drug rivaroxaban, following a challenge by generic pharmaceutical companies seeking to produce and market a generic version. The court found that the claimed invention—once-daily dosing—was obvious to a person skilled in the art at the relevant time, on the basis of prior published research and common general knowledge, and thus did not involve an inventive step. The judge preferred the evidence of the plaintiffs’ expert witnesses, noting that relevant prior art explicitly suggested the dosing regimen, and that the defendant’s counterarguments placed unjustifiable weight on technical data gaps and the absence of clinical correlation for certain biomarker assays. The court also considered and distinguished foreign judgments, ultimately finding that secondary documentary evidence supported the view that the once-daily dosing was not an unexpected or innovative development, and ordered that the patent be revoked.