Today in Actavis v ICOS the Supreme Court unanimously ruled that the ICOS patent for a Tadalafil dosing regime was invalid. Lord Hodge gave the only judgment, with Lady Hale, Lord Kerr, Lord Sumption and Lord Briggs in agreement. The case attracted significant attention from the pharmaceutical community, with four interventions from industry bodies.
The patent
EP 1 173 181 relates to a dosage regime for Tadalafil: a "second-in-class" treatment for erectile dysfunction (ED), which followed the blockbuster drug sildenafil (VIAGRA). The patent claims doses of 1-5 mg of Tadalafil up to a maximum total dose of 5mg per day and discloses that such doses exhibit fewer side effects than sildenafil whilst retaining efficacy.
Tadalafil is marketed for the treatment of ED in unit doses of 10mg and 20mg for on-demand administration and in unit doses of 2.5mg and 5mg for daily administration. Sildenafil is marketed on demand at doses of 25mg, 50mg and 100mg.
Actavis brought revocation proceedings in respect of the 181 patent in December 2014, which were later combined with related proceedings brought by Teva UK Limited and Teva Pharmaceutical Industries Limited and Generics (UK) Limited (trading as Mylan) (the Claimants/Respondents). ICOS and its exclusive licensee, Eli Lilly and Company, (together "Lilly") counterclaimed for infringement.
The decision
The Supreme Court decision focuses on the correct approach to assessing obviousness. The obviousness argument was based on a prior art patent application (WO 97/03675) known as "Daugan" which disclosed the use of Tadalafil for the treatment of ED, giving a 50mg dose as a formulation example.
Lilly argued that the correct question to be asked when assessing obviousness was whether at the priority date, before the skilled team embarked on any testing, it was obvious in the light of Daugan that a 5mg daily dose of Tadalafil would be safe and effective with minimal side effects for sexual dysfunction. That is, was it obvious to try a low dose of 5mg because there was a reasonable expectation of success at the outset, before any testing. Lilly argued that this was in line with the second of the Windsurfing/Pozzoli obviousness questions requiring one to "identify the inventive concept of the claim". This approach then excludes any consideration of whether the steps required to reach the invention were routine.
The Respondents (Actavis et al) argued that, on the basis of the fundamental principles of patent law, a patent should not cover subject matter which was already in the skilled person's "repertoire", i.e. products or processes which the skilled person was already able…