Patent – Pharmaceutical patent. Actavis Group PTC EHF and other companies (the respondents) had appealed against the trial judge's decision that the dosage patent owned by ICOS Corporation and Eli Lilly & Co (the appellants), relating to the use of tadalafil in a dosage form for the treatment of sexual dysfunction was valid as it involved an inventive step. The Court of Appeal, Civil Division, reached a contrary conclusion and allowed the respondents' appeal, deciding that the patent was invalid for lacking an inventive step. The Supreme Court, in upholding the Court of Appeal's decision and dismissing the appellants' against that decision, set out the factors which were relevant considerations concerning the application of the test of obviousness pursuant to s 3 of the Patents Act 1977.