Patent – Petition for revocation. The claimant issued proceedings, seeking a declaration that a European patent for a dosage regimen for use of levonorgestrel as a method of emergency contraception was invalid and should be revoked on grounds including obviousness. The Patents Court, having considered relevant person skilled in the art, held that it had been obvious from a report, discussing interim results of research regarding the effectiveness of a regimen involving a single dose as compared a two-dose regimen, that such a regimen could be pursued and investigated with a reasonable or fair expectation of success. Accordingly, the challenge to the validity of the patent on the ground of obviousness succeeded.