Actavis Group PTC EHF and others v ICOS Corporation and another

Obviousness under section 3 of the Patents Act 1977 requires a fact-specific assessment of all relevant circumstances. Uninventive work which the skilled person would undertake after the priority date to implement prior art may be considered. A step-by-step analysis is legitimate where the research path can be identified without hindsight.

For a dosage patent, the skilled team need not foresee the precise claimed dose before testing. The claim is obvious where the team would very likely pursue routine dose-ranging studies until it identified a product within the claim. Routine research has no overriding significance, and unexpected benefits may indicate invention. An unexpected benefit cannot support a patent, however, where the claimed innovation is already obvious for another purpose.

ICOS Corporation owned, and Eli Lilly exclusively licensed, a dosage patent claiming low-dose tadalafil for treating sexual dysfunction. Generic manufacturers sought revocation, principally for lack of inventive step under section 3 of the Patents Act 1977. Birss J held relevant claims inventive in [2016] EWHC 1955 (Pat), although a skilled team would very likely test a 5mg dose after discovering a therapeutic plateau.

The Court of Appeal allowed the generic manufacturers’ appeal in [2017] EWCA Civ 1671; [2018] RPC 7. It held that routine Phase IIb dose-ranging studies would very likely reveal that 5mg tadalafil was safe and effective. ICOS and Lilly appealed. The issues were how obviousness applies to a dosage patent and whether the Court of Appeal could reverse the trial judge’s evaluative conclusion without disturbing his primary findings.

Appeal dismissed unanimously. Lord Hodge delivered the sole judgment, with which Lady Hale, Lord Kerr, Lord Sumption and Lord Briggs agreed.

1. Section 3 of the Patents Act 1977 asks whether the invention was obvious to the skilled person in light of the state of the art at the priority date. The skilled person lacks inventive capacity but exercises ordinary professional skill. The court may therefore consider uninventive steps which that person would take after the priority date to implement the prior art. Neither the Windsurfing/Pozzoli structure nor the EPO problem-and-solution approach should be applied mechanically; each disciplines the statutory inquiry.

2. Obviousness is fact-sensitive. Relevant considerations may include whether the step was obvious to try, the routine character and established endpoint of the research, burden and cost, necessary value judgments, alternative avenues, motive, unexpected results, hindsight, and whether a claimed feature is merely an added benefit. No factor has primacy. Routine methods can produce a patentable invention, and a reasonable expectation of success is relevant but not invariably required.

3. For a dosage patent, the skilled team need not identify the precise claimed dose before Phase IIb testing. It is sufficient that a hindsight-free, step-by-step analysis shows that the team would very likely continue the tests until it found a product within the claim. Dosage regimes can be patentable, but standard practice normally seeks an appropriate, usually low effective, dose.

4. The prior patent enabled tadalafil to be used for erectile dysfunction. The skilled team’s predetermined task was to find an appropriate safe, tolerable and effective dosage. Familiar Phase IIb studies aimed to establish the dose-response relationship. On the trial judge’s findings, after discovering a therapeutic plateau the team would very likely test lower doses, including 5mg. The absence of an initial expectation that 5mg would be effective, and the need for value judgments, therefore carried little weight.

5. The 5mg dose’s unexpectedly reduced side effects were an added benefit. They did not make inventive a dose which routine completion of the studies would identify for another purpose. Daily dosing also could not establish inventiveness: the half-life would inevitably be discovered, and the claims extended beyond daily dosing.

6. The Court of Appeal could intervene because the trial judge failed to give effect to his central finding that further low-dose testing was very likely. That was an evaluative error of principle. The claims lacked an inventive step, so the alternative revocation grounds did not arise.

1. United Kingdom Supreme Court: dismissed the appeal and upheld the invalidity of the relevant patent claims for lack of inventive step: [2019] UKSC 15.
2. Court of Appeal: allowed the generic manufacturers’ appeal and held claims 1, 7 and 10 invalid for obviousness: [2017] EWCA Civ 1671; [2018] RPC 7.
3. High Court, Patents Court: Birss J held that claim 7 involved an inventive step and that a 5mg daily dose was not obvious: [2016] EWHC 1955 (Pat).