Synthon BV (Appellants) v. Smithkline Beecham plc (Respondents) (HTML version)

Anticipation requires both disclosure and enablement. The prior art must disclose subject matter whose performance necessarily infringes the patent. A merely possible or likely infringing result is insufficient. The disclosure must be construed through the skilled person’s common general knowledge at its date, without hindsight from the later patent.

The disclosed invention must also be performable by the ordinarily skilled person. The enablement standard is the same as for sufficiency. It permits reasonable skill, common knowledge and routine trial and error, but not invention or prolonged research. Disclosure and enablement remain distinct inquiries. An erroneous but superfluous description does not prevent anticipation where performing the disclosed subject matter inevitably produces the patented product.

Synthon BV sought revocation of Smithkline Beecham plc’s patent for a specified crystalline form of paroxetine methanesulfonate. Synthon relied on its earlier patent application as prior art under section 2(3) of the Patents Act 1977. That application disclosed crystalline paroxetine methanesulfonate, but stated an incorrect infrared spectrum and described a crystallisation example which did not work as written.

Jacob J found that the compound was monomorphic. Any sufficiently pure crystal would therefore possess the characteristics claimed by the patent. He also found that an ordinarily skilled chemist could obtain crystals within a reasonable time by routine changes of solvent and method. He revoked the patent for lack of novelty.

The Court of Appeal, [2003] EWCA Civ 861, reversed that decision. The central issues before the House were whether the earlier application disclosed subject matter which necessarily fell within the patent claim and whether it enabled the skilled person to make that subject matter.

1. Appeal allowed unanimously. Lord Hoffmann delivered the leading speech. Lord Bingham, Lord Walker, Baroness Hale and Lord Brown agreed that the decision of Jacob J should be restored.

2. Per Lord Hoffmann, anticipation has two distinct requirements: disclosure and enablement. Disclosure requires prior art which, if performed, necessarily infringes the patent. It is insufficient that infringement is possible or likely, or that the skilled person could adapt the prior teaching to reach the patented invention. This necessity requirement separates lack of novelty from obviousness and reflects the approach in General Tire and Rubber Co v Firestone Tyre and Rubber Co Ltd [1972] RPC 457.

3. Per Lord Hoffmann, the prior disclosure is construed as the skilled person would understand it at its date, using common general knowledge and without hindsight from the later patent. Knowledge that the disclosed activity infringes is unnecessary. Once the meanings of the prior art and the patent are established, the disclosure question is objective.

4. Per Lord Hoffmann, enablement asks whether the ordinarily skilled person could perform the invention disclosed by the prior art. The standard is the same as the sufficiency standard under section 72(1)(c) of the Patents Act 1977. The skilled person may use reasonable skill, common knowledge and routine trial and error, but may not exercise invention or undertake prolonged research. In cases of inherent anticipation, the invention which must be enabled is the invention disclosed by the prior art, not the unrecognised patented consequence.

5. Lord Walker added, with the express agreement of Baroness Hale and Lord Brown, that “enabling disclosure” summarises two distinct statutory requirements. They arise explicitly under section 14 and implicitly when determining the state of the art under sections 2 and 3. Keeping the components separate prevents the permissibility of experimentation for enablement from diluting the stricter requirement of necessary infringement at the disclosure stage.

6. On the facts, per Lord Hoffmann, the earlier application clearly disclosed crystalline paroxetine methanesulfonate. Because the compound was monomorphic, performance necessarily produced the patented crystal. The incorrect infrared spectrum was superfluous. Jacob J was entitled to find that a skilled chemist could overcome the failed example by straightforward changes and crystallise the compound within a reasonable time. The Court of Appeal had intermingled disclosure and enablement and had given no adequate reason for disturbing that factual finding.

1. House of Lords: The appeal was allowed unanimously. The Court of Appeal’s order was set aside and Jacob J’s decision revoking the patent was restored: [2005] UKHL 59 .

2. Court of Appeal: Aldous, Sedley and Rix LJJ reversed Jacob J’s decision and upheld the patent: [2003] EWCA Civ 861 .

3. High Court (Jacob J): The judge found that the prior application disclosed and enabled crystalline paroxetine methanesulfonate. He held the patent invalid for lack of novelty and ordered revocation.