Synthon BV (Appellants) v Smithkline Beecham plc (Respondents) (Html version)

The House of Lords, in an appeal from the Court of Appeal, considered a dispute between Synthon BV, a Dutch pharmaceutical company, and Smithkline Beecham plc (SB), a UK pharmaceutical company, concerning the novelty of a patent held by SB for a crystalline form of paroxetine methanesulfonate (PMS). Synthon argued that SB's patent was invalid as it was anticipated by Synthon's earlier patent application. The central legal issues revolved around the requirements of "disclosure" and "enablement" in patent law, particularly under sections 2(2) and 2(3) of the UK Patents Act 1977.

The Court of Appeal had reversed the decision of Jacob J, who found that SB's patent was invalid due to anticipation by Synthon's application. The House of Lords, however, held that the appeal should be allowed and the decision of Jacob J restored. Lord Hoffmann, delivering the opinion of the House, clarified that for a prior disclosure to anticipate a patent, it must disclose an invention which, if performed, would necessarily infringe the patent. He emphasised that the concepts of "disclosure" and "enablement" are distinct, each with its own rules. Disclosure requires that the prior art must disclose an invention which, if performed, would necessarily infringe the patent. Enablement, on the other hand, requires that the ordinary skilled person would be able to perform the disclosed invention.

In this case, the Lords found that Synthon's application did disclose the existence of crystalline PMS, which, if performed, would necessarily infringe SB's patent. The fact that the IR spectrum attributed to PMS in Synthon's application was incorrect did not matter because, based on the judge's findings, PMS was monomorphic, meaning any PMS crystal would have the characteristics described in SB's patent. Furthermore, the Lords concluded that the skilled person would have been able to make crystalline PMS within a reasonable time, satisfying the requirement of enablement.

The House of Lords thus restored the decision of Jacob J, holding that SB's patent was invalid due to anticipation by Synthon's application. The final orders would reflect the restoration of Jacob J's decision, invalidating SB's patent on the grounds that it lacked novelty.