Bird & Bird secures patent win against SKB for client Synthon

Bird & Bird has won a major House of Lords victory for Dutch pharmaceutical company Synthon against SmithKline Beecham (SKB) (now GlaxoSmithKline).

The case concerned the validity of a patent for the compound paroxetine mesylate, which incorporates the active ingredient for one of the world's most widely prescribed antidepressant drugs.

On 20 October, the Lords ruled that SKB's UK patent number for the compound was invalid and upheld an appeal brought by Synthon against the decision of the Court of Appeal, which was made in June 2003.

Synthon challenged the validity of SKB's patent and asserted that its own pre-existing application for the compound "anticipated" the SKB patent.

Lord Hoffman, who gave the main judgment, said that to invalidate the SKB patent, Synthon had to demonstrate that its application provided enough information to enable a suitably qualified person to make the compound.

Lord Hoffman added that such a person was entitled to utilise their own general knowledge in the field to supplement the information contained in the patent application. He therefore made a clear distinction between what is 'disclosed' on the one hand and what is a 'sufficient description' on the other.

The ruling brought to an end a hotly contested four-year battle that has helped clarify the test for 'novelty' in patent law.

Bird & Bird partner and head of IP Morag Macdonald and partner Robert Williams led the team advising Synthon.

Bird & Bird instructed Simon Thorley QC and Piers Acland of Three New Square and 11 South Square respectively. Simmons & Simmons advised SKB, instructing Andrew Waugh QC and Justin Turner, both of Three New Square.