Bird & Bird Wins Patent Trial for Synthon

03 December 2002

SmithKline Beecham Patent for antidepressant found invalid

International law firm Bird & Bird has just won a case for Synthon B.V (“Synthon”) against SmithKline Beecham plc (“SKB”), for a compound which incorporates the active ingredient for one of the most widely prescribed antidepressant drugs in the world. The English High Court ruled today that the UK patent no 2 336 364 owned by SKB for the compound paroxetine mesylate, was invalid.

The validity of the UK patent was challenged by Dutch pharmaceutical company, Synthon, who asserted that their own patent application for paroxetine mesylate pre-dated and, hence, anticipated the SKB patent. In his decision, Mr Justice Jacob agreed with Synthon and dismissed SKB’s assertion that their patent was in fact for a different “polymorph” of paroxetine mesylate (i.e. the same chemical substance but in a different crystalline form).

The Bird & Bird team was led by partner and head of Bird & Bird’s international IP Group, Morag Macdonald, with partner Robert Williams and assistant Rachel Bunn. Bird & Bird were instructing Michael Silverleaf QC and Piers Acland.

Paroxetine mesylate is manufactured by Synthon and marketed on their behalf in a number of countries under a number of different brand names, including EUPLIX Ò, MELOXATÒ, ENNOSÒ, DAPAROX® and PAROXETINE 20mgÒ.

Commenting on the decision, Theo Peters from Synthon said:

“There are currently over 40 sets of proceedings pending between SKB and Synthon in various countries including the US, relating to the corresponding SKB patents on paroxetine mesylate. We are therefore delighted that a specialist Patents Judge in the English High Court has found in our favour in this action”.

“We are delighted. Bird & Bird have been highly supportive throughout this process and given the complexities of this case we are very pleased with the outcome”.

For more information, please contact Larry Cattle, Director of Marketing, on +44 (0) 20 7415 6156.