Senior Judge James Cacheris of the US District Court of Eastern Virginia today enjoined the US Patent and Trademark Office (PTO) from putting its new patent prosecution Rules into effect. The Rules otherwise would have become effective tomorrow, November 1, 2007.

GlaxoSmithKline (GSK) argued that the new Rules exceeded the Patent Office's authority and were contrary to the US patent laws, and that it (and by implication thousands of other patent applicants) would be irreparably harmed if the new Rules were permitted to go into effect. A number of other companies, and the American Intellectual Property Law Association, filed briefs supporting GSK's position. In granting GSK's request for a preliminary injunction, the District Court rejected the PTO's argument that the PTO would be irreparably harmed if the implementation of the Rules was delayed.

The Court's opinion should be available later today. Although no schedule has yet been set, further proceedings, such as summary judgment brief and arguments, may begin in January.