New US Patent Rules were due to come into effect 1 November 2007 to limit the number and type of claims an applicant may have in an application as of right, the number of continuation (divisional) applications that may be filed as of right and limit the number of requests for continued prosecution to one as of right.

Court action by GlaxoSmithKline resulted in the US Patent and Trade Mark Office being prevented from implemented these changes as scheduled.

On 1 April 2008 this court action was successful on the basis that the rule changes were not procedural and effectively changed patent law and the rights of applicants. The court permanently prevented the rule changes being enforced.