It will no longer assess new patents, but will process those already on its books, which is expected to take until October.
The system was launched two years ago as an attempt to harness the wisdom of web users to ensure that nobody was granted a patent monopoly on things that had already been invented.
Patents are assessed by employees of patent offices but one of the problems they face, particularly with highly technical patent applications, is knowing whether or not a claimed invention is truly new.
The Peer-to-Patent project aimed to solve that problem by allowing third parties to tell hearing officers anything they know of which pre-dates an application and covers the same ground. This is known as 'prior art'.
It was an experiment that depended on amateur experts who submitted knowledge to patent examiners while applications were being considered. This was against US patent law, which bars third party submissions. An exception was made for the programme, but only for patent applicants who opted in to the system.
The US Patents and Trademarks Office (USPTO), though, decided to end the pilot after two years.
"New York Law School's Center for Patent Innovations will continue to process all active applications until they have all completed the normal peer review cycle," said a statement from Peer to Patent. "Based on applications presently on hand or anticipated, we believe the peer review process will conclude on or about October 15, 2009."
It said that it was hit with "a deluge" of applications before that deadline. The organisers of the project said that it had been a success and that its report of its second year in operation showed that it was viable in the long term.
"As a baseline, the first year data showed that an open network of reviewers could improve the quality of information available to patent examiners," a Peer to Patent statement said. "The second year data expanded on these results by illustrating that Peer-to-Patent reviewers possessed the time and motivation to voluntarily participate as a community in reviewing more patent applications covering broader subject matter."
The service may be reinstated after a period of analysis, though. US President Barack Obama has named a supporter of the programme as the next head of the USPTO. David Kappos has been named as Under Secretary of Commerce for Intellectual Property and Director of the USPTO.
"David presently serves as Vice President and Assistant General for Intellectual Property at IBM. In his role at IBM David was one of the early proponents of Peer-to-Patent and directed IBM in providing both financial and technical assistance in the development of the Peer-to-Patent website and platform," said the Peer to Patent programme on the announcement.