The United States Patent and Trademark Office launched a reexamination of the patent covering Singulair on May 28, 2009. The decision was driven by the discovery of references that were not included in the original patent application process. The references were submitted through Article One Partners , an online research community focused on finding literature relating to existing patents. The references included a scientific article produced by a Merck employee on the active ingredient in Singulair. A previously filed patent had been submitted in the same technology area.  Seven months later the . Patent and Trademark Office determined that the patent in question was valid based on the initial reexamination and new information provided, submitting their decision on December 17, 2009.