Osiris Therapeutics, Inc. (NASDAQ: OSIR) announced today that it has been notified by Swissmedic, the Swiss agency responsible for the evaluation of drugs, that Prochymal® (remestemcel-L) will be evaluated under its Rapid Authorization Procedures. This designation, also known in Switzerland as Fast Track, typically cuts the evaluation period for promising new drugs in half. Swissmedic approved the use of the Rapid Authorization Procedures following an initial review of summary clinical data for Prochymal used for the management of acute graft-versus-host disease (GvHD). Use of the Rapid Authorization Procedures is only permitted if the clinical data demonstrates a high potential for benefit for a severe, disabling or life-threatening disease, and where no alternative treatment option exists. As a result of this decision, Osiris intendeds to promptly submit the full Common Technical Document to Swissmedic in the electronic or eCTD format to facilitate review. The Common Technical Document for Prochymal contains over 90,000 pages of data on the stem cell drug and is similar to the applications filed in Canada and New Zealand. Prochymal is now approved in Canada and New Zealand, and is currently available in seven other countries, including the United States, under an Expanded Access Program. About GvHD GvHD represents a major unmet medical need with no approved treatment until Prochymal. GvHD is the leading cause of transplant related mortality, in which immune cells contained within the transplanted marrow recognize the recipient as foreign and mount an immunologic attack. Severe GvHD can cause blistering of the skin, intestinal hemorrhage and liver failure. Severe GvHD is extremely painful and fatal in up to 80 percent of cases. Currently, steroids are used as first-line therapy with a success rate of only 30-50 percent. When steroids fail, treatment options are limited to immunosuppressive agents used off-label with little benefit and significant toxicities.