UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 17, 2012

OSIRIS THERAPEUTICS, INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (443) 545 - 1800

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14d-2(b))

o    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

ITEM 8.01 Other Information

On May 17, 2012, Osiris Therapeutics, Inc. announced that it has received market authorization from Health Canada to market its stem cell therapy Prochymal (remestemcel-L), for the treatment of acute graft vs host disease (GvHD) in children. Prochymal was authorized under Health Canada’s Notice of Compliance with conditions (NOC/c) pathway, which provides access to therapeutic products that addresses unmet medical conditions and that have demonstrated a favorable risk/benefit profile in clinical trials. Under the NOC/c pathway, Osiris, as the sponsor, agreed to further evaluate the benefits of Prochymal, in a case matched confirmatory trial and all patients receiving Prochymal will be encouraged to participate in a registry that will monitor the long-term effects of therapy.

Information presented in this Current Report on Form 8-K may contain forward-looking statements and certain assumptions upon which such forward-looking statements are in part based.  Forward-looking statements are subject to known and unknown risks and uncertainties and are based on potentially inaccurate assumptions that could cause actual results to differ materially from those expected or implied by the forward-looking statements.  Risks and that could cause our actual results to differ materially from those anticipated in forward-looking statements, include the factors described in the sections entitled “Risk Factors” in our Annual Report on Form 10-K filed with the United States Securities and Exchange. You should not unduly rely on forward-looking statements.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

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