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): March 31, 2014

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 5.02. Departures of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers.

On March 31, 2014, Michelle LeRoux Williams, who has served as our Chief Scientific Officer since February 2009, tendered her resignation, effective on April 15, 2014.  Alla Danilkovitch, Ph.D., Head of Discovery, has been promoted to Vice President of Research and Development, and she will lead innovation and R&D at Osiris. Dr. Danilkovitch has been with Osiris since April 2003 as our principal scientist and has been integral to the development of our products  Osteocel®, Prochymal®, Grafix®, OvationOS™ and Cartiform®.

Dr. Williams’ compensation will cease upon the termination of her employment, consistent with the Company’s usual employment practices.

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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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