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  <p align="center" style="border:none;margin:0in 0in .0001pt;padding:0in;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
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  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">United
  States<br>
  SECURITIES AND EXCHANGE COMMISSION</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">WASHINGTON, D.C. 20549</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM&nbsp;8-K</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">CURRENT
  REPORT</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">Pursuant
  to Section&nbsp;13 OR 15(d)&nbsp;of the Securities Exchange Act of 1934</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Date of Report (Date of earliest event reported): May&nbsp;8,
  2008</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">OSIRIS
  THERAPEUTICS, INC.</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Exact Name of Registrant as Specified in Charter)</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <div align="center">
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">&nbsp;Delaware</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">001-32966</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">71-0881115</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(State
    or other jurisdiction of</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission
    File Number)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(IRS
    Employer</font></p>
    </td>
   </tr>
   <tr>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">incorporation)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Identification
    No.)</font></p>
    </td>
   </tr>
   <tr>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="66%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:66.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">7015 Albert Einstein Drive, Columbia, Maryland</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">21046</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="66%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:66.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Address
    of principal executive offices)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Zip
    Code)</font></p>
    </td>
   </tr>
  </table>
  
  </div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Registrant&#146;s
  telephone number, including area code: <b>(443)
  545 - 1800</b></font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Not Applicable</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Former
  name or former address, if changed since last report)</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt 12.0pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Check the appropriate box
  below if the Form&nbsp;8-K filing is intended to simultaneously satisfy the
  filing obligation of the registrant under any of the following provisions:</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Written communications
    pursuant to Rule&nbsp;425 under the Securities Act (17 CFR 230.425)</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Soliciting material
    pursuant to Rule&nbsp;14a-12 under the Exchange Act (17 CFR 240.14d-2(b))</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pre-commencement
    communications pursuant to Rule&nbsp;14d-2(b)&nbsp;under the Exchange Act (17
    CFR 240.14d-2(b))</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="42" valign="top" style="padding:0in 0in 0in 0in;width:31.5pt;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>
    </td>
    <td width="658" valign="top" style="padding:0in 0in 0in 0in;width:6.85in;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pre-commencement
    communications pursuant to Rule&nbsp;13e-4(c)&nbsp;under the Exchange Act (17
    CFR 240.13e-4(c))</font></p>
    </td>
   </tr>
  </table>
  
  <div style="border:none;border-bottom:double windowtext 6.0pt;padding:0in 0in 0in 0in;">
  
  <p style="border:none;margin:0in 0in .0001pt;padding:0in;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  </div>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <div style="margin:0in 0in .0001pt;text-autospace:none;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='',FILE='C:\JMS\brosent\08-14037-2\task2934103\14037-2-ba.htm',USER='brosent',CD='May 12 13:03 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div style="font-family:Times New Roman;">
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">ITEM&nbsp;1.01.
  ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.</font></b></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On May&nbsp;8, 2008, Osiris
  Therapeutics,&nbsp;Inc. (&#147;Osiris&#148;) signed a definitive agreement to sell all of
  its assets related to its Osteocel<sup>&#174;</sup> and Osteocel<sup>&#174;</sup> XO
  products to NuVasive,&nbsp;Inc., a medical device company headquartered in San
  Diego, California and focused on the design, development and marketing of products
  for the surgical treatment of spine disorders.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pursuant
  and subject to the terms of the asset purchase agreement, the sale will be
  effected at two closings &#151; a technology assets closing which is expected to
  occur as soon as practicable following the satisfaction of various conditions
  precedent; and a manufacturing assets closing which is expected to occur within
  approximately eighteen months following the technology assets closing.&#160; During the period between the technology assets
  closing and the manufacturing assets closing, Osiris will continue to
  manufacture or have manufactured, and supply, Osteocel pursuant to a
  manufacturing agreement to be entered into between the parties at the time of
  the technology assets closing.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The
  initial purchase price to be paid to Osiris at the technology assets closing
  will be $35 million in cash.&#160; In
  addition, during the interim period between the technology assets closing and
  the manufacturing assets closing and, if applicable, after the manufacturing assets
  closing, Osiris has the ability to earn milestone payments not to exceed approximately
  $50 million in the aggregate.&#160; Receipt of
  each of the milestone payments is conditioned upon the satisfaction of certain
  conditions, including conditions relating to the production and delivery by
  Osiris of agreed upon quantities of product on or before certain agreed upon
  dates, and completion of the transfer of the manufacturing assets in accordance
  with agreed upon terms.&#160; Osiris has the
  ability to derive additional fee revenue from the manufacture and supply of
  Osteocel under the manufacturing agreement, which imposes minimum purchase
  order obligations on NuVasive during the interim period.&#160; NuVasive has the right to pay the milestone
  payments in cash or, subject to certain conditions, by the issuance of shares
  of NuVasive common stock having then equivalent market value.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The
  transaction is structured as a sale of assets and assumption of certain
  liabilities.&#160; The assets to be
  transferred at the technology asset closing include intellectual property,
  permits, data and records, and contract rights related to the development,
  manufacturing, marketing and sale of Osteocel and Osteocel XO.&#160; The assets to be sold at the manufacturing
  closing include the processing facility and equipment now employed by Osiris in
  the manufacture of Osteocel.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Osiris
  intends to use the proceeds from the sale of the Osteocel assets to further its
  core research and development business focused on biologic drug candidates,
  including Prochymal<sup>&#174;</sup>.&#160; The assets
  of Osiris relative to its biologic drug candidates, including Prochymal, are
  not included among the transferred assets.&#160;
  Also excluded are assets related to Osteocel<sup>&#174;</sup> XC, a second
  generation mesenchymal stem cell product under development by Osiris, for bone
  repair and utilizing culture expanded mesenchymal stem cells to create a
  synthetic version of Osteocel.&#160; Pursuant
  to the terms of the asset purchase agreement, however, Osiris has granted
  NuVasive a right to acquire exclusive rights to Osteocel XC through December&nbsp;31,
  2009 on generally predefined terms subject to final negotiation. Through that
  same date, NuVasive is also afforded a right of first negotiation prior to any
  other transaction involving the transfer by Osiris of Osteocel XC.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman"><font style="font-size:10.0pt;">The
  asset purchase agreement contains customary representations and warranties, as
  well as mutual indemnification for breaches of representations, warranties and
  covenants.&#160; The asset purchase agreement
  also provides for the payment by Osiris to NuVasive of </font>a termination fee
  of $2,000,000, and expense reimbursement of $350,000, following</font> termination under certain circumstances.</p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The
  consummation of the technology assets closing is subject to satisfaction of
  customary conditions for transactions of this type, including approval of the asset
  purchase agreement by the Osiris stockholders and receipt of authorizations,
  consents, approvals and permits of governmental authorities as specified in the
  asset purchase agreement, including the expiration of any waiting period (including
  any extension) under the Hart-Scott-Rodino Act.</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">2</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='2',FILE='C:\JMS\brosent\08-14037-2\task2934103\14037-2-ba.htm',USER='brosent',CD='May 12 13:03 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div style="font-family:Times New Roman;">
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Officers
  and directors of Osiris, and certain of their affiliates, holding approximately
  38% of the outstanding voting stock of Osiris, have executed voting agreements
  committing to vote for the approval of the asset purchase agreement and related
  transactions, subject in some cases to certain exceptions typical in voting
  agreements of this type, which allow for a reduction of the committed shares to
  38%. Included among those who have executed voting agreements are Peter
  Friedli, the Chairman of our Board of Directors and single largest stockholder,
  and certain of his affiliates, including Venturetec,&nbsp;Inc. and U.S. Venture
  05, Inc, and C. Randal Mills, President and CEO of Osiris.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The
  foregoing summary discussion of the terms of the transactions provided for
  under the asset purchase agreement and the form of manufacturing agreement is
  qualified in its entirety by the actual terms and provisions of those
  documents. A copy of the asset purchase agreement, with form of manufacturing
  agreement attached, and a copy of the form of voting agreement are filed as
  Exhibits 10.1 and 10.2, respectively, to this Current Report on Form&nbsp;8-K,
  and are incorporated into this Item 1.01 by reference.&#160; Osiris expects to mail a proxy statement to
  its stockholders in advance of the Special Meeting of Stockholders to be called
  to consider the transaction.&#160; Osiris
  expects to hold the Special Meeting of Stockholders before the end of the
  second quarter, or early in the third quarter.&#160;
  Osiris&#146; Board of Directors unanimously voted to recommend approval of
  the transaction by Osiris&#146; stockholders.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:1.0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:0in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">ITEM 9.01.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; FINANCIAL
  STATEMENTS AND EXHIBITS.</font></b></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(a)</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Financial Statements of Businesses Acquired.</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None.</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(b)</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pro Forma Financial Information.</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None.</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.04%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(d)</font></p>
    </td>
    <td width="93%" valign="top" style="padding:0in 0in 0in 0in;width:93.96%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Exhibits.</font></p>
    </td>
   </tr>
  </table>
  
  <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="8%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:8.12%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;No.</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.22%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="89%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:89.66%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Description</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="8%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:8.12%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">10.01.</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.22%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="89%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:89.66%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Asset
    Purchase Agreement dated as of May&nbsp;8, 2008, by and between the
    Registrant and NuVasive,&nbsp;Inc., together with form of Manufacturing
    Agreement by and between the Registrant and NuVasive,&nbsp;Inc., to be
    entered into pursuant and subject to the terms of the Asset Purchase
    Agreement.</font></p>
    </td>
   </tr>
   <tr>
    <td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.12%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.22%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="89%" valign="top" style="padding:0in 0in 0in 0in;width:89.66%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.12%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">10.02.</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.22%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="89%" valign="top" style="padding:0in 0in 0in 0in;width:89.66%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Form
    of Voting Agreement dated as of May 8, 2008 by and among each of Peter
    Friedli, Venturetec, Inc., U.S. Venture 05, Inc., Joyce, Ltd. and C Randal
    Mills, Ph.D, and NuVasive, Inc.</font></p>
    </td>
   </tr>
  </table>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;text-indent:0in;"><i><font size="2" face="Times New Roman" style="font-size:10.0pt;font-style:italic;">Information presented in this Current Report on Form&nbsp;8-K
  may contain forward-looking statements and certain assumptions upon which such
  forward-looking statements are in part based. </font></i><i>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.&#160; Risks and uncertainties related to the
  proposed sale of our assets related to Osteocel include the risk that the
  conditions relating to the closing of the sale transaction may not be satisfied,
  or may be delayed, or that the terms may be altered for any reason; changing
  relationships with customers, suppliers or employees; and the risk that we may
  not be able to fully perform or to manufacture sufficient quantities of product
  for any reason, including raw material availability, to generate milestone
  payments and manufacturing revenue.&#160;
  Additional factors that could cause our actual results to differ
  materially from those anticipated in forward-looking statements, include the
  factors described in the section entitled &#147;Risk Factors&#148; in our Annual Report
  on Form&nbsp;10-K filed with the United States Securities and Exchange
  Commission. You should not unduly rely on&#160;
  forward-looking statements.</i><i>.</i></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">3</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='3',FILE='C:\JMS\brosent\08-14037-2\task2934103\14037-2-ba.htm',USER='brosent',CD='May 12 13:03 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">SIGNATURES</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">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.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.76%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.26%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">OSIRIS THERAPEUTICS, INC.</font></p>
    </td>
   </tr>
   <tr>
    <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.76%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.26%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.76%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated: May&nbsp;12, 2008</font></p>
    </td>
    <td width="4%" valign="top" style="padding:0in 0in 0in 0in;width:4.02%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
    </td>
    <td width="47%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:47.24%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/ PHILIP R. JACOBY, JR.</font></p>
    </td>
   </tr>
   <tr>
    <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.76%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="4%" valign="top" style="padding:0in 0in 0in 0in;width:4.02%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="47%" valign="top" style="padding:0in 0in 0in 0in;width:47.24%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Philip R. Jacoby,&nbsp;Jr.</font></p>
    </td>
   </tr>
   <tr>
    <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.76%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="4%" valign="top" style="padding:0in 0in 0in 0in;width:4.02%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="47%" valign="top" style="padding:0in 0in 0in 0in;width:47.24%;">
    <p style="margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Interim Chief Financial Officer</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4</font></p>
  
  <div style="margin:0in 0in .0001pt;text-autospace:none;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='4',FILE='C:\JMS\brosent\08-14037-2\task2934103\14037-2-ba.htm',USER='brosent',CD='May 12 13:03 2008' -->
  
  
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metadata_filer: {"company-data": {"conformed-name": "OSIRIS THERAPEUTICS, INC.", "cik": "0001360886", "assigned-sic": "2836", "irs-number": "710881115", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-32966", "film-number": "08823367"}, "business-address": {"street1": "7015 ALBERT EINSTEIN DRIVE", "city": "COLUMBIA", "state": "MD", "zip": "21046", "phone": "443-545-1819"}, "mail-address": {"street1": "7015 ALBERT EINSTEIN DRIVE", "city": "COLUMBIA", "state": "MD", "zip": "21046"}}
text: 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 8,
  2008
  OSIRIS
  THERAPEUTICS, INC.
  (Exact Name of Registrant as Specified in Charter)
  Delaware
  001-32966
  71-0881115
  (State
    or other jurisdiction of
  (Commission
    File Number)
  (IRS
    Employer
  incorporation)
  Identification
    No.)
  7015 Albert Einstein Drive, Columbia, Maryland
  21046
  (Address
    of principal executive offices)
  (Zip
    Code)
  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 1.01.
  ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.
  On May 8, 2008, Osiris
  Therapeutics, Inc. ("Osiris") signed a definitive agreement to sell all of
  its assets related to its Osteocel
  ®
  and Osteocel
  ®
  XO
  products to NuVasive, Inc., a medical device company headquartered in San
  Diego, California and focused on the design, development and marketing of products
  for the surgical treatment of spine disorders.
  Pursuant
  and subject to the terms of the asset purchase agreement, the sale will be
  effected at two closings — a technology assets closing which is expected to
  occur as soon as practicable following the satisfaction of various conditions
  precedent; and a manufacturing assets closing which is expected to occur within
  approximately eighteen months following the technology assets closing.  During the period between the technology assets
  closing and the manufacturing assets closing, Osiris will continue to
  manufacture or have manufactured, and supply, Osteocel pursuant to a
  manufacturing agreement to be entered into between the parties at the time of
  the technology assets closing.
  The
  initial purchase price to be paid to Osiris at the technology assets closing
  will be $35 million in cash.  In
  addition, during the interim period between the technology assets closing and
  the manufacturing assets closing and, if applicable, after the manufacturing assets
  closing, Osiris has the ability to earn milestone payments not to exceed approximately
  $50 million in the aggregate.  Receipt of
  each of the milestone payments is conditioned upon the satisfaction of certain
  conditions, including conditions relating to the production and delivery by
  Osiris of agreed upon quantities of product on or before certain agreed upon
  dates, and completion of the transfer of the manufacturing assets in accordance
  with agreed upon terms.  Osiris has the
  ability to derive additional fee revenue from the manufacture and supply of
  Osteocel under the manufacturing agreement, which imposes minimum purchase
  order obligations on NuVasive during the interim period.  NuVasive has the right to pay the milestone
  payments in cash or, subject to certain conditions, by the issuance of shares
  of NuVasive common stock having then equivalent market value.
  The
  transaction is structured as a sale of assets and assumption of certain
  liabilities.  The assets to be
  transferred at the technology asset closing include intellectual property,
  permits, data and records, and contract rights related to the development,
  manufacturing, marketing and sale of Osteocel and Osteocel XO.  The assets to be sold at the manufacturing
  closing include the processing facility and equipment now employed by Osiris in
  the manufacture of Osteocel.
  Osiris
  intends to use the proceeds from the sale of the Osteocel assets to further its
  core research and development business focused on biologic drug candidates,
  including Prochymal
  ®
  .  The assets
  of Osiris relative to its biologic drug candidates, including Prochymal, are
  not included among the transferred assets. 
  Also excluded are assets related to Osteocel
  ®
  XC, a second
  generation mesenchymal stem cell product under development by Osiris, for bone
  repair and utilizing culture expanded mesenchymal stem cells to create a
  synthetic version of Osteocel.  Pursuant
  to the terms of the asset purchase agreement, however, Osiris has granted
  NuVasive a right to acquire exclusive rights to Osteocel XC through December 31,
  2009 on generally predefined terms subject to final negotiation. Through that
  same date, NuVasive is also afforded a right of first negotiation prior to any
  other transaction involving the transfer by Osiris of Osteocel XC.
  The
  asset purchase agreement contains customary representations and warranties, as
  well as mutual indemnification for breaches of representations, warranties and
  covenants.  The asset purchase agreement
  also provides for the payment by Osiris to NuVasive of
  a termination fee
  of $2,000,000, and expense reimbursement of $350,000, following
  termination under certain circumstances.
  The
  consummation of the technology assets closing is subject to satisfaction of
  customary conditions for transactions of this type, including approval of the asset
  purchase agreement by the Osiris stockholders and receipt of authorizations,
  consents, approvals and permits of governmental authorities as specified in the
  asset purchase agreement, including the expiration of any waiting period (including
  any extension) under the Hart-Scott-Rodino Act.
  2
  Officers
  and directors of Osiris, and certain of their affiliates, holding approximately
  38% of the outstanding voting stock of Osiris, have executed voting agreements
  committing to vote for the approval of the asset purchase agreement and related
  transactions, subject in some cases to certain exceptions typical in voting
  agreements of this type, which allow for a reduction of the committed shares to
  38%. Included among those who have executed voting agreements are Peter
  Friedli, the Chairman of our Board of Directors and single largest stockholder,
  and certain of his affiliates, including Venturetec, Inc. and U.S. Venture
  05, Inc, and C. Randal Mills, President and CEO of Osiris.
  The
  foregoing summary discussion of the terms of the transactions provided for
  under the asset purchase agreement and the form of manufacturing agreement is
  qualified in its entirety by the actual terms and provisions of those
  documents. A copy of the asset purchase agreement, with form of manufacturing
  agreement attached, and a copy of the form of voting agreement are filed as
  Exhibits 10.1 and 10.2, respectively, to this Current Report on Form 8-K,
  and are incorporated into this Item 1.01 by reference.  Osiris expects to mail a proxy statement to
  its stockholders in advance of the Special Meeting of Stockholders to be called
  to consider the transaction.  Osiris
  expects to hold the Special Meeting of Stockholders before the end of the
  second quarter, or early in the third quarter. 
  Osiris' Board of Directors unanimously voted to recommend approval of
  the transaction by Osiris' stockholders.
  ITEM 9.01.            FINANCIAL
  STATEMENTS AND EXHIBITS.
  (a)
  Financial Statements of Businesses Acquired.
  None.
  (b)
  Pro Forma Financial Information.
  None.
  (d)
  Exhibits.
  Exhibit No.
  Description
  10.01.
  Asset
    Purchase Agreement dated as of May 8, 2008, by and between the
    Registrant and NuVasive, Inc., together with form of Manufacturing
    Agreement by and between the Registrant and NuVasive, Inc., to be
    entered into pursuant and subject to the terms of the Asset Purchase
    Agreement.
  10.02.
  Form
    of Voting Agreement dated as of May 8, 2008 by and among each of Peter
    Friedli, Venturetec, Inc., U.S. Venture 05, Inc., Joyce, Ltd. and C Randal
    Mills, Ph.D, and NuVasive, Inc.
  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 uncertainties related to the
  proposed sale of our assets related to Osteocel include the risk that the
  conditions relating to the closing of the sale transaction may not be satisfied,
  or may be delayed, or that the terms may be altered for any reason; changing
  relationships with customers, suppliers or employees; and the risk that we may
  not be able to fully perform or to manufacture sufficient quantities of product
  for any reason, including raw material availability, to generate milestone
  payments and manufacturing revenue. 
  Additional factors that could cause our actual results to differ
  materially from those anticipated in forward-looking statements, include the
  factors described in the section entitled "Risk Factors" in our Annual Report
  on Form 10-K filed with the United States Securities and Exchange
  Commission. You should not unduly rely on 
  forward-looking statements.
  .
  3
  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.
  OSIRIS THERAPEUTICS, INC.
  Dated: May 12, 2008
  By:
  /s/ PHILIP R. JACOBY, JR.
  Philip R. Jacoby, Jr.
  Interim Chief Financial Officer
  4