<SUBMISSION>
<ACCESSION-NUMBER>0001104659-03-028204
<TYPE>8-K
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031208
<ITEMS>5
<FILING-DATE>20031210
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>CERUS CORP
<CIK>0001020214
<ASSIGNED-SIC>2836
<IRS-NUMBER>680262011
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>8-K
<ACT>34
<FILE-NUMBER>000-21937
<FILM-NUMBER>031046982
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>2411 STANWELL DR
<CITY>CONCORD
<STATE>CA
<ZIP>94520
<PHONE>9252886000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2525 STANWELL DRIVE
<STREET2>STE 300
<CITY>CONCORD
<STATE>CA
<ZIP>94520
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>CERUS TECHNOLOGIES INC
<DATE-CHANGED>19960731
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>a03-6159_18k.htm
<DESCRIPTION>8-K
<TEXT>
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<p style="border:none;margin:0in 0in .0001pt;padding:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">SECURITIES AND EXCHANGE COMMISSION</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Washington, D.C. 20549</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM 8-K</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">CURRENT REPORT<br>
Pursuant to Section 13 or 15(d) of the<br>
Securities Exchange Act of 1934</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&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;">Date of Report (Date of
earliest event reported):&#160; <b><font style="font-weight:bold;">December 8, 2003</font></b></font></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">CERUS CORPORATION</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Exact name of registrant
as specified in its charter)</font></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&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="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.6%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Delaware</font></b></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.66%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.56%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">0-21937</font></b></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.64%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.54%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">68-0262011</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.6%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(State of jurisdiction)</font></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.66%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.56%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission File No.)</font></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.64%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.54%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(IRS Employer
  Identification No.)</font></p>
  </td>
 </tr>
 <tr>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.6%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.66%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.56%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.64%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.54%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="5" valign="top" style="padding:0in 0in 0in 0in;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">2411
  Stanwell Drive<br>
  Concord, California 94520</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="5" valign="top" style="padding:0in 0in 0in 0in;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Address of principal
  executive offices and zip code)</font></p>
  </td>
 </tr>
 <tr>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.6%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.66%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.56%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.64%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="31%" valign="top" style="padding:0in 0in 0in 0in;width:31.54%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="5" valign="top" style="padding:0in 0in 0in 0in;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Registrant&#146;s telephone
  number, including area code: <b><font style="font-weight:bold;">(925) 288-6000</font></b></font></p>
  </td>
 </tr>
</table>

</div>

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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>


<div style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

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</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 5.&#160; Other Events
and Required FD Disclosure.</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On December 8, 2003, a class action complaint was filed in the United
States District Court for the Northern District of California against Cerus
Corporation (the &#147;Company&#148;) and the Company&#146;s Chief Executive Officer, Chief
Financial Officer, Vice President, Research and Development, Vice President,
New Science Opportunities and Vice President, Legal Affairs.&#160; The complaint alleges that the defendants
violated the federal securities laws, specifically Sections 10(b) and 20(a) of
the Securities Exchange Act of 1934 and Rule 10b-5 of the Securities and
Exchange Commission, by making certain alleged false and misleading statements.&#160; The plaintiff seeks unspecified damages on
behalf of a purported class of purchasers of the Company&#146;s securities during
the period from October 25, 2000 through September 3, 2003.&#160; It is conceivable that additional actions of
a similar nature may be filed in the future.&#160;
The Company believes that it has strong defenses to the allegations
contained in the complaint and intends to vigorously defend itself.</font></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The preceding discussion includes
forward-looking statements that involve risks and uncertainties.&#160; When used herein, the words &#147;anticipate,&#148;
&#147;believe,&#148; &#147;estimate,&#148; &#147;expect&#148; and similar expressions are intended to
identify such forward-looking statements.&#160;
There can be no assurance that these statements will prove to be
correct.&#160; These forward-looking
statements are subject to risks and uncertainties that could cause actual
results to differ materially from the results indicated by such forward-looking
statements.&#160; Important factors that
could cause results to differ include, but are not limited to, whether we will
be able to successfully defend any lawsuit, including the purported class
action, the inherent uncertainties and risks of litigation that may cause us to
review and alter our litigation strategy and the risk of potential adverse
rulings in any litigation.&#160; We undertake
no obligation to update any of the forward-looking statements contained herein
to reflect any future events or developments.</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;">&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;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

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</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">SIGNATURE</font></b></p>

<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="margin:0in 0in .0001pt;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, the Registrant has duly caused this report to be signed
on its behalf by the undersigned hereunto duly authorized.</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;">&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:48.16%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="51%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:51.84%;">
  <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">CERUS
  CORPORATION</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="51%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:51.84%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="51%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:51.84%;">
  <p style="font-size:10.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated:&#160;
  December 10, 2003</font></p>
  </td>
  <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.5%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
  </td>
  <td width="30%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in 0in 0in 0in;width:30.34%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/ Gregory W. Schafer</font></p>
  </td>
  <td width="18%" valign="top" style="padding:0in 0in 0in 0in;width:18.0%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.5%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.34%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Gregory W. Schafer</font></p>
  </td>
  <td width="18%" valign="top" style="padding:0in 0in 0in 0in;width:18.0%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.5%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.34%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Vice President, Finance and</font></p>
  </td>
  <td width="18%" valign="top" style="padding:0in 0in 0in 0in;width:18.0%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.16%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.5%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
  <td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.34%;">
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Chief Financial Officer</font></p>
  </td>
  <td width="18%" valign="top" style="padding:0in 0in 0in 0in;width:18.0%;">
  <p style="font-size:1.0pt;margin:0in 0in .0001pt;">&nbsp;</p>
  </td>
 </tr>
</table>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&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;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

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