-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CGaPQK6qtJscN+cwC6eAOkpUXjVzPfdu1bv7VbdeVmsQqm+2ClrVJ/nClXtoDd5X
 oGHsK7TrDbkrB9x3SiJbKg==

<SEC-DOCUMENT>0001193125-09-069486.txt : 20091026
<SEC-HEADER>0001193125-09-069486.hdr.sgml : 20091026
<ACCEPTANCE-DATETIME>20090331164554
<PRIVATE-TO-PUBLIC>
ACCESSION NUMBER:		0001193125-09-069486
CONFORMED SUBMISSION TYPE:	CORRESP
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20090331

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			REPLIGEN CORP
		CENTRAL INDEX KEY:			0000730272
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				042729386
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	FILING VALUES:
		FORM TYPE:		CORRESP

	BUSINESS ADDRESS:	
		STREET 1:		41 SEYON STREET
		STREET 2:		BUILDING 1, SUITE 100
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453
		BUSINESS PHONE:		7814499560

	MAIL ADDRESS:	
		STREET 1:		41 SEYON STREET
		STREET 2:		BUILDING 1, SUITE 100
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453
</SEC-HEADER>
<DOCUMENT>
<TYPE>CORRESP
<SEQUENCE>1
<FILENAME>filename1.htm
<TEXT>
<HTML><HEAD>
<TITLE>Correspondence</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Repligen Corporation </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">41 Seyon Street, Building #1, Suite 100 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Waltham, Massachusetts 02453 </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">March&nbsp;31, 2009 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">United States Securities and Exchange
Commission </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Division of Corporation Finance </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">100 F Street N.E.
</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Washington, D.C. 20549 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Attention:&nbsp;&nbsp;Jeffrey
Riedler, Assistant Director </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="2%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="95%"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">RE:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Repligen Corporation</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Form 10-K for the Year Ended March 31, 2008</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Filed June 13, 2008</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">File No. 000-14656</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Dear Mr.&nbsp;Riedler: </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">This letter is being furnished in response to the comments of the Staff (the &#147;Staff&#148;) of the Securities and Exchange Commission (the &#147;Commission&#148;) in the Commission&#146;s letter dated
March&nbsp;2, 2009 (the &#147;Comment Letter&#148;) to Dr.&nbsp;Walter&nbsp;C. Herlihy, Ph.D., President, Chief Executive Officer and Director of Repligen Corporation (&#147;Repligen&#148; or the &#147;Company&#148;), with respect to the
Company&#146;s Annual Report on Form 10-K for the fiscal year ended March&nbsp;31, 2008. The response set forth below has been organized in the same manner in which the Commission&#146;s comments and headings were organized in the Comment Letter.
</FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>Form l0-K for year ended March&nbsp;31, 2008 </U></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2"><B><U>Item&nbsp;1. Business, page 3 </U></B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>1.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>Please file as an exhibit to the Form l0-K the supply agreement between the company and Applied Biosystems, Inc. </I></FONT></TD></TR></TABLE> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that the Company has not filed the supply agreement with Applied Biosystems, Inc. (&#147;Applied&#148;) because
the Company does not believe that it is a material contract pursuant to Item&nbsp;601(b)(10) of Regulation S-K. The supply agreement is such as ordinarily accompanies the business of the Company and does not fall into any of the subcategories
contained in Item&nbsp;601(b)(10)(ii). The supply agreement relates to the sale of Protein A, one of the Company&#146;s products. The supply agreement itself does not obligate Applied to purchase any specific quantity of Protein A from the Company
nor does it obligate the Company to sell any specific quantity of Protein A to Applied. Pursuant to the supply agreement, Applied periodically provides </FONT>
</P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%">
<FONT FACE="Times New Roman" SIZE="2">the Company with a medium term forecast (less than six months) of its need for Protein A on an informational basis, again without a requirement of either
party to buy or sell Protein A. Applied also provides short term forecasts of its Protein A needs, covering a period less than three months. For the first three years of the supply agreement, Applied must buy and the Company must sell Applied 100%
of such short term forecast. For the fourth year of the supply agreement, Applied must buy and the Company must sell to Applied 50% of such short term forecast. The price of such purchases is determined by a matrix set forth in the supply agreement
and is based on volume. While the amount varies from year to year, Applied&#146;s purchases of Protein A from the Company constitute less than 10% of the Company&#146;s product revenues and less than 4% of total revenues. Therefore, the Company does
not believe that the supply agreement with Applied is a material contract required to be filed as an exhibit to its Form 10-K. </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>2.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>We note your discussion in this section of the exclusive license agreement between the company and the Massachusetts Institute of Technology on page 4. Please describe the
material terms of this agreement in this section and file the agreement as an exhibit to the Form 10-K pursuant to Item&nbsp;60l(b)(10) of Regulation S-K. Alternatively, please provide us with an analysis supporting your determination that the
agreement is not material to the company. </I></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that the license agreement with the
Massachusetts Institute of Technology (&#147;MIT&#148;) dated May&nbsp;4, 2004 terminated on the last to expire patents covered by such license. The last to expire patent expired in May 2005. The patents covered by the license were related to the
use of DNA enhancers. Pursuant to the license, the Company was required to pay a certain percentage of any amounts received by the Company from third parties for use of the intellectual property covered by the license. For at least the last 10
years, the technology covered by the license was not relevant to the Company&#146;s core operations. Since May 2005, the license merely acted as a requirement to pay money, if any, upon a successful outcome in the litigation described below.
</FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">Prior to the termination of the License, in May 2004, the Company and MIT sued ImClone Systems, Incorporated (&#147;ImClone&#148;) claiming
infringement of the patents which were the subject of the license. In settlement of such claims, ImClone agreed to pay the Company and MIT $65 million of which approximately $11 million, or 17%, was paid to MIT pursuant to the terms of the license.
The Company has no further obligations or other responsibilities to MIT under this license. </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">The Company is currently engaged in the
development and sale, if approved for sale, of (i)&nbsp;Protein A which is used in the manufacture of monoclonal antibodies, (ii)&nbsp;synthetic hormones which, among other things, may assist in the diagnosis of pancreatitis and related disorders,
and (iii)&nbsp;therapeutic product candidates for, among other things, the treatment of bipolar disorder and Friedreich&#146;s ataxia. The Company was incorporated in 1981 and has always been focused, among other things, on the research and
development of therapeutic candidates for various diseases. The Company has frequently in-licensed various technologies and inventions, including those covered by patents. The in-license </FONT>
</P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">2 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%">
<FONT FACE="Times New Roman" SIZE="2">of patents is one that ordinarily accompanies the business of researching and developing therapeutic product candidates as contemplated by
Item&nbsp;601(b)(10) of Regulation S-K and does not fall into any of the subcategories contained in Item&nbsp;601(b)(10)(ii). In addition, all patent rights under the license have expired and no further payments are due under the license. Therefore,
the Company does not believe the license from MIT is a material contract required to be filed as an exhibit to its Form 10-K. </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>3.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>We note your discussion of the exclusive license agreement between the company and the University of Michigan on page 4, which agreement has been filed as a material contract and
incorporated by reference to your 10-K. Please describe the material terms of the agreement in this section of the 10-K. </I></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman"
SIZE="2">RESPONSE: We respectfully advise the Staff that we propose to include in the Company&#146;s annual report on Form 10-K for the year ended March&nbsp;31, 2009, the following disclosure regarding the material terms of the license agreement
with the University of Michigan. All proposed changes to such disclosure compared to previously submitted disclosures in our annual report on Form 10-K for the year ended March&nbsp;31, 2008 to incorporate the Staff&#146;s recommendations are
highlighted in <B><I>bold italic</I></B> print: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2"><B>&#147;CTLA4-Ig</B> </FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">CTLA4 is a key regulator of the activity of the immune system. CTLA4 &#147;turns off&#148; the immune system after it has successfully cleared a bacterial
or viral infection by blocking the activation of T-cells, the immune cells responsible for initiating an immune response. In the 1990&#146;s, our collaborators at the University of Michigan and the U.S. Navy demonstrated in animal models that a
fusion protein consisting of fragments of CTLA4 and an antibody (&#147;CTLA4-Ig&#148;) could be used to treat certain autoimmune diseases. This research finding resulted in the granting of U.S. patent No.&nbsp;6,685,941 (&#147;the &#145;941
Patent&#148;) covering the treatment of certain auto-immune disorders including rheumatoid arthritis with CTLA4-Ig. The &#145;941 Patent is owned by the University of Michigan and exclusively licensed to Repligen. <B><I>In consideration of this
exclusive license, Repligen agreed to pay the University of Michigan 15% of all royalty income received, after deducting legal expenses. </I></B>CTLA4-Ig&#146;s mechanism of action is different from the current therapies for autoimmune disease or
organ transplant rejection, thus it may provide a treatment for patients who are refractory to existing therapies. </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%;padding-bottom:3px;line-height:95%; vertical-align:top"><FONT
FACE="Times New Roman" SIZE="2">In December 2005, the FDA approved Bristol&#146;s application to market CTLA4-Ig, under the brand name Orencia<FONT FACE="Times New Roman" SIZE="1"><SUP>&reg;</SUP></FONT>, for treatment of rheumatoid arthritis. In
January 2006, Repligen and the University of Michigan jointly filed a lawsuit against Bristol in the United States District Court for the Eastern District of Texas for patent infringement. In April 2008, Repligen and the University of Michigan
entered into a settlement agreement with Bristol pursuant to which, Bristol made an initial payment of $5 million to Repligen and will pay us royalties on the U.S. net sales of Orencia<FONT FACE="Times New Roman" SIZE="1"><SUP>&reg;</SUP></FONT> for
any clinical indication at a rate of 1.8% for the first $500 million of annual sales, 2.0% for the next $500 million and 4% of annual sales in excess of $1 billion for each year from January&nbsp;1, 2008 until December&nbsp;31, 2013.&#148;
</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>4.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>We note your discussion of the settlement agreement between the company and Bristol-Myers Squibb on pages 4, 6 and 55. Please file this agreement as an exhibit to the Form l0-K
pursuant to Item&nbsp;60l(b)(10) of Regulation S-K. </I></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that the Settlement and
Release Agreement between the Company, the Regents of the University of Michigan and Bristol-Myers Squibb Company was executed and became effective on April&nbsp;7, 2008 (the &#147;Bristol Agreement&#148;), after the end of our fiscal year 2008
which ended on March&nbsp;31, 2008. Item&nbsp;601(a)(4) of Regulation S-K requires the Company to file as exhibits to Form 10-K material contracts, pursuant to Item&nbsp;601(b)(10), a material contract which is executed or becomes effective during
the reporting period reflected by the Form 10-Q or Form 10-K. Since the Bristol Agreement was executed after the reporting period reflected in the Form 10-K it was not filed as an exhibit thereto. We advise the Staff that the execution of the
Bristol Agreement was disclosed pursuant to Item&nbsp;1.01 of a Form 8-K which was filed on April&nbsp;11, 2008 and the Bristol Agreement itself was filed as Exhibit 10.1 to the Company&#146;s Form 10-Q for the three month period ending
June&nbsp;30, 2008 which was filed on August&nbsp;8, 2008. We further advise the Staff that we intend to incorporate by reference the Bristol Agreement as an exhibit to the Company&#146;s Form 10-K for the year ending March&nbsp;31, 2009 as required
by Item&nbsp;601 of Regulation S-K. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>Item&nbsp;5. Market for Registrant&#146;s Common Equity, Related Stockholder Matters and Issuer Purchases of
Equity Securities, page 14 </U></B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>5.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>Please revise to disclose the information required by Item&nbsp;201(e) of Regulation S-K. </I></FONT></TD></TR></TABLE> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that pursuant to Instruction 7 to Item&nbsp;201(e), the Company has included the performance graph required by
Item&nbsp;201(e) of Regulation S-K in an annual report to security holders required by Exchange Act Rule 14a-3 (the &#147;2008 Annual Report&#148;) that accompanied the registrant&#146;s proxy relating to the Company&#146;s 2008 annual meeting of
security holders at which directors were to be elected. Pursuant to Rule 14a-3(b)(9), the performance graph required by Item&nbsp;201(e) of Regulation S-K is required to be included in an annual report to shareholders. In lieu of providing
shareholders with the Company&#146;s Annual Report on Form 10-K in satisfaction of the requirements of Rule 14a-3, the Company delivered the 2008 Annual Report which met the conditions required therein. As required by Rule 14a-3(c), seven copies of
the Company&#146;s 2008 Annual Report were filed with the Commission. For our 2009 annual report to shareholders, we intend to include the performance graph as we did in the 2008 Annual Report. </FONT></P> <P
STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>Notes to Consolidated Financial Statements </U></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>11. Scripps
Agreement, page 54 </U></B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>6.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>You state that, pursuant to the company&#146;s license agreement with The Scripps Research Institute, Repligen has agreed to make certain additional payments in
the event it achieves specified developmental and commercial milestones. Notwithstanding that the </I></FONT>
</P></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P>
<FONT FACE="Times New Roman" SIZE="2"><I>company has been granted confidential treatment for portions of this agreement, including the amount of specific potential milestone payments, please
disclose the aggregate potential milestone payments to be made under the agreement, Alternatively, please provide your analysis why these aggregate potential payments are not material. </I></FONT></P></TD></TR></TABLE> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully agree with the Staff&#146;s recommendation that further disclosure of the aggregate potential milestone payments is appropriate.
In response to the Staff&#146;s comment, we would have made the following revised disclosure as of March&nbsp;31, 2008 and are planning to include equivalent disclosure in our future filings on form 10-K. We have included the first two paragraphs of
the related disclosure as of March&nbsp;31, 2008 below for reference. All proposed changes or additions to such disclosure to incorporate the Staff&#146;s recommendations are highlighted in <B><I>bold italic</I></B> print: </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>&#147;11. Scripps Agreements </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2"><I>License Agreement </I></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">On April&nbsp;6, 2007 (&#147;the Effective Date&#148;), the Company entered into an
exclusive worldwide commercial license agreement (&#147;License Agreement&#148;) with The Scripps Research Institute (&#147;Scripps&#148;). Pursuant to the License Agreement, the Company obtained a license to use, commercialize and sublicense
certain patented technology and improvements thereon, owned or licensed by Scripps, relating to compounds which may have utility in treating Friedreich&#146;s Ataxia, an inherited neurodegenerative disease. Research in tissues derived from patients,
as well as in mice, indicates that the licensed compounds increase production of the protein frataxin, which suggests potential utility of these compounds in slowing or stopping progression of the disease. There are currently no approved treatments
for Friedreich&#146;s ataxia. </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Pursuant to the License Agreement, the Company agreed to pay Scripps an initial license fee
of $300,000, certain royalty and sublicense fees and, in the event the Company achieves specified developmental and commercial milestones, certain additional milestone payments. <B><I>Total future milestone payments, were all milestones to be
achieved, would be approximately $4.3 million. </I></B>In addition, the Company issued Scripps and certain of its designees 87,464 shares of the Company&#146;s common stock (the &#147;Shares&#148;) representing $300,000 as of the Effective Date. The
Company recorded the initial license payment and the value of the shares issued as research and development costs in the Company&#146;s statement of operations in fiscal 2008.&#148; </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT
FACE="Times New Roman" SIZE="2"><B><U>Definitive Proxy Statement </U></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>Compensation Discussion and Analysis, page 18 </U></B></FONT></P> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>7.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>We note your statements on page 18 that the Compensation Committee set total executive officer compensation in fiscal 2008 based on the Radford Biotechnology
Survey. Please revise your discussion to identify the companies from the survey that were reviewed by </I></FONT>
</P></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">5 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P>
<FONT FACE="Times New Roman" SIZE="2"><I>the Compensation Committee and used as a basis for the salaries paid to Repligen&#146;s executive officers. If the companies are too numerous to list,
please disclose the criteria for including these companies in the Survey. </I></FONT></P></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully agree with the
Staff&#146;s recommendation that further identification of the criteria used for inclusion in the Radford Biotechnology Survey is appropriate. In response to the Staff&#146;s comment, we would have revised our Definitive Proxy Statement and are
planning to include equivalent disclosure in future filings as appropriate. We have included the first two paragraphs of the related disclosure as of March&nbsp;31, 2008 below for reference. All proposed changes or additions to such disclosure to
incorporate the Staff&#146;s recommendations are highlighted in <B><I>bold italic</I></B> print: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>&#147;Executive Compensation
</B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><I>Base Salary</I>. Each executive officer (except the Chief Executive Officer whose performance is reviewed by the
Compensation Committee) has an annual performance review with the Chief Executive Officer, who makes recommendations on salary increases, promotions and equity grants to the Compensation Committee. The recommended salary increases are based on the
executive officer&#146;s qualifications, performance, experience, responsibilities and the average salary increases expected in the biopharmaceutical and biotechnology industries based on information contained in the Radford Biotechnology Survey
<B><I>(&#147;the Radford Survey&#148;), a publicly available compensation data subscription service. The Radford Survey for our peer group included both publicly traded and privately held companies operating primarily in the biotechnology and other
life science industries with 50 to 149 employees. This peer group included approximately 175 national and regional companies ranging from research and development stage companies on upward. </I></B>For fiscal year 2008, the Company increased base
salaries for Drs. Herlihy, Rusche and Witt and Mr.&nbsp;Muehl by 3.0%, 3.1%, 3.1% and 3.0%, respectively. Mr.&nbsp;Kelly joined the Company on March&nbsp;31, 2008 and therefore did not have an increase in base salary. The Company believes that the
base salaries paid to the executive officers during fiscal year 2008 achieved its compensation objectives and compared favorably to its peer group.&#148; </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2"><B><U>Annual Cash Incentive Compensation, page 19 </U></B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>8.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>We note your discussion concerning the performance criteria considered by the Compensation Committee in making its awards for fiscal year 2008, which was comprised of company and
individual objectives. </I></FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>(a)</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>With respect to company performance objectives, your disclosure is too general. Please disclose the specific targets against which company performance was
measured. Please note that disclosure of these specific targets is warranted unless the company believes that competitive harm would result from such disclosure, in which case it may omit disclosure of the specific targets as long as it complies
</I></FONT>
</P></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">6 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="8%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P>
<FONT FACE="Times New Roman" SIZE="2"><I>with Instruction 4 to 402(b). In accordance with that instruction, please supplementally explain to us your basis for keeping the individual performance
target information confidential. Please explain why, based upon your specific facts and circumstances, publicly releasing this information will cause Repligen competitive harm; and </I></FONT></P></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>(b)</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>With respect to individual executive performance, to the extent that the performance criteria you have listed was subject to quantification for purposes of the Compensation
Committee&#146;s performance evaluation, please provide the metrics used. If not, please explain how the Compensation Committee determined the percentage of completion of individual results, as described on pages 21 and 22.
</I></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that in response to both (a)&nbsp;and (b)&nbsp;above, the Company does employ
a calculation to determine and subsequently measure performance against various company and individual performance targets. The complete disclosure of these targets and the detailed metrics of the calculation would provide our current and potential
competitors, customers partners and suppliers with significant insight into the strategic goals of the company, disclosure of which would represent, in our opinion, a competitive disadvantage to the company. </FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">We do, however, agree with the general principal that additional disclosure for the investor would be beneficial and would have revised and are planning
on providing similar disclosure in future filings as indicated below. For reference, we would have updated our disclosure beginning at the bottom of page 21, which has been presented below. All proposed changes or additions to such disclosure to
incorporate the Staff&#146;s recommendations are highlighted in <B><I>bold italic</I></B> print: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><I>&#147;Achievement of objectives and
cash incentive determination: </I></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The portion of cash incentive tied to corporate results is determined based on evaluation
of the percentage completion of the established corporate objectives determined at the beginning of the fiscal year. The objectives are designed to be difficult to achieve 100% completion. These objectives include financial performance objectives
(30% of total), product development objectives (30% of total), intellectual property objectives (20% of total) and business and organizational development objectives (20% of total). </FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B><I>Financial performance objectives, which comprise 30% of the overall corporate objectives included certain revenue, net income and
end of year cash targets. Actual reported results included product revenue of $18.6 million, net income of $37.1m after recognition of a $40.2 million net gain from litigation settlement, and end of year cash and investments of $60.6 million.
Overall performance resulted in the achievement of most of the defined financial performance objectives. </I></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2"><B><I>Product development objectives included certain clinical trial milestones including the initiation of the Phase 3 clinical trial for RG1068, and the conclusion of the phase 2 clinical trial for RG2417. In addition, various objectives
were established including </I></B></FONT>
</P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">7 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%">
<FONT FACE="Times New Roman" SIZE="2"><B><I>assessing the suitability of our existing clinical candidate of HDAC inhibitors for Friedreich&#146;s ataxia and advancing the development of certain
product attributes and market development objectives for our Protein A business. The Company performed well in the advancement of these product development objectives, but did not fully meet the initial high targets set. </I></B></FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B><I>Intellectual property objectives centered on maximizing the value of our intellectual property portfolio, particularly as it related
to the ongoing litigation with both Imclone and Bristol-Myers Squibb. Imclone litigation was completed during the year and Bristol-Myers Squibb litigation concluded just after year end. While the Company was pleased with the results of these
activities, we did not fully meet our stretch objectives. </I></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B><I>Business and organizational development objectives
included a number of objectives designed to strengthen the overall foundation of the company, including refinement of the Company&#146;s strategic plan, the hiring of several key management and board positions, and other such initiatives. The
Company achieved most of the targets, however, based on the assessment of remaining work still to be completed as of year end, the Company did not fully achieve these targets. </I></B></FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B><I>Individual objectives are aligned with the company performance objectives noted above as appropriate for the given function.
</I></B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The Chief Executive Officer determined and the compensation committee agreed that the aggregate percentage
completion of the objectives for financial performance, product development, intellectual property and business and organizational development was 86.3%. The corporate portion of cash incentive for all officers was paid calculated at this level of
achievement.&#148; </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>Equity Compensation Plan Information, page 35 </U></B></FONT></P> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><I>9.</I></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><I>Please revise the equity compensation plan table to reflect information as of March&nbsp;31, 2008, the end of the most recently completed fiscal year, rather than as of
December&nbsp;31, 2007, pursuant to Item&nbsp;201(d) of Regulation S-K. </I></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT FACE="Times New Roman" SIZE="2">RESPONSE: We respectfully advise the Staff that
the equity compensation plan table incorrectly refers to information contained therein for the year ended December&nbsp;31, 2007 instead of March&nbsp;31, 2008 as you note. The information, however, is for the year ended March&nbsp;31, 2008.
Therefore, the information included therein is correct and the date reference is inadvertently incorrect. We further advise that with respect to the Company&#146;s definitive proxy statement for the annual meeting of shareholders to be held in
September 2009, the information contained in the equity plan compensation table, and the description thereof, will be for the year ended March&nbsp;31, 2009. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">*** </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">The Company acknowledges that: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="1%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the Company is responsible for the adequacy and accuracy of the disclosure in the filing; </FONT></P></TD></TR></TABLE> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">8 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="1%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">staff comments or changes to disclosure in response to staff comments do not foreclose the Commission from taking any action with respect to the filing; and
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="1%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the Company may not assert staff comments as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United
States. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">If you have any questions with regard to the Company&#146;s responses, need further supplemental information or
would like to discuss any of the matters covered in this letter, please contact the undersigned at (781)&nbsp;250-0111. </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0">

<TR>
<TD WIDTH="100%"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Sincerely,</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ William J. Kelly</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">William J. Kelly</FONT></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Chief Financial Officer</FONT></TD></TR>
</TABLE></DIV> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">9 </FONT></P>

</BODY></HTML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
