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  <TITLE>FORM S-8</TITLE>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>As filed with the Securities and Exchange Commission on March&nbsp;24, 2025 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Registration No.&#8195;&#8195;&#8195; </B></P> <P STYLE="font-size:4pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
  <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES
  AND EXCHANGE COMMISSION </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT STYLE="white-space:nowrap">S-8</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>UNDER </I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>THE
  SECURITIES ACT OF 1933 </I></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>Abivax SA </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact name
  of Registrant as specified in its charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:8pt" ALIGN="center">
  
  
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  <TD VALIGN="top" ALIGN="center"><B>France</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"><B>Not Applicable</B></TD></TR>
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  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction of</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>incorporation or organization)</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(I.R.S. Employer</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification Number)</B></P></TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">7-11</FONT> boulevard Haussmann 75009 Paris, France </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Address of Registrant&#146;s principal executive offices) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2023-3</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2023-4</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2023-5</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-1</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-2</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-3</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-4</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-5</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2024-7</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2025-1</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2025-2</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2025-3</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Free share plan AGA <FONT STYLE="white-space:nowrap">2025-4</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Share warrants plan <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">BSA-2018-1</FONT></FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Share warrants plan <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">BSA-2024-1</FONT></FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Share warrants plan <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">BSA-2025-1</FONT></FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Share warrants plan <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">BSA-2025-2</FONT></FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Full title of the plans) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Marc de Garidel </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Chief
  Executive Officer </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">7-11</FONT> boulevard Haussmann </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>75009 Paris, France </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Tel.
  No. +33 (0) 1 53 83 09 63 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Name, address and telephone number of agent for service) </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
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  <TD VALIGN="top" COLSPAN="3" ALIGN="center"><B><I>Copies to:</I></B></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Divakar Gupta, Esq.</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Ryan Sansom, Esq.</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Minkyu Park, Esq.</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Cooley LLP</I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>55
  Hudson Yards</I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>New York, New York 10001</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Tel: +1 212 <FONT STYLE="white-space:nowrap">479-6000</FONT></I></B></P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Alain Decombe</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Vianney Toulouse</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Dechert (Paris) LLP</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>22 rue Bayard</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>75008 Paris</I></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>France</I></B></P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Tel: +33
  1 57 57 80 00</I></B></P></TD></TR>
  </TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a <FONT STYLE="white-space:nowrap">non-accelerated</FONT>
  filer, a smaller reporting company or an emerging growth company. See definitions of &#147;large accelerated filer,&#148; &#147;accelerated filer,&#148; &#147;small reporting company,&#148; and &#147;emerging growth company&#148; in Rule <FONT
  STYLE="white-space:nowrap">12b-2</FONT> of the Exchange Act. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
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  <TD VALIGN="bottom">Large&nbsp;accelerated&nbsp;filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Accelerated&nbsp;filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9746;</TD></TR>
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  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"><FONT STYLE="white-space:nowrap">Non-accelerated&nbsp;filer</FONT></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Smaller&nbsp;reporting&nbsp;company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
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  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD>
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  <TD VALIGN="bottom"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Emerging growth company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9746;</TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with any new or revised financial accounting standards provided pursuant to Section&nbsp;7(a)(2)(B) of the Securities Act.&#8194;&#9746; </P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
  <P STYLE="font-size:18pt; margin-top:0pt; margin-bottom:0pt">&nbsp;</P>
  </DIV></Center>
  
  
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  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>PART I </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The information required by Part I of Form <FONT STYLE="white-space:nowrap">S-8</FONT> is omitted from this filing in accordance with Rule 428
  under the Securities Act of 1933, as amended (the &#147;Securities Act&#148;) and the introductory note to Part I of Form <FONT STYLE="white-space:nowrap">S-8.</FONT> The documents containing the information specified in Part I will be delivered to
  the participants in the plans covered by this Registration Statement as required by Rule 428(b)(1) under the Securities Act. </P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>PART II
  </B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>INFORMATION REQUIRED IN THE REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;3. Incorporation of Documents by Reference. </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">This Registration Statement on Form <FONT STYLE="white-space:nowrap">S-8</FONT> hereby incorporates by reference the contents of the following
  reports of Abivax SA (the &#147;Registrant&#148; or &#147;we&#148;) filed with, or furnished to, the Securities and Exchange Commission (the &#147;Commission&#148;) pursuant to the Securities Exchange Act of 1934, as amended (the &#147;Exchange
  Act&#148;): </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
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  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(a)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Registrant&#146;s Annual Report on <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1956827/000195682725000010/abvx-20241231.htm">Form
   <FONT STYLE="white-space:nowrap">20-F</FONT></A> for the year ended December&nbsp;31, 2024, as filed with the Commission on March&nbsp;24, 2025 (Commission File <FONT STYLE="white-space:nowrap">No.&nbsp;001-41842)</FONT> (the &#147;Form <FONT
  STYLE="white-space:nowrap">20-F&#148;);</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(b)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Registrant&#146;s Reports on Form <FONT STYLE="white-space:nowrap">6-K</FONT> furnished to the Commission
  on <A HREF="http://www.sec.gov/Archives/edgar/data/1956827/000119312525004163/d905529d6k.htm">January<U></U>&nbsp;10, 2025</A> (Commission File <FONT STYLE="white-space:nowrap">No.&nbsp;001-41842);</FONT> </P></TD></TR></TABLE>
  <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(c)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The description of the Registrant&#146;s ordinary shares contained in <A HREF="http://www.sec.gov/Archives/edgar/data/1956827/000195682725000010/abivax-20xfxex21descriptio.htm">Exhibit
   2.1</A> to the Form <FONT STYLE="white-space:nowrap">20-F,</FONT> including any amendment or report filed for the purpose of updating such description; and </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(d)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">All documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
  Exchange Act prior to the filing of a post-effective amendment indicating that all securities offered have been sold or that deregisters all securities then remaining unsold shall be deemed to be incorporated by reference in this Registration
  Statement and to be part hereof from the date of filing of such document incorporated by reference. </P></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Notwithstanding the
  foregoing, no document, report or exhibit (or portion of any of the foregoing) or any other information that we have &#147;furnished&#148; to the Commission pursuant to the Exchange Act shall be incorporated by reference into this prospectus unless
  such document, report or exhibit expressly provides to the contrary. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Statements contained in the foregoing documents incorporated by
  reference shall be deemed to be modified or superseded hereby to the extent that statements contained in the Prospectus, or in any subsequently filed documents that are amendments hereto or that are incorporated herein by reference, shall modify or
  replace such statements. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;4. Description of Securities. </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;5. Interests of
  Named Experts and Counsel. </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P>
  <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;6. Indemnification of Directors and Officers. </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Under French law, provisions of <FONT STYLE="white-space:nowrap">by-laws</FONT> that limit the liability of directors are prohibited. However,
  French law allows <I>soci&eacute;t&eacute; anonyme</I> to contract for and maintain liability insurance against civil liabilities incurred by any of their directors and officers involved in a third-party action, provided that they acted in good
  faith and within their capacities as directors or officers of the company. Criminal liability cannot be indemnified under French law, whether directly by the company or through liability insurance. We maintain liability insurance for our directors
  and officers, including insurance against liability under the Securities Act. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Certain of our
  <FONT STYLE="white-space:nowrap">non-employee</FONT> directors may, through their relationships with their employers or partnerships, be insured and/or indemnified against certain liabilities in their capacity as members of our board of directors.
  </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;7. Exemption from Registration Claimed. </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;8. Exhibits.
  </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">See the Exhibit Index, below. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">1 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Item&#8201;9. Undertakings. </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The undersigned Registrant hereby undertakes: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(1)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">To file, during any period in which offers or sales are being made, a post-effective amendment to this
  Registration Statement: </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="9%">&nbsp;</TD>
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(i)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">To include any prospectus required by Section&nbsp;10(a)(3) of the Securities Act; </P></TD></TR></TABLE>
  <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="9%">&nbsp;</TD>
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(ii)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement
  (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this Registration Statement. Notwithstanding the foregoing, any increase or decrease in
  volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus
  filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the &#147;Calculation of Registration Fee&#148; table in
  the effective Registration Statement; and </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="9%">&nbsp;</TD>
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(iii)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">To include any material information with respect to the plan of distribution not previously disclosed in the
  Registration Statement or any material change to such information in the Registration Statement; </P></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>provided</I>,<I> however</I>, that
  paragraphs (i)&nbsp;and (ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Registrant pursuant to
  Section&nbsp;13 or 15(d) of the Exchange Act that are incorporated by reference in the Registration Statement; </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(2)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment
  shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof; and </P></TD></TR></TABLE>
  <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%">&nbsp;</TD>
  <TD WIDTH="5%" VALIGN="top" ALIGN="left">(3)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">To remove from registration by means of a post-effective amendment any of the securities being registered which
  remain unsold at the termination of the offering. </P></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act, each filing of the Registrant&#146;s annual report pursuant to Section&nbsp;13(a) or Section&nbsp;15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan&#146;s
  annual report pursuant to Section&nbsp;15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such
  securities at that time shall be deemed to be the initial <I>bona fide</I> offering thereof. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Insofar as indemnification for liabilities
  arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such
  indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or
  paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the
  Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the
  Securities Act and will be governed by the final adjudication of such issue. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">2 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>EXHIBIT INDEX </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
  <TR>
  
  <TD></TD>
  
  <TD VALIGN="bottom" WIDTH="5%"></TD>
  <TD WIDTH="92%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; border-bottom:1.00pt solid #000000; display:table-cell; font-size:8pt; font-family:Times New Roman; "><B>Exhibit&nbsp;No.</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Description of Document</B></P></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.1</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1956827/000195682725000010/abivax-20xfxex11bylaws6feb.htm"><FONT STYLE="white-space:nowrap">By-laws</FONT> (statuts) of the Registrant (English translation) (incorporated by reference to
   Exhibit 1.1 to the Registrant&#146;s Annual Report on Form <FONT STYLE="white-space:nowrap">20-F</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-41842)</FONT> filed with the Commission on March&nbsp;24, 2025) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.2</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1472033/000119380523001353/e618972_ex99-a.htm">Form of Deposit Agreement (incorporated by reference to Exhibit (a)&nbsp;to the Registrant&#146;s Registration Statement on Form <FONT
  STYLE="white-space:nowrap">F-6</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;333-274845),</FONT> filed with the Commission on October&nbsp;3, 2023) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.3</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1472033/000119380523001353/e618972_ex99-a.htm">Form of American Depositary Receipt (included in Exhibit 4.2) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.4</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1956827/000195682725000010/abivax-20xfxex416summaryof.htm">Summary of BSA <FONT STYLE="white-space:nowrap">2015-11,</FONT> BSA <FONT STYLE="white-space:nowrap">2015-12,</FONT> BSA <FONT
  STYLE="white-space:nowrap">2017-1,</FONT> BSA <FONT STYLE="white-space:nowrap">2018-1,</FONT> BSA <FONT STYLE="white-space:nowrap">2024-1,</FONT> BSA <FONT STYLE="white-space:nowrap">2024-2,</FONT> <FONT STYLE="white-space:nowrap"><FONT
  STYLE="white-space:nowrap">BSA-2025-1</FONT></FONT> and <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">BSA-2025-2</FONT></FONT> Plans (incorporated by reference to Exhibit 4.16 to the Registrant&#146;s Annual Report on Form <FONT
  STYLE="white-space:nowrap">20-F</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-41842)</FONT> filed with the Commission on March&nbsp;24, 2025) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.5</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1956827/000195682725000010/abivax-20xfxex418summaryof.htm">Summary of <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2023-1,</FONT></FONT> <FONT
  STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2023-2,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2023-3,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2023-4,
  </FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2023-5,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-1,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT
  STYLE="white-space:nowrap">AGA-2024-2,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-3,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-4,</FONT></FONT> <FONT
  STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-5,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-6,</FONT></FONT>
  <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2024-7,</FONT></FONT> <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2025-1,</FONT></FONT>
  <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2025-2,</FONT></FONT> AGA <FONT STYLE="white-space:nowrap">2025-3</FONT> and <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">AGA-2025-4</FONT></FONT> Free Share
  Plans (incorporated by reference to Exhibit 4.18 to the Registrant&#146;s Annual Report on Form <FONT STYLE="white-space:nowrap">20-F</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-41842)</FONT> filed with the Commission on
  March&nbsp;24, 2025) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;5.1*</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d845340dex51.htm">Opinion of Dechert (Paris) LLP</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.1*</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d845340dex231.htm">Consent of PricewaterhouseCoopers Audit - Independent Registered Public Accounting Firm </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.3*</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d845340dex51.htm">Consent of Dechert (Paris) LLP (included in Exhibit 5.1 above) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;24*</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="#sig">Power of Attorney (included on the signature page) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>107*</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d845340dexfilingfees.htm">Filing fee table </A></TD></TR>
  </TABLE> <P STYLE="line-height:8.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000;width:11%">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Filed herewith. </P></TD></TR></TABLE>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">3 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><A NAME="sig"></A>SIGNATURES </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act, Abivax SA certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form <FONT STYLE="white-space:nowrap">S-8</FONT> and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Paris, France on March&nbsp;24, 2025. </P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="12%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="87%"></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" COLSPAN="3">Abivax SA</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">By:</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Marc de Garidel</P></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">Name:</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top">Marc de Garidel</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">Title:</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top">Chief Executive Officer</TD></TR>
  </TABLE></DIV> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>POWER OF ATTORNEY AND SIGNATURES </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">We, the undersigned directors, officers and/or authorized representative of Abivax SA, hereby severally constitute and appoint Marc de Garidel
  and Didier Blondel, and each of them singly, our true and lawful attorneys with full power to any of them, and to each of them singly, to sign for us and in our names in the capacities indicated below the Registration Statement on Form <FONT
  STYLE="white-space:nowrap">S-8</FONT> filed herewith and any and all amendments (including post-effective amendments) to said Registration Statement, and to file or cause to be filed the same, with all exhibits thereto and other documents in
  connection therewith, with the Securities and Exchange Commission, and generally to do all such things in our name and on our behalf in our capacities as members of the board of directors to enable Abivax SA to comply with the provisions of the
  Securities Act of 1933, as amended, and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming all that said attorneys, and each of them, or their substitute or substitutes, shall do or cause to be done by virtue
  hereof. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the
  following persons in the capacities and on the dates indicated. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
  <TR>
  
  <TD WIDTH="35%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="32%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="31%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Name</B></P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Title</B></P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Date</B></P></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Marc de Garidel</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Marc de Garidel</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Chief Executive Officer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(<I>Principal Executive Officer</I>)</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Didier Blondel</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Didier Blondel</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Chief&nbsp;Financial&nbsp;Officer&nbsp;and&nbsp;Board&nbsp;Secretary</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(<I>Principal Financial Officer and Principal</I><I></I><I>&nbsp;Accounting Officer</I>)</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Sylvie Gr&eacute;goire</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Sylvie Gr&eacute;goire</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Chair of the Board</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Corinna zur Bonsen-Thomas</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Corinna zur Bonsen-Thomas</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ June Lee</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">June Lee</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Kinam Hong</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Sofinnova&nbsp;Partners,&nbsp;represented&nbsp;by&nbsp;Kinam&nbsp;Hong</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Troy Ignelzi</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Troy Ignelzi</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Camilla Soenderby</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Camilla Soenderby</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">March&nbsp;24, 2025</TD></TR>
  </TABLE>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURE OF AUTHORIZED U.S. REPRESENTATIVE </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the Securities Act of 1933, as amended, the undersigned, the duly authorized representative in the United States of Abivax SA, has signed this
  registration statement on March&nbsp;24, 2025. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="100%"></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Marc de Garidel</P></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">Name: Marc de Garidel</TD></TR>
  </TABLE></DIV>
  </DIV></Center>
  
  </BODY></HTML>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "d845340ds8.htm", "description": "FORM S-8", "secsgml_size_bytes": 53321}]
metadata_filer: {"company-data": {"conformed-name": "Abivax S.A.", "cik": "0001956827", "assigned-sic": "2834", "organization-name": "03 Life Sciences", "ein": "000000000", "state-of-incorporation": "I0", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-286069", "film-number": "25765198"}, "business-address": {"street1": "7 BD HAUSSMANN", "city": "PARIS", "state": "I0", "zip": "75009", "phone": "01 53 83 09 63"}, "mail-address": {"street1": "7 BD HAUSSMANN", "city": "PARIS", "state": "I0", "zip": "75009"}}
text: FORM S-8
  As filed with the Securities and Exchange Commission on March 24, 2025
  Registration No.
  UNITED STATES
  SECURITIES
  AND EXCHANGE COMMISSION
  Washington, D.C. 20549
  FORM
  S-8
  REGISTRATION STATEMENT
  UNDER
  THE
  SECURITIES ACT OF 1933
  Abivax SA
  (Exact name
  of Registrant as specified in its charter)
  France
  Not Applicable
  (State or other jurisdiction of
  incorporation or organization)
  (I.R.S. Employer
  Identification Number)
  7-11
  boulevard Haussmann 75009 Paris, France
  (Address of Registrant's principal executive offices)
  Free share plan AGA
  2023-3
  Free share plan AGA
  2023-4
  Free share plan AGA
  2023-5
  Free share plan AGA
  2024-1
  Free share plan AGA
  2024-2
  Free share plan AGA
  2024-3
  Free share plan AGA
  2024-4
  Free share plan AGA
  2024-5
  Free share plan AGA
  2024-7
  Free share plan AGA
  2025-1
  Free share plan AGA
  2025-2
  Free share plan AGA
  2025-3
  Free share plan AGA
  2025-4
  Share warrants plan
  BSA-2018-1
  Share warrants plan
  BSA-2024-1
  Share warrants plan
  BSA-2025-1
  Share warrants plan
  BSA-2025-2
  (Full title of the plans)
  Marc de Garidel
  Chief
  Executive Officer
  7-11
  boulevard Haussmann
  75009 Paris, France
  Tel.
  No. +33 (0) 1 53 83 09 63
  (Name, address and telephone number of agent for service)
  Copies to:
  Divakar Gupta, Esq.
  Ryan Sansom, Esq.
  Minkyu Park, Esq.
  Cooley LLP
  55
  Hudson Yards
  New York, New York 10001
  Tel: +1 212
  479-6000
  Alain Decombe
  Vianney Toulouse
  Dechert (Paris) LLP
  22 rue Bayard
  75008 Paris
  France
  Tel: +33
  1 57 57 80 00
  Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a
  non-accelerated
  filer, a smaller reporting company or an emerging growth company. See definitions of "large accelerated filer," "accelerated filer," "small reporting company," and "emerging growth company" in Rule
  12b-2
  of the Exchange Act.
  Large accelerated filer
  ☐
  Accelerated filer
  ☒
  Non-accelerated filer
  ☐
  Smaller reporting company
  ☐
  Emerging growth company
  ☒
  If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☒
  PART I
  INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS
  The information required by Part I of Form
  S-8
  is omitted from this filing in accordance with Rule 428
  under the Securities Act of 1933, as amended (the "Securities Act") and the introductory note to Part I of Form
  S-8.
  The documents containing the information specified in Part I will be delivered to
  the participants in the plans covered by this Registration Statement as required by Rule 428(b)(1) under the Securities Act.
  PART II
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  Item 3. Incorporation of Documents by Reference.
  This Registration Statement on Form
  S-8
  hereby incorporates by reference the contents of the following
  reports of Abivax SA (the "Registrant" or "we") filed with, or furnished to, the Securities and Exchange Commission (the "Commission") pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange
  Act"):
  (a)
  The Registrant's Annual Report on
  Form
  20-F
  for the year ended December 31, 2024, as filed with the Commission on March 24, 2025 (Commission File
  No. 001-41842)
  (the "Form
  20-F");
  (b)
  The Registrant's Reports on Form
  6-K
  furnished to the Commission
  on
  January
  10, 2025
  (Commission File
  No. 001-41842);
  (c)
  The description of the Registrant's ordinary shares contained in
  Exhibit
   2.1
  to the Form
  20-F,
  including any amendment or report filed for the purpose of updating such description; and
  (d)
  All documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
  Exchange Act prior to the filing of a post-effective amendment indicating that all securities offered have been sold or that deregisters all securities then remaining unsold shall be deemed to be incorporated by reference in this Registration
  Statement and to be part hereof from the date of filing of such document incorporated by reference.
  Notwithstanding the
  foregoing, no document, report or exhibit (or portion of any of the foregoing) or any other information that we have "furnished" to the Commission pursuant to the Exchange Act shall be incorporated by reference into this prospectus unless
  such document, report or exhibit expressly provides to the contrary.
  Statements contained in the foregoing documents incorporated by
  reference shall be deemed to be modified or superseded hereby to the extent that statements contained in the Prospectus, or in any subsequently filed documents that are amendments hereto or that are incorporated herein by reference, shall modify or
  replace such statements.
  Item 4. Description of Securities.
  Not applicable.
  Item 5. Interests of
  Named Experts and Counsel.
  Not applicable.
  Item 6. Indemnification of Directors and Officers.
  Under French law, provisions of
  by-laws
  that limit the liability of directors are prohibited. However,
  French law allows
  société anonyme
  to contract for and maintain liability insurance against civil liabilities incurred by any of their directors and officers involved in a third-party action, provided that they acted in good
  faith and within their capacities as directors or officers of the company. Criminal liability cannot be indemnified under French law, whether directly by the company or through liability insurance. We maintain liability insurance for our directors
  and officers, including insurance against liability under the Securities Act.
  Certain of our
  non-employee
  directors may, through their relationships with their employers or partnerships, be insured and/or indemnified against certain liabilities in their capacity as members of our board of directors.
  Item 7. Exemption from Registration Claimed.
  Not applicable.
  Item 8. Exhibits.
  See the Exhibit Index, below.
  1
  Item 9. Undertakings.
  The undersigned Registrant hereby undertakes:
  (1)
  To file, during any period in which offers or sales are being made, a post-effective amendment to this
  Registration Statement:
  (i)
  To include any prospectus required by Section 10(a)(3) of the Securities Act;
  (ii)
  To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement
  (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this Registration Statement. Notwithstanding the foregoing, any increase or decrease in
  volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus
  filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in
  the effective Registration Statement; and
  (iii)
  To include any material information with respect to the plan of distribution not previously disclosed in the
  Registration Statement or any material change to such information in the Registration Statement;
  provided
  ,
  however
  , that
  paragraphs (i) and (ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Registrant pursuant to
  Section 13 or 15(d) of the Exchange Act that are incorporated by reference in the Registration Statement;
  (2)
  That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment
  shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof; and
  (3)
  To remove from registration by means of a post-effective amendment any of the securities being registered which
  remain unsold at the termination of the offering.
  The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's
  annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such
  securities at that time shall be deemed to be the initial
  bona fide
  offering thereof.
  Insofar as indemnification for liabilities
  arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such
  indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or
  paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the
  Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the
  Securities Act and will be governed by the final adjudication of such issue.
  2
  EXHIBIT INDEX
  Exhibit No.
  Description of Document
  4.1
  By-laws
  (statuts) of the Registrant (English translation) (incorporated by reference to
   Exhibit 1.1 to the Registrant's Annual Report on Form
  20-F
  (File
  No. 001-41842)
  filed with the Commission on March 24, 2025)
  4.2
  Form of Deposit Agreement (incorporated by reference to Exhibit (a) to the Registrant's Registration Statement on Form
  F-6
  (File
  No. 333-274845),
  filed with the Commission on October 3, 2023)
  4.3
  Form of American Depositary Receipt (included in Exhibit 4.2)
  4.4
  Summary of BSA
  2015-11,
  BSA
  2015-12,
  BSA
  2017-1,
  BSA
  2018-1,
  BSA
  2024-1,
  BSA
  2024-2,
  BSA-2025-1
  and
  BSA-2025-2
  Plans (incorporated by reference to Exhibit 4.16 to the Registrant's Annual Report on Form
  20-F
  (File
  No. 001-41842)
  filed with the Commission on March 24, 2025)
  4.5
  Summary of
  AGA-2023-1,
  AGA-2023-2,
  AGA-2023-3,
  AGA-2023-4,
  AGA-2023-5,
  AGA-2024-1,
  AGA-2024-2,
  AGA-2024-3,
  AGA-2024-4,
  AGA-2024-5,
  AGA-2024-6,
  AGA-2024-7,
  AGA-2025-1,
  AGA-2025-2,
  AGA
  2025-3
  and
  AGA-2025-4
  Free Share
  Plans (incorporated by reference to Exhibit 4.18 to the Registrant's Annual Report on Form
  20-F
  (File
  No. 001-41842)
  filed with the Commission on
  March 24, 2025)
  5.1*
  Opinion of Dechert (Paris) LLP
  23.1*
  Consent of PricewaterhouseCoopers Audit - Independent Registered Public Accounting Firm
  23.3*
  Consent of Dechert (Paris) LLP (included in Exhibit 5.1 above)
  24*
  Power of Attorney (included on the signature page)
  107*
  Filing fee table
  *
  Filed herewith.
  3
  SIGNATURES
  Pursuant to the requirements of the Securities Act, Abivax SA certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form
  S-8
  and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Paris, France on March 24, 2025.
  Abivax SA
  By:
  /s/ Marc de Garidel
  Name:
  Marc de Garidel
  Title:
  Chief Executive Officer
  POWER OF ATTORNEY AND SIGNATURES
  We, the undersigned directors, officers and/or authorized representative of Abivax SA, hereby severally constitute and appoint Marc de Garidel
  and Didier Blondel, and each of them singly, our true and lawful attorneys with full power to any of them, and to each of them singly, to sign for us and in our names in the capacities indicated below the Registration Statement on Form
  S-8
  filed herewith and any and all amendments (including post-effective amendments) to said Registration Statement, and to file or cause to be filed the same, with all exhibits thereto and other documents in
  connection therewith, with the Securities and Exchange Commission, and generally to do all such things in our name and on our behalf in our capacities as members of the board of directors to enable Abivax SA to comply with the provisions of the
  Securities Act of 1933, as amended, and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming all that said attorneys, and each of them, or their substitute or substitutes, shall do or cause to be done by virtue
  hereof.
  Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the
  following persons in the capacities and on the dates indicated.
  Name
  Title
  Date
  /s/ Marc de Garidel
  Marc de Garidel
  Chief Executive Officer
  (
  Principal Executive Officer
  )
  March 24, 2025
  /s/ Didier Blondel
  Didier Blondel
  Chief Financial Officer and Board Secretary
  (
  Principal Financial Officer and Principal
  Accounting Officer
  )
  March 24, 2025
  /s/ Sylvie Grégoire
  Sylvie Grégoire
  Chair of the Board
  March 24, 2025
  /s/ Corinna zur Bonsen-Thomas
  Corinna zur Bonsen-Thomas
  Director
  March 24, 2025
  /s/ June Lee
  June Lee
  Director
  March 24, 2025
  /s/ Kinam Hong
  Sofinnova Partners, represented by Kinam Hong
  Director
  March 24, 2025
  /s/ Troy Ignelzi
  Troy Ignelzi
  Director
  March 24, 2025
  /s/ Camilla Soenderby
  Camilla Soenderby
  Director
  March 24, 2025
  SIGNATURE OF AUTHORIZED U.S. REPRESENTATIVE
  Pursuant to the Securities Act of 1933, as amended, the undersigned, the duly authorized representative in the United States of Abivax SA, has signed this
  registration statement on March 24, 2025.
  /s/ Marc de Garidel
  Name: Marc de Garidel