<html><head>
<!-- Document created using Wdesk -->
<!-- Copyright 2025 Workiva -->
<title>Document</title></head><body><div id="i641c0883f870473f91babce901e94b73_1"></div><div style="min-height:36pt;width:100%"><div><font><br></font></div></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">As filed with the Securities and Exchange Commission on January 16, 2025</font></div><div style="text-align:right"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Registration No.</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:12pt;font-weight:700;line-height:120%">&#160;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">333-</font></div><div style="margin-bottom:6pt"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:97.756%"><tr><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.260%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.260%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.260%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.260%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.619%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.260%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.629%"></td><td style="width:0.1%"></td></tr><tr style="height:5pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="9" style="border-bottom:1.5pt double #000000;padding:0 1pt"></td><td colspan="9" style="border-bottom:1.5pt double #000000;padding:0 1pt"></td><td colspan="9" style="border-bottom:1.5pt double #000000;padding:0 1pt"></td><td colspan="9" style="border-bottom:1.5pt double #000000;padding:0 1pt"></td><td colspan="9" style="border-bottom:1.5pt double #000000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:18pt;font-weight:700;line-height:120%">UNITED STATES</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:18pt;font-weight:700;line-height:120%">SECURITIES AND EXCHANGE COMMISSION</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:14pt;font-weight:700;line-height:120%">Washington, D.C. 20549</font></div><div><font><br></font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:18pt;font-weight:700;line-height:120%">FORM S-8</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:18pt;font-weight:700;line-height:120%">REGISTRATION STATEMENT</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">UNDER</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">THE SECURITIES ACT OF 1933</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">____________________________________________</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:18pt;font-weight:700;line-height:120%">X4 Pharmaceuticals, Inc.</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">(Exact name of registrant as specified in its charter)</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">___________________________________________</font></div><div style="margin-bottom:6pt"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:97.916%"><tr><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:35.233%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:36.379%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:20.176%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.622%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Delaware</font></td><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">27-3181608</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(State or other jurisdiction of<br>incorporation or organization)</font></td><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(I.R.S. Employer<br>Identification No.)</font></td></tr><tr style="height:3pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="18" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">61 North Beacon Street, 4th Floor</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Boston, Massachusetts</font></div></td><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">02134</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(Address of Principal Executive Offices)</font></td><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(Zip Code)</font></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">X4 Pharmaceuticals, Inc. Amended and Restated 2017 Equity Incentive Plan</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:120%">(Full title of the plan)</font></div><div style="text-align:center"><font><br></font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Paula Ragan, Ph.D.</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">President and Chief Executive Officer</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">X4 Pharmaceuticals, Inc.</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">61 North Beacon Street, 4th Floor</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Boston, Massachusetts 02134</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">(857) 529-8300</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(Name, address and telephone number, including area code, of agent for service)</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">_________________________________</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Copy to&#58;</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Gabriela Morales-Rivera</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">William D. Collins</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Goodwin Procter LLP</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">100 Northern Avenue</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Boston, MA 02210</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">(617) 570-1000</font></div><div style="text-align:center"><font><br></font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">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 the definitions of &#8220;large accelerated filer,&#8221; &#8220;accelerated filer,&#8221; &#8220;smaller reporting company&#8221; and &#8220;emerging growth company&#8221; in Rule 12b-2 of the Exchange&#160;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Act.</font></div><div style="margin-bottom:6pt"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:97.916%"><tr><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:23.449%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:15.593%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:41.616%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.618%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:8.392%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.624%"></td><td style="width:0.1%"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Large accelerated filer</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">&#9744;</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Accelerated filer</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">&#9744;</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Non-accelerated filer</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">&#9746;</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Smaller reporting company</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">&#9746;</font></td></tr><tr><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:0 1pt"></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Emerging growth company</font></td><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">&#9744;</font></td></tr></table></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">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. </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">&#9744;</font></div><div><font><br></font></div><div><font><br></font></div><div style="height:45pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div><hr style="page-break-after:always"><div style="min-height:36pt;width:100%"><div><font><br></font></div></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div id="i641c0883f870473f91babce901e94b73_4"></div><div style="text-align:center"><font><br></font></div><div style="text-align:center"><font><br></font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">INCORPORATION OF DOCUMENTS BY REFERENCE</font></div><div><font><br></font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">This Registration Statement on Form S-8 is being filed for the purpose of increasing the number of securities of the same class as other securities for which a Registration Statement on Form S-8 of the Registrant relating to the same employee benefit plans is effective. Accordingly, pursuant to General Instruction E to Form S-8, this Registration Statement incorporates by reference the contents of  (i) the Registration Statement on Form S-8 (File No. 333-221622) filed with the Securities and Exchange Commission (&#8220;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">SEC</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">&#8221;) on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312517345721/d493744ds8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">November 16, 2017</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the Registrant&#8217;s Amended and Restated 2017 Equity Incentive Plan (the &#8220;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">2017 Plan</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">&#8221;) and certain other employee benefit plans of the Registrant&#59;  (ii) the Registration Statement on Form S-8 (File No. 333-223539) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312518076441/d535539ds8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">March 9, 2018</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan&#59;  (iii) the Registration Statement on Form S-8 (File No. 333-230181) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312519070143/d715399ds8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">March  11, 2019</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59; (iv) the Registration Statement on Form S-8 (File No. 333-237164) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312520072921/d884915ds8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">March 13, 2020</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59;  (v) the Registration Statement on Form S-8 (File No 333-239082) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828020009216/xfor-2020062020xsx8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">June 10, 2020</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan&#59; (vi) the Registration Statement on Form S-8 (File No 333-254618) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828021005363/a032021s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">March 23, 2021</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59;  (vii) the Registration Statement on Form S-8 (File No 333-263430) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828022005734/a032022s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">March 10, 2022</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59;  (viii) the Registration Statement on Form S-8 (File No 333-269335) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828023001353/a032023s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">January 20, 2023</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59; (xi) the Registration Statement on Form S-8 (File No 333-273960) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828023029155/forms-3shelfaugust2023.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">August 1</a><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828023029155/forms-3shelfaugust2023.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">4</a><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828023029155/forms-3shelfaugust2023.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">, 2023</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan and certain other employee benefit plans of the Registrant&#59; and (xii) the Registration Statement on Form S-8 (File No 333-276691) filed with the SEC on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828024002243/a012024s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">January 2</a><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828024002243/a012024s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">5</a><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828024002243/a012024s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">, 202</a><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828024002243/a012024s-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">4</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> relating to the 2017 Plan&#59; in each case except for Item 8, Exhibits, with respect to which the Exhibit Index below is incorporated herein by reference. </font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div><font><br></font></div><div style="text-align:center"><font><br></font></div><div style="text-align:center"><font><br></font></div><div style="height:45pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div><div id="i641c0883f870473f91babce901e94b73_7"></div><hr style="page-break-after:always"><div style="min-height:72pt;width:100%"><div><font><br></font></div></div><div style="-sec-extract:summary;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">PART II</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Item 8. Exhibits</font></div><div><font><br></font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">The exhibits to this Registration Statement are listed in the Exhibit Index attached hereto and incorporated by reference herein. </font></div><div><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:99.679%"><tr><td style="width:0.1%"></td><td style="width:2.372%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.372%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:3.240%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:18.514%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:18.514%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:8.707%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.211%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:4.205%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.282%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:1.086%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:3.240%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:3.080%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.282%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.603%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:5.973%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.453%"></td><td style="width:0.1%"></td></tr><tr><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Exhibit Number</font></td><td colspan="6" style="border-bottom:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Exhibit Description</font></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Filed Herewith</font></td><td colspan="21" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Incorporated Reference herein from Form or Schedule</font></td><td colspan="12" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Filing Date</font></td><td colspan="15" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">SEC File&#47;Reg. Number</font></td></tr><tr><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">4.1</font></td><td colspan="6" style="border-top:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828022024161/x4-ex31to8xkxcharteramen.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Restated Certificate of Incorporation, as amended, as of September 1, 2022</a></font></div></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"></td><td colspan="21" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">8-K<br>(Exhibit 3.1)</font></td><td colspan="12" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">9&#47;1&#47;2022</font></td><td colspan="15" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">4.2</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312517348213/d495338dex32.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Amended and Restated By-laws of the Registrant</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">8-K<br>(Exhibit 3.2)</font></td><td colspan="12" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">11&#47;20&#47;2017</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">4.3</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312519073465/d702482dex41.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Common Stock Certificate</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">8-K<br>(Exhibit 4.1)</font></td><td colspan="12" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">03&#47;13&#47;2019</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">5.1</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="xforex51jan162025.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Opinion of Goodwin Procter LLP with respect to the legality of the securities being registered.</a></font></div></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">X</font></td><td colspan="21" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="15" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">23.1</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="ex_231xpwcconsentjan162025.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm to X4 Pharmaceuticals, Inc.</a></font></div></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">X</font></td><td colspan="21" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="15" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">23.2</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="xforex51jan162025.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Consent of Goodwin Procter LLP (included in Exhibit 5.1)</a></font></div></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">X</font></td><td colspan="21" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="15" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">24.1</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="#i641c0883f870473f91babce901e94b73_10" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Power of Attorney to file future amendments (set forth on the signature page of this Registration Statement)</a></font></div></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">X</font></td><td colspan="21" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="15" style="padding:0 1pt"></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.1</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828020009216/xfor_06102020xamendedandre.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">X4 Pharmaceuticals Inc. Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">S-8 </font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(Exhibit 99.1)</font></div></td><td colspan="12" style="background-color:#ffffff;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">6&#47;10&#47;2020</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">333-239082</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.2</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312517315505/d427310dex108.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Incentive Stock Option Agreement under the Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">S-1<br>(Exhibit 10.8)</font></td><td colspan="12" style="background-color:#ffffff;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">10&#47;20&#47;2017</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.3</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312517315505/d427310dex109.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Nonstatutory Stock Option Agreement under the Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">S-1<br>(Exhibit 10.9)</font></td><td colspan="12" style="background-color:#ffffff;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">10&#47;20&#47;2017</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.4</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312518334447/d663229dex106.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Restricted Stock Agreement under the Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">8-K<br>(Exhibit 10.6)</font></td><td colspan="12" style="background-color:#ffffff;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">11&#47;27&#47;2018</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.5</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000119312519176532/d765457dex105.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Restricted Stock Unit Agreement under the Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">8-K<br>(Exhibit 10.5)</font></td><td colspan="12" style="background-color:#ffffff;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">06&#47;19&#47;2019</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">001-38295</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">99.6</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1501697/000162828020009216/x4-2017planxformofperforma.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%;text-decoration:underline">Form of Performance-Based Restricted Stock Unit Agreement under the Amended and Restated 2017 Equity Incentive Plan</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="21" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">S-8 </font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(Exhibit 99.6)</font></div></td><td colspan="12" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">6&#47;10&#47;2020</font></td><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">333-239082</font></td></tr><tr><td colspan="9" style="padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">107</font></td><td colspan="6" style="padding:2px 1pt;text-align:left;vertical-align:top"><div><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="ex107calculationoffilingfe.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%;text-decoration:underline">Filing Fee Table</a></font></div></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">X</font></td><td colspan="21" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="15" style="padding:0 1pt"></td></tr></table></div><div style="height:72pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div><div id="i641c0883f870473f91babce901e94b73_10"></div><hr style="page-break-after:always"><div style="min-height:58.5pt;width:100%"><div><font><br></font></div></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">SIGNATURES</font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Pursuant to the requirements of the Securities Act of 1933, the Registrant 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 the City of Boston, Commonwealth of Massachusetts, on January 16, 2025.</font></div><div style="text-indent:288pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">X4 PHARMACEUTICALS, INC.</font></div><div style="text-indent:288pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">By&#58;&#160;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">&#47;s&#47; Paula Ragan, Ph.D.</font></div><div style="text-indent:306pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Paula Ragan, Ph.D.</font></div><div style="text-indent:306pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">President and Chief Executive Officer</font></div><div style="text-indent:306pt"><font><br></font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">SIGNATURES AND POWER OF ATTORNEY</font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We, the undersigned officers and directors of X4 Pharmaceuticals, Inc., hereby severally constitute and appoint Paula Ragan, Ph.D.&#160;and Adam S. Mostafa, and each of them singly (with full power to each of them to act alone), our true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution in each of them for him or her and in his or her name, place and stead, and in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8 of X4 Pharmaceuticals, Inc., and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as full to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.</font></div><div><font><br></font></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.</font></div><div><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:98.076%"><tr><td style="width:0.1%"></td><td style="width:0.453%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:11.971%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:17.690%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:1.760%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:15.730%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:10.174%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:15.730%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:1.597%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:7.560%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:3.965%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:3.970%"></td><td style="width:0.1%"></td></tr><tr><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Signature</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Title</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Date</font></td></tr><tr style="height:3pt"><td colspan="9" style="border-top:1pt solid #000000;padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:15pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Paula Ragan</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">President, Chief Executive Officer and Director</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">(principal executive officer)</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:15pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Paula Ragan, Ph.D.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:15pt"><td colspan="9" style="border-bottom:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Adam S. Mostafa</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Chief Financial Officer and Treasurer</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">(principal financial officer and principal accounting officer)</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:20pt"><td colspan="9" style="border-top:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Adam S. Mostafa</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:15pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Michael S. Wyzga</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Chairman of the Board of Directors, Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Michael S. Wyzga</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:15pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; William E. Aliski</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">William E. Aliski</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Gary J. Bridger</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Gary J. Bridger, Ph.D.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Francoise De Craecker</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Francoise De Craecker</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Alison F. Lawton</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Alison F. Lawton</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="9" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td><td colspan="12" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; David McGirr</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">David McGirr, M.B.A.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="33" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Murray W. Stewart, M.D.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:12pt"><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Murray W. Stewart, M.D.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:5pt"><td colspan="33" style="padding:0 1pt"></td></tr><tr style="height:14pt"><td colspan="9" style="border-bottom:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Robert K. Woods</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="9" rowspan="2" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">January 16, 2025</font></td></tr><tr style="height:17pt"><td colspan="9" style="border-top:1pt solid #000;padding:2px 1pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Robert K. Woods</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr></table></div><div style="height:72pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div></body></html>
[{"type": "S-8", "sequence": "1", "filename": "a012025s-8.htm", "description": "S-8", "secsgml_size_bytes": 72685}]
{"company-data": {"conformed-name": "X4 Pharmaceuticals, Inc", "cik": "0001501697", "assigned-sic": "2836", "organization-name": "03 Life Sciences", "irs-number": "273181608", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-284320", "film-number": "25536167"}, "business-address": {"street1": "61 NORTH BEACON STREET", "street2": "4TH FLOOR", "city": "BOSTON", "state": "MA", "zip": "02134", "phone": "857-529-8300"}, "mail-address": {"street1": "61 NORTH BEACON STREET", "street2": "4TH FLOOR", "city": "BOSTON", "state": "MA", "zip": "02134"}, "former-company": {"former-conformed-name": "Arsanis, Inc.", "date-changed": "20100920"}}
Document
As filed with the Securities and Exchange Commission on January 16, 2025
Registration No.
333-
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM S-8
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933
____________________________________________
X4 Pharmaceuticals, Inc.
(Exact name of registrant as specified in its charter)
___________________________________________
Delaware
27-3181608
(State or other jurisdiction of
incorporation or organization)
(I.R.S. Employer
Identification No.)
61 North Beacon Street, 4th Floor
Boston, Massachusetts
02134
(Address of Principal Executive Offices)
(Zip Code)
X4 Pharmaceuticals, Inc. Amended and Restated 2017 Equity Incentive Plan
(Full title of the plan)
Paula Ragan, Ph.D.
President and Chief Executive Officer
X4 Pharmaceuticals, Inc.
61 North Beacon Street, 4th Floor
Boston, Massachusetts 02134
(857) 529-8300
(Name, address and telephone number, including area code, of agent for service)
_________________________________
Copy to:
Gabriela Morales-Rivera
William D. Collins
Goodwin Procter LLP
100 Northern Avenue
Boston, MA 02210
(617) 570-1000
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 the definitions of "large accelerated filer," "accelerated filer," "smaller 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.
☐
INCORPORATION OF DOCUMENTS BY REFERENCE
This Registration Statement on Form S-8 is being filed for the purpose of increasing the number of securities of the same class as other securities for which a Registration Statement on Form S-8 of the Registrant relating to the same employee benefit plans is effective. Accordingly, pursuant to General Instruction E to Form S-8, this Registration Statement incorporates by reference the contents of  (i) the Registration Statement on Form S-8 (File No. 333-221622) filed with the Securities and Exchange Commission ("
SEC
") on
November 16, 2017
relating to the Registrant's Amended and Restated 2017 Equity Incentive Plan (the "
2017 Plan
") and certain other employee benefit plans of the Registrant;  (ii) the Registration Statement on Form S-8 (File No. 333-223539) filed with the SEC on
March 9, 2018
relating to the 2017 Plan;  (iii) the Registration Statement on Form S-8 (File No. 333-230181) filed with the SEC on
March  11, 2019
relating to the 2017 Plan and certain other employee benefit plans of the Registrant; (iv) the Registration Statement on Form S-8 (File No. 333-237164) filed with the SEC on
March 13, 2020
relating to the 2017 Plan and certain other employee benefit plans of the Registrant;  (v) the Registration Statement on Form S-8 (File No 333-239082) filed with the SEC on
June 10, 2020
relating to the 2017 Plan; (vi) the Registration Statement on Form S-8 (File No 333-254618) filed with the SEC on
March 23, 2021
relating to the 2017 Plan and certain other employee benefit plans of the Registrant;  (vii) the Registration Statement on Form S-8 (File No 333-263430) filed with the SEC on
March 10, 2022
relating to the 2017 Plan and certain other employee benefit plans of the Registrant;  (viii) the Registration Statement on Form S-8 (File No 333-269335) filed with the SEC on
January 20, 2023
relating to the 2017 Plan and certain other employee benefit plans of the Registrant; (xi) the Registration Statement on Form S-8 (File No 333-273960) filed with the SEC on
August 1
4
, 2023
relating to the 2017 Plan and certain other employee benefit plans of the Registrant; and (xii) the Registration Statement on Form S-8 (File No 333-276691) filed with the SEC on
January 2
5
, 202
4
relating to the 2017 Plan; in each case except for Item 8, Exhibits, with respect to which the Exhibit Index below is incorporated herein by reference.
PART II
INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
Item 8. Exhibits
The exhibits to this Registration Statement are listed in the Exhibit Index attached hereto and incorporated by reference herein.
Exhibit Number
Exhibit Description
Filed Herewith
Incorporated Reference herein from Form or Schedule
Filing Date
SEC File/Reg. Number
4.1
Restated Certificate of Incorporation, as amended, as of September 1, 2022
8-K
(Exhibit 3.1)
9/1/2022
001-38295
4.2
Amended and Restated By-laws of the Registrant
8-K
(Exhibit 3.2)
11/20/2017
001-38295
4.3
Form of Common Stock Certificate
8-K
(Exhibit 4.1)
03/13/2019
001-38295
5.1
Opinion of Goodwin Procter LLP with respect to the legality of the securities being registered.
X
23.1
Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm to X4 Pharmaceuticals, Inc.
X
23.2
Consent of Goodwin Procter LLP (included in Exhibit 5.1)
X
24.1
Power of Attorney to file future amendments (set forth on the signature page of this Registration Statement)
X
99.1
X4 Pharmaceuticals Inc. Amended and Restated 2017 Equity Incentive Plan
S-8
(Exhibit 99.1)
6/10/2020
333-239082
99.2
Form of Incentive Stock Option Agreement under the Amended and Restated 2017 Equity Incentive Plan
S-1
(Exhibit 10.8)
10/20/2017
001-38295
99.3
Form of Nonstatutory Stock Option Agreement under the Amended and Restated 2017 Equity Incentive Plan
S-1
(Exhibit 10.9)
10/20/2017
001-38295
99.4
Form of Restricted Stock Agreement under the Amended and Restated 2017 Equity Incentive Plan
8-K
(Exhibit 10.6)
11/27/2018
001-38295
99.5
Form of Restricted Stock Unit Agreement under the Amended and Restated 2017 Equity Incentive Plan
8-K
(Exhibit 10.5)
06/19/2019
001-38295
99.6
Form of Performance-Based Restricted Stock Unit Agreement under the Amended and Restated 2017 Equity Incentive Plan
S-8
(Exhibit 99.6)
6/10/2020
333-239082
107
Filing Fee Table
X
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, the Registrant 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 the City of Boston, Commonwealth of Massachusetts, on January 16, 2025.
X4 PHARMACEUTICALS, INC.
By:
/s/ Paula Ragan, Ph.D.
Paula Ragan, Ph.D.
President and Chief Executive Officer
SIGNATURES AND POWER OF ATTORNEY
We, the undersigned officers and directors of X4 Pharmaceuticals, Inc., hereby severally constitute and appoint Paula Ragan, Ph.D. and Adam S. Mostafa, and each of them singly (with full power to each of them to act alone), our true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution in each of them for him or her and in his or her name, place and stead, and in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8 of X4 Pharmaceuticals, Inc., and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as full to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.
Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.
Signature
Title
Date
/s/ Paula Ragan
President, Chief Executive Officer and Director
(principal executive officer)
January 16, 2025
Paula Ragan, Ph.D.
/s/ Adam S. Mostafa
Chief Financial Officer and Treasurer
(principal financial officer and principal accounting officer)
January 16, 2025
Adam S. Mostafa
/s/ Michael S. Wyzga
Chairman of the Board of Directors, Director
January 16, 2025
Michael S. Wyzga
/s/ William E. Aliski
Director
January 16, 2025
William E. Aliski
/s/ Gary J. Bridger
Director
January 16, 2025
Gary J. Bridger, Ph.D.
/s/ Francoise De Craecker
Director
January 16, 2025
Francoise De Craecker
/s/ Alison F. Lawton
Director
January 16, 2025
Alison F. Lawton
/s/ David McGirr
Director
January 16, 2025
David McGirr, M.B.A.
/s/ Murray W. Stewart, M.D.
Director
January 16, 2025
Murray W. Stewart, M.D.
/s/ Robert K. Woods
Director
January 16, 2025
Robert K. Woods