X0609 4 2026-10-16 0 0001501697 X4 Pharmaceuticals, Inc XFOR 0001339498 Craig Adam R false C/O X4 PHARMACEUTICALS INC. 61 NORTH BEACON STREET, 4TH FLOOR BOSTON MA 02134 1 1 0 0 Executive Chairman 0 Common Stock 2026-10-16 4 P 0 4600 2.5834 A 333251 D Of the shares of common stock reported, 193,254 shares represent restricted stock units. The Reporting Person has agreed to disgorge to the Issuer all profits deemed to be realized from this transaction pursuant to Section 16(b) of the Securities Exchange Act of 1934, as amended. /s/ David Kirske, Attorney-In-Fact 2026-10-19