X0202 SCHEDULE 13D/A 0001193125-20-204865 0001643828 XXXXXXXX LIVE 3 Common Stock, par value $0.001 per share 05/27/2026 false 0001810182 00166B105 ALX Oncology Holdings Inc.

323 ALLERTON AVENUE SOUTH SAN FRANCISCO CA 94080

Travis Boettner (617) 933-3770 c/o Lightstone Ventures 420 Boylston St. Suite 602 Boston MA 02116 0001643828 N LSV Associates, LLC b AF N DE 0.00 1549132.00 0.00 1549132.00 1549132.00 N 1.2 OO 0001572522 N Lightstone Ventures, L.P. b WC N DE 0.00 1363262.00 0.00 1363262.00 1363262.00 N 1.0 PN 0001572523 N Lightstone Ventures (A), L.P. b WC N DE 0.00 185870.00 0.00 185870.00 185870.00 N 0.1 PN 0001818388 N LSV Associates II, LLC b AF N DE 0.00 1393393.00 0.00 1393393.00 1393393.00 N 1.0 OO 0001699565 N Lightstone Ventures II, L.P. b WC PF N DE 0.00 1315255.00 0.00 1315255.00 1315255.00 N 1.0 PN 0001706610 N Lightstone Ventures II (A), L.P. b WC N DE 0.00 78138.00 0.00 78138.00 78138.00 N 0.1 PN 0001306506 N Michael A Carusi b AF N X1 0.00 2942525.00 0.00 2942525.00 2942525.00 N 2.2 IN 0001291804 N Jean George b AF N X1 0.00 2942525.00 0.00 2942525.00 2942525.00 N 2.2 IN 0001384286 N Henry A. Plain Jr b AF N X1 0.00 2942525.00 0.00 2942525.00 2942525.00 N 2.2 IN Common Stock, par value $0.001 per share ALX Oncology Holdings Inc. 323 ALLERTON AVENUE SOUTH SAN FRANCISCO CA 94080 This Amendment No. 3 (this "Amendment No. 3" or this "Schedule 13D/A") amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on July 31, 2020, and amended on December 20, 2023 and February 14, 2024 (as amended, the "Statement") by the Reporting Persons. This Amendment No. 3 is being filed to report the dilution of the Reporting Persons' beneficial ownership in the Issuer's common stock and not as a result of any acquisition or disposition of securities by the Reporting Persons. Unless otherwise defined herein, capitalized terms used in this Amendment No. 3 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged. Rows 11 and 13 of each Reporting Person's cover page to this Schedule 13D/A set forth the aggregate number of shares of common stock and percentages of the shares of common stock beneficially owned by such Reporting Person and are incorporated by reference. The percentage set forth in each row 13 is based upon 134,562,917 shares of common stock outstanding as of May 1, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2026. The Reporting Persons' beneficial ownership of the Issuer's securities includes (i) 1,363,262 shares held by LV LP; (ii) 185,870 shares held by LV(A) LP; (iii) 1,315,255 shares held by LV II LP; and (iv) 78,138 shares held by LV II(A) LP. LSV Associates serves as the general partner of each of LV LP and LV(A) LP. LSV Associates II serves as the general partner of each of LV II LP and LV II(A) LP. Messrs. Carusi and Plain, and Ms. George, the individual managing directors of each of LSV Associates and LSV Associates II, share voting and dispositive power with respect to the shares held of record by each of LV LP, LV(A) LP, LV II LP and LV II(A) LP, and may be deemed to own beneficially the shares held by each of LV LP, LV(A) LP, LV II LP and LV II(A) LP. Rows 7 through 10 of each Reporting Person's cover page to this Schedule 13D/A set forth the number of shares of common stock as to which such Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition and are incorporated by reference. No transactions with respect to the securities of the Issuer have been effected during the past sixty days by any Reporting Person. No other person is known to have the right to receive or the power to direct the receipt of dividends from, or any proceeds from the sale of, the securities beneficially owned by any of the Reporting Persons. The Reporting Persons ceased to be the beneficial owners of more than five percent of the Issuer's common stock on or about February 2, 2026 by virtue of dilution resulting from the Issuer's issuance of additional shares of common stock and not as a result of any transaction by the Reporting Persons. Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit A to the Reporting Persons' Schedule 13D/A filed with the SEC on February 14, 2024). LSV Associates, LLC /s/ Travis Boettner 05/27/2026 Lightstone Ventures, L.P. /s/ Travis Boettner 05/27/2026 Lightstone Ventures (A), L.P. /s/ Travis Boettner 05/27/2026 LSV Associates II, LLC /s/ Travis Boettner 05/27/2026 Lightstone Ventures II, L.P. /s/ Travis Boettner 05/27/2026 Lightstone Ventures II (A), L.P. /s/ Travis Boettner 05/27/2026 Michael A Carusi /s/ Travis Boettner 05/27/2026 Jean George /s/ Travis Boettner 05/27/2026 Henry A. Plain Jr /s/ Travis Boettner 05/27/2026