Sec Form 4 Filing - GILEAD SCIENCES, INC. @ Xilio Therapeutics, Inc. - 2025-06-05

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person GILEAD SCIENCES, INC. 2. Issuer Name and Ticker or Trading Symbol Xilio Therapeutics, Inc. [ XLO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 333 LAKESIDE DRIVE 3. Date of Earliest Transaction (MM/DD/YY) 06/05/2025 (Street) FOSTER CITY, CA94404 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Prefunded Warrants (right to buy) ( 1 ) $ 0.0001 06/05/2025 P 13,335,000 ( 2 ) ( 2 ) Common Stock 13,335,000 ( 1 ) 23,310,266 D Series A Warrants (right to buy) ( 1 ) $ 0.75 06/05/2025 P 13,335,000 ( 3 ) ( 3 ) Common Stock 13,335,000 ( 1 ) 13,335,000 D Series B Warrants (right to buy) ( 1 ) $ 0.75 06/05/2025 P 13,335,000 ( 4 ) ( 4 ) Common Stock 13,335,000 ( 1 ) 13,335,000 D Series C Warrants (right to buy) ( 1 ) $ 0.75 06/05/2025 P 13,335,000 ( 5 ) ( 5 ) Common Stock 13,335,000 ( 1 ) 13,335,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other GILEAD SCIENCES, INC. 333 LAKESIDE DRIVE FOSTER CITY, CA94404 X Signatures Gilead Sciences, Inc. By: /s/ Andrew D. Dickson 06/06/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each Prefunded Warrant was acquired together with an accompanying Series A Warrant, Series B Warrant and Series C Warrant at a combined offering price of $0.7499. A holder of any such warrant may not exercise such warrant if, after giving effect to such exercise, the holder and its affiliates would beneficially own, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, more than 19.99% of the outstanding shares of Common Stock of the Issuer (the "Common Stock"). ( 2 )The Prefunded Warrants are exercisable at any time on or after the date of issuance and have no expiration date. ( 3 )The Series A Warrants will be exercisable at any time on or after the earlier of (i) December 1, 2025 and (ii) the trading day immediately following a period of five consecutive trading days on which the closing price of the Common Stock is a minimum of $1.50 per share and will expire on the earlier of (A) June 5, 2030 and (B) immediately upon exercise of the reporting person's Prefunded Warrants issued on June 5, 2025 if such exercise is prior to December 1, 2025, but with respect to only that number of Series A Warrants that is equal to the number of Prefunded Warrants that are exercised. ( 4 )The Series B Warrants are exercisable at any time on or after November 1, 2025 and expire on December 2, 2025, provided that if the closing price of the Common Stock is below the exercise price on such date, the exercise price will reset to the closing price on December 1, 2025 and the expiration time will be extended to December 31, 2025. ( 5 )The Series C Warrants are exercisable at any time on or after June 1, 2026 and expire on the earlier of (i) December 2, 2026 and (ii) the expiration time of the Series B Warrants held by the reporting person to the extent that the corresponding Series B Warrants expire without being exercised, but with respect to only that number of Series C Warrants that is equal to the number of Series B Warrants that expire without being exercised. In addition, if the closing price of the Common Stock is below the exercise price on December 2, 2026, the exercise price will reset to the closing price on December 1, 2026 and the expiration time will be extended to December 31, 2026.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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