Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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

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1. Name and Address of Reporting Person * Koppel Adam 2. Issuer Name and Ticker or Trading Symbol Kailera Therapeutics, Inc. [KLRA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC 200 CLARENDON STREET 3. Date of Earliest Transaction (Month/Day/Year) 04/16/2026 (Street) BOSTON, MA 02116 4. If Amendment, Date Original Filed (Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 Common Stock 04/20/2026 C 16,875,000 A (1) 16,875,000 I See footnotes(4)(5) Common Stock 04/20/2026 C 4,145,768 A (2) 21,020,768 I See footnotes(4)(5) Common Stock 04/20/2026 P 1,562,500 A $16 22,583,268 I See footnotes(4)(5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Series A-1 Preferred Stock

(1)

04/20/2026

C

16,875,000

(1)

(1)

Common Stock

16,875,000

$ 0

0

I

See footnotes(4)(5)

Series B Preferred Stock

(2)

04/20/2026

C

4,145,768

(2)

(2)

Common Stock

4,145,768

$ 0

0

I

See footnotes(4)(5)

Stock Option (right to buy)

$16

04/16/2026

A

38,300

(3)

04/16/2036

Common Stock

38,300

$ 0

38,300

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Koppel Adam C/O BAIN CAPITAL LIFE SCIENCES INVESTORS LLC 200 CLARENDON STREET BOSTON, MA 02116	X	X

Signatures

/s/ Adam Koppel		04/20/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each share of the Issuer's Series A-1 Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date.
(2)	Each share of the Issuer's Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date.
(3)	The options vest and become exercisable as to 100% of the underlying shares on April 16, 2027, subject to Dr. Koppel's continued service through each such vesting date.
(4)	Represents securities held directly by BCLS Fund IV Investments, LP ("BCLS Fund IV Investments").
(5)	Dr. Koppel is a Partner of Bain Capital Life Sciences Investors, LLC ("BCLSI"). BCLSI is the ultimate general partner of BCLS Fund IV Investments. As a result, Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund IV Investments. Dr. Koppel disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.

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