Sec Form 4 Filing - AKKARAJU SRINIVAS @ Kalaris Therapeutics, Inc. - 2026-05-20

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 AKKARAJU SRINIVAS 2. Issuer Name and Ticker or Trading Symbol Kalaris Therapeutics, Inc. [ KLRS] 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 SAMSARA BIOCAPITAL, LLC, 628 MIDDLEFIELD ROAD 3. Date of Earliest Transaction (MM/DD/YY) 05/20/2026 (Street) PALO ALTO, CA94301 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 Common Stock 05/20/2026 P( 1 ) 244,300 A $ 4.83 2,224,147 I By Samsara Opportunity Fund, L.P. ( 2 ) Common Stock 05/20/2026 J( 3 ) 66,906 D $ 0 10,657,028 ( 4 ) I By Samsara BioCapital, L.P. ( 5 ) Common Stock 05/20/2026 J( 6 ) 14,937 A $ 0 14,937 I By Samsara BioCapital GP, LLC ( 7 ) Common Stock 05/20/2026 J( 6 ) 4,471 A $ 0 19,408 I By Samsara BioCapital Partners, L.P. ( 8 )

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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other AKKARAJU SRINIVAS C/O SAMSARA BIOCAPITAL, LLC 628 MIDDLEFIELD ROAD PALO ALTO, CA94301 X X Samsara BioCapital, L.P. C/O SAMSARA BIOCAPITAL, LLC 628 MIDDLEFIELD ROAD PALO ALTO, CA94301 X Samsara BioCapital GP, LLC C/O SAMSARA BIOCAPITAL, LLC 628 MIDDLEFIELD ROAD PALO ALTO, CA94301 X Samsara Opportunity Fund, L.P. C/O SAMSARA BIOCAPITAL, LLC 628 MIDDLEFIELD ROAD PALO ALTO, CA94301 X Samsara Opportunity Fund GP, LLC C/O SAMSARA BIOCAPITAL, LLC 628 MIDDLEFIELD ROAD PALO ALTO, CA94301 X Signatures /s/ Srinivas Akkaraju 05/22/2026 Signature of Reporting Person Date Samsara BioCapital, L.P., By: Samsara BioCapital GP, LLC, its General Partner, By /s/ Srinivas Akkaraju, Managing Member 05/22/2026 Signature of Reporting Person Date Samsara BioCapital GP, LLC, By /s/ Srinivas Akkaraju, Managing Member 05/22/2026 Signature of Reporting Person Date Samsara Opportunity Fund, L.P., By Samsara Opportunity Fund GP, LLC, its General Partner, By /s/ Srinivas Akkaraju, Managing Member 05/22/2026 Signature of Reporting Person Date Samsara Opportunity Fund GP, LLC, By /s/ Srinivas Akkaraju, Managing Member 05/22/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents the purchase of shares from Samsara BioCapital, L.P. ("Samsara LP") in a privately negotiated transaction. ( 2 )Securities are directly held by Samsara Opportunity Fund, L.P. ("Samsara Opportunity Fund"). Samsara Opportunity Fund GP, LLC ("Samsara Opportunity GP") is the general partner of Samsara Opportunity Fund and may be deemed to beneficially own the securities held by Samsara Opportunity Fund. Dr. Srinivas Akkaraju, MD, Ph.D. has voting and investment power over the securities held by Samsara Opportunity Fund and, accordingly, may be deemed to beneficially own the securities held by Samsara Opportunity Fund. Each of the Reporting Persons disclaims beneficial ownership in these securities except to the extent of its or his pecuniary interest therein. ( 3 )Represents a pro rata, in-kind distribution, without additional consideration, and not a purchase or sale of securities, by Samsara LP in respect of redeemed interests in Samsara LP. Of the shares distributed by Samsara LP, (i) 47,498 were distributed to redeeming limited partners, (ii) 14,937 shares were distributed to Samsara BioCapital GP, LLC ("Samsara LLC"), the general partner of Samsara LP, in respect of redeemed interests of non-managing members of Samsara LLC that were retained by Samsara LLC, and (iii) 4,471 shares were distributed to Samsara BioCapital Partners, L.P. ("Samsara BioCapital Partners"), in respect of the redeemed interest of a limited partner of Samsara LP that has been acquired by Samsara BioCapital Partners. ( 4 )The shares held by Samsara LP reflects the disposition of 244,300 shares, to Samsara Opportunity Fund as described in footnote (1), in which each of Samsara LLC and Dr. Akkaraju had no pecuniary interest. ( 5 )Securities are held by Samsara LP. Samsara LLC is the general partner of Samsara LP and may be deemed to beneficially own the shares held by Samsara LP. Dr. Akkaraju has voting and investment power over the shares held by Samsara LP and, accordingly, may be deemed to beneficially own the shares held by Samsara LP. Each of the Reporting Persons disclaims beneficial ownership in these shares except to the extent of its or his respective pecuniary interest therein. ( 6 )Represents receipt of shares in the distribution in kind described in footnote (3). ( 7 )Securities are held by Samsara LLC. Dr. Akkaraju has voting and investment power over the shares held by Samsara LLC and, accordingly, may be deemed to beneficially own the shares held by Samsara LLC. Each of the Reporting Persons disclaims beneficial ownership in these shares except to the extent of its or his respective pecuniary interest therein. ( 8 )Securities are held by Samsara BioCapital Partners. Dr. Akkaraju has voting and investment power over the shares held by Samsara BioCapital Partners and, accordingly, may be deemed to beneficially own the shares held by Samsara BioCapital Partners. Each of the Reporting Persons disclaims beneficial ownership in these shares except to the extent of its or his respective pecuniary interest therein.

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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