Sec Form 3 Filing - Nussbaum Ran @ LB PHARMACEUTICALS INC - 2025-09-10

FORM 3 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 Nussbaum Ran 2. Issuer Name and Ticker or Trading Symbol LB PHARMACEUTICALS INC [ LBRX] 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 LB PHARMACEUTICALS INC, ONE PENNSYLVANIA PLAZA, SUITE 1025 3. Date of Earliest Transaction (MM/DD/YY) 09/10/2025 (Street) NEW YORK, NY10119 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 Series C Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 411,681 I See footnote ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Nussbaum Ran C/O LB PHARMACEUTICALS INC ONE PENNSYLVANIA PLAZA, SUITE 1025 NEW YORK, NY10119 X X Signatures /s/ Marc Panoff, Attorney-in-Fact 09/10/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of Series C Preferred Stock is convertible at anytime at the option of the holder, without payment of additional consideration, into Common Stock and has no expiration date. Immediately prior to the closing of the Issuer's initial public offering, the Series C Preferred Stock will convert automatically at a conversion ratio that is dependent upon the initial price per share to the public in the Issuer's initial public offering. ( 2 )Consists of (i) 261,938 shares of common stock issuable upon conversion of shares of our redeemable convertible preferred stock held by Pontifax (Israel) VI Limited Partnership, or Pontifax Israel, and (ii) 149,743 shares of common stock issuable upon conversion of shares of our redeemable convertible preferred stock held by Pontifax (Cayman) VI Limited Partnership, or Pontifax Cayman. Pontifax Israel and Pontifax Cayman are collectively referred to as the Pontifax Entities. Pontifax VI G.P. L.P., or Pontifax VI G.P., is the general partner of each of the Pontifax Entities and Pontifax Management IV G.P. (2015) Ltd., or Pontifax Management, is the general partner of Pontifax VI G.P. Messrs. Tomer Kariv and Ran Nussbaum, are the Managing Partners of Pontifax Management and, as a result, may be deemed to share voting and investment power with respect to the shares held by each of the Pontifax Entities.

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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