Sec Form 3 Filing - Deep Track Biotechnology Master Fund, Ltd. @ 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 Deep Track Biotechnology Master Fund, Ltd. 2. Issuer Name and Ticker or Trading Symbol LB PHARMACEUTICALS INC [ LBRX] 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) C/O WALKERS CORPORATE LIMITED, 190 ELGIN AVE 3. Date of Earliest Transaction (MM/DD/YY) 09/10/2025 (Street) GEORGE TOWN, E9KY1-9001 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

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 686,138 D ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Deep Track Biotechnology Master Fund, Ltd. C/O WALKERS CORPORATE LIMITED 190 ELGIN AVE GEORGE TOWN, E9KY1-9001 X Deep Track Capital, LP 200 GREENWICH AVE, 3RD FLOOR GREENWICH, CT06830 X KROIN DAVID C/O DEEP TRACK CAPITAL, LP 200 GREENWICH AVE, 3RD FLOOR GREENWICH, CT06830 X Signatures Deep Track Biotechology Master Fund, Ltd. /s/ David Kroin, Director 09/10/2025 Signature of Reporting Person Date Deep Track Capital, LP /s/ David Kroin, Managing Member of the General Partner of the Investment Adviser 09/10/2025 Signature of Reporting Person Date /s/ David Kroin 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 )Represents securities held by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP is the investment manager of Deep Track Biotechnology Master Fund, Ltd. Mr. David Kroin is the managing member of Deep Track Capital GP, LLC, the general partner of Deep Track Capital, LP., and by virtue of such status may be deemed to be the beneficial owner of the shares owned by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP and Mr. Kroin disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests.

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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