LB PHARMACEUTICALS INC — Director's Dealing 2025

Sep 11, 2025

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: LB PHARMACEUTICALS INC (LBRX)
CIK: 0001691082
Period of Report: 2025-09-10

Reporting Person: Vida Ventures GP III, L.L.C. (N/A)
Reporting Person: Vida Ventures III, L.P. (10% Owner)
Reporting Person: Vida Ventures III-A, L.P. (10% Owner)
Reporting Person: Belldegrun Arie (10% Owner)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1434	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series C Preferred Stock	$		Common Stock (547648)		Indirect
Series C Preferred Stock	$		Common Stock (1262)		Indirect

Footnotes

F1: These shares are held directly by Vida Ventures Management Co., LLC ("Vida Management"). Each Investment Committee Member (as defined below) disclaims beneficial ownership of the securities held of record by Vida Management, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interest therein, if any.

F2: 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.

F3: These shares are held directly by Vida Ventures III, L.P. ("Vida III"). Vida Ventures GP III, L.L.C. ("Vida III GP") is the general partner of Vida III and may be deemed to have voting, investment, and dispositive power with respect to these securities. Arie Belldegrun, Helen Kim and Rajul Jain, a member of the Issuer's board of directors, are the members of the investment committee of Vida III GP (each, an "Investment Committee Member" and such committee, the "Investment Committee").

F4: (Continued from Footnote 3) The Investment Committee and each of the Investment Committee Members may be deemed to share voting, investment and dispositive power with respect to these securities. Vida III GP, the Investment Committee and each of the Investment Committee Members disclaims beneficial ownership of the securities held of record by Vida III, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interest therein, if any.

F5: These shares are held directly by Vida Ventures III-A, L.P. ("Vida III-A"). Vida III GP is the general partner of Vida III-A and may be deemed to have voting, investment, and dispositive power with respect to these securities. The Investment Committee and each of the Investment Committee Members may be deemed to share voting, investment and dispositive power with respect to these securities. Vida III GP, the Investment Committee and each of the Investment Committee Members disclaims beneficial ownership of the securities held of record by Vida III-A, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interest therein, if any.