[SCHEDULE 13D] LB PHARMACEUTICALS INC SEC Filing

Rhea-AI Filing Summary

Pontifax entities and two individual managing partners report ownership of 1,411,681 shares of LB Pharmaceuticals Inc. common stock, representing 6.3% of the outstanding shares. The holdings arise from a prior $15,000,000 purchase of Series C preferred stock that converted into 411,681 common shares upon the issuer's IPO, plus additional purchases by Pontifax (Cayman) and Pontifax (Israel) of 363,737 and 626,263 common shares, respectively, in the IPO at $15.00 per share. The reporting group states the securities were acquired for investment purposes and may review, discuss or transact in the securities over time. One Reporting Person, Ran Nussbaum, serves on the issuer's board and may influence corporate matters. The filing otherwise discloses no recent transactions in the past 60 days and no relevant legal proceedings.

Positive

• Established economic commitment: Pontifax invested $15,000,000 in Series C preferred that converted to common stock, showing prior support for the issuer.
• Substantial post-IPO participation: Pontifax entities purchased additional IPO shares at $15.00 per share, increasing their stake to 1,411,681 shares (6.3%).
• Board representation: A Reporting Person serves on the issuer's board, enabling direct engagement with corporate management and governance.

Negative

• None.

Insights

Corporate Governance Expert

TL;DR: Pontifax holds a meaningful minority stake and has a board representative, enabling engagement but not control.

The Schedule 13D reports a 6.3% beneficial ownership stake aggregated across Pontifax entities and two managing partners, with a board seat held by a Reporting Person. This combination typically permits active engagement with management and the board on strategy or governance without unilateral control. The filing expressly states the investment purpose is review and potential dialogue with management and other shareholders. There are no disclosed arrangements or plans to pursue corporate actions beyond routine investor engagement. No litigation or adverse regulatory history is reported for the Reporting Persons.

Financial Analyst

TL;DR: Investment stems from a $15.0M preferred investment and follow-on IPO purchases at $15.00, totaling 1,411,681 shares (6.3%).

The Schedule 13D quantifies the economic exposure: a prior $15,000,000 preferred holding converted into 411,681 common shares and additional IPO purchases of 990,000 shares at $15.00 per share by the Pontifax partnerships, yielding the reported aggregate ownership. The filing signals typical investor stewardship and potential future trading activity but discloses no recent transactions within 60 days. For investors, the material facts are the stake size, the per-share IPO price, and the board affiliation; the filing contains no financial performance or forecasts for the issuer.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

LB Pharmaceuticals Inc

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

50180M108

(CUSIP Number)

Asaf Shinar
Pontifax, 14 Shenkar Street
Herzliya Pituach, L3, 46140
972-9-9725617

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

09/12/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 50180M108

1

Name of reporting person

Pontifax Management 4 G.P. (2015) Ltd.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

ISRAEL

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,411,681.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,411,681.00

11

Aggregate amount beneficially owned by each reporting person

1,411,681.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.3 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

1. Includes (i) 898,201 Ordinary Shares held by Pontifax (Israel) VI Limited Partnership and (ii) 513,480 Ordinary Shares held by Pontifax (Cayman) VI Limited Partnership. Pontifax VI G.P. L.P. is the general partner of each of Pontifax (Israel) VI Limited Partnership and Pontifax (Cayman) VI Limited Partnership. Pontifax Management 4 G.P. (2015) Ltd. is the general partner of Pontifax VI G.P. L.P. 2. Based on 22,442,989 shares of Common Stock outstanding as of September 10, 2025, as provided for in LB Pharmaceuticals Inc.'s prospectus filed with the Securities and Exchange Commission ("SEC") on September 12, 2025.

SCHEDULE 13D

CUSIP No. 50180M108

1

Name of reporting person

Pontifax VI G.P. L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

ISRAEL

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,411,681.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,411,681.00

11

Aggregate amount beneficially owned by each reporting person

1,411,681.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.3 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person:

1. Includes (i) 898,201 Ordinary Shares held by Pontifax (Israel) VI Limited Partnership and (ii) 513,480 Ordinary Shares held by Pontifax (Cayman) VI Limited Partnership. Pontifax VI G.P. L.P. is the general partner of each of Pontifax (Israel) VI Limited Partnership and Pontifax (Cayman) VI Limited Partnership. 2. Based on 22,442,989 shares of Common Stock outstanding as of September 10, 2025, as provided for in LB Pharmaceuticals Inc.'s prospectus filed with the SEC on September 12, 2025.

SCHEDULE 13D

CUSIP No. 50180M108

1

Name of reporting person

Ran Nussbaum

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

ISRAEL

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,411,681.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,411,681.00

11

Aggregate amount beneficially owned by each reporting person

1,411,681.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.3 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

1. Includes (i) 898,201 Ordinary Shares held by Pontifax (Israel) VI Limited Partnership and (ii) 513,480 Ordinary Shares held by Pontifax (Cayman) VI Limited Partnership. Pontifax VI G.P. L.P. is the general partner of each of Pontifax (Israel) VI Limited Partnership and Pontifax (Cayman) VI Limited Partnership. Pontifax Management 4 G.P. (2015) Ltd. is the general partner of Pontifax VI G.P. L.P. Tomer Kariv and Ran Nussbaum are the Managing Partners of Pontifax Management 4 G.P. (2015) Ltd. 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 listed above. 2. Based on 22,442,989 shares of Common Stock outstanding as of September 10, 2025, as provided for in LB Pharmaceuticals Inc.'s prospectus filed with the SEC on September 12, 2025.

SCHEDULE 13D

CUSIP No. 50180M108

1

Name of reporting person

Tomer Kariv

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

ISRAEL

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,411,681.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,411,681.00

11

Aggregate amount beneficially owned by each reporting person

1,411,681.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.3 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

1. Includes (i) 898,201 Ordinary Shares held by Pontifax (Israel) VI Limited Partnership and (ii) 513,480 Ordinary Shares held by Pontifax (Cayman) VI Limited Partnership. Pontifax VI G.P. L.P. is the general partner of each of Pontifax (Israel) VI Limited Partnership and Pontifax (Cayman) VI Limited Partnership. Pontifax Management 4 G.P. (2015) Ltd. is the general partner of Pontifax VI G.P. L.P. Tomer Kariv and Ran Nussbaum, are the Managing Partners of Pontifax Management 4 G.P. (2015) Ltd. 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 listed above. 2. Based on 22,442,989 shares of Common Stock outstanding as of September 10, 2025, as provided for in LB Pharmaceuticals Inc.'s prospectus filed with the SEC on September 12, 2025.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.0001 par value per share
(b)	Name of Issuer: LB Pharmaceuticals Inc
(c)	Address of Issuer's Principal Executive Offices: One Pennsylvania Plaza,, Suite 1025, New York, NEW YORK , 10119.
Item 2.	Identity and Background
(a)	Each of the following is hereinafter individually referred to as a "Reporting Person" and collectively as the "Reporting Persons". This statement is filed on behalf of: i. Pontifax Management 4 G.P. (2015) Ltd., an Israeli private company ("Pontifax Management"); ii. Pontifax VI G.P. L.P., an Israeli limited partnership ("Pontifax VI G.P."); iii. Ran Nussbaum, an Israeli citizen; and iv. Tomer Kariv, an Israeli citizen. The Reporting Persons have entered into an agreement of joint filing, a copy of which is attached hereto as Exhibit 99.1.
(b)	The business address of the Reporting Persons is c/o The Pontifax Group, 14 Shenkar Street, Herzliya, Israel.
(c)	The principal business of Pontifax Management and Pontifax VI G.P. is serving as the investment manager of Pontifax (Cayman) VI Limited Partnership, a Cayman Islands limited partnership ("Pontifax (Cayman)") and Pontifax (Israel) VI Limited Partnership, an Israeli limited partnership ("Pontifax (Israel)"), and other persons. The principal business of Messrs. Tomer Kariv and Ran Nussbaum is serving as the Managing Partners of Pontifax Management, the general partner of Pontifax VI G.P. L.P., which, in turn, is the general partner of both Pontifax (Israel) and Pontifax (Cayman).
(d)	During the last five years, none of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the last five years, none of the Reporting Persons has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and, as a result of such proceeding, was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.
(f)	See Item 2(a) above.
Item 3.	Source and Amount of Funds or Other Consideration
	Pontifax (Cayman) and Pontifax (Israel) previously paid an aggregate of $15,000,000 to purchase Series C Preferred Stock of the Issuer. Upon the consummation of the Issuer's initial public offering ("IPO") that closed on September 12, 2025, these shares of preferred stock converted into 411,681 shares of Common Stock, of which 261,938 shares of Common Stock are held by Pontifax (Israel) and 149,743 shares of Common Stock are held by Pontifax (Cayman). On September 12, 2025, each of Pontifax (Cayman) and Pontifax (Israel) purchased an additional 363,737 and 626,263 shares of Common Stock, respectively, in the IPO at a price of $15.00 per share. The source of funds for the purchase of the Issuer securities reported herein by both Pontifax (Cayman) and Pontifax (Israel) was from working capital.
Item 4.	Purpose of Transaction
	The Reporting Persons acquired the securities reported herein for investment purposes, subject to the following: The Reporting Persons intend to review on a continuing basis the investments in the Issuer by the Reporting Persons. The Reporting Persons may engage in discussions with management, the board of directors of the Issuer (the "Board"), other shareholders of the Issuer and other relevant parties concerning the Reporting Persons' investment in the Issuer's securities. Depending on various factors, including, without limitation, the price and availability of the Issuer's securities, subsequent developments affecting the Issuer, the Issuer's business and the Issuer's prospects, other investment and business opportunities available to such Reporting Persons, general industry and economic conditions, the securities markets in general, tax considerations and other factors deemed relevant by such Reporting Persons, the Reporting Persons may seek to sell or otherwise dispose some or all of the Issuer's securities or any derivatives thereof (which may include distributing some or all of such securities to such Reporting Person's respective partners or beneficiaries, as applicable) from time to time, and/or may seek to acquire additional securities of the Issuer or any derivatives thereof (which may include rights or securities exercisable or convertible into securities of the Issuer) from time to time, in each case, in open market or private transactions, block sales or otherwise. Ran Nussbaum, a Managing Director at Pontifax Management or one of its affiliates, serves as a member of the Board and, in such capacity, may have influence over the corporate activities of the Issuer, including activities which may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Except as described in this Schedule 13D, the Reporting Person does not have any present plans or proposals that relate to or would result in any of the actions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D, although, the Reporting Person, at any time and from time to time, may review, reconsider and change their position and/or purpose and/or develop such plans.
Item 5.	Interest in Securities of the Issuer
(a)	The information set forth in the cover pages of this Schedule 13D is hereby incorporated by reference into this Item 5. Calculation of the percentage of shares of Common Stock beneficially owned by each Reporting Person is based on 22,442,989 shares of Common Stock outstanding following the Issuer's IPO based on information set forth in the Issuer's prospectus filed with the SEC on September 12, 2025. The aggregate number and percentage of Common Shares beneficially owned by each Reporting Person and, for each Reporting Person, the number of shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Schedule 13D and are incorporated herein by reference. Pontifax (Israel) and Pontifax (Cayman) directly hold 898,201 and 513,480 shares of the Common Stock, respectively. The Managing Partners of Pontifax Management, the general partner of Pontifax VI G.P. L.P., which, in turn, is the general partner of both Pontifax (Israel) and Pontifax (Cayman), are Messrs. Tomer Kariv and Ran Nussbaum.
(b)	See Item 5(a) above.
(c)	Except as set forth in this Schedule 13D, none of the Reporting Persons has effected any transaction in Common Stock in the past 60 days.
(d)	To the best knowledge of the Reporting Persons, no one other than the Reporting Persons, or the partners, members, affiliates or shareholders of the Reporting Persons, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock reported herein as beneficially owned by the Reporting Persons.
(e)	Not applicable.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	Except for the matters described herein, the Reporting Persons have no contract, arrangement, understanding or relationship (legal or otherwise) among the Reporting Persons or between the Reporting Persons and any other person with respect to the securities of the Issuer.
Item 7.	Material to be Filed as Exhibits.
	Item 7 of Schedule 13D is hereby amended and supplemented as follows: Exhibit No. Description 99.1 Joint Filing Agreement by and among the Reporting Persons

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Pontifax Management 4 G.P. (2015) Ltd.

Signature:	/s/ Ran Nussbaum
Name/Title:	Ran Nussbaum Managing Partner
Date:	09/25/2025

Pontifax VI G.P. L.P.

Signature:	/s/ Ran Nussmabum
Name/Title:	Ran Nussbaum Managing Partner
Date:	09/25/2025

Ran Nussbaum

Signature:	/s/ Ran Nussbaum
Name/Title:	Ran Nussbaum
Date:	09/25/2025

Tomer Kariv

Signature:	/s/ Tomer Kariv
Name/Title:	Tomer Kariv
Date:	09/25/2025

FAQ

What stake do Pontifax and related Reporting Persons hold in LB Pharmaceuticals (LBRX)?

The Reporting Persons beneficially own 1,411,681 shares, representing 6.3% of outstanding common stock as reported in the Schedule 13D.

How did Pontifax acquire its LBRX shares and at what price?

Pontifax previously invested $15,000,000 in Series C preferred that converted into 411,681 common shares and purchased additional IPO shares (363,737 and 626,263) at $15.00 per share.

Does any Reporting Person have a role at LB Pharmaceuticals?

Yes. The filing states that Ran Nussbaum serves as a member of the issuer's board of directors.

Does the Schedule 13D disclose any plans to change LB Pharmaceuticals' operations or governance?

No. The Reporting Persons state the securities were acquired for investment purposes and disclose no present plans to effect actions described in Item 4 beyond potential engagement and review.

Are there any recent transactions by the Reporting Persons in LBRX within 60 days?

The filing states that, except as set forth in the Schedule 13D, none of the Reporting Persons effected any transaction in the issuer's common stock in the past 60 days.