Rein Therapeutics (RNTX) investor Lytton reports 4.9% stake in amended 13G

Rhea-AI Filing Summary

Rein Therapeutics, Inc. has a significant shareholder, Laurence W. Lytton, reporting updated ownership of its common stock. Lytton beneficially owns 4,238,628 shares of common stock, representing 4.9% of the class, based on 85,539,032 shares outstanding as of May 13, 2026. He reports sole voting power and sole dispositive power over all 4,238,628 shares, with no shared voting or dispositive power. This amendment reflects that his holdings are now reported as ownership of 5 percent or less of the outstanding common stock.

Key Figures

Shares beneficially owned: 4,238,628 shares Percent of class: 4.9% Shares outstanding: 85,539,032 shares +2 more

5 metrics

Shares beneficially owned 4,238,628 shares Common Stock beneficially owned by Laurence W. Lytton

Percent of class 4.9% Portion of Rein Therapeutics common stock class held by Lytton

Shares outstanding 85,539,032 shares Common Stock outstanding as of May 13, 2026, per Form 10-Q

Sole voting power 4,238,628 shares Shares over which Lytton has sole power to vote

Sole dispositive power 4,238,628 shares Shares over which Lytton has sole power to dispose

Key Terms

beneficially owned, sole voting power, sole dispositive power, percent of class

4 terms

beneficially owned financial

"Amount beneficially owned: 4,238,628"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole voting power financial

"Sole Voting Power 4,238,628.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

sole dispositive power financial

"Sole Dispositive Power 4,238,628.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

percent of class financial

"Percent of class: 4.9%"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

FAQ

What percentage of Rein Therapeutics (RNTX) does Laurence W. Lytton currently own?

Laurence W. Lytton beneficially owns 4.9% of Rein Therapeutics’ common stock, representing 4,238,628 shares, calculated based on 85,539,032 shares outstanding as of May 13, 2026, as reported by the company.

How many Rein Therapeutics (RNTX) shares does Laurence W. Lytton control?

Laurence W. Lytton controls 4,238,628 shares of Rein Therapeutics common stock, with sole voting and sole dispositive power over all of these shares and no shared voting or dispositive authority reported.

What does the Schedule 13G/A amendment indicate for RNTX ownership?

The amendment indicates that Laurence W. Lytton now reports ownership of 5 percent or less of Rein Therapeutics’ common stock, specifically 4.9%, while retaining full voting and dispositive control over his 4,238,628 shares.

On what share count is Laurence W. Lytton’s 4.9% RNTX ownership based?

The reported 4.9% ownership is based on 85,539,032 shares of Rein Therapeutics common stock outstanding as of May 13, 2026, as referenced from the issuer’s Form 10-Q for the quarter ended March 31, 2026.

Does Laurence W. Lytton share voting power for his RNTX holdings?

No. The filing states that Laurence W. Lytton has sole voting power and sole dispositive power over all 4,238,628 Rein Therapeutics shares, with 0 shares reported as subject to shared voting or shared dispositive power.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/13/2026 - 02:03 PM Accepted by SEC EDGAR 08/13/2026 - 02:02 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Rein Therapeutics, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

00887A204

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 00887A204

1

Names of Reporting Persons

LYTTON LAURENCE W

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 4,238,628.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 4,238,628.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,238,628.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

4.9 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: The percentage reported herein is calculated based on 85,539,032 shares of Common Stock outstanding as of May 13, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Rein Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 12407 N. Mopac Expy., Suite 250, #390, Austin, Texas 78758
Item 2.
(a)	Name of person filing: Laurence W. Lytton
(b)	Address or principal business office or, if none, residence: 467 Central Park West New York, NY 10025
(c)	Citizenship: USA
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 00887A204
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 4,238,628
(b)	Percent of class: 4.9%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 4,238,628
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 4,238,628
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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.

LYTTON LAURENCE W

Signature:	/s/ Laurence W Lytton
Name/Title:	Reporting Person
Date:	08/13/2026