Rein Therapeutics, Inc. ownership disclosure: a Lynwood group reports beneficial ownership of 4,750,000 shares of Common Stock, representing 6.1% of the class as of May 4, 2026. The percentages are based on 78,039,032 shares outstanding as of May 4, 2026.
The Schedule 13G names Lynwood Capital Management Inc., Benjamin Shapiro and Lynwood Opportunities Master Fund as reporting persons and states the Fund directly beneficially owns the reported shares, with the Investment Manager and Mr. Shapiro potentially deemed to beneficially own those shares.
Positive
None.
Negative
None.
Insights
Lynwood discloses a passive stake of 6.1% in Rein Therapeutics.
The filing reports 4,750,000 shares beneficially owned by the Lynwood group as of May 4, 2026, using the issuer's outstanding share count of 78,039,032. The Schedule 13G format indicates a passive reporting posture rather than an active acquisition intent.
Further activity will appear in subsequent filings if the position changes; cash‑flow treatment and sale/transfer plans are not included in this excerpt.
Joint filing clarifies reporting relationships and voting/dispositive powers.
The cover-page breakdown shows the Fund holds the shares with sole voting and dispositive power listed as 4,750,000. Mr. Shapiro and the Investment Manager are named as related reporting persons and include disclaimers of ownership except for direct holdings.
Investors tracking ownership changes should watch future amendments or Forms 13D/13G that disclose any change from a passive to an active intent.
Key Figures
Shares beneficially owned:4,750,000 sharesPercent of class:6.1%Shares outstanding:78,039,032 shares+2 more
5 metrics
Shares beneficially owned4,750,000 sharesBeneficial ownership reported by Lynwood group as of May 4, 2026
Percent of class6.1%Percentage of Common Stock based on 78,039,032 shares outstanding as of May 4, 2026
Shares outstanding78,039,032 sharesOutstanding Common Stock figure used to calculate percentages as of May 4, 2026
Filing date05/04/2026Date used for ownership snapshot and issuer prospectus reference
CUSIP00887A204CUSIP for Rein Therapeutics Common Stock
Key Terms
Schedule 13G, beneficially owns, sole dispositive power, joint filing agreement
4 terms
Schedule 13Gregulatory
"Item 1. Name of issuer: Rein Therapeutics, Inc. (Schedule 13G filing)"
A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.
beneficially ownsfinancial
"The Fund directly beneficially owns the Common Stock reported in this Statement"
Beneficially owns means a person or entity enjoys the economic benefits and control of a security even if the legal title or registration is held in another name. Think of it like having the keys and profits from a car that is registered to a friend: you use it, benefit from it, and make decisions about it even though the official paperwork lists someone else. For investors, this matters because it reveals who truly controls shares, affects voting power, potential conflicts of interest, and regulatory disclosure obligations.
sole dispositive powerregulatory
"Sole Dispositive Power 4,750,000.00"
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.
joint filing agreementlegal
"Exhibit 99.1 - Joint Filing Agreement"
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Rein Therapeutics, Inc.
(Name of Issuer)
Common Stock, $0.001 par value per share
(Title of Class of Securities)
00887A204
(CUSIP Number)
05/04/2026
(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
Lynwood Capital Management Inc.
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
ONTARIO, CANADA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
4,750,000.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
4,750,000.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,750,000.00
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)
6.1 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP Number(s):
00887A204
1
Names of Reporting Persons
Benjamin Shapiro
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
CANADA (FEDERAL LEVEL)
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
4,750,000.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
4,750,000.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,750,000.00
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)
6.1 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
CUSIP Number(s):
00887A204
1
Names of Reporting Persons
Lynwood Opportunities Master Fund
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
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
4,750,000.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
4,750,000.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,750,000.00
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)
6.1 %
12
Type of Reporting Person (See Instructions)
OO
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, TX, 78758
Item 2.
(a)
Name of person filing:
This Schedule 13G (this "Statement" or this "Schedule 13G") is being filed by: (1) Lynwood Capital Management Inc., an Ontario corporation (the "Investment Manager"); (2) Benjamin Shapiro ("Mr. Shapiro"); and (3) Lynwood Opportunities Master Fund, a Cayman Islands entity (the "Fund") (all of the foregoing, collectively, the "Reporting Persons"). The Fund is an investment vehicle. The Fund directly beneficially owns the Common Stock (as defined below) reported in this Statement. The Investment Manager is the investment manager of the Fund. Mr. Shapiro is the President, Chief Executive Officer, Chief Investment Officer, sole director and indirect controlling stockholder of the Investment Manager. Mr. Shapiro and the Investment Manager may be deemed to beneficially own the Common Stock directly beneficially owned by the Fund. Each Reporting Person disclaims beneficial ownership with respect to any Common Stock other than the Common Stock directly beneficially owned by such Reporting Person.
(b)
Address or principal business office or, if none, residence:
The principal business office of the Fund is FG Services Limited, Suite 2206, Cassia Court, 72 Market Street, Camana Bay, P.O. Box 30869, Grand Cayman KY1-1204, Cayman Islands. The principal business office of the Investment Manager and Mr. Shapiro is 200 Bay St, Suite 1304, Royal Bank Plaza, South Tower, Toronto, Ontario M5J 2J1.
(c)
Citizenship:
For citizenship or place of organization see Item 4 of the cover page of each Reporting Person.
(d)
Title of class of securities:
Common Stock, $0.001 par value per share
(e)
CUSIP Number(s):
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:
See Item 9 on the cover page for each Reporting Person, and Item 2, which information is given as of the close of business on May 4, 2026.
(b)
Percent of class:
See Item 11 on the cover page for each Reporting Person. The percentages of beneficial ownership contained herein are based on 78,039,032 shares of Common Stock outstanding as of May 4, 2026 (after giving effect to the closing of an offering by the Issuer on such date) as reported by the Issuer in a Prospectus filed with the SEC on May 4, 2026.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See Item 5 on the cover page for each Reporting Person.
(ii) Shared power to vote or to direct the vote:
See Item 6 on the cover page for each Reporting Person.
(iii) Sole power to dispose or to direct the disposition of:
See Item 7 on the cover page for each Reporting Person.
(iv) Shared power to dispose or to direct the disposition of:
See Item 8 on the cover page for each Reporting Person.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
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.
What stake does Lynwood report in Rein Therapeutics (RNTX)?
Lynwood reports beneficial ownership of 4,750,000 shares, or 6.1%. The percentage is calculated using 78,039,032 shares outstanding as of May 4, 2026, after an offering that closed on that date and was reported in a Prospectus filed the same day.
Who are the reporting persons on the Schedule 13G for RNTX?
The filing lists three reporting persons: Lynwood Capital Management Inc., Benjamin Shapiro, and Lynwood Opportunities Master Fund. The Fund directly beneficially owns the reported shares; the Investment Manager and Mr. Shapiro are related parties identified in the joint filing agreement.
Does the Schedule 13G indicate active acquisition or passive ownership?
The use of Schedule 13G in this filing indicates a passive reporting posture. The document reports beneficial ownership without stating an intent to influence control; any change to an active intent would typically be shown by an amended filing or a Form 13D.
What voting and dispositive powers are reported by Lynwood for RNTX shares?
The cover details show sole voting power and sole dispositive power of 4,750,000 shares for each listed reporting person. Shared voting/dispositive powers are reported as 0 in the provided cover-page breakdown.
What outstanding share count does the filing use to calculate the percentage?
The filing uses 78,039,032 shares outstanding as of May 4, 2026. That figure reflects the company's reported outstanding shares after giving effect to an offering that closed on that date, as disclosed in a Prospectus filed with the SEC on May 4, 2026.
