Rein Therapeutics (NASDAQ: RNTX) sells $2M discounted unsecured note

Rhea-AI Filing Summary

Rein Therapeutics, Inc. entered into a securities purchase agreement with Funicular Funds, LP under which it issued an unsecured promissory note with an original principal amount of $2,500,000 in a private placement. Funicular paid a purchase price of $2,000,000, reflecting a 20% original issue discount instead of cash interest. The note matures on the earlier of the closing of the Company’s next securities financing that raises at least $10,000,000 in gross proceeds (excluding this note) or June 30, 2026. The obligations are unsecured, and the agreement includes customary representations, warranties, covenants and other terms. The note was sold as a private offering under Section 4(a)(2) and Rule 506 of Regulation D.

Insights

Capital structure and credit analyst

Rein raises $2,000,000 via a short-term, discounted unsecured note.

Rein Therapeutics entered into a financing with Funicular Funds, issuing an unsecured promissory note with an original principal of $2,500,000 for proceeds of $2,000,000. The 20% original issue discount effectively replaces a cash interest coupon, so the economic cost is embedded in the higher principal versus cash received.

The note has a relatively short stated maturity, expiring on the earlier of the next qualifying equity or securities financing of at least $10,000,000 in gross proceeds or June 30, 2026. Because the obligation is unsecured, it ranks behind any secured debt but ahead of equity, which is typical for this kind of bridge-style financing.

This transaction provides immediate liquidity without ongoing interest payments, at the cost of a higher repayment amount at maturity. Future company filings will clarify whether the note is repaid through a new capital raise of at least $10,000,000 or in cash at the stated maturity date.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): January 15, 2026

REIN THERAPEUTICS, INC.

(Exact Name of Registrant as Specified in Its Charter)

Delaware		001-38130		13-4196017
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(I.R.S. Employer Identification Number)

12407 N. Mopac Expy., Suite 250, #390

Austin, Texas 78758

(Address of principal executive offices)

(737) 802-1989

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions.

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14d-2(b)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common stock: Par value $.001		RNTX		Nasdaq Capital Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Definitive Material Agreement.

On January 15, 2026, Rein Therapeutics, Inc. (the “Company”) entered into a securities purchase agreement (the “Purchase Agreement”) with Funicular Funds, LP, a Delaware limited partnership managed by Cable Car Capital, LP (“Funicular”), pursuant to which the Company issued and sold to Funicular, in a private placement, an unsecured promissory note, dated January 15, 2026, in the original principal amount of $2,500,000 (the “Note”). Pursuant to the Purchase Agreement, the Company issued and sold to Funicular for a purchase price of $2,000,000, inclusive of an original issue discount of 20%.

The Note has a stated maturity date of the earlier of (i) the date of the closing of the next issuance and sale of securities of the Company, in a single transaction or series of related transactions, to investors resulting in gross proceeds to the Company of at least $10,000,000 (exclusive of the Note proceeds) or (ii) June 30, 2026. The Company’s obligations under the Note are unsecured. There is no interest payable under the Note other than the 20% original issue discount. The Purchase Agreement contained representations, warranties, covenants and other terms customary for agreements of such nature.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth under Item 1.01 of this Current Report on Form 8-K is hereby incorporated by reference in its entirety.

Item 3.02 Unregistered Sales of Equity Securities.

The information set forth under Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference. The Note sold pursuant to the Purchase Agreement was offered and sold pursuant to exemptions from the registration requirements of the Securities Act of 1933, as amended, afforded by Section 4(a)(2) thereof and Rule 506 of Regulation D promulgated thereunder, for the sale of securities not involving a public offering.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

The following exhibits are filed with this report:

Exhibit Number		Exhibit Description
4.1		Unsecured Promissory Note dated January 15, 2026
10.1		Securities Purchase Agreement dated January 15, 2026 between the Registrant and Funicular Funds, LP
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

				REIN THERAPEUTICS, INC.
Dated: January 16, 2026						/s/ Brian Windsor
						Brian Windsor, Ph.D.,
						President and Chief Executive Officer

FAQ

What financing did Rein Therapeutics (RNTX) announce in this 8-K?

Rein Therapeutics entered into a securities purchase agreement with Funicular Funds, LP and issued an unsecured promissory note with an original principal amount of $2,500,000 in a private placement.

How much cash does Rein Therapeutics (RNTX) receive from the new note?

Rein Therapeutics sells the unsecured promissory note to Funicular Funds for a purchase price of $2,000,000, reflecting a 20% original issue discount from the $2,500,000 principal.

When does the new Rein Therapeutics (RNTX) note mature?

The note matures on the earlier of the closing of the Company’s next securities financing raising at least $10,000,000 in gross proceeds (excluding this note) or June 30, 2026.

Is the Rein Therapeutics (RNTX) promissory note secured or unsecured?

The filing states that Rein Therapeutics’ obligations under the promissory note are unsecured, meaning no specific company assets are pledged as collateral.

Does the Rein Therapeutics (RNTX) note pay cash interest?

There is no interest payable under the note other than the 20% original issue discount, which is reflected in the difference between the $2,500,000 principal and the $2,000,000 purchase price.

Under what exemptions was the Rein Therapeutics (RNTX) note offering made?

The note was offered and sold as a private offering relying on exemptions from registration under Section 4(a)(2) of the Securities Act and Rule 506 of Regulation D.