Fortress Biotech (NASDAQ: FBIO) reports 13.4% Avenue (ATXI) stake with voting control

Rhea-AI Filing Summary

Fortress Biotech, Inc. filed Amendment No. 8 to its Schedule 13D for Avenue Therapeutics, Inc., reporting beneficial ownership of 439,955 shares of Avenue common stock, equal to 13.4% of the outstanding common shares. This total includes 250,000 shares of Class A preferred stock, which are convertible into 222 shares of common stock and are structured so that the Class A preferred will at all times constitute a voting majority. Fortress owns all outstanding Class A preferred shares, giving it majority voting control despite a minority economic stake.

Fortress’s ownership also reflects an Annual Equity Grant under a Founders Agreement, through which Avenue issues to Fortress each year shares equal to 2.5% of Avenue’s fully diluted outstanding equity. In addition, as holder of the Class A preferred, Fortress is entitled each January 1 to stock dividends in Avenue common equal to 2.5% of Avenue’s fully diluted outstanding capitalization. The filing notes 296 Avenue common shares underlying outstanding warrants granted by Fortress to two of its executives, with Fortress retaining sole voting power but shared dispositive power over those warrant shares.

Insights

Equity ownership and governance analyst

Fortress shows 13.4% economic stake but maintains majority voting control in Avenue.

The filing states that Fortress Biotech beneficially owns 439,955 Avenue common shares, or 13.4% of outstanding common stock, based on 3,183,558 Avenue common shares as of November 12, 2025 plus specified adjustments. This figure includes 250,000 Avenue Class A preferred shares, which are convertible into 222 common shares. While the economic stake is modest on a common-stock basis, the Class A preferred are designed so that they "will at all times constitute a voting majority," and Fortress owns all of them.

The document explains that each Class A preferred share has a formula-based voting right tied to Avenue’s fully diluted capitalization, ensuring Fortress retains majority voting power regardless of additional equity issued. It also describes two recurring equity mechanisms: an Annual Equity Grant where Avenue issues to Fortress 2.5% of its fully diluted equity each year, and an annual January 1 stock dividend on the Class A preferred equal to 2.5% of Avenue’s fully diluted outstanding capitalization. Together, these provisions indicate ongoing share issuance to Fortress, with the precise future impact depending on Avenue’s total capitalization in each period.

The filing additionally notes 296 Avenue common shares underlying warrants held by two Fortress executives, with an exercise price of $492.75 per share and an expiration in July 2035. Fortress must reserve these shares from its Avenue common holdings and has sole voting but shared dispositive power over them. Overall, the disclosure highlights a structure where Fortress’s contractual rights and preferred stock terms give it durable voting control and recurring equity-based consideration from Avenue.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 8)

Avenue Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.0001 Par Value

(Title of Class of Securities)

05360L403

(CUSIP Number)

Fortress Biotech, Inc.
1111 Kane Concourse, Suite 301,
Bay Harbor Islands, FL, 33154
(718) 652-4500

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

01/02/2026

(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. 05360L403

1

Name of reporting person

Fortress Biotech, Inc.

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)

OO

5

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

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 439,955.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 439,659.00
10	Shared Dispositive Power 296.00

11

Aggregate amount beneficially owned by each reporting person

439,955.00

12

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

13

Percent of class represented by amount in Row (11)

13.4 %

14

Type of Reporting Person (See Instructions)

CO, HC

Comment for Type of Reporting Person:

Sole Voting Power includes 296 shares of Issuer's common stock underlying Warrants and 250,000 shares of the Issuer's Class A preferred stock (both of which are described further below). The Issuer's Class A preferred stock is identical to its common stock other than as to voting rights, conversion rights and the PIK Dividend (as defined below) rights. Each share of the Issuer's Class A preferred stock is entitled to the number of votes per share that is equal to one and one-tenth (1.1) times a fraction, the numerator of which is the sum of (A) the number of shares of the Issuer's outstanding common stock and (B) the number of whole shares of the Issuer's common stock into which any shares of outstanding Class A preferred stock are convertible and the denominator of which is the number of shares of outstanding Class A preferred stock. All shares of the Class A preferred stock are convertible into 222 shares of the Issuer's common stock. Thus, the Class A preferred stock will at all times constitute a voting majority. The Reporting Person owns all outstanding shares of the Issuer's Class A preferred stock. As holders of Class A preferred stock, the Reporting Person will receive on each January 1 (each a "PIK Dividend Payment Date") until the date all outstanding Class A preferred stock is converted into common stock or redeemed (and the purchase price is paid in full), pro rata per share dividends paid in additional fully paid and nonassessable shares of Issuer common stock ("PIK Dividends") such that the aggregate number of shares of common stock issued pursuant to such PIK Dividend is equal to two and one-half percent (2.5%) of the Issuer's fully-diluted outstanding capitalization on the date that is one (1) business day prior to any PIK Dividend Payment Date. An aggregate 296 shares of Issuer common stock are issuable under Common Stock Warrants dated July 15, 2012, as amended by the Amended and Restated Common Stock Warrant dated December 12, 2016, issued by the Reporting Person to Lindsay A. Rosenwald, M.D., the Reporting Person's Chairman, President and Chief Executive Officer, and Michael S. Weiss, the Reporting Person's Executive Vice Chairman, Strategic Development, pursuant to the Fortress Biotech, Inc. Long-Term Incentive Plan (the "Warrants"). The Warrants, which have an exercise price of $492.75 per share, are exercisable until July 15, 2035. The Reporting Person must reserve from its holdings of the Issuer's common stock the shares underlying the Warrants until the Warrants are exercised. The foregoing description of the Warrants is not complete and is qualified in its entirety by reference to the full text of the form of the Amended and Restated Common Stock Warrant which is attached as Exhibit 7.02 and incorporated herein by reference. Sole Dispositive Power excludes the 296 shares of Issuer's common stock underlying the Warrants. Shared Dispositive Power consists solely of the 296 shares of Issuer's common stock underlying the Warrants. All percentage calculations set forth herein are based upon 3,183,558 shares of the Issuer's common stock as of November 12, 2025 as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 13, 2025, the conversion of all 250,000 shares of Issuer's Class A preferred stock into 222 shares of the Issuer's common stock, and 111,209 shares of Issuer's common stock issued as an Annual Equity Grant (defined below). This Amendment No. 8 to Schedule 13D (this "Amendment No. 8") amends and supplements the Schedule 13D filed on October 19, 2017 (as amended and supplemented through the date of this Amendment No. 8, collectively, the "Schedule 13D") relating to the Common Stock of Avenue Therapeutics, Inc. (the "Issuer"), by Fortress Biotech, Inc. (the "Reporting Person"). Except as specifically provided herein, this Amendment No. 8 does not modify any of the information previously reported on the Schedule 13D. Capitalized terms used but not defined herein shall have the same meanings as are ascribed to them in the Schedule 13D, as applicable

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.0001 Par Value
(b)	Name of Issuer: Avenue Therapeutics, Inc.
(c)	Address of Issuer's Principal Executive Offices: 1111 Kane Concourse, Suite 301, Bay Harbor Islands, FLORIDA , 33154.
Item 2.	Identity and Background
(a)	This Schedule 13D/A is being filed on behalf of the Reporting Person pursuant to Rule 13d-1 of Regulation D-G under the Act.
(b)	The address of the Reporting Person's principal business and principal office is 1111 Kane Concourse, Suite 301, Bay Harbor Islands, Florida 33154.
(c)	The principal business of the Reporting Person is acquiring, developing and commercializing novel pharmaceutical and biotechnology products both within the Reporting Person and through certain of its subsidiary companies.
(d)	During the last five years, the Reporting Person has not been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the last five years, the Reporting Person has not been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction resulting in it being 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)	The Reporting Person is organized under the laws of the state of Delaware.
Item 3.	Source and Amount of Funds or Other Consideration
	The Reporting Person is filing this Schedule 13D as a result of the issuance by the Issuer of: 111,209 shares of the Issuer's common stock as an Annual Equity Grant under the Founders Agreement (defined below).
Item 4.	Purpose of Transaction
	The Reporting Person is party to that certain Second Amended and Restated Founders Agreement with the Issuer (as amended, the "Founders Agreement"), in connection with the Issuer's formation. Pursuant to the Issuer's Third Amended and Restated Certificate of Incorporation (as amended, the "Charter"), the Issuer issues annually to the Reporting Person shares of common stock equal to two and one-half percent (2.5%) of the fully-diluted outstanding equity of the Issuer, as measured as of the date of such issuance (the "Annual Equity Grant"). The foregoing description of the Charter and Founders Agreement are qualified in its entirety by reference to the full text of the Charter and Founders Agreement which are incorporated herein by reference as Exhibits 7.01 and 7.03.
Item 5.	Interest in Securities of the Issuer
(a)	The Reporting Person is the beneficial owner of 439,955 shares of the Issuer's common stock (including 250,000 shares of Class A preferred stock, which are convertible into 222 shares of the Issuer's common stock), representing beneficial ownership of 13.4% of all outstanding shares of the Issuer's common stock.
(b)	The Reporting Person has sole voting power of 439,955 shares of the Issuer's common stock (including 250,000 shares of Class A preferred stock, which are convertible into 222 shares of the Issuer's common stock).
(c)	Not applicable.
(d)	Except with respect to the Warrants described in the Comments, no person has the power to direct the receipt of dividends on, or the proceeds of sales of, the shares of common stock owned by the Reporting Person.
(e)	Not applicable.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	Reference is made to the Founders Agreement in Item 3 and the Warrants in the Comments above.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 7.01 Third Amended and Restated Certificate of Incorporation of Avenue Therapeutics, Inc., filed as Exhibit 3.1 to Form 8-K filed on June 27, 2017 (File No. 001-38114) and incorporated herein by reference.* Exhibit 7.02 Form of Common Stock Warrant filed as Exhibit 4.2 to Form 10-12G filed by the Issuer with the SEC on January 12, 2017 (File No. 000-55556) and incorporated herein by reference.* Exhibit 7.03 Amended and Restated Founders Agreement between Fortress Biotech, Inc. and Avenue Therapeutics, Inc., dated September 13, 2016, incorporated by reference to Exhibit 10.2 to the Form 10-12G filed by the Issuer with the SEC on January 12, 2017 (File No. 000-55556).* * Previously filed.

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.

Fortress Biotech, Inc.

Signature:	/s/ Lindsay A. Rosenwald
Name/Title:	Lindsay A. Rosenwald, M.D. / Chairman, President and Chief Executive Officer
Date:	01/06/2026

FAQ

What percentage of Avenue Therapeutics (ATXI) does Fortress Biotech beneficially own?

Fortress Biotech reports beneficial ownership of 439,955 Avenue Therapeutics common shares, representing 13.4% of Avenue’s outstanding common stock. This percentage is calculated using 3,183,558 Avenue common shares outstanding as of November 12, 2025, adjusted for the Class A preferred share conversion and an Annual Equity Grant.

How does Fortress Biotech maintain voting control over Avenue Therapeutics (ATXI)?

Fortress Biotech owns all outstanding shares of Avenue’s Class A preferred stock. The filing states that all Class A preferred shares are structured so they "will at all times constitute a voting majority." Each Class A preferred share carries a variable number of votes based on Avenue’s fully diluted capitalization, allowing Fortress to hold majority voting power even though its economic ownership of common stock is 13.4%.

What are the key terms of Avenue’s Class A preferred stock held by Fortress Biotech?

The Class A preferred stock is described as identical to Avenue’s common stock except for voting, conversion, and PIK dividend rights. All outstanding Class A preferred shares are convertible into 222 Avenue common shares in total and are entitled to voting rights calculated by a formula tied to Avenue’s fully diluted capitalization. As long as these terms apply, the Class A preferred "will at all times constitute a voting majority," and Fortress owns all such shares.

What recurring share issuances does Fortress Biotech receive from Avenue Therapeutics (ATXI)?

The filing describes two recurring mechanisms. First, under a Founders Agreement and Avenue’s charter, Avenue issues Fortress an Annual Equity Grant of common stock equal to 2.5% of Avenue’s fully diluted outstanding equity, measured at the time of issuance. Second, as holder of the Class A preferred stock, Fortress receives yearly PIK (payment-in-kind) stock dividends each January 1 in Avenue common equal to 2.5% of Avenue’s fully diluted outstanding capitalization, calculated one business day before the dividend date.

What warrants related to Avenue Therapeutics stock are mentioned in the Fortress Biotech filing?

The document notes warrants for an aggregate of 296 Avenue common shares, issued by Fortress Biotech to its executives Lindsay A. Rosenwald, M.D. and Michael S. Weiss under the Fortress Long-Term Incentive Plan. These warrants have an exercise price of $492.75 per Avenue share and are exercisable until July 15, 2035. Fortress must reserve Avenue common shares underlying the warrants, has sole voting power over those shares, and shares dispositive power with the warrant holders.

Why did Fortress Biotech file Amendment No. 8 to its Schedule 13D for Avenue Therapeutics (ATXI)?

The filing states that Fortress Biotech is submitting this amendment as a result of Avenue issuing 111,209 Avenue common shares to Fortress as an Annual Equity Grant under the Founders Agreement. This new issuance affects Fortress’s beneficial ownership calculation and is reflected in the updated 13.4% ownership figure and 439,955 common shares reported.