SCHEDULE 13D

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 whole number of 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 percent) 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 7.01 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 1,911,633 shares of the Issuer's common stock as of November 11, 2024 as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 14, 2024, the assumed conversion of the Class A preferred stock, the issuance of 112,850 shares of the Issuer's common stock pursuant to that certain Subscription and Forgiveness Agreement, dated as of November 13, 2024, between the Reporting Person and the Issuer, 12,662 shares of Issuer's common stock issued as Offering Equity Grants (defined below) and the 101,935 shares of Issuer's common stock issued as an Annual Equity Grant (defined below). This Amendment No. 6 to Schedule 13D (this 'Amendment No. 6') amends and supplements the Schedule 13D filed on October 19, 2017 (as amended and supplemented through the date of this Amendment No. 6, 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. 6 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.