# EDGAR Filing Document

**Accession Number:** 0000109657
**File Stem:** 0001641172-25-014722
**Filing Date:** 2025-6
**Character Count:** 2370
**Document Hash:** c983a325ec64be536b7bc3a6449ec42a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001641172-25-014722.hdr.sgml**: 20250611

**ACCESSION NUMBER**: 0001641172-25-014722

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250611

**DATE AS OF CHANGE**: 20250611

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** GT Biopharma, Inc.
- **CENTRAL INDEX KEY:** 0000109657
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 941620407
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40023
- **FILM NUMBER:** 251040479

**BUSINESS ADDRESS:**
- **STREET 1:** 505 MONTGOMERY STREET
- **STREET 2:** 10TH FLOOR
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94111
- **BUSINESS PHONE:** (800) 304-9888

**MAIL ADDRESS:**
- **STREET 1:** 505 MONTGOMERY STREET
- **STREET 2:** 10TH FLOOR
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94111

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** OXIS INTERNATIONAL INC
- **DATE OF NAME CHANGE:** 19940916

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DDI PHARMACEUTICALS INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DIAGNOSTIC DATA INC /DE/
- **DATE OF NAME CHANGE:** 19850312

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

**SCHEDULE 14A**

**Proxy Statement Pursuant to Section 14(a) of the Securities**

**Exchange Act of 1934**

Filed by the registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

---

| | | | |
|:---|:---|:---|:---|
| ☐ | Preliminary Proxy Statement | ☐ | Confidential, For Use of the Commission Only |
| ☐ | Definitive Proxy Statement |  | (as permitted by Rule 14a-6(e)(2)) |
| ☒ | Definitive Additional Materials |  |  |
| ☐ | Soliciting Material under Rule 14a-12 |  |  |

---

**GT BIOPHARMA, INC.**

(Name of Registrant as Specified in Its Charter)

------

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box):

☒ No Fee Required

☐ Fee paid previously with preliminary materials

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

![](proxy_001.jpg)

![](proxy_002.jpg)