# EDGAR Filing Document

**Accession Number:** 0000109657
**File Stem:** 0001683168-25-004168
**Filing Date:** 2025-6
**Character Count:** 12586
**Document Hash:** 5942d1eb6fc0deadf8a10f752bbb45a3
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001683168-25-004168.hdr.sgml**: 20250602

**ACCESSION NUMBER**: 0001683168-25-004168

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250602

**DATE AS OF CHANGE**: 20250602

**SUBJECT COMPANY**: 

**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:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-32837
- **FILM NUMBER:** 251016837

**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
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BRISTOL INVESTMENT FUND LTD
- **CENTRAL INDEX KEY:** 0001174866

**ORGANIZATION NAME:**
- **EIN:** 000000000

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**BUSINESS ADDRESS:**
- **STREET 1:** 89 NEXUS WAY
- **STREET 2:** CAMANA BAY, PO BOX 311063
- **CITY:** GRAND CAYMAN
- **STATE:** E9
- **ZIP:** KY1-1205
- **BUSINESS PHONE:** (310) 331-8485

**MAIL ADDRESS:**
- **STREET 1:** 89 NEXUS WAY
- **STREET 2:** CAMANA BAY, PO BOX 311063
- **CITY:** GRAND CAYMAN
- **STATE:** E9
- **ZIP:** KY1-1205

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BRISTOL INVESTMENT FUND INC
- **DATE OF NAME CHANGE:** 20020605

## Ex-1

Exhibit 1

**JOINT FILING AGREEMENT**

This JOINT FILING AGREEMENT (this " Agreement"), dated as of January 1, 2025, is entered into by and among Bristol Investment Fund, Ltd., a Cayman Islands exempted company ("Bristol Fund") and Bristol Capital, LLC, a Delaware limited liability company ("BC") (Bristol Fund and BC are collectively referred to herein as the "Joint Filers").

WHEREAS, each of the Joint Filers have filed or is filing a Schedule 13G under the Securities Exchange Act of 1934 (the "Exchange Act") with respect to securities of GT Biopharma, Inc. (the "Schedule 13G");

WHEREAS, each of the Joint Filers is individually eligible to file a Schedule 13G;

WHEREAS, each of the Joint Filers wishes to file an amendment to the Schedule 13G jointly and on behalf of each of the Joint Filers, pursuant to Rule 13d-1(k)(1) under the Exchange Act;

NOW, THEREFORE, in consideration of these premises and other good and valuable consideration, the parties hereto agree as follows:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. The Joint Filers hereby agree that the Schedule 13G is, and any amendments thereto will be, filed on behalf of each of the Joint Filers pursuant to Rule 13d-1(k)(1) under the Exchange Act.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. Each of the Joint Filers hereby acknowledges that, pursuant to Rule 13d-1(k)(1)(ii) under the Exchange Act, it is responsible for the timely filing of the Schedule 13G and any amendments thereto, and for the completeness and accuracy of the information concerning it contained therein, and is not responsible for the completeness and accuracy of the information concerning any of the other parties contained therein, unless it knows or has reason to know that such information is inaccurate.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. Each of the Joint Filers hereby agrees that this Agreement shall be filed as an Exhibit to the Schedule 13G, pursuant to Rule 13d-1(k)(1)(iii) under the Exchange Act.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. This Agreement may be executed in counterparts, each of which shall be deemed an original and all of which, taken together, shall constitute but one and the same instrument, which may be sufficiently evidenced by one counterpart.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed as of the day and year first above written.

BRISTOL INVESTMENT FUND, LTD. BRISTOL CAPITAL, LLC

---

| | |
|:---|:---|
| By: /s/ Paul Kessler | By: /s/ Paul Kessler |
| Paul Kessler, Director | Paul Kessler, Manager |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 18)**

**Issuer:** GT Biopharma, Inc.

**Title of Class of Securities:** Common Stock

**CUSIP Number:** 36254L308

**Date of Event Which Requires Filing of this Statement:** 05/29/2025

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Bristol Investment Fund, Ltd. | Names of Reporting Persons<br>Bristol Investment Fund, Ltd. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>E9 | Citizenship or Place of Organization<br>E9 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>74524.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>74524.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>0.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>74524.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>74524.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>2.367% | Percent of Class Represented by Amount in Row (9)<br>2.367% |
| 12. | Type of Reporting Person (See Instructions)<br>CO | Type of Reporting Person (See Instructions)<br>CO |

**Comment for Type of Reporting Person:** For Items 5 and 7: does not include shares underlying convertible preferred stock subject to a 9.9% beneficial ownership limitation

---

| 1. | Names of Reporting Persons<br>Bristol Capital, LLC | Names of Reporting Persons<br>Bristol Capital, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>150000.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>150000.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>0.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>0.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>0.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>4.76% | Percent of Class Represented by Amount in Row (9)<br>4.76% |
| 12. | Type of Reporting Person (See Instructions)<br>CO | Type of Reporting Person (See Instructions)<br>CO |

---

**Item 1(a). Name of Issuer:**
GT Biopharma, Inc.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
505 Montgomery Street, 10th Floor, San Francisco, CA 94111

**Item 2(a). Name of Person Filing:**
(i) Bristol Investment Fund, Ltd.
(ii) Bristol Capital, LLC

**Item 2(b). Address of Principal Business Office:**
(i) Citco Trustees (Cayman) Limited, 89 Nexus Way, Camana Bay, PO Box 311063, Grand Cayman KY1-1205, Cayman Islands
(ii) 1090 Center Drive, Park City, UT 84098

**Item 2(c). Citizenship:**
(i) Cayman Islands
(ii) Delaware, USA

**Item 2(d). Title of Class of Securities:**
Common Stock

**Item 2(e). CUSIP Number:**
36254L308

**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:**

(i) 74,524
(ii) 150,000

**(b) Percent of class:**

(i)  2.367%
(ii) 4.76%

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

(i) 74,524
(ii) 150,000

**(ii) Shared power to vote or to direct the vote:**

—

**(iii) Sole power to dispose or to direct the disposition of:**

(i) 74,524
(ii) 150,000

**(iv) Shared power to dispose or to direct the disposition of:**

—

**Item 5. Ownership of Five Percent or Less of a Class.**

[ ] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

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. Certification:**

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.

**Bristol Investment Fund, Ltd.**

**Date:** 06/02/2025

**By:** /s/ Paul Kessler

**Name & Title:** Paul Kessler, Director

**Bristol Capital, LLC**

**Date:** 06/02/2025

**By:** /s/ Paul Kessler

**Name & Title:** Paul Kessler, Manager, Bristol Capital, LLC