GT Biopharma, Inc.

Previous wording

GTB-5550 is a B7-H3 targeted TriKE® which targets B7-H3 on the surface of advanced solid tumors (figure above). GTB-5550 is our first dual camelid TriKE®. B7-H3 is expressed on a broad spectrum of solid tumor malignancies, allowing our team to target these malignancies through GTB-5550. Pre-clinical work has shown that this molecule has NK-cell targeted activity against a variety of solid tumors, including head and neck cancer squamous cell carcinoma (figure below), prostate cancer, breast cancer, ovarian cancer, glioblastoma, and lung cancer (amongst others). We are advancing GTB-5550 through preclinical studies and initiated a GMP manufacturing campaign in anticipation of filing an IND. A pre-IND packet was submitted to the FDA in October 2023 with a written response from the FDA in December 2023. The main question from the FDA was regarding pre-clinical toxicology and a pivot to subcutaneous dosing. The initial trial is designed as a basket trial for patients with B7-H3+ solid tumors using Monday through Friday dosing (2 weeks on and 2 weeks off to prevent immune exhaustion), and is dependent on manufacturing of clinical materials.

Current wording

GTB-5550 is a B7-H3 targeted TriKE® which targets B7-H3 on the surface of advanced solid tumors (figure above). GTB-5550 is our first dual camelid TriKE®. B7-H3 is expressed on a broad spectrum of solid tumor malignancies, allowing our team to target these malignancies through GTB-5550. Pre-clinical work has shown that this molecule has NK-cell targeted activity against a variety of solid tumors, including head and neck cancer squamous cell carcinoma (figure below), prostate cancer, breast cancer, ovarian cancer, glioblastoma, and lung cancer (amongst others). We are advancing GTB-5550 through preclinical studies and initiated a GMP manufacturing campaign in anticipation of filing an IND. A pre-IND packet was submitted to the FDA in October 2023 with a written response from the FDA in December 2023. The main question from the FDA was regarding pre-clinical toxicology and a pivot to subcutaneous dosing. The initial trial is designed as a basket trial for patients with B7-H3+ solid tumors using Monday through Friday dosing (2 weeks on and 2 weeks off to prevent immune exhaustion), and is dependent on manufacturing of clinical materials. We anticipate submission of an IND application for GTB-5550 in late December 2025 or in January 2026.

Previous wording

Comparison of the Three and Six Months Ended June 30, 2025 and 2024

Current wording

Comparison of the Three and Nine Months Ended September 30, 2025 and 2024

Previous wording

Research and development expenses decreased by approximately $1.4 and $1.1 million for the three and six months ended June 30, 2025, respectively, compared to the same prior year periods, primarily due to a decrease in production and scientific research costs.

Current wording

Research and development expenses decreased by approximately $0.7 and $1.8 million for the three and nine months ended September 30, 2025, respectively, compared to the same prior year periods, primarily due to a decrease in production and material costs.

Previous wording

Research and development expenses relate to our continued licensing, development and production of our most advanced TriKE® product candidates GTB-3650 and GTB-5550 along with the progression on other promising candidates. In late June 2024, we received clearance from the FDA with respect to our IND Application in relation to our next generation GTB-3650 camelid nanobody product. Study enrollment began in early 2025 and we have advanced into the clinic, enrolling patients, and performing tests for data collection throughout the year. Following our May 2025 financing we have restarted the final phase of product development of GTB-5550 and anticipate submission of an IND application for GTB-5550 in fourth quarter of 2025.

Current wording

Research and development expenses relate to our continued licensing, development and production of our most advanced TriKE® product candidates GTB-3650 and GTB-5550 along with the progression on other promising candidates. In late June 2024, we received clearance from the FDA with respect to our IND Application in relation to our next generation GTB-3650 camelid nanobody product. Study enrollment began in early 2025 and we have advanced into the clinic, enrolling patients, and performing tests for data collection throughout the year. Following our May 2025 financing we have restarted the final phase of product development of GTB-5550 and anticipate submission of an IND application for GTB-5550 in late December 2025 or in January 2026.

Previous wording

Selling, general, and administrative expenses decreased by approximately $856,000 and $2.2 million for the three and six months ended June 30, 2025, compared to the same prior year periods, was primarily due to a significant reduction in legal fees and other cost reduction measures.

Current wording

Selling, general, and administrative expenses remained relatively flat, increasing by approximately $72,000 for the three months ended September 30, 2025, compared to the same prior year period. Selling, general, and administrative expenses decreased by approximately $2.2 million for the nine months ended September 30, 2025, compared to the same prior year period, and was primarily due to a significant reduction in legal fees and other cost reduction measures, and partially offset by increased marketing expenses.

Previous wording

Interest income decreased by $67,000 and $177,000 for the three and six months ended June 30, 2025, respectively, compared to the same prior year periods, due to lower money market fund and short term investment balances.

Current wording

Interest income decreased by $60,000 and $237,000 for the three and nine months ended September 30, 2025, respectively, compared to the same prior year periods, due to lower money market fund and short term investment balances.

Previous wording

The change in fair value of warrant liability decreased by approximately $231,000 and $763,000 for the three and six months ended June 30, 2025, respectively, compared to the same prior year periods, resulting from a reduction in our warrant liability primarily due to the decline in the Company’s relative stock price at June 30, 2025 as compared to the prior comparable periods.

Current wording

The change in fair value of warrant liability increased by approximately $137,000 for the three months ended September 30, 2025, compared to the same prior year period, resulting from a reduction in our warrant liability primarily due to the relative decline in the Company’s stock price at September 30, 2025 as compared to the prior comparable period.

Previous wording

In March 2025, a legal services firm currently engaged by the Company agreed to reduce the Company’s prior year unpaid fees by approximately $1 million. The Company classified this transaction as other income during the period ended June 30, 2025.

Current wording

In March 2025, a legal services firm currently engaged by the Company agreed to reduce the Company’s prior year unpaid fees by approximately $1 million. The Company classified this transaction as other income in June 30, 2025.

Previous wording

In May 2025 the Company issued warrants underlying 24,390 shares of common stock exercisable at $2.24 per share with a fair value of approximately $44,000 in exchange for the waiver of a variable rate transaction (“VRT”). The Company classified this transaction as other income during the period ended June 30, 2025. The Company also recorded other income of $200,000 in June 2025 due to the extinguishment of an accrual of consulting fees recorded in prior years.

Current wording

In May 2025 the Company issued warrants underlying 24,390 shares of common stock exercisable at $2.24 per share with a fair value of approximately $44,000 in exchange for the waiver of a variable rate transaction (“VRT”). The Company classified this transaction as other income in June 30, 2025. The Company also recorded other income of $200,000 in June 2025 due to the extinguishment of an accrual of consulting fees recorded in prior years.

Previous wording

Net loss decreased by approximately $2.3 and $3.8 million for the three and six months ended June 30, 2025, respectively, compared to the same prior year periods, primarily due to a decrease research and development expenses and legal fees, as described above.

Current wording

Net loss decreased by approximately $300,00 and $4.1 million for the three and nine months ended September 30, 2025, respectively, compared to the same prior year periods, primarily due to a decrease research and development expenses and legal fees, as described above.

Previous wording

The accompanying unaudited condensed financial statements have been prepared assuming that we will continue as a going concern. We do not have any product candidates approved for sale and have not generated any revenue from our product sales. We have sustained operating losses since inception, and we expect such losses to continue into the foreseeable future. Historically, we have financed our operations through public and private sales of common stock, the issuance of preferred and common stock, the issuance of convertible debt instruments, and strategic collaborations. For the six months ended June 30, 2025, we recorded a net loss of approximately $2.2 million and used cash in operations of approximately $5.2 million. These factors raise substantial doubt about our ability to continue as a going concern within one year of the date that the financial statements are issued. In addition, the Company’s independent registered public accounting firm, in its report on the Company’s December 31, 2024, financial statements, raised substantial doubt about the Company’s ability to continue as a going concern. The financial statements do not include any adjustments that might be necessary if the Company is unable to continue as a going concern.

Current wording

The accompanying unaudited condensed financial statements have been prepared assuming that we will continue as a going concern. We do not have any product candidates approved for sale and have not generated any revenue from our product sales. We have sustained operating losses since inception, and we expect such losses to continue into the foreseeable future. Historically, we have financed our operations through public and private sales of common stock, the issuance of preferred and common stock, the issuance of convertible debt instruments, and strategic collaborations. For the nine months ended September 30, 2025, we recorded a net loss of approximately $5.3 million and used cash in operations of approximately $8.9 million. These factors raise substantial doubt about our ability to continue as a going concern within one year of the date that the financial statements are issued. In addition, the Company’s independent registered public accounting firm, in its report on the Company’s December 31, 2024, financial statements, raised substantial doubt about the Company’s ability to continue as a going concern. The financial statements do not include any adjustments that might be necessary if the Company is unable to continue as a going concern.

Previous wording

Net cash used in operating activities was approximately $ 7.7 million for the six months ended June 30, 2024 and was primarily due to a net loss of $6.0 million and a decrease in accounts payable and accrued expenses of $1.3 million

Current wording

Net cash used in operating activities was approximately $8.9 million for the nine months ended September 30, 2025 and was primarily due to a decrease in accounts payable and accrued expenses of $2.4 million and a net loss of $5.3 million.

Previous wording

Net cash used in operating activities was approximately $5.2 for the six months ended June 30, 2025 and was primarily due to a decrease in accounts payable and accrued expenses of $1.6 million and a net loss of $2.2 million.

Current wording

Net cash used in operating activities was approximately $ 10.4 million for the nine months ended September 30, 2024 and was primarily due to a net loss of $9.4 million and a decrease in warrant liability of $0.9 million

Previous wording

Net cash provided by financing activities was approximately $12.9 million for the six months ended June 30, 2024, resulted from proceeds of the sale of short-term investments.

Current wording

Net cash provided by financing activities was approximately $12.9 million for the nine months ended September 30, 2024, resulted from proceeds of the sale of short-term investments.

Previous wording

Net cash provided by financing activities was approximately $6.5 million for the six months ended June 30, 2025 and resulted from net proceeds from issuance of Series L Convertible Preferred Stock and warrants, and net proceeds from the exercise of warrants for cash and inducement warrants.

Current wording

Net cash provided by financing activities was approximately $7.5 million for the nine months ended September 30, 2025 and resulted from net proceeds from issuance of Series L Convertible Preferred Stock and warrants, and net proceeds from the exercise of warrants for cash and inducement warrants.

Previous wording

Net cash provided by financing activities approximately $3.0 million for the six months ended June 30, 2024 and resulted from net proceeds from issuance of common stock and warrants.

Current wording

Net cash provided by financing activities approximately $3.0 million for the nine months ended September 30, 2024 and resulted from net proceeds from issuance of common stock and warrants.