1. An early-stage Kite Pharma (pioneer of CAR-T cancer therapy) for immune-engaging cancer drugs.

2. A clinical-stage Genentech (known for innovative biotech cancer drugs) focused on supercharging immune cells to fight cancer.

• GTB-3550: A single-chain tri-specific recombinant fusion protein conjugate in Phase I/II clinical trials for myelodysplastic syndromes, refractory/relapsed acute myeloid leukemia, advanced systemic mastocytosis, and CD33+ malignancies.
• GTB-3650: A preclinical stage drug candidate targeting CD33 on the surface of myeloid leukemias.
• GTB-5550: A preclinical stage drug candidate for treating patients with B7-H3 positive solid tumors.

Therefore, GT Biopharma does not currently have commercialized products on the market, and consequently, it does not have major customers in the traditional sense of companies or individuals purchasing its products. Its primary activities are drug development and clinical trials.

Michael Breen

Executive Chairman, Chief Executive Officer

Michael Breen is an English qualified solicitor/attorney with extensive experience in corporate law and management. He was appointed Chief Executive Officer of GT Biopharma on April 29, 2025. Prior to his CEO appointment, he had been with the company in various leadership roles since 2021, and served as Executive Chairman of the Board. Mr. Breen was formerly the Managing Director of the Sports and Entertainment Division of Bank Insinger de Beaufort N.V., a wealth management organization that was part of the BNP Paribas Group. He was also a director and major shareholder of an affiliate of Insinger de Beaufort Holdings S.A., which was listed on the Luxembourg Stock Exchange. Additionally, Mr. Breen is a former senior equity partner in the law firm Clyde & Co.

Alan L. Urban

Chief Financial Officer

Alan L. Urban was appointed Chief Financial Officer of GT Biopharma on June 3, 2024. He brings over 30 years of corporate finance and accounting experience from a variety of public and private companies. Mr. Urban's past roles include serving as Chief Financial Officer for Research Solutions, Inc. for over a decade from 2011 to 2021, Chief Financial Officer for SRAX, Inc. from March 2023 to July 2023, and Chief Financial Officer for Creek Road Miners, Inc. from November 2021 to March 2023. Earlier in his career, he served as Chief Financial Officer and Senior Vice President of Finance and Accounting for ReachLocal, Inc., and as Vice President of Finance and Treasurer for Infotrieve, Inc. Mr. Urban is a Certified Public Accountant (currently inactive) and previously served as a member of GT Biopharma's Board of Directors from June 2022 to May 2023.

Dr. Gregory Berk

President of R&D and Chief Medical Officer

Dr. Gregory Berk serves as the President of R&D and Chief Medical Officer at GT Biopharma. He previously served as interim Chief Executive Officer in November 2021 during a restructuring of the executive management team.

Dr. Gavin Choy

Chief Clinical Development Officer

Dr. Gavin Choy holds the position of Chief Clinical Development Officer. He has more than 20 years of experience in the pharmaceutical and biotechnology industry, holding various executive leadership roles including Chief Operating Officer at Apollomics, Inc., and President at CG Pharmaceuticals, Inc. Dr. Choy holds a Master of Business Administration with a focus on Health Care from the University of California, Irvine, Paul Merage School of Business. He was appointed acting Chief Financial Officer in November 2021 during a management restructuring.

The key risks for GT Biopharma (GTBP) are:

1. Clinical Trial Failure and Regulatory Approval: As a clinical-stage biopharmaceutical company, GT Biopharma's success hinges on the successful completion of clinical trials for its drug candidates, particularly GTB-3550, which is in Phase I/II. There is a significant risk that these trials may not demonstrate sufficient safety or efficacy, leading to failure to obtain regulatory approval for its immuno-oncology products. This would prevent the company from bringing its products to market and generating revenue.

2. Dependence on Proprietary TriKE Technology Platform: GT Biopharma's entire pipeline, including GTB-3550, GTB-3650, and GTB-5550, is based on its proprietary Tri-specific Killer Engager (TriKE) fusion protein immune cell engager technology platform. The company's future success is heavily reliant on the continued viability and broad applicability of this specific technology. If unforeseen limitations, safety concerns, or competitive technologies emerge that challenge the fundamental efficacy or safety profile of the TriKE platform, it could adversely impact all of GT Biopharma's development programs.

GTB-3550 and GTB-3650 (targeting CD33+ malignancies, including Myelodysplastic Syndromes and Acute Myeloid Leukemia, and Advanced Systemic Mastocytosis)

• Myelodysplastic Syndromes (MDS): The global myelodysplastic syndrome drugs market was estimated at USD 2.88 billion in 2023 and is projected to reach USD 5.28 billion by 2030, growing at a CAGR of 9.1%. North America held the largest share of the global market for myelodysplastic syndrome treatment, accounting for 39.20% in 2026. The U.S. myelodysplastic syndrome market size was nearly USD 2,000 million in 2023.
• Acute Myeloid Leukemia (AML): The global acute myeloid leukemia treatment market size was estimated at USD 3.47 billion in 2024 and is projected to reach USD 6.29 billion by 2030, growing at a CAGR of 10.6%. The global market size for acute myeloid leukemia was valued at USD 2.1 billion in 2023 and is estimated to observe a 10.7% CAGR between 2024 and 2032. North America dominated the global acute myeloid leukemia treatment market with a 37.6% share in 2024. The U.S. acute myeloid leukemia treatment market constituted 90.9% of the North American market in 2024.
• Advanced Systemic Mastocytosis: The global systemic mastocytosis treatment market size was calculated at USD 562.18 million in 2025 and is predicted to increase to approximately USD 1,326.01 million by 2035, expanding at a CAGR of 8.96% from 2026 to 2035. Another report indicates the global systemic mastocytosis treatment market is projected to grow from USD 1.2 billion in 2024 to USD 1.9 billion by 2030, expanding at a 7.8% CAGR. The U.S. market for systemic mastocytosis treatment is expected to rise from USD 0.36 billion in 2024 to USD 0.54 billion by 2030, with a 7.1% CAGR. North America is estimated to contribute 44% to the growth of the global market.

GTB-5550 (targeting B7-H3 positive solid tumors)

• B7-H3 Positive Solid Tumors: The global B7-H3 targeted therapies market size reached USD 484 million in 2024 and is projected to expand at a CAGR of 21.8% from 2025 to 2033, reaching an estimated USD 3.4 billion by 2033. North America accounted for approximately 43% of the global B7-H3 targeted therapies market in 2024, valued at USD 210 million. B7-H3 is an immune checkpoint molecule found in over 70% of various solid tumors. The global solid tumors market size was valued at USD 362.21 billion in 2024 and is projected to reach USD 1557.42 billion by 2032, with a CAGR of 20.00%.

Expected Drivers of Future Revenue Growth for GT Biopharma (GTBP)

1. Advancement of GTB-3650 in Clinical Trials: Continued progress of GTB-3650, currently in a Phase 1 dose-escalation trial for CD33-positive leukemias, is a primary driver. Successful completion of current and planned dose cohorts in 2026, leading to positive safety and preliminary efficacy data, would position the drug for further clinical development and eventual commercialization for conditions like refractory acute myeloid leukemia and high-risk myelodysplastic syndrome.
2. Initiation and Progress of GTB-5550 in Clinical Trials: The planned initiation of a Phase 1 basket trial for GTB-5550 in mid-2026 represents a significant expansion into solid tumors expressing B7-H3. Successful dose escalation and progression into Phase 2 expansion cohorts across various metastatic disease types, including prostate, ovarian, breast, lung, pancreatic, and bladder cancers, would be critical milestones towards future revenue generation from this novel candidate.
3. Validation and Expansion of the TriKE Platform: Positive clinical outcomes from GTB-3650 and GTB-5550 trials would further validate GT Biopharma's proprietary TriKE fusion protein immune cell engager technology platform. This validation could accelerate the development of additional TriKE candidates, attract new co-development partnerships, or lead to licensing opportunities for various oncology indications, thereby broadening the company's product pipeline and long-term revenue potential.

Share Issuance

• GT Biopharma significantly increased its issued and outstanding common shares from 2,234,328 as of December 31, 2024, to 25,534,173 as of December 31, 2025.
• The company's additional paid-in capital increased from $693,554,000 in 2024 to $729,661,000 in 2025, indicating capital raised through equity.
• In May 2025, GT Biopharma completed a Series L 10% Convertible Preferred Stock and warrant financing, which generated net proceeds of $5.441 million.

Inbound Investments

• GT Biopharma received net proceeds of $5.441 million from a Series L 10% Convertible Preferred Stock and warrant financing completed in May 2025.
• The company established a $20 million committed equity facility to potentially access additional capital.

Capital Expenditures

• Research and Development (R&D) expenses were approximately $3.5 million for the year ended December 31, 2025, a decrease of $2.3 million from $5.8 million in the prior year, mainly due to reduced production and material costs.
• The company anticipates initiating a Phase 1 basket trial for GTB-5550 in mid-2026.
• Enrollment in the Phase 1 dose-escalation trial for GTB-3650 is currently active, with an update expected in Q3 2026.