GT Biopharma, Inc. (NASDAQ:GTBP) Offers Near-Term Catalyst Opportunity with Advancing Phase 1 Trials

Rhea-AI Summary

GT Biopharma (NASDAQ:GTBP) is advancing second‑generation NK cell engagers with clinical and preclinical milestones through early 2026.

Key points: GTB 3650 is in a Phase 1 dose‑escalation trial for CD33+ hematologic malignancies; Cohorts 1–3 (six patients) completed with no tolerability issues reported in Cohort 3 and signs of increased NK cell activity. GTB 5550 aims for an IND submission in Dec 2025–Jan 2026 with subcutaneous dosing; GTB 7550 remains preclinical with manufacturing planned in 2026. Cash was $2.6M as of Q3 2025, funding operations into early 2026.

Positive

• Cohorts 1–3 completed with six patients treated
• Cohort 3 safety review found no tolerability issues
• Early cohorts showed increased NK cell activity
• GTB 5550 IND planned for Dec 2025–Jan 2026

Negative

• Cash balance of $2.6M as of Q3 2025 funds operations only to early 2026
• Phase 1 data limited to six patients across early cohorts
• Efficacy not yet demonstrated beyond biomarker signals

Insights

Clinical development strategist

Early Phase 1 safety and biomarker signals with defined near‑term IND and cohort milestones; limited cash runway raises execution risk.

GT Biopharma advances its NK cell engager platform via the lead candidate GTB 3650, now in a Phase 1 dose‑escalation study for CD33‑positive hematologic malignancies. Enrollment began in January 2025 and cohorts 1–3 (six patients) were treated by October 2025, with a formal safety review for Cohort 3 permitting progression to Cohort 4 at 10 µg/kg/day. Reported early pharmacodynamic findings show increased NK cell activity, which aligns with the proposed TriKE mechanism and supports continued dose escalation and biomarker assessment.

Key dependencies and risks include the remaining dose‑escalation safety data, demonstration of meaningful clinical activity beyond biomarker changes, and the company’s funding sufficiency. The company reported $2.6 million in cash as of Q3 2025, stated to fund operations into early 2026, which constrains the timeline for next‑stage data readouts and the planned IND submission for GTB 5550 in late December 2025 or January 2026. Manufacturing plans for another program are set for 2026, which also depends on financing and regulatory progress.

Watch for confirmation of tolerability and any dose‑limiting toxicities as cohorts expand, pharmacokinetic/pharmacodynamic correlations that link NK expansion to clinical responses, and the timing of the GTB 5550 IND filing and subsequent dosing approach. Expect meaningful near‑term updates within the next several months given the stated IND timing and the company’s cash runway into early 2026.

NAPLES, FL / ACCESS Newswire / November 19, 2025 / Patients battling aggressive blood cancers face limited treatment options and uncertain outcomes. Scientists have increasingly turned to the body's own defenses, developing therapies that empower natural killer (NK) cells to seek and destroy malignant cells. These next-generation approaches combine precision, potency, and the potential for fewer side effects than conventional treatments.

The global oncology market is projected to nearly double from $139.4 billion in 2025 to $268.3 billion by 2034, expanding at a compound annual growth rate of 7.5%, according to Global Market Insights Inc. This growth reflects both rising cancer prevalence and increasing demand for innovative, targeted therapies.

Within this landscape, GT Biopharma (NASDAQ:GTBP) is advancing a proprietary platform designed to harness NK cells against cancer. Its main candidate, GTB 3650, is currently being tested in Phase 1 trials for patients with relapsed or refractory acute myeloid leukemia, and the company is also working on treatments Early clinical progress and multiple upcoming milestones position GTBP as a notable player in the evolving immuno-oncology market.

Advancing a Potent Platform
GTBP's TriKE platform focuses on NK cell engagers designed to activate and expand a patient's own immune cells. Second-generation TriKE molecules, built with camelid nanobody technology, are reported to be 10 to 40 times more potent than first-generation constructs. The lead program, GTB 3650, is undergoing a Phase 1 dose escalation study targeting CD33-positive hematologic malignancies, including AML and high-risk MDS. The FDA cleared t-positive2024, and enrollment began in January 2025.

Clear Progress in Early Cohorts
The trial includes up to seven cohorts, two patients each, with dose levels ranging from 1.25 µg/kg/day to 100 µg/kg/day. As of October 2025, all six patients in Cohorts 1 through 3 had been successfully treated. The Cohort 3 formal safety review revealed no tolerability issues. enabling progression to Cohort 4 at 10 µg/kg/day. Management described this dose as "more reflective of the potential efficacy threshold," citing positive trends in immunologic biomarkers.

Early cohorts also demonstrated increased NK cell activity, supporting the TriKE mechanism of immune activation and expansion. GTB 3650 is administered as a 72-hour continuous infusion in two-week blocks, allowing assessment of safety, pharmacokinetics, pharmacodynamics, NK cell expansion, and early clinical activity.

Pipeline Growth and Financial Health
GTB 5550, GTBP's B7H3-targeting TriKE, is preparing for an IND submission in late December 2025 or January 2026. This dual camelid nanobody design will use subcutaneous dosing, offering a more patient-friendly alternative to continuous infusion. Preclinical studies support activity against breast, lung, ovarian, pancreatic, bladder, prostate, and head and neck cancers.

Additionally, GTB 7550 targets CD19-positive lymphoid malignancies and autoimmune diseases and remains in preclinical development, with manufacturing plans underway for 2026. GTBP is building a pipeline that spans hematologic, solid tumor, and immune-mediated indications.

Financially, the company reported $2.6 million in cash as of Q3 2025, expected to fund operations into early 2026. R&D expenses decreased year-over-year, while SG&A costs remained stable, reflecting disciplined management during clinical advancement.

GT Biopharma, Inc. (NASDAQ:GTBP) is developing a unique NK cell engager platform with several projects targeting blood cancers and solid tumors. Early safety results for GTB 3650, along with signs of immune activation, support the promise of second-generation TriKEs. As they continue to increase doses, prepare for a new solid tumor application, and work on more early-stage programs, GTBP provides investors with several upcoming opportunities while gradually establishing a presence in NK cell-based immuno-oncology.

Mark McKelvie
RazorPitch Inc
https://razorpitch.com/
Markrmckelvie@gmail.com
585 301 7700

SOURCE: GT Biopharma, Inc.

View the original press release on ACCESS Newswire

FAQ

What is GT Biopharma (GTBP) announcing about GTB 3650 in November 2025?

GTBP reported Phase 1 dose‑escalation progress: Cohorts 1–3 (six patients) treated and Cohort 3 showed no tolerability issues.

How far does GTBP's cash runway extend after Q3 2025 for GTBP stock (NASDAQ:GTBP)?

The company reported $2.6M in cash as of Q3 2025, expected to fund operations into early 2026.

When is GT Biopharma planning the IND submission for GTB 5550 (GTBP)?

GTBP is preparing an IND for GTB 5550 targeted for late December 2025 or January 2026.

What clinical signals has GTBP reported for GTB 3650 as of October 2025?

Early cohorts showed increased NK cell activity and no tolerability issues in Cohort 3; dosing continues upward.

What is the dosing method for GTB 3650 and how is it administered?

GTB 3650 is given as a 72‑hour continuous infusion in two‑week blocks during the Phase 1 study.

What development plans exist for GTB 7550 in GTBP's pipeline?

GTB 7550 is in preclinical development with manufacturing plans scheduled for 2026.