GT Biopharma Provides Enrollment Update on GTB-3650 Phase 1 Trial in Patients with Relapsed or Refractory (r/r) CD33 Expressing Hematologic Malignancies
GT Biopharma (NASDAQ: GTBP) said Phase 1 enrollment for GTB-3650 in r/r CD33‑expressing hematologic malignancies is progressing on schedule.
Both patients in Cohort 3 have begun treatment with no dose‑limiting toxicities or tolerability concerns observed to date. The first Cohort 3 patient showed immune activation biomarkers consistent with activity seen in Cohorts 1–2. If Cohort 3 completes without new safety findings, dosing will escalate; Cohort 4 initiation is planned by year‑end 2025 with additional data updates anticipated in Q1 2026. The protocol allows up to ~14 patients across seven cohorts with doses from 1.25 μg/kg/day to 100 μg/kg/day, dosed in two‑week on/off cycles for up to four months.
GT Biopharma (NASDAQ: GTBP) ha dichiarato che l'arruolamento di fase 1 per GTB-3650 nelle neoplasie ematologiche recidivanti/refrattarie che esprimono CD33 è in corso come previsto.
Entrambi i pazienti della Cohort 3 hanno iniziato il trattamento senza tossicità dose‑limitante né preoccupazioni di tollerabilità osservate fino ad ora. Il primo paziente della Cohort 3 ha mostrato biomarcatori di attivazione immunitaria coerenti con l'attività osservata nelle Coorti 1–2. Se la Cohort 3 si completa senza nuove peculiarità di sicurezza, la somministrazione verrà aumentata; l'inizio della Cohort 4 è pianificato entro la fine del 2025 con ulteriori aggiornamenti dei dati attesi nel Q1 2026. Il protocollo consente fino a ~14 pazienti distribuiti in sette coorti con dosi da 1,25 μg/kg/giorno a 100 μg/kg/giorno, somministrate in cicli di due settimane ON/OFF per un massimo di quattro mesi.
GT Biopharma (NASDAQ: GTBP) informó que el reclutamiento de la fase 1 para GTB-3650 en neoplasias hematológicas expresando CD33 que son recidivantes/refractarias (r/r) está progresando según lo previsto.
Ambos pacientes de la Cohort 3 han comenzado el tratamiento sin toxicidad límite de dosis ni preocupaciones de tolerabilidad observadas hasta la fecha. El primer paciente de la Cohort 3 mostró biomarcadores de activación inmunitaria consistentes con la actividad observada en las Cohortes 1–2. Si la Cohort 3 se completa sin nuevos hallazgos de seguridad, se aumentará la dosis; la iniciación de la Cohort 4 está planificada para finales de 2025 con nuevos datos esperados en el Q1 2026. El protocolo permite hasta ~14 pacientes en siete cohortes con dosis desde 1,25 μg/kg/día hasta 100 μg/kg/día, administradas en ciclos de dos semanas de actividad/descanso durante hasta cuatro meses.
GT Biopharma (NASDAQ: GTBP)은 CD33를 발현하는 재발성/난치성 혈액종양에서 GTB-3650의 1상 등록이 예정대로 진행 중이라고 밝혔다.
코호트 3의 두 명의 환자 모두 용량 제한성 독성이나 내약성 우려가 아직 관찰되지 않은 채 치료를 시작했다. 코호트 3의 첫 환자는 1–2코호트에서 관찰된 활성과 일치하는 면역 활성 생물지표를 보였다. 코호트 3이 새로운 안전성 소견 없이 완료되면 용량이 증가할 예정이며, 코호트 4의 시작은 2025년 말까지 예정되어 있으며 2026년 1분기에 추가 데이터 업데이트가 기대된다. 프로토콜은 총 7개의 코호트에 걸쳐 최대 약 14명의 환자를 허용하며, 1.25 μg/kg/일에서 100 μg/kg/일까지의 용량과 2주 간격의 온/오프 사이클로 최대 4개월간 투여된다.
GT Biopharma (NASDAQ: GTBP) a déclaré que l'inclusion en phase 1 pour GTB-3650 dans les malignités hématologiques réfractaires exprimant CD33 progresse comme prévu.
Les deux patients de la cohorte 3 ont commencé le traitement sans toxicité limitant la dose ni inquiétudes de tolérabilité observées à ce jour. Le premier patient de la cohorte 3 a montré des biomarqueurs d'activation immunitaire cohérents avec l'activité observée dans les cohortes 1 et 2. Si la cohorte 3 se complète sans nouvelles constatations de sécurité, l'administration de la dose sera augmentée; le lancement de la cohorte 4 est prévu d'ici fin 2025 avec des mises à jour des données prévues au 1er trimestre 2026. Le protocole permet jusqu'à ~14 patients répartis sur sept cohortes avec des doses allant de 1,25 μg/kg/jour à 100 μg/kg/jour, administrées en cycles de deux semaines activés/désactivés pendant jusqu'à quatre mois.
GT Biopharma (NASDAQ: GTBP) sagte, dass die Rekrutierung der Phase-1-Studie für GTB-3650 bei r/r CD33‑ausdrückenden hämatologischen Erkrankungen planmäßig voranschreitet.
Beide Patienten der Kohorte 3 haben die Behandlung begonnen, ohne dosislimitierende Toxizität oder Verträglichkeitsbedenken, die bisher beobachtet wurden. Der erste Patient der Kohorte 3 zeigte immunaktivierungsbasierte Biomarker, die mit der in den Kohorten 1–2 beobachteten Aktivität übereinstimmen. Falls die Kohorte 3 ohne neue Sicherheitsbefunde abgeschlossen wird, wird die Dosis erhöht; der Beginn der Kohorte 4 ist bis Ende 2025 geplant, mit weiteren Datennachträgen voraussichtlich im Q1 2026. Das Protokoll erlaubt bis zu ca. 14 Patienten über sieben Kohorten mit Dosen von 1,25 μg/kg/Tag bis 100 μg/kg/Tag, verabreicht in zweiwöchentlichen On/Off-Zyklen für bis zu vier Monate.
GT Biopharma (NASDAQ: GTBP) ذكرت أن التسجيل في المرحلة 1 لـ GTB-3650 في الأورام الدمويّة الخبيثة التي تعبر عن CD33 والقابلة للعلاج الرجوعي/المستمر يتقدم وفق الجدول الزمني.
كلا المرضين في المجموعة 3 قد بدءا العلاج بدون سمية مقيدة للجرعة أو مخاوف تحمل لوحظت حتى الآن. المريض الأول في المجموعة 3 أظهر biomarkers لتنشيط المناعة متوافقة مع النشاط الملاحظ في المجموعتَين 1 و2. إذا اكتملت المجموعة 3 دون نتائج سلامة جديدة، سيتم رفع الجرعة؛ من المزمع بدء المجموعة 4 بنهاية 2025 مع توقع تحديثات بيانات إضافية في الربع الأول من 2026. يسمح البروتوكول بما يصل إلى حوالي 14 مريضاً عبر سبع مجموعات مع جرعات من 1.25 μg/kg/يوم إلى 100 μg/kg/يوم، تُعطى في دورات أسبوعين من التشغيل/الإيقاف لمدة تصل إلى أربعة أشهر.
GT Biopharma (NASDAQ: GTBP)表示，GTB-3650在CD33表达的难治性/复发性血液肿瘤中的1/2期注册正在按计划进行。
第3队列的两名患者已开始治疗，尚未观察到任何<剂量限制性毒性或耐受性问题。截至目前，第一名第3队列患者的免疫刺激生物标志物与前两组的活性相符。如果第3队列在没有新的安全性发现的情况下完成，剂量将上调；计划在2025年底开启第4队列，预计在2026年第一季度提供更多数据更新。该方案允许七个队列共约
- Cohort 3 dosing initiated with no dose‑limiting toxicities observed
- First Cohort 3 patient showed immune activation consistent with Cohorts 1–2
- Cohort 4 dosing planned by year‑end 2025 with Q1 2026 data updates
- Protocol permits evaluation up to ≈14 patients across seven cohorts
- None.
Insights
Early Phase 1 enrollment progress with biomarker evidence and no dose‑limiting toxicities so far; next milestones by year‑end and Q1 2026.
GT Biopharma has completed Cohorts 1–2 and initiated treatment for both patients in Cohort 3 with no evidence of dose‑limiting toxicities or tolerability concerns to date. The first Cohort 3 patient showed immune activation across multiple biomarkers consistent with responses seen in the first four patients, supporting continued dose escalation under the protocol that allows up to seven cohorts (~14 patients total).
The main dependency remains safety: successful completion of the Cohort 3 safety assessment is the gating item before starting Cohort 4, currently planned by
Watch for three concrete near‑term items: confirmation of no new safety findings on Cohort 3 and formal completion of that assessment, initiation of Cohort 4 by
The Company is well on track with Phase 1 enrollment now that both patients in Cohort 3 have successfully initiated treatment with no evidence of dose-limiting toxicities or tolerability concerns to date
The first patient in Cohort 3 has shown promising evidence of immune activation consistent with levels of activity observed in patients from the previous two lower-dose cohorts; additional update anticipated by year-end
Upon successful completion of the Cohort 3 safety assessment, the trial will continue to dose escalate with initiation of Cohort 4 dosing planned by year-end 2025, and flexibility to dose up to 7 cohorts if necessary; additional data updates anticipated in Q1 2026
SAN FRANCISCO, CALIFORNIA, Oct. 08, 2025 (GLOBE NEWSWIRE) -- GT Biopharma, Inc. (the “Company”) (NASDAQ: GTBP), a clinical stage immuno-oncology company focused on developing innovative therapeutics based on the Company's proprietary TriKE® natural killer (NK) cell engager platform, today announced that enrollment in the dose escalation cohorts of the Phase 1 trial, evaluating GTB-3650 for the treatment of relapsed or refractory (r/r) CD33 expressing hematologic malignancies, is well on track.
Enrollment in Cohorts 1 and 2 were successfully completed; both patients in Cohort 3 have now initiated treatment with no evidence of dose-limiting toxicities or safety concerns to date. The level of immune activation observed from multiple biomarkers in the first patient of Cohort 3 is consistent with the evidence of heightened immune activity in the first four patients from Cohorts 1 and 2. Assuming Cohort 3 is completed with no new safety findings, the trial will continue to dose-escalate into the higher ranges of GTB-3650 anticipated to be necessary to translate heightened immune activation into clinically meaningful evidence of therapeutic activity. Initiation of dosing in Cohort 4 is planned by year-end 2025 and additional data updates are anticipated in Q1 2026.
The Phase 1 protocol allows evaluation of GTB-3650 in up to approximately 14 patients (two patients in each of seven cohorts), with doses ranging from 1.25ug/kg/day in Cohort 1 to 100ug/kg/day in Cohort 7. GTB-3650 will be dosed in two-week blocks, two weeks on and two weeks off (defining a treatment cycle), for up to four months based on clinical benefit. The trial will assess safety, pharmacokinetics, pharmacodynamics, in vivo expansion of endogenous patient NK cells and clinical activity. More details can be found on clinicaltrials.gov with the identifier: NCT06594445.
About GT Biopharma, Inc.
GT Biopharma, Inc. is a clinical stage biopharmaceutical company focused on the development and commercialization of immuno-oncology therapeutic products based on our proprietary TriKE® NK cell engager platform. Our TriKE® platform is designed to harness and enhance the cancer killing abilities of a patient’s immune system’s natural killer cells. GT Biopharma has an exclusive worldwide license agreement with the University of Minnesota to further develop and commercialize therapies using TriKE® technology. For more information, please visit gtbiopharma.com.
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TriKE® is a registered trademark owned by GT Biopharma, Inc.
Investor Relations Contact:
LifeSci Advisors
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212-915-2577
FAQ
What did GTBP announce about GTB-3650 Phase 1 enrollment on October 8, 2025?
When does GTBP plan to start dosing Cohort 4 for GTB-3650?
What timing of additional GTB-3650 data updates did GTBP disclose?
How many patients and dose range does the GTB-3650 Phase 1 protocol allow?
What endpoints will the GTB-3650 Phase 1 trial assess?
Has GTBP reported any safety concerns for GTB-3650 so far?
