NCT06594445

Brief Summary

This is a Phase I dose finding study of GTB-3650 (anti-CD16/IL-15/anti-CD33) Tri-Specific Killer Engager (TriKE®) for the treatment of select CD33-expressing refractory/relapsed myeloid malignancies in adults ≥ 18 years of age who are not a candidate for potentially curative therapy, including hematopoietic stem cell transplantation, and are refractory to, intolerant of, or ineligible for therapy options that are known to provide clinical benefit. The hypothesis is GTB-3650 TriKE will induce natural killer (NK) cell function by targeting malignant cells, as well as, CD33+ myeloid derived suppressor cells (MDSC) which contribute to a tumor induced immunosuppression. Because CD16 is the most potent activating receptor on NK cells, this single agent may induce a targeted antiCD33+ tumor response

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
45

participants targeted

Target at P50-P75 for phase_1

Timeline
18mo left

Started Nov 2024

Typical duration for phase_1

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress50%
Nov 2024Oct 2027

First Submitted

Initial submission to the registry

September 10, 2024

Completed
9 days until next milestone

First Posted

Study publicly available on registry

September 19, 2024

Completed
2 months until next milestone

Study Start

First participant enrolled

November 19, 2024

Completed
2.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 30, 2027

Expected
7 months until next milestone

Study Completion

Last participant's last visit for all outcomes

October 30, 2027

Last Updated

June 29, 2025

Status Verified

June 1, 2025

Enrollment Period

2.4 years

First QC Date

September 10, 2024

Last Update Submit

June 27, 2025

Conditions

Outcome Measures

Primary Outcomes (1)

  • MTD (ug/kg/day)

    Maximum tolerated dose (MTD) of GTB-3650 TriKE defined as the dose level that most closely corresponds to the target dose limiting toxicity (DLT) proportion of 20% or less.

    6 months

Secondary Outcomes (3)

  • Number of Participants With Adverse Events as a Measure of Safety and Feasibility ofGTB-3650 TriKE.

    6 months

  • Event free survival

    6 months

  • Overall survival (OS)

    6 months

Study Arms (7)

Arm 1: Dose Level 1: 1.25 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 2: Dose Level 2: 2.5 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 3: Dose Level 3: 5 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 4: Dose Level 4: 10 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 5: Dose Level 5: 25 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 6: Dose Level 6: 50 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Arm 7: Dose Level 7: 100 ug/kg/day

EXPERIMENTAL

GTB-3650 is administered during an inpatient stay by continuous infusion (CI) consisting of three consecutive 24 hour infusion "bags" over a 72 hour period. Each 72-hour infusion period is designated a "block". A 28-day treatment cycle consists of two blocks followed by approximately 18 days of no treatment. Prior to each block start, the patient must meet the safety criteria.GTB-3650 may continue for up to four treatment cycles total provided disease based response criteria is met and the patient is otherwise eligible to continue.

Drug: GTB-360

Interventions

GTB-3650 is administered by a continuous infusion (CI). A patient's dose of GTB-3650 is calculated using their assigned Dose Level and their actual body weight (ABW) obtained within 5 days prior to or on Cycle 1, Day 1. Dose Level 1: 1.25 ug/kg/day Dose Level 2: 2.5 ug/kg/day Dose Level 3: 5 ug/kg/day Dose Level 4: 10 ug/kg/day Dose Level 5: 25 ug/kg/day Dose Level 6: 50 ug/kg/day Dose Level 7: 100 ug/kg/day

Also known as: anti-CD16/IL-15/anti-CD33
Arm 1: Dose Level 1: 1.25 ug/kg/dayArm 2: Dose Level 2: 2.5 ug/kg/dayArm 3: Dose Level 3: 5 ug/kg/dayArm 4: Dose Level 4: 10 ug/kg/dayArm 5: Dose Level 5: 25 ug/kg/dayArm 6: Dose Level 6: 50 ug/kg/dayArm 7: Dose Level 7: 100 ug/kg/day

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Diagnosis of a high risk myelodysplastic syndromes (MDS), treatment related MDS, OR relapsed/refractory acute myelogenous leukemia (AML).
  • Absolute lymphocyte count (ALC) ≥ 200 cells/µL OR absolute circulating CD56+/CD3- NK cell count \>25 cells/µL within the 14 days prior to Cycle 1 Day 1.
  • Peripheral blasts ≤20,000 at the time of treatment start. Hydroxyurea may be used up to Day 1 of the 1st cycle to achieve this threshold and continued for the 1st two weeks of Cycle 1 to maintain it.
  • Karnofsky performance status ≥ 70%
  • Adequate organ function within 14 days (30 days for cardiac) of Cycle 1 Day 1
  • Sexually active persons of childbearing potential or persons with partners of childbearing potential must agree to use a highly effective form of contraception during study treatment and for at least 4 months after the last dose of GTB-3650. Non-childbearing is defined as \>1 year postmenopausal or surgically sterilized.
  • For the Dose Finding Component Only: Must agree to stay within a 60- minute drive of the Study Center through the Cycle 1 Day 29 visit (end of the Dose Limiting Toxicity period).
  • Provides voluntary written consent prior to the performance of any research related activity.
  • Pulmonary: room air 0 2 saturation at ≥ 95%

You may not qualify if:

  • Pregnant or breast-feeding. The effect of GTB-3650 TriKE on the fetus is unknown. Persons of childbearing potential must have a negative serum or urine test within 7 days prior to Cycle 1 Day 1 to rule out pregnancy.
  • A candidate for hematopoietic stem cell transplant (HSCT) or newly relapsed after HSCT (e.g. no post-HSCT therapy given).
  • Bi-phenotypic acute leukemia or mixed lineage leukemia.
  • Acute promyelocytic leukemia (APL).
  • No anticancer therapy within 14 days of Cycle 1 Day 1; any AEs from therapy given prior must have resolved to Grade 1 or baseline
  • New or progressive pulmonary infiltrates on screening chest x-ray or chest CT scan unless cleared for study by Pulmonary. Infiltrates attributed to infection must be stable/improving with associated clinical improvement after 1 week of appropriate therapy (4 weeks for presumed or documented fungal infections).
  • Active systemic infection requiring parenteral antibiotic therapy. Any prior systemic infections must have resolved following optimal therapy.
  • Known history of HIV.
  • Active Hepatitis B or Hepatitis C (virus detectable by PCR) - chronic asymptomatic viral hepatitis is allowed.
  • Positive test results from chronic hepatitis B infection (defined as positive HBsAg serology) and/or positive test results for hepatitis C (HCV antibody serology test).
  • Prior malignancy except for the following: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I or II cancer currently in complete remission, or any other cancer from which the patient has been disease-free for 1 year
  • Active central nervous system (CNS) malignancy or symptoms of CNS spread or administration of IT chemotherapy within 14 days prior to Day 1.
  • Extramedullary disease causing symptoms and/or involving the CNS or spinal canal - asymptomatic extramedullary disease outside the CNS and spinal canal is eligible provided the marrow has measurable disease.
  • Known autoimmune disease requiring active treatment with steroids or other immunosuppressive medications within 14 days before Cycle 1 Day. Inhaled or topical steroids, and adrenal replacement steroid doses ≤ 10 mg daily prednisone equivalent, are permitted in the absence of active autoimmune disease.
  • Persons with a condition requiring systemic treatment with steroids (\> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days before Cycle 1 Day 1.
  • +5 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Masonic Cancer Center

Minneapolis, Minnesota, 55455, United States

RECRUITING

MeSH Terms

Conditions

Leukemia, Myeloid, AcuteMyelodysplastic Syndromes

Condition Hierarchy (Ancestors)

Leukemia, MyeloidLeukemiaNeoplasms by Histologic TypeNeoplasmsHematologic DiseasesHemic and Lymphatic DiseasesBone Marrow Diseases

Central Study Contacts

Mark Juckett, MD

CONTACT

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
SEQUENTIAL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 10, 2024

First Posted

September 19, 2024

Study Start

November 19, 2024

Primary Completion (Estimated)

March 30, 2027

Study Completion (Estimated)

October 30, 2027

Last Updated

June 29, 2025

Record last verified: 2025-06

Locations