New antibody TST003 takes on Hard-to-Treat cancers
NCT ID NCT05731271
First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This early-phase trial is testing a new drug called TST003 in about 111 people with advanced solid tumors (cancers that have spread or cannot be removed by surgery). TST003 is an antibody that blocks a protein called GREM1, which may help tumors grow. The main goals are to find a safe dose, check for side effects, and see if the drug can shrink tumors. Participants receive the drug through an IV once every three weeks.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- TST003 (a lab-made antibody that targets a protein called GREM1)
- What this could lead to
- If it works, this could lead to a new treatment option for people with certain advanced solid tumors that have not responded to other therapies.
- What could go wrong
- This is an early-phase trial (Phase 1/2) with only 111 participants, so the drug may not prove effective or may have unexpected side effects. It is also only for patients with tumors that have a specific marker (GREM1 positive).
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 1/2
Runs two stages together: safety and dose first, then whether the treatment works.
- Participants
-
111 people
The number who actually took part.
- Started
-
Feb 2023
- Expected to finish
-
Dec 2026
An estimate. End dates often move.
- Lead sponsor
-
A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 years and older
- Sex
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Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. At least 18 years of age at the time of informed consent. 2. Voluntary agreement to provide written informed consent and the willingness and ability to comply with all aspects of the protocol. 3. Part 1: Subjects with histological or cytological diagnosed unresectable locally advanced or metastatic malignant solid tumors and who can provide archival tumor tissue. For Part 2: Subjects with histological or cytological diagnosed unresectable locally advanced or metastatic CRC and who can provide archival tumor tissue 4. Subjects who have tumor progression during or after prior therapy and for whom no standard therapy exists that would confer clinical benefit. 5. At least 1 measurable lesion per RECIST v1.1 ( Part 2 only). 6. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1. 7. Life expectancy of 12 weeks or more. 8. Calculated creatinine clearance ≥30 mL/min per the Cockcroft and Gault formula. 9.Adequate bone marrow function: * Absolute neutrophil count (ANC) ≥ 1500/mm3 (≥ 1.5 ×103/L); * Platelets ≥ 100,000/mm3 (≥ 100 × 109/L); * Hemoglobin ≥ 9.0 g/dL; 10.Adequate blood coagulation function as evidenced by an International Normalized Ratio (INR) ≤ 1.5 and Activated Partial Thromboplastin Time (aPTT) ≤ 1.5 ULN (unless subjects are receiving therapeutic anti-coagulation which affects these parameters, and patients receiving therapeutic anticoagulation should be on a stable dose). 11.Adequate liver function as evidenced by bilirubin ≤1.5 × ULN and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3×ULN. 12.Women of childbearing potential (WOCBP) and men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception during the treatment period and for at least 90 days after the last dose of TST003. Contraception methods should be consistent with local regulations. Exclusion Criteria: 1. Untreated or symptomatic central nervous system (CNS) metastases. Note: Subjects with asymptomatic treated CNS metastases are eligible provided they have been clinically stable and not requiring steroid for at least 4 weeks following CNS -directed therapy are eligible for study entry. 2. Prior systemic anti-cancer treatment (chemotherapy, immunotherapy, biologic therapy, or targeted therapy or herbal medicine) within 4 weeks or 5 half-lives (whichever is shorter) prior to the first dose of study drug. 3. Radical radiation or local-regional therapies (transarterial chemoembolization or radiofrequency ablation) within 4 weeks prior to the first dose of study drug; palliative radiotherapy to a non-target lesion within 2 weeks prior to of study drug. 4. Any unresolved Grade 2 or greater toxicity from previous anticancer therapy except alopecia. 5. Any herbal medicine without anti-tumor intent within one week before the first dose of study drug. 6. History of interstitial lung disease, noninfectious pneumonitis, or uncontrolled lung diseases, including but not limited to pulmonary fibrosis, active pneumonitis. 7. Severe cardiovascular disease, including cerebrovascular accident, transient ischemic attack, myocardial infarction, or unstable angina, New York Heart Association (NYHA) class III or IV heart failure or uncontrolled arrhythmia within 6 months of the first dose. 8. Has the average corrected QT interval by Fridericia's formula (QTcF) prolongation to \> 480 millisecond (ms) based on 12-lead ECG in triplicate, or with a history of additional risk factors for torsade de pointes (e.g., heart failure, hypokalemia, family history of long QT syndrome or unexplained sudden death under 40 years of age in first degree relatives). 9. Uncontrolled hypertension (systolic pressure \>150mmHg or diastolic pressure \> 90mmHg). 10. Severe intestinal disease, including but not limited to: 1. Peptic ulcer disease in the past 3 months prior to the first dosing. 2. Clinically significant gastrointestinal bleeding as evidenced by hematemesis, hematochezia, or melena in the past 3 months prior to the first dosing without evidence of resolution documented by endoscopy or colonoscopy. 3. Active colitis requiring ongoing treatment within 4 weeks prior to the first dosing, including infectious colitis, radiation colitis and ischemic colitis. 4. History of ulcerative colitis or Crohn's disease. 11. Active or uncontrolled infections requiring IV of antibiotics, antivirals, or antifungals. 12. Active viral (any etiology) hepatitis except with the viral load below the limit quantification (hepatitis B virus (HBV) deoxyribonucleic acid (DNA) \< 1000 copies/mL or 200 IU/mL; hepatitis C virus (HCV) ribonucleic acid (RNA) below the limit of quantification). 13. Known human immunodeficiency virus (HIV) infection or known acquired immunodeficiency syndrome. 14. Females who are pregnant or nursing. 15. Has known hypersensitivity to either the drug substances or inactive ingredients in the drug product. 16. Prior severe hypersensitivity to other antibodies, which in the opinion of the Investigator suggests an increased potential for hypersensitivity to study drug. 17. Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigation device within 4 weeks prior to the first dose of study drug. 18. Has a history or current evidence of any severe condition, concurrent therapy (e.g., psychiatric, substance abuse), or laboratory abnormality that might confound the interpretation of the study results, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the investigator. Additional Exclusion Criteria for Part 2 only (for Pharmacodynamic Cohorts) 19. Prior treatment with a GREM1 targeted therapy. 20. Any malignancy within 3 years prior to the first dosing of study drug except adequately treated localized carcinomas where standard therapy has been administered and patient is considered cured. 21. Subject will not be able to undergo on-treatment tumor biopsy on C3D1 per investigator's best judgement as baseline.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Mary Crowley
Dallas, Texas, 75231, United States
-
NEXT Oncology
San Antonio, Texas, 78229, United States
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OHSU
Portland, Oregon, 97239, United States
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