Phase I Study of TX103 CAR-T Cells in Participants With Advanced Solid Tumors

NCT07231081 | Recruiting Phase 1

• 1 other identifier: TX103T-RP007
• Study Type: interventional
• Target: 85
• Locations: 1 country
• Sites: 2

Brief Summary

This is a single-arm, open-label, Phase I study to evaluate the safety, tolerability, and antitumor activity of TX103 CAR-T cells in subjects with TX103-positive advanced solid tumors. The study also aims to explore the maximum tolerated dose (MTD) and determine the recommended Phase II dose (RP2D) of TX103 CAR-T cell therapy.

Conditions

Solid Tumors

Outcome Measures

Primary Outcomes (3)

• Safety#Incidence and severity of adverse events (AEs)

  To evaluate the possible adverse events after TX103 infusion, including the incidence, and severity of AEs.

  1 year post CAR-T cells infusion

• Safety#Incidence of Dose Limiting Toxicity (DLT)

  Type, incidence, and severity of dose limiting toxicities (DLTs) within 28 days after the first TX103 infusion.

  28 days after the first TX103 infusion

• The maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of TX103

  From first dose of TX103 until the end of Dose Limiting Toxicity (DLT) observation period (typically 28 days post-infusion for each dose).

Secondary Outcomes (7)

• Progression Free Survival (PFS)

  1 year post CAR-T cells infusion

• Disease Control Rate (DCR)

  1 year post CAR-T cells infusion.

• Overall survival (OS)

  6 and 12 months post CAR-T cells infusion

• Objective response rate (ORR)

  1 year post CAR-T cells infusion

• Time to Remission (TTR)

  1 year post CAR-T cells infusion.

Other Outcomes (5)

• The immunogenicity of TX103

  Up to 12 months

• The positive rate of replication competent lentivirus tests.

  Up to 15 years.

• Peak Concentration (Cmax) of TX103 CAR gene.

  Up to 12 months

Study Arms (3)

IV Dose-Escalation Cohort

EXPERIMENTAL

Subjects in this arm will receive TX103 CAR-T cells via intravenous infusion. A standard 3+3 dose-escalation design will be used to evaluate safety, tolerability, and preliminary antitumor activity. The planned dose levels are as follows:Dose Level 1: 1.0 × 10⁸ CAR-T cells;Dose Level 2: 3.0 × 10⁸ CAR-T cells;Dose Level 3: 9.0 × 10⁸ CAR-T cells;Dose Level 4: 2.0 × 10⁹ CAR-T cells.

Biological: Anti-B7-H3 Chimeric Antigen Receptor T-Cell (CAR-T Cell) Injection/TX103

IP Dose-Escalation Cohort

EXPERIMENTAL

Subjects in this arm will receive TX103 CAR-T cells via intraperitoneal (IP) infusion. This cohort will be initiated sequentially after the IV dose-escalation cohort. The starting dose for the IP cohort will be based on the safe and potentially efficacious dose identified in the IV cohort. Further dose escalation will be determined by the Safety Science Committee based on accumulated safety and efficacy data. The planned dose levels are as follows:Dose Level 1: 1.0 × 10⁸ CAR-T cells;Dose Level 2: 3.0 × 10⁸ CAR-T cells;Dose Level 3: 9.0 × 10⁸ CAR-T cells;Dose Level 4: 2.0 × 10⁹ CAR-T cells;Dose Level 5: 4.0 × 10⁹ CAR-T cells. Dose escalation will proceed sequentially, with safety evaluation at each dose level before escalation.

Biological: Anti-B7-H3 Chimeric Antigen Receptor T-Cell (CAR-T Cell) Injection/TX103

Expansion Cohort (Phase Ib)

EXPERIMENTAL

Subjects in this arm will receive TX103 CAR-T cells at the dose determined to be safe and potentially efficacious in the Phase Ia dose-escalation cohorts. The expansion cohort will focus on tumor types that showed preliminary signs of antitumor activity in Phase Ia, and selection will also consider clinical needs and other relevant factors. The purpose of this cohort is to further evaluate the safety, tolerability, and preliminary efficacy of TX103 CAR-T therapy in these selected tumor types.

Biological: Anti-B7-H3 Chimeric Antigen Receptor T-Cell (CAR-T Cell) Injection/TX103

Interventions

Anti-B7-H3 Chimeric Antigen Receptor T-Cell (CAR-T Cell) Injection/TX103 BIOLOGICAL

TX103 CAR-T cells are autologous T cells genetically engineered to express a chimeric antigen receptor (CAR) targeting TX103-positive tumor cells. This therapy is designed to recognize and kill TX103-expressing malignant cells. TX103 CAR-T cells are administered either via intravenous (IV) infusion or intraperitoneal (IP) infusion, depending on the cohort. For dose-escalation cohorts (Phase Ia), a standard 3+3 design is used: 1. IV dose-escalation cohort: planned doses range from 1.0 × 10⁸ to 2.0 × 10⁹ CAR-T cells. 2. IP dose-escalation cohort: initiated sequentially after the IV cohort; starting dose is based on the safe and potentially efficacious dose from IV cohort, with planned escalation up to 4.0 × 10⁹ CAR-T cells. The Phase Ib expansion cohort administers TX103 CAR-T at the dose determined to be safe and potentially efficacious in Phase Ia, focusing on tumor types that showed preliminary signs of antitumor activity and meet clinical needs. TX103 CAR-T therapy is distinct fro

Expansion Cohort (Phase Ib); IP Dose-Escalation Cohort; IV Dose-Escalation Cohort

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \. Voluntary participation: Subjects must voluntarily participate in this clinical trial, fully understand and sign the informed consent form (ICF), and be willing and able to comply with all study procedures.
• \. Age: Male or female patients aged ≥18 years and \<75 years at the time of signing the ICF.
• \. Diagnosis: Subjects must have B7-H3/CD276-positive advanced solid tumors confirmed by pathology, who have failed standard therapy or are intolerant to standard treatment.
• Intraperitoneal infusion cohort: limited to subjects with recurrent or metastatic ovarian cancer, fallopian tube cancer, primary peritoneal cancer, or other advanced solid tumors with peritoneal metastases confined to the peritoneal cavity.
• Intravenous infusion cohort: subjects with advanced solid tumors regardless of peritoneal metastasis, preferably including head and neck squamous cell carcinoma, esophageal cancer, lung malignancies, triple-negative breast cancer, colorectal cancer, and mesenchymal-derived malignancies.
• \. B7-H3/CD276 expression: Tumor tissue immunohistochemistry (IHC) results show B7-H3/CD276 positivity ≥20%, defined as the percentage of viable tumor cells with positive membrane expression of B7-H3/CD276 in non-necrotic tumor tissue.
• \. Measurable/evaluable disease:
• Intraperitoneal infusion cohort, Phase Ia: at least one evaluable lesion per RECIST 1.1;
• Intravenous infusion cohorts (Ia and Ib) and intraperitoneal infusion cohort (Ib): at least one measurable lesion per RECIST 1.1.
• \. Performance status: Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• \. Life expectancy: Expected survival of \>6 months. 8. Apheresis capability: Adequate venous access for leukapheresis and no contraindications to the procedure.
• \. Adequate organ function (per NCI CTCAE v5.0) within screening period:
• Hematologic: WBC ≥ 3.0×10⁹/L; hemoglobin ≥ 8.0 g/dL; absolute neutrophil count ≥ 1.5×10⁹/L; platelet count ≥ 75.0×10⁹/L. No transfusions or supportive treatments (e.g., G-CSF, erythropoietin, TPO agonists, IL-11) within 14 days before testing.
• Renal: Serum creatinine ≤ 1.5× upper limit of normal (ULN) and estimated glomerular filtration rate (eGFR) or creatinine clearance (CrCl, per Cockcroft-Gault formula) \> 50 mL/min.
• Hepatic: ALT and AST ≤ 2.5× ULN (≤ 5.0× ULN for patients with liver metastases).

You may not qualify if:

• \. Pregnant or lactating women. 2. Viral infections:
• Positive for HIV antibody or syphilis serologic test;
• Positive for HBsAg or HBcAb with HBV DNA ≥ 2000 IU/mL;
• Positive for HCV antibody with detectable HCV RNA;
• Presence of other active viremia. 3. Known hypersensitivity, allergy, intolerance, or contraindication to TX103 CAR-T or any component of the study drugs (including fludarabine, cyclophosphamide, or tocilizumab), or history of severe allergic reactions.
• \. Active autoimmune diseases, including but not limited to autoimmune hepatitis, interstitial pneumonitis, uveitis, enteritis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism, or hypothyroidism.
• Subjects with vitiligo or childhood asthma that has resolved and requires no intervention may be included.
• Subjects requiring medical intervention for asthma (e.g., bronchodilators) are excluded.
• \. Receiving systemic immunosuppressive therapy, or judged by the investigator to require long-term immunosuppressants during the study. Topical, inhaled, or intranasal corticosteroids are permitted.
• \. Prior exposure to any gene-engineered T-cell therapy (including CAR-T or TCR-T) or any other gene therapy.
• \. History of organ transplantation. 8. Untreated or symptomatic central nervous system (CNS) metastases or leptomeningeal metastases.
• Subjects previously treated for brain/leptomeningeal metastases may be eligible if neurologically stable for ≥1 month (MRI) and off systemic corticosteroids for \>2 weeks.
• \. Imaging (CT/MRI) showing tumor invasion of major blood vessels (e.g., aorta, pulmonary arteries/veins, vena cava) or indistinct vascular margins.
• \. History of epilepsy or seizure-provoking disorders within 1 year prior to infusion.
• \. Unresolved toxicities from prior anticancer therapy not recovered to CTCAE v5.0 Grade ≤1, except for investigator-judged non-safety-risk toxicities (e.g., alopecia, Grade 2 peripheral neuropathy, stable hypothyroidism with replacement therapy).

Sponsors & Collaborators

• Tcelltech Inc.: lead

Study Sites (2)

Beijing Cancer Hospital

Beijing, China

NOT YET RECRUITING

Beijing Gaobo Hospital

Beijing, China

RECRUITING

MeSH Terms

Interventions

Immunotherapy, Adoptive; Injections

Intervention Hierarchy (Ancestors)

Adoptive Transfer; Immunization, Passive; Immunization; Immunotherapy; Immunomodulation; Biological Therapy; Therapeutics; Immunologic Techniques; Investigative Techniques; Drug Administration Routes; Drug Therapy

Study Officials

• Gangxiong Huang, MD

  Tcelltech Inc.

  STUDY CHAIR

Central Study Contacts

Rui Feng, MD

CONTACT

+(86)13509312934; fengrui@tcelltech.com

Xianzhen Chen, MM

CONTACT

+(86)18649725652; chenxianzhen@tcelltech.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 13, 2025
• First Posted: November 17, 2025
• Study Start: October 16, 2025
• Primary Completion (Estimated): December 20, 2027
• Study Completion (Estimated): December 20, 2027
• Last Updated: November 17, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

CN (2)