DIT309 for advanced bone and soft tissue sarcomas

A Single-Arm, Open-Label Clinical Study to Evaluate the Safety and Efficacy of DIT309 Cell Injection in Subjects With Advanced Bone and Soft Tissue Sarcomas

This trial will test DIT309, a CAR‑T cell therapy given by IV, to see if it helps people with advanced bone or soft tissue sarcomas who have not responded to standard treatments.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 15 (estimated)
• Ages: 8 Years and up
• Sex: All
• Sponsor: Tcelltech Inc. (Industry-sponsored)
• Drugs / interventions: trastuzumab, CAR-T, cyclophosphamide, fludarabine
• Locations: 1 site (Shanghai, Shanghai Municipality)
• Trial ID: NCT07052383 on ClinicalTrials.gov

What this trial studies

This open‑label, phase 1 dose‑escalation trial gives DIT309 by intravenous infusion on Day 1 of each 28‑day cycle using a traditional 3+3 design across three dose levels. Leukapheresis is performed to manufacture the CAR‑T cells and dose‑limiting toxicities are monitored during the first treatment cycle to identify the maximum tolerated dose and a recommended Phase II dose. Each dose level will enroll 3 to 6 patients and participants must have measurable, antigen‑positive tumors and adequate organ function. The study’s primary goals are to characterize safety and tolerability and to look for early signs of antitumor activity in advanced bone and soft tissue sarcoma patients.

Who should consider this trial

Good fit: Ideal candidates are people age ≥8 weeks with histologically confirmed advanced bone or soft tissue sarcoma that express the target antigen, have failed or are intolerant to standard therapies, have measurable disease, and meet ECOG and laboratory criteria.

Not a fit: Patients whose tumors lack the required target antigen, who have poor performance status, short life expectancy, or contraindications to leukapheresis or lymphodepletion are unlikely to benefit.

Why it matters

Potential benefit: If successful, DIT309 could provide a new targeted option that shrinks tumors or controls disease in patients with advanced bone and soft tissue sarcomas.

How similar studies have performed: CAR‑T therapies have been highly successful in some blood cancers but have shown limited and inconsistent results in solid tumors such as sarcomas, making this approach still largely experimental.

Eligibility criteria

Inclusion Criteria:

1. Voluntarily agrees to participate in the clinical trial; is fully informed about the study and has signed the informed consent form (ICF); is willing and able to comply with all study procedures.
2. Male or female patients aged ≥8 weeks.
3. Histologically confirmed diagnosis of advanced bone and soft tissue sarcoma, who have failed or are intolerant to prior standard therapies.
4. At least one measurable lesion as defined by RECIST version 1.1.
5. Tumor tissue demonstrates positive expression for the target antigen according to the protocol-defined criteria.
6. ECOG performance status of 0-1 within 24 hours prior to leukapheresis and prior to lymphodepletion.
7. Life expectancy of more than 6 months.
8. Adequate venous access for leukapheresis, with no contraindications for the procedure.
9. Laboratory parameters must meet the following criteria:

   1. Hematologic function: WBC ≥ 3.0 × 10⁹/L; Hemoglobin ≥ 8.0 g/dL; ANC ≥ 1.5 × 10⁹/L; Platelets ≥ 75.0 × 10⁹/L
   2. Renal function: Serum creatinine ≤ 1.5 × upper limit of normal (ULN)
   3. Hepatic function: ALT and AST ≤ 2.5 × ULN (≤ 5.0 × ULN for subjects with liver metastasis)
   4. Total bilirubin ≤ 2.0 × ULN (excluding patients with Gilbert's syndrome, defined as persistent or recurrent unconjugated hyperbilirubinemia without evidence of hemolysis or hepatic pathology)
   5. Coagulation: Without anticoagulation therapy, PT, APTT, or INR ≤ 1.5 × ULN
   6. Negative pregnancy test for female subjects of childbearing potential
10. Subjects of childbearing potential must agree to use effective contraception from the date of signing the informed consent through 6 months after the last infusion.

Exclusion Criteria:

1. Pregnant or breastfeeding women
2. Viral infections:

   1. Positive serology for HIV antibodies or syphilis
   2. Positive HBsAg or HBcAb with HBV DNA above the lower limit of detection in peripheral blood
   3. Positive HCV antibody with detectable HCV RNA in peripheral blood
3. Medical history and comorbidities:

   1. Known hypersensitivity to DIT309 cells or any component of the investigational products (including fludarabine, cyclophosphamide, or trastuzumab), or history of severe allergic reactions
   2. Known active autoimmune diseases (e.g., Crohn's disease, systemic lupus erythematosus); subjects with vitiligo or childhood asthma in complete remission and not requiring treatment in adulthood may be eligible; subjects requiring medical intervention such as bronchodilators for asthma are not eligible
   3. Currently receiving systemic immunosuppressive therapy or anticipated need for long-term immunosuppression during the study (topical, inhaled, or intranasal corticosteroids used intermittently are allowed)
   4. Prior exposure to any gene-modified T cell therapy (e.g., CAR-T or TCR-T) or any form of gene therapy\*
   5. History of uncontrolled neurological or psychiatric disorders that may increase the risk of participation or interfere with study results in the investigator's opinion, including but not limited to epilepsy, dementia, or major depression
   6. Untreated or symptomatic CNS or leptomeningeal metastases
   7. Unresolved toxicities from prior treatment that have not recovered to Grade ≤1 per CTCAE v5.0 (except for toxicities deemed not to pose safety risk by the investigator, such as alopecia, Grade 2 peripheral neuropathy, or hypothyroidism managed with replacement therapy)
   8. History of other primary solid malignancies
   9. Major surgery or significant trauma within 1 month prior to leukapheresis
   10. Any serious or uncontrolled comorbidity that, in the investigator's opinion, may increase risks associated with study participation or investigational drug administration, including but not limited to: cardiovascular or cerebrovascular disease, renal insufficiency, pulmonary embolism, coagulation disorders requiring long-term anticoagulation, active or uncontrolled infections requiring systemic treatment.

Where this trial is running

Shanghai, Shanghai Municipality

• Shanghai General Hospital — Shanghai, Shanghai Municipality, China (Recruiting)

Study contacts

• Study coordinator: Rui Feng, MD

Conditions Osteosarcoma; Soft Tissue Sarcoma; Advanced