The goal of this clinical trial is to evaluate the safety, tolerability, and preliminary efficacy in adult patients with relapsed or refractory (r/r) CD19-positive B-cell Non-Hodgkin Lymphoma (B-NHL) or B-cell Leukemia. The main questions it aims to answer are:

• What are the safety and tolerability profiles of GI001, specifically regarding the incidence of Dose-Limiting Toxicities (DLTs) and the determination of the Maximum Tolerated Dose (MTD)?
• What is the preliminary efficacy of GI001, measured by Objective Response Rate (ORR), Complete Response Rate (CRR), and Duration of Response (DOR)?
• What are the pharmacokinetic (expansion and persistence of CAR-T cells) and pharmacodynamic (cytokine changes) characteristics of GI001?

Participants will:

• Undergo a screening process (D-30 to D-3) and baseline evaluation to ensure eligibility, including confirmation of CD19-positive disease.
• Receive a single intravenous infusion of GI001 at one of four designated dose levels (1E8, 3E8, 7E8 or 1E9 TU) following an "Accelerated Titration" and "3+3" dose-escalation design.
• Remain hospitalized for at least 14 days post-infusion for intensive safety monitoring, specifically for Cytokine Release Syndrome (CRS) and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS).
• Provide multiple blood, saliva, and urine samples for pharmacokinetic (PK), pharmacodynamic (PD), and exploratory analysis (including immunogenicity and viral shedding).
• Participate in efficacy and safety follow-ups through Month 24, followed by a long-term safety follow-up for up to 15 years.

Study Design and Methodology This is an investigator-initiated, open-label, single-arm, dose-escalation, and expansion exploratory clinical study. The study utilizes an "Accelerated Titration" combined with a standard "3+3" design to evaluate the safety, tolerability, and preliminary anti-tumor activity of GI001 injection-an innovative in vivo CAR-T therapy-in patients with relapsed or refractory (r/r) CD19+ B-cell malignancies.

Dose Escalation Phase Four dose levels have been pre-specified: 1E8, 3E8, 7E8 or 1E9 TU

1. Accelerated Titration: The first subject will be enrolled at the starting dose ( TU). If no Dose-Limiting Toxicity (DLT) or Grade 2 treatment-related adverse events occur within the 28-day DLT observation period, the study may proceed to the next dose level with a single subject.
2. Standard 3+3 Design: If a DLT or significant toxicity (as defined in the protocol) is observed during the accelerated phase, the study will transition to a traditional 3+3 escalation model to ensure subject safety and more robustly determine the Maximum Tolerated Dose (MTD).

Dose Expansion Phase Upon completion of the escalation phase and determination of the MTD or Recommended Dose for Expansion (RDE), an additional 12-18 subjects will be enrolled to further characterize the safety profile and provide a more comprehensive assessment of preliminary efficacy.

Treatment and Monitoring Subjects will receive a single intravenous infusion of GI001. Due to the risk of Cytokine Release Syndrome (CRS) and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS), subjects must be hospitalized for intensive monitoring for at least 14 days post-infusion. Clinical assessments, including physical examinations, vital signs, and laboratory tests (hematology, biochemistry, and coagulation), will be conducted at frequent intervals.

Pharmacokinetics (PK) and Pharmacodynamics (PD)

A central laboratory will analyze peripheral blood, saliva, and urine samples to:

• Quantify the expansion and persistence of GI001 CAR-T cells using qPCR and/or Flow Cytometry.
• Monitor systemic cytokine levels (e.g., IL-6, IFN-, TNF-) to correlate with safety and efficacy outcomes.
• Assess immunogenicity (Anti-Drug Antibodies) and potential viral shedding (RCL testing) to ensure long-term biological safety.

Long-Term Follow-up Following the initial 24-month efficacy and safety evaluation period, subjects will be invited to participate in a long-term safety follow-up study for up to 15 years, in accordance with regulatory guidelines for gene therapy products, to monitor for delayed adverse events such as secondary malignancies or prolonged B-cell aplasia.

Inclusion Criteria:

1. Age: 18 years and older (inclusive).

2. Diagnosis: Diagnosis of CD19-positive relapsed/refractory B-cell lymphoma/leukemia:

   • 1) CD19-positive relapsed or refractory B-cell lymphoma/leukemia must meet the following criteria:
   • Histopathological diagnosis includes: indolent lymphoma (iNHL), including but not limited to follicular lymphoma (FL), marginal zone lymphoma (MZL), small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), lymphoplasmacytic lymphoma (LPL), hairy cell leukemia (HCL), etc.; aggressive B-cell lymphoma, including but not limited to diffuse large B-cell lymphoma (DLBCL, including Richter-transformed DLBCL), primary mediastinal large B-cell lymphoma (PMBCL), lymphoblastic lymphoma (LBL), transformed follicular lymphoma (TFL), and T-cell/histiocyte-rich large B-cell lymphoma (TCRBCL), etc., and patients in the lymphoma leukemia phase involving the bone marrow.
   • Definition of refractory: Best response to first-line standard therapy is PD; or response to first-line therapy is SD for 6 months after at least 4 cycles; or no response to second-line or later therapies, including PD as best response to the most recent therapy; or SD for 6 months after at least 2 cycles of the most recent therapy; or disease progression or biopsy-confirmed relapse within 12 months after autologous hematopoietic stem cell transplantation (ASCT); or patients undergoing salvage therapy after ASCT with no remission or relapse (SD or PD) after the last treatment; or relapse more than 3 months after CAR-T cell therapy in CD19+ patients.
   • Definition of relapse: PD again after achieving remission (including PR or CR) following adequate treatment.
   • Note: Subjects must have been adequately treated and failed or relapsed after guideline-recommended first-line therapy (including anti-CD20 monoclonal antibody combination therapy or BTK inhibitors).
   • 2) B-cell lymphoma/leukemia patients with bone marrow relapse must meet the following criteria:
   • Definition of relapse: Hematological relapse: re-emergence of B-lymphoma cells ( 5%) in peripheral blood or bone marrow in patients who achieved CR, or appearance of extramedullary disease; OR bone marrow or peripheral blood molecular relapse: MRD positivity reappears after HCR and MRD negativity, with an increase of 1 log in MRD levels between two positive samples.
   • Definition of refractory: Failure to achieve CR after at least two cycles of standard chemotherapy; or failure to achieve CR after at least one cycle of treatment following late relapse ( 12 months) after CR; or relapse after HSCT; or patients undergoing salvage therapy after HSCT failing to achieve remission after the last treatment; or Philadelphia chromosome-positive patients who failed to achieve CR or relapsed after at least two types of TKI treatment, or are intolerant/contraindicated to TKI treatment.
   • 3) Patients unsuitable for stem cell transplantation, or with documented refusal of other existing treatments, or for whom no standard treatment plan exists, may also be included.

3. CD19 expression: CD19 positivity detected by IHC or FACS in tumor specimens, bone marrow, or peripheral blood during screening.

4. Measurable disease: B-cell lymphoma subjects must have measurable lesions per Lugano 2014 (LDi > 1.5 cm for nodal, LDi > 1.0 cm for extranodal); B-lymphoma/leukemia subjects must have B-lymphoma cell proportion 5% at screening.

5. ECOG performance status: 0-2.

6. Life expectancy: 12 weeks.

7. Organ function: Adequate organ function meeting the following laboratory results before enrollment:

   • Blood routine: For B-cell lymphoma patients, bone marrow reserve must meet: ANC > 0.5 10E9/L (no short-acting G-CSF within 7 days or long-acting G-CSF within 14 days); ALC 0.5 10E9/L; Platelets 30 10E9/L (no transfusion within 7 days); Hemoglobin 80 g/L (no RBC transfusion within 7 days; EPO allowed). All patients (B-cell lymphoma/leukemia) require absolute CD3+ T-cell count 150/L.
   • Liver function: ALT and AST 3 ULN; Total bilirubin 2 ULN.
   • Renal function: CrCl 60 ml/min (Cockcroft-Gault).
   • Coagulation: Fibrinogen 1.0 g/L; APTT 1.5 ULN; PT 1.5 ULN.
   • Heart: LVEF 55%.
   • Oxygen saturation: > 91%.

8. Steroids: Therapeutic doses of steroids must be stopped 72 hours before GI001 infusion (except physiological replacement doses).

9. CNS prophylaxis: Must be stopped 1 week before GI001 infusion (e.g., intrathecal methotrexate).

10. Contraception: Subjects and spouses agree to use effective contraception from signing ICF until one year after GI001 infusion or until CAR-T cells are not detected in two consecutive PCR tests (whichever is longer).

11. Informed Consent: Voluntarily sign the EC-approved ICF before screening.

Exclusion Criteria:

1. Prior antitumor therapy (except drugs proven to enhance or not affect CAR-T efficacy after elution):

   • Cytotoxic chemotherapy within 2 weeks before administration.
   • Small molecule targeted therapy within 2 weeks before administration.
   • Antibody therapy within 3 weeks before administration.
   • PEG-asparaginase within 4 weeks before administration.
   • Immunosuppressive therapy within 4 weeks before administration or requirement for long-term use.
   • Radiotherapy within 4 weeks before administration.
   • Bendamustine within 6 months before administration.
   • Previous gene therapy products, including CAR-T therapy (except patients with no CAR-T in vivo, normal T-cell count/function, and CD19+ tumor).
   • Previous anti-CD19/anti-CD3 or any other anti-CD19 therapy (except patients with normal T-cell count/function and CD19+ tumor).
   • Other interventional clinical trial drugs or antitumor therapies within 4 weeks or 5 half-lives before administration (whichever is shorter).

2. Other malignancies: Malignancies within 2 years before screening, excluding adequately treated cervical carcinoma in situ, skin cancers, or radically treated localized prostate, breast (DCIS), or papillary thyroid cancers.

3. Organ transplant: History of solid organ transplantation.

4. Immunomodulators: Use within 2 weeks before administration or potential use during the study (e.g., thalidomide, lenalidomide, pomalidomide).

5. Corticosteroids: Requirement for long-term therapeutic doses (Prednisone > 15 mg/day or equivalent), except physiological replacement or topical/inhaled use.

6. CNS involvement: History or presence of CNS infiltration (leukemia/lymphoma cells in CSF; imaging showing masses/enhancement; or neurological symptoms with abnormal CSF).

7. Hypertension: Uncontrolled hypertension despite drug therapy.

8. Cardiac disease: Severe cardiac disease: MI or CABG/stenting within 6 months; unstable angina; NYHA Class III heart failure; severe arrhythmia; severe non-ischemic cardiomyopathy.

9. Systemic disease: Unstable systemic disease: severe liver, kidney, or metabolic disease requiring medication.

10. Infection: Uncontrolled active infection (bacterial, fungal, viral) requiring IV anti-infectives (continuous signs/symptoms without improvement).

11. Neurological/Psychiatric: Stroke or epilepsy within 6 months; other CNS diseases; uncontrolled psychiatric disorders; history deemed to increase risk or interfere with results.

12. Thrombosis: History of DVT or PE within 6 months.

13. Vaccine: Live vaccine within 6 weeks before screening.

14. Surgery: Major surgery within 2 weeks before screening or planned surgery within 2 weeks after administration (except local anesthesia).

15. Pregnancy/Lactation: Pregnant or nursing women, or those planning pregnancy during/after treatment.

16. Toxicity: Prior non-hematological toxicities not resolved to baseline or Grade 2 (except alopecia, fatigue, peripheral neuropathy).

17. Viral pseudotyping: Prior treatment using VSV-G or Nipah virus pseudotyping.

18. Infectious serology: HBsAg+ and/or HBcAb+ with HBV-DNA > detection limit; HCV antibody+ with HCV-RNA > detection limit; HIV antibody+; Syphilis serology+.

19. Extramedullary relapse: B-cell leukemia patients with isolated extramedullary relapse.

20. Allergy: Allergy to the study drug, excipients, or Tocilizumab.

21. Immunodeficiency: Patients with primary immunodeficiency.

22. HSCT: Planned HSCT within 28 days after GI001 injection.

23. Other: Other conditions deemed unsuitable by the investigator.