Phase I Clinical Study to Evaluate SYS6055 Injection in Participants With Relapsed/Refractory B-Cell Malignancies

Phase I Clinical Study to Evaluate the Safety, Tolerability, Pharmacokinetic Profile and Preliminary Efficacy of SYS6055 Injection in Participants With Relapsed/Refractory B-Cell Malignancies

(Limit: 5000 characters) The purpose of this phase I clinical study aims to evaluate the safety, tolerability, pharmacokinetic characteristics and preliminary efficacy of SYS6055 Injection in participants with relapsed/refractory B-cell malignancies, and to provide evidence for recommending a dosage regimen for subsequent studies.

Study Overview

• Status: Not yet recruiting
• Conditions: Relapsed/Refractory B-Cell Malignancies
• Intervention / Treatment: Drug: SYS6055

Detailed Description

(Limit: 32,000 characters)

• Study Type: Interventional
• Enrollment (Estimated): 86
• Phase: Phase 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age≥18 year, and voluntarily signed the Informed Consent Form (ICF);
• Histologically confirmed B-cell malignancy with CD19 antigen-positive tumor cells;
• Patients with relapsed/refractory B-cell malignancies who have failed standard therapy, including B-cell leukemia and B-cell lymphoma;
• At least one measurable lesion according to the 2014 Lugano Response Criteria for Lymphoma;
• ECOG performance status score of 0-1;
• Expected survival of at least 3 months;
• Adequate organ and bone marrow function;
• Eligible participants (males and females) of reproductive potential must agree to use a reliable method of contraception (hormonal contraception, barrier method, or abstinence) with their partner during the trial and for at least 1 year after dosing. Female participants of childbearing potential must have a negative serum pregnancy test within 7 days prior to enrollment. In addition, female participants must agree not to donate oocytes (eggs, ova) for assisted reproductive technology for 1 year after dosing, and male participants must agree not to donate sperm for assisted reproductive technology for 1 year after dosing;
• Willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.

Exclusion Criteria:

• History of other malignancy within 3 years or concurrent other active malignancy (participants with cured localized tumors such as basal cell carcinoma of the skin, squamous cell carcinoma of the skin, superficial bladder cancer, carcinoma in situ of the prostate, carcinoma in situ of the cervix, carcinoma in situ of the breast, etc., may be enrolled);
• Participants with bleeding diathesis, active bleeding, hemoptysis, or history of major bleeding within the previous 6 months; tumor invasion of major blood vessels shown by imaging (CT or MRI), or tumor judged by the investigator as highly likely to invade major blood vessels and cause fatal massive bleeding during the subsequent study period;
• Participants with B-cell malignancies involving the central nervous system;
• Received autologous hematopoietic stem cell transplantation within 3 months prior to the first dose;
• Previous allogeneic bone marrow transplantation, gene therapy, or adoptive cell therapy (including CAR-T therapy);
• Received anti-PD-1, anti-PD-L1, or T-cell engager therapy within 3 months prior to the first dose; received fludarabine or bendamustine within 6 months prior to the first dose;
• Adverse events from prior antineoplastic therapy have not recovered to CTCAE Version 6.0 grade ≤1 (except for alopecia or other toxicities without safety risk as judged by the investigator);
• Received major surgery, chemotherapy, radical radiotherapy, antibody-based targeted therapy, imunotherapy, or other antineoplastic therapy within 28 days prior to dosing; or received palliative radiotherapy, chemotherapy, or small-molecule targeted therapy within 14 days prior to dosing; or received antineoplastic herbal preparations or traditional Chinese patent medicines within 14 days prior to dosing;
• Simultaneously participating in another clinical trial, unless it is an observational (non-interventional) clinical trial or in the follow-up phase of an interventional trial (without impact on the follow-up data of this study);
• Received live vaccine within 4 weeks prior to dosing;
• Active bacterial, fungal, or viral infection prior to dosing. Individuals receiving prophylactic antimicrobial therapy without clinical manifestations of active infection prior to dosing may be considered for enrollment;
• Autoimmune disease requiring systemic therapy;
• History of central nervous system disease or current persistent central nervous system disease that may interfere with neurological assessments;
• History of immunodeficiency or positive HIV antibody test during screening;
• History of tuberculosis treatment within 2 years prior to dosing; history of active syphilis;
• Active hepatitis B or hepatitis C during screening. Active hepatitis B is defined as HBsAg-positive and HBV DNA above the upper limit of normal (ULN). Active hepatitis C is defined as HCV antibody-positive and HCV RNA > ULN;
• History of severe cardiovascular disease;
• Hypersensitivity or intolerance to the excipients of SYS6055 (mainly human albumin);
• Any other conditions in participants that may interfere with compliance with study procedures, are not in the best interest of participants, or may affect study results: e.g., history of psychiatric disorders, drug addiction or substance abuse, any other clinically significant diseases or conditions, etc.;
• Pregnant or lactating female;
• Any other reason judged by the investigator that the participant is not suitable for participation in this clinical trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dose Escalation and Backfill; In the dose escalation phase, participants will receive escalating doses of SYS6055. During the backfill phase, participants will receive selected doses of SYS6055. Participants will be administered a single dose on Day 0 of Cycle 1.	Drug: SYS6055; The dose will be selected based on the dose cohort, with a single administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Dose-limiting toxicities (DLTs)	Dose-limiting toxicities (DLTs) will be assessed 28 days after the first dose.
Occurrence of Adverse Events (AE) and Serious Adverse Events (SAE)	Up to 24 months after administration of 6055
Recommended Phase 2 Dose (RP2D) or Maximum Tolerated Dose (MTD) of SYS6055	through study completion, an average of 3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-free survival (PFS)		through study completion, an average of 3 years
Objective Response Rate (ORR)		through study completion, an average of 3 years
Duration of Response (DoR)		through study completion, an average of 3 years
PD	CRP	2 years
PD	ferritin levels	2 years
PD	immunoglobulin levels (IgG, IgA, IgM)	2 years
PD	peripheral blood lymphocyte subsets (proportion and absolute counts of T, B, and NK cells)，Lymphocyte subsets will be analyzed by flow cytometry.	2 years
Viral shedding	Peripheral blood, urine, saliva, and fecal samples will be collected at predefined time points for the assessment of viral shedding.	2 years
Replication-competent virus detection	Peripheral blood, urine, saliva, and fecal samples will be collected at predefined time points for the assessment of viral shedding.	2 years
Time to Response（TTR）		through study completion, an average of 3 years
Overall Survival (OS)		through study completion, an average of 3 years
PK, CD19-CAR copy number and CD19 CAR-T cell content of SYS6055	The levels of CD19 CAR RNA and DNA in peripheral blood will be determined by qPCR, with the proportion of CD19 CAR-T cells assessed by flow cytometry.	2 years
PK, CD19 CAR-T cell phenotypes	CD19 CAR-T cell phenotypes will be analyzed by flow cytometry, including CD4/CD8 ratio, naïve cells, memory cells, and effector cells.	2 years
PD	Levels of cytokines in peripheral blood (IL-6, IL-10, IFN-γ, TNF-α, etc.).	2 years
Immunogenicity	Incidence of anti-CD19-CAR antibodies and antiviral antibodies.	2 years
Viral integration site analysis	Peripheral blood, urine, saliva, and fecal samples will be collected at predefined time points for the assessment of viral shedding.	2 years

Collaborators and Investigators

• Sponsor: Institute of Hematology & Blood Diseases Hospital, China

Study record dates

Study Major Dates

• Study Start (Estimated): April 15, 2026
• Primary Completion (Estimated): April 15, 2028
• Study Completion (Estimated): April 15, 2030

Study Registration Dates

• First Submitted: March 19, 2026
• First Submitted That Met QC Criteria: March 19, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 13, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Pathological Conditions, Signs and Symptoms; Recurrence
• Other Study ID Numbers: IIT2026024

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No