This clinical trial is an open-label, dose-escalation study designed to evaluate the safety, tolerability, pharmacokinetic, and preliminary efficacy of YB1-X7 injection in subjects with advanced solid tumors. YB1-X7 injection is an attenuated Salmonella-based tumor therapy. It selectively accumulates in hypoxic tumor regions while being rapidly cleared from normal organs. After proliferating in the tumor microenvironment, YB1-X7 invades tumor cells and releases its therapeutic payload, leading to tumor cell death and tumor regression. Conditions:To treat subjects with advanced and/or metastatic solid tumors who do not to respond to conventional standard treatment or who lack effective standard treatment.
YB1-X7 is a genetically engineered attenuated Salmonella enterica strain. It has been further optimized based on the attenuated model of VNP20009 while inserting an anaerobic-targeting enrichment system, transforming YB1-X7 into a nutrient-deficient strain under aerobic conditions. This modification allows YB1-X7 to selective proliferation in hypoxic tumor regions while being cleared in normal oxygenated tissues, thereby achieving selective enrichment in tumor. Additionally, YB1-X7 carries plasmids encoding the drug protein. Upon reaching the tumor region, YB1-X7 invades tumor cells, expressing and releasing drug protein, leading to tumor cell death and tumor regression. This study is divided into two parts based on the route of administration: Part 1: Subjects receiving intratumoral injection (IT). Part 2: Subjects receiving intravenous infusion (IV). Both administration routes will have three dose cohorts (low, medium, and high dose) following the standard 3+3 dose-escalation design, with single-dose multiple administrations in an escalating dose scheme. Each subject will receive only one administration method (IT or IV) and be assigned to only one dose cohort, completing the full treatment regimen for that dose level. YB1-X7 injection will be administrated in 28-days cycles (once weekly for 3 weeks followed by 1-week rest). For Subjects receiving intratumoral injection, superficial lesions can be injected directly, while deep-seated lesions may require ultrasound, CT, or endoscopic guidance for precise administration.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
36
Intratumoral injection
Intravenous infusion
Incidence of dose limiting toxicity (DLTs)
DLT is defined as any toxic reaction associated with the study drug occurring within 28 days after the first administration, graded refer to the NCI Common Terminology Criteria for Adverse Events (CTCAE v5.0).
Time frame: Up to 28 days post first dose.
Adverse events (AEs)
An AE is any untoward medical occurrence in a patient or clinical investigation patient, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.
Time frame: From receiving study drug and throughout the study, until 28 days after the last dosing
Serious adverse events(SAEs)
A serious adverse event (SAE) refers to any medical event that results in: * Death * Life-threatening conditions ③ Permanent or severe disability or loss of function ④ Hospitalization or prolonged hospitalization ⑤ Congenital abnormalities or birth defects Other important medical events, which may not immediately threaten life, death, or require hospitalization, but still necessitate medical interventions to prevent one of the above outcomes, are also considered serious. Examples include: * Urgent treatments in an emergency room * Allergic bronchospasm (even if not requiring hospitalization) ③ Severe cachexia or seizures ④ Drug dependence or addiction Death due to drug-related adverse events (e.g., ventricular fibrillation) is classified as an SAE. However, if the death is due to the progression of the underlying disease (e.g., cancer) and the adverse event was mild (e.g., a rash or abdominal pain), it is not considered an SAE.
Time frame: From receiving study drug and throughout the study, until 28 days after the last dosing.
YB1-X7 level in blood for PK analysis
Evaluate the drug concentration and pharmacokinetics for subjects in different dose groups after the dose of either intratumoral injection or intravenous infusion.
Time frame: Before the first administration up to 28 days after the last dosing.
Immunogenicity (anti-drug antibodies)
The changes in the levels of anti-YB1-X7 antibodies (ADA) will be evaluated at different time points.
Time frame: Before the first administration up to 28 days after the last dosing.
YB1-X7 level in blood for bacterial shedding.
For subjects receiving intratumoral injection or intravenous infusion, blood samples will be collected in different dose groups.
Time frame: Before the first administration up to 28 days after the last dosing.
YB1-X7 shedding level analysis in urine, saliva, faeces using qPCR
For subjects receiving intratumoral injection or intravenous infusion, samples will be collected in different dose groups, including urine, saliva and faeces (or rectal swab), and the shedding level will be analysed using quantitative polymerase chain reaction (qPCR).
Time frame: Before the first administration up to 28 days after the last dosing.
Cytokines
Changes in cytokines in the blood at different time points. Cytokines including IFN-γ, IL-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8, TNF-α.
Time frame: Before the first administration up to 28 days after the last dosing.
Objective Response Rate (ORR)
ORR represents the proportion of subjects with complete or partial response, assessed using RECIST 1.1 criteria based on imaging.
Time frame: From signing the informed consent form until 28 days after the last dose.
Progression Free Survival (PFS)
PFS is defined as the time interval from date of first dose of YB1-X7 injection to the date of documented disease progression (iRECIST is used when the patient is suspected to be pseudo disease progression) or death due to any cause, whichever occurs first.
Time frame: From signing the informed consent form until 28 days after the last dose.
ime to Progression (TTP)
Time to Progression (TTP) is defined as the time from the start of treatment to the objective progression of the tumor.
Time frame: From signing the informed consent form until 28 days after the last dose.
Duration of Response (DOR)
Duration of Response (DOR) is defined as the time from the first assessment of Complete Response (CR) or Partial Response (PR) until Disease Progression (PD). It represents the duration that the tumor remains reduced following the treatment.
Time frame: From signing the informed consent form until 28 days after the last dose.
Overall Survival (OS)
OS will be evaluated for subjects in different dose groups who received intratumoral injection or intravenous infusion at Week 52 (1 year). Overall Survival (OS) is defined as the time from the start of treatment to death from any cause.
Time frame: 1 year
ECOG Performance Status Before and After Treatment
Changes in ECOG performance status will be assessed for subjects in different dose groups who received intratumoral injection or intravenous infusion compared to baseline. The score will refer to the Eastern Cooperative Oncology Group (ECOG) Performance Status.
Time frame: From baseline to week 12
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