Skip to content

A Study of SPX-303, a Bispecific Antibody Targeting LILRB2 and PD-L1 in Patients With Solid Tumors

A Phase 1, Open-label Study to Evaluate Safety, Tolerability, and Pharmacokinetics of an Anti-LILRB2 / PD-L1 Bispecific Antibody SPX- 303 in Patients With Solid Tumors

Status
Recruiting
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06259552
Acronym
SPX-303
Enrollment
232
Registered
2024-02-14
Start date
2024-03-20
Completion date
2027-09-30
Last updated
2024-09-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

CRC, HNSCC, RCC, Solid Tumor

Keywords

Solid Tumor

Brief summary

Part 1 of this study is an open-label, dose-escalation, and safety expansion study of an anti-LILRB2 / anti-PD-L1 bispecific antibody SPX- 303 in patients with solid tumors. Part 2 of this study is an indication-specific dose expansion study of SPX-303.

Detailed description

This study is an open-label, dose escalation study of SPX-303 monotherapy to evaluate safety and tolerability, and to identify the MTD or MAD as well as evaluate preliminary anti-tumor efficacy, pharmacokinetics, and pharmacodynamics of various doses of SPX- 303 in patients with measurable disease who have progressed on or after prior therapy and who are not eligible or decline treatment options.

Interventions

BIOLOGICALSPX- 303 Injection, a bispecific anti-LILRB2 / anti-PD-L1 Antibody

SPX- 303 Injection

Sponsors

SparX Biotech(Jiangsu) Co., Ltd.
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Masking description

This study is an open-label, dose escalation study of single agent SPX-303

Intervention model description

Part 1: After the first dose escalation cohort of one patient, further dose escalation cohorts will recruit patients to receive SPX-303 in a 3+3 design; cohorts will be expanded in the event of a DLT. A safety dose expansion of up to 10 patients will confirm the MTD or MAD. Part 2: Once the MTD or MAD has been established, the RP2D and preliminary efficacy will be determined by evaluating two dose levels in specific indications.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Males and females ≥18 years of age who comprehend, are not incarcerated, are willing and able to provide consent by signing an ICF, and able to comply with scheduled visits, treatment schedule, and laboratory tests, including other requirements for the study 2. Histologically or cytologically documented locally advanced or metastatic solid tumor malignancy 3. Patients who have progressed on or after prior therapy and who are not eligible for available treatment options 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 5. Has at least 1 measurable lesion per RECIST 1.1 criteria 6. Recovery from previous treatment related adverse events (TRAEs) to allow safety evaluations of SPX-303. Previous TRAEs include adverse drug reactions, and consequences of radiation, surgery, and other therapeutic modalities 7. Adequate hepatic function; bilirubin ≤1.5x upper limit of normal (ULN) (except for patients with Gilbert syndrome: ≤ 3xULN), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) ≤2.5 x ULN (≤5 x ULN if liver metastases present). 8. Adequate renal function as calculated (e.g. Cockroft Gault) creatine clearance (CrCl) ≥ 30 mL/min or 24-hour urine CrCl ≥ 30 mL/min. 9. Adequate hematological function: absolute neutrophil count (ANC) ≥1 x 10\^9/L; platelets ≥75 x 10\^9/L, hemoglobin ≥9 g/dL. 10. Patients with well controlled HIV infection (ie CD4+ count \>350 cells/uL and viral copies less than 400/mL after at least 4 weeks of ART) are eligible for the trial. 11. Adequate coagulation function: INR, PT and aPPT ≤ 1.5x ULN except for patients on anti-coagulation as long as PT, aPPT, or INR are within intended range. 12. Adequate cardiac function: Left Ventricular Ejection Fraction (LVEF) ≥ 45% by multi-gated acquisition (MUGA) or echocardiography (ECHO) scan. 13. Fridericia-corrected QT interval (QTcF) ≤480 msec. 14. Women of childbearing potential must have a negative pregnancy test and must agree to use of 2 different methods of acceptable contraception from screening until 4 months after the last dose of study drug. Acceptable methods of contraception are defined as those that result, alone or in combination, in a low failure rate (ie, less than 1% per year) when used consistently and correctly, such as surgical sterilization, an intrauterine device, hormonal contraception in combination with a barrier method or abstinence). 15. Males who are sexually active with a female partner of childbearing potential must agree to use a barrier contraception (eg, condom with spermicidal foam/gel/film/cream/suppository) from screening until 4 months following the last dose of study drug, in addition to their female partner using either an intrauterine device or hormonal contraception and continuing until 4 months following the last dose of study drug. This criterion may be waived for male patients who have had a vasectomy \>6 months before signing the ICF.

Exclusion criteria

1. History of prior malignancy, except for adequately treated in situ cancer, basal cell, or squamous cell skin cancer, or other cancers (eg, breast, prostate) for which the patient has been disease free for at least 3 years. Prostate cancer patients on active surveillance are eligible. 2. Active brain or leptomeningeal metastasis. Except patients with known brain metastases if they have been treated and MRI shows no evidence of progression for at least 8 weeks and require less than 10 mg/day prednisone/prednisolone or equivalent. 3. Treatment with anti neoplastic therapy ≤ 28 days or ≤ 5× elimination half life, whichever is shorter, before the first dose of study drug. 4. Major surgery requiring general anesthesia ≤ 28 days prior to dosing. 5. History of permanent discontinuation of prior IO therapy due to irAE. 6. Prior treatment targeting ILT2 and/or ILT4 or targeting HLA G. 7. Live or live attenuated vaccine ≤ 28days prior to dosing. 8. Immunosuppressive systemic medication, except topical corticosteroids or systemic corticosteroids at a dose level of ≤ 10 mg/d of prednisone/prednisolone or equivalent. Note: patients with adrenal insufficiency requiring hormonal replacement may receive higher dose of steroids. 9. Prior solid organ or bone marrow transplantation (except cornea transplantation). 10. History of clinically significant cardiovascular events (e.g. DVT ≤ 6 months, PE ≤ 12 months, MI or hospitalization for CHF ≤ 12 months, bleeding disorder or bleeding event ≤ 6 months, current clinically significant arrhythmia or unstable angina pectoris, current uncontrolled history of cerebrovascular accident in the past 6 months, current uncontrolled hypertension).

Design outcomes

Primary

MeasureTime frameDescription
Part 1: Number of participants with dose limiting toxicities (DLTs)First 21 days of Cycle 1A DLT is defined as the clinically significant TRAE(treatment-related adverse events) or abnormal laboratory values assessment during the first 21 days of Cycle 1 and excludes events that are deemed clearly related to underlying disease, progression, or intercurrent illness.
Part 1: Treatment-Related Adverse Events (TRAE)3.5 yearsTreatment related adverse events (TRAEs) by seriousness per CTCAE v. 5.0. as well as tolerability (TRAEs leading to discontinuation, TRAEs leading to dose delays, duration of TRAEs, and semi-quantitative assessments of TRAE treatments)
Part 1: Potential Phase 2 dose (RP2D) to be further evaluated in Part 23-6 monthsUp to 10 patients will be evaluated for safety and tolerability at maximum tolerated dose/maximum accpeted dose or a lower, already cleared dose level.
Part 2: Phase 2 dose (RP2D) determination1-3 yearsRP2D is determined evaluating two dose levels in each specific indications.

Secondary

MeasureTime frameDescription
Part 1: Pharmacokinetics (PK)1-3 yearsPK is evaluated using serum concentration of SPX-303.
Part 1: Objective Response Rate (ORR)1-3 yearsORR is defined as the percentage of participants with complete response (CR) or partial response (PR) per RECIST v 1.1.
Part 2: Preliminary anti-tumor activity at RP2D1-3 yearsPreliminary anti-tumor activity is evaluated in RP2D cohorts.
Part 1: Pharmacodynamics (PD)1-3 yearsPD is evaluated using receptor occupancy of SPX-303.
Part 1: Duration of Response (DOR)1-3 yearsDOR is defined as the time from the participant's initial objective response (CR or PR) to disease progression per CTCAE v5.0 or death due to any cause, whichever occurs first.
Part 1: Disease Control Rate (DCR)1-3 yearsDCR is defined as percentage of participants with complete response (CR), partial response (PR), or stable disease (SD) per CTCAE v5.0.
Part 1: Progression-free Survival (PFS)1-3 yearsPFS is defined as the interval of time between the date of first treatment to the earliest date of disease progression per CTCAE v5.0 or death which occurs first.

Countries

United States

Contacts

Primary ContactSparX Biotech
SPX-303@sparxbio.com847-739-6251

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026