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Fc-Engineered Anti-CTLA-4 Monoclonal Antibody in Advanced Cancer

A Phase 1 Study of AGEN1181, an Fc-Engineered Anti-CTLA-4 Monoclonal Antibody as Monotherapy and in Combination With AGEN2034 (Balstilimab), an Anti-PD-1 Monoclonal Antibody, in Subjects With Advanced Cancer

Status
Active, not recruiting
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03860272
Enrollment
499
Registered
2019-03-01
Start date
2019-03-20
Completion date
2027-12-01
Last updated
2026-03-30

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

Conditions

Advanced Cancer, Angiosarcoma, Colorectal Cancer Without Liver Metastases, Endometrial Cancer, Fibrolamellar Carcinoma, Non-small-cell Lung Cancer, Ovarian Cancer, Prostate Cancer

Keywords

Solid Tumors, Advanced Cancer, Open-label, Monotherapy, Combination Therapy, Anti-CTLA-4, Anti-PD-1, Immunotherapy

Brief summary

This study is an open-label, Phase 1, multicenter study to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamic (PD) profiles of a novel fragment crystallizable (Fc)-engineered immunoglobulin G1 anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4) human monoclonal antibody (botensilimab) monotherapy and in combination with an anti-programmed cell death protein-1 (PD-1) antibody (balstilimab), and to assess the maximum tolerated dose (MTD) in participants with advanced solid tumors. This study will also determine the recommended phase 2 dose (RP2D) of botensilimab monotherapy and in combination with balstilimab.

Detailed description

This Phase 1 study will enroll up to approximately 550 evaluable adult participants with refractory, advanced cancer (solid tumors). The study will consist of a 3+3 dose escalation. Different dose levels of botensilimab, both monotherapy and in combination with balstilimab, will be evaluated in individual cohorts based upon dose. Each participant will remain in the cohort of the dose level and schedule assigned at study entry. Participants can be replaced for any reason other than a dose-limiting toxicity (DLT). Participants will receive treatment for ≤ 2 years or until progressive disease, unacceptable toxicity, or any criterion for stopping the study drug or withdrawal of trial occurs. Additionally, the study is intended to further explore the safety, PK, PD, and clinical activity in selected cancer types at dose levels (botensilimab monotherapy and combination therapy with balstilimab) determined as potentially effective. Indications of interest include, but are not limited to, non-small-cell lung cancer, melanoma, endometrial cancer, ovarian cancer, angiosarcoma, colorectal cancer without liver metastases, prostate cancer, and fibrolamellar carcinoma.

Interventions

DRUGBotensilimab

An Fc-engineered anti-CTLA-4 monoclonal antibody

DRUGBalstilimab

A fully human monoclonal anti-PD-1 antibody

Sponsors

Agenus Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Dose escalation

Eligibility

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

Inclusion criteria

For inclusion in the trial, all of the following inclusion criteria must be fulfilled, as no waivers will be permitted: 1. Provision of signed and dated written informed consent prior to any study specific procedures. Participation in pharmacogenomics testing is optional. 2. Histologically or cytologically confirmed diagnosis of metastatic or locally advanced solid tumor for which no standard therapy is available or standard therapy has failed. 3. Measurable disease on imaging based on RECIST 1.1, except for prostate cancer. 4. Life expectancy of ≥ 3 months and Eastern Cooperative Oncology Group performance status of 0 or 1. 5. Adequate organ and bone marrow reserve function, as indicated by the following laboratory values: 1. Adequate hematological function, defined as absolute neutrophil count ≥ 1.5 × 10\^9/liter (L), platelet count ≥ 100 × 10\^9/L, and hemoglobin ≥ 8 grams/deciliter without recent transfusion (defined as a transfusion that has occurred within 2 weeks of the hemoglobin measurement). 2. Adequate liver function, defined as total bilirubin level ≤ 1.5 × institutional upper limit of normal (IULN) (except for participants with Gilbert syndrome who must have a total bilirubin level of ≤ 3.0 × IULN), aspartate aminotransferase ≤ 2.5 × IULN, and alanine aminotransferase ≤ 2.5 × IULN. 3. Adequate renal function defined as creatinine ≤ 1.5 × IULN or measured or calculated creatinine clearance ≥ 40 milliliters (mL)/minute per institutional standard. Assessment methods should be recorded. 4. Adequate coagulation, defined as international normalized ratio or prothrombin time ≤ 1.5 × IULN and activated partial thromboplastin time ≤ 1.5 × IULN (unless participant receiving anticoagulant therapy) or stable known coagulopathy with sponsor approval. 6. A sufficient and adequate formalin-fixed paraffin embedded tumor tissue sample (fresh or archival tumor tissue) collected since last treatment and before the first dose from a site not previously irradiated, if clinically feasible. 7. Female participants of childbearing potential must have a negative serum pregnancy test at screening (within 72 hours of first dose of study medication). Non-childbearing potential is defined as 1 of the following: 1. ≥ 45 years of age and has not had menses for \> 1 year and there is no alternative medical cause. 2. Amenorrheic for \> 2 years without a hysterectomy and/or oophorectomy and follicle stimulating hormone value in the postmenopausal range upon pretrial (screening) evaluation. 3. Status is post-hysterectomy, -oophorectomy, or -tubal ligation. 8. Female participants of childbearing potential must be willing to use highly effective contraceptive measures starting with the Screening visit through 90 days after last dose of study treatment. For the UK only, highly effective contraceptive measures are defined as follows: 1. Combined (estrogen and progesterone containing) hormonal contraception associated with inhibition of ovulation. * Oral * Intravaginal * Transdermal 2. Progesterone-only hormonal contraception associated with inhibition of ovulation. * Oral * Injectable * Implantable 3. Intrauterine device 4. Intrauterine hormone-releasing system 5. Bilateral tubal occlusion 6. Vasectomized partner 7. Sexual abstinence 9. Male participants with a female partner(s) of childbearing potential must agree to use highly effective contraceptive measures throughout the trial starting with the Screening visit through 90 days after the last dose of study treatment is received. Males with pregnant partners must agree to use a condom (which is not considered "highly effective"); no additional method of contraception is required for the pregnant partner. Note: Abstinence is acceptable if this is the established and preferred contraception method for the participant. The following inclusion criteria are in addition to the above criteria. If there are criteria below that differs from above, the below indication-specific criteria take precedence. Additional Inclusion Criteria for Angiosarcoma Cohort 10. Histologically or cytologically confirmed diagnosis of metastatic or locally advanced angiosarcoma for which no standard therapy is available or standard therapy has failed. Additional Inclusion Criteria for the Hepatocellular Cancer (HCC) Cohort 11. Histologically or cytologically confirmed diagnosis or radiological diagnosis following the guidelines from the American Association for the Study of Liver Diseases of metastatic or locally advanced HCC. 12. Must have progressed while receiving, or following, programmed death-ligand 1 (PD(L)-1)-based therapy. 13. Child-Pugh score of A. Note: Participants on anticoagulant treatment would have an assigned value of 1 point when scoring prothrombin time/international normalized ratio so the overall Child-Pugh score is not adversely affected. 14. Adequate organ and bone marrow reserve function as indicated by the following laboratory values: 1. Platelet count ≥ 60 × 10\^6/cubic millimeter (mm\^3) and absolute neutrophil count ≥ 1,000 × 10\^6/L are acceptable provided that the investigator assesses these abnormalities as being due to liver disease. 2. Adequate liver function, defined as aspartate aminotransferase and alanine aminotransferase ≤ 5 × IULN, bilirubin ≤ 2 × IULN. 15. Participants are eligible to enroll if they have non-viral-HCC or if they have hepatitis B (HBV), or hepatitis C virus (HCV) related HCC, defined as follows: 1. Chronic HBV infection as evidenced by detectable HBV surface antigen or HBV DNA. Participants with chronic HBV infection must be on antiviral therapy and have HBV DNA \< 500 international units/mL. 2. Active or resolved HCV infection as evidenced by detectable HCV RNA or antibody. Additional Inclusion Criteria for the Non-Small Cell Lung Cancer (NSCLC) Cohort 16. Histologically or cytologically confirmed diagnosis of metastatic or locally advanced NSCLC for which no standard therapy is available or standard therapy has failed: 1. Adenocarcinoma or squamous cell carcinoma at the time of enrollment. If other histologies are also present, must be approved by the medical monitor prior to study entry. 2. For participants without targetable alterations: Prior treatment with anti PD(L)-1-based therapy. 3. Participants with targetable alterations (for example, estimated glomerular filtration rate, anaplastic lymphoma kinase, Kirsten rat sarcoma virus-single point mutation with a glycine-to-cysteine substitution at codon 12, reactive oxygen species, mesenchymal epithelial transition factor receptor, etc.): must have received or be intolerant of at least one approved targeted therapy. Additional Inclusion Criteria for the Prostate Cancer Cohort 17. Diagnosis of metastatic castrate resistant prostate cancer. 18. Must have demonstrated serologic or radiographic progression on or following the most recent therapy in the setting of castrate-level testosterone (\< 50 nanograms per mL \[ng/mL\] and/or maintained on medical/surgical castration throughout) as defined by at least one of the following: 1. Baseline PSA ≥ 2.0 ng/mL and 2 sequential rises in prostate-specific antigen (PSA) with each rising value being at least 1 week apart. 2. Progression by RECIST 1.1. 3. Progression by PCWG3 criteria for bone disease ("2+2" rule) with or without PSA progression. 19. Must maintain castration status defined as serum testosterone \< 50 ng/mL. Must be either surgically castrate or on luteinizing hormone-releasing hormone analog for the duration of the study. Additional Inclusion Criteria for Breast Cancer 20. Must have received PD-(L)1 therapy if indicated. Note: Premenopausal participants may continue ongoing ovarian suppression on study. Permitted agents are goserelin, triptorelin or analogs.

Exclusion criteria

For inclusion in the trial, participant must meet none of the following

Design outcomes

Primary

MeasureTime frameDescription
Incidence Of Treatment-emergent Adverse Events (TEAEs)First dose through 90 days following last study dose (up to 2 years)TEAEs will include adverse events of special interest, immune-related adverse events, and adverse drug reactions, according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version 5.0.
DLT Of BotensilimabFirst 28 days of treatmentDLTs will include any Grade 2 or greater drug related toxicity for all dose groups, according to NCI CTCAE version 5.0 and protocol specifications.
RP2D Of BotensilimabFirst dose through 90 days following last study doseMTD based on DLT occurrence at DLT period (28 days after first dose) and all TEAEs seen through 90 days following last study dose.

Secondary

MeasureTime frameDescription
Objective Response Rate (ORR) According To Response Evaluation Criteria In Solid Tumors Version 1.1 (RECIST 1.1)First dose through up to 2 yearsConfirmed ORR will be in the analysis population.
ORR According to Prostate Cancer Working Group 3 (PCWG3)First dose through up to 2 yearsConfirmed ORR will be in the analysis population.
Duration Of Response (DOR) According To RECIST 1.1From first dose to first observation of documented disease progression (or death within 12 weeks of last tumor assessment) (up to 2 years)
DOR According to PCWG3From first dose to first observation of documented disease progression (or death within 12 weeks of last tumor assessment) (up to 2 years)
Disease Control Rate (DCR) According To RECIST 1.1First study dose through 24 weeksDCR will include complete response, partial response, and stable disease.
DCR According to PCWG3First study dose through 24 weeksDCR will include complete response, partial response, and stable disease.
Progression-free Survival (PFS) According To RECIST 1.1First study dose to first observation of documented disease progression (or death within 12 weeks of last tumor assessment) (up to 2 years)PFS time will be assessed.
PFS According to PCWG3First study dose to first observation of documented disease progression (or death within 12 weeks of last tumor assessment) (up to 2 years)PFS time will be assessed.
Overall Survival TimeFirst study dose through up to 3 yearsDuration of survival will be assessed.
Maximum Drug Concentration At Steady-state (Cmax-ss)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Minimum Drug Concentration At Steady-state (Cmin-ss)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentration measured throughout the study
Area Under The Drug Concentration-time Curve Within Time Span t1 To t2 At Steady-state (AUC(t1-t2)-ss)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Area Under The Drug Concentration-time Curve From Time Zero To Infinity [AUC(0-∞)]First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Terminal Elimination Rate Constant (λz)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Terminal Elimination Half-life (t1/2)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Systemic Clearance (CL)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Volume Of Distribution (Vd)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab concentrations measured throughout the study
Anti-drug Antibodies (ADAs)First study dose (pre-dose) through 3 months following last study dose (up to 2 years)Serum botensilimab ADAs measured throughout the study

Countries

United Kingdom, United States

Contacts

STUDY_DIRECTORMedical Director

Agenus Inc.

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 29, 2026