Investigational Drug
Balstilimab (AGEN2034; BAL) is an investigational, fully human IgG4 monoclonal antibody targeting PD‑1. It has been evaluated as monotherapy and in combination with the CTLA‑4 antibody zalifrelimab in previously treated recurrent/metastatic cervical cancer, with published phase 2 data. A U.S. BLA for second‑line cervical cancer was submitted in April 2021, accepted for Priority Review in June 2021, and voluntarily withdrawn in October 2021 after full approval of pembrolizumab in the same setting; development has continued in combinations. (pubmed.ncbi.nlm.nih.gov)
Cervical cancer (previously treated, recurrent/metastatic)
Balstilimab monotherapy (open‑label, single‑arm, phase 2; n=140 efficacy‑evaluable): Confirmed ORR 15.0% (95% CI, 10.0–21.8), including 3.6% complete responses; median duration of response (DoR) 15.4 months. ORR 20.0% in PD‑L1–positive tumors and 7.9% in PD‑L1–negative tumors. DCR 49.3%. Dosing: 3 mg/kg IV every 2 weeks (up to 24 months). (pubmed.ncbi.nlm.nih.gov)
Balstilimab + zalifrelimab (open‑label, single‑arm, phase 2; n=125 efficacy‑evaluable): Confirmed ORR 25.6% (95% CI, 18.8–33.9), with 10 complete and 22 partial responses; median DoR not reached at median follow‑up 21 months (response durability 64.2% at 12 months). ORR 32.8% in PD‑L1–positive and 9.1% in PD‑L1–negative tumors. DCR 52%. Dosing: balstilimab 3 mg/kg Q2W + zalifrelimab 1 mg/kg Q6W (up to 24 months). (pubmed.ncbi.nlm.nih.gov)
Other tumor types (early signals)
Note: Additional early‑phase combination studies with botensilimab (next‑generation CTLA‑4) have reported responses in ovarian and other solid tumors, but these are primarily from conference presentations and company communications and remain exploratory. (cancernetwork.com)
Balstilimab monotherapy (phase 2 cervical cancer): Most common grade ≥3 treatment‑related AEs were immune‑mediated enterocolitis (3.1%) and diarrhea (1.9%). Overall safety was consistent with PD‑1 inhibitors. (pubmed.ncbi.nlm.nih.gov)
Balstilimab + zalifrelimab (phase 2 cervical cancer): Grade ≥3 treatment‑related AEs occurred in 20.0%; common immune‑mediated AEs included hypothyroidism (14.2%) and hyperthyroidism (7.1%). Serious TRAEs occurred in 10.3%; three treatment‑related deaths (pneumonitis, immune‑mediated nephritis, diabetes mellitus) were reported. (ascopubs.org)
Doxorubicin + zalifrelimab + balstilimab in soft tissue sarcoma: Grade 3/4 TRAEs in 45%; immune‑mediated AEs requiring immunosuppression in 9%. (pubmed.ncbi.nlm.nih.gov)
Notes: Balstilimab is not FDA‑approved as of October 7, 2025. Efficacy and safety summaries above reflect non‑randomized trials; comparative effectiveness versus approved PD‑1 inhibitors has not been established. (investor.agenusbio.com)
Last updated: Oct 2025
Found 10 active trials using this drug:
HealthScout AI summary: Adults with metastatic, microsatellite-stable pancreatic ductal adenocarcinoma that has progressed on at least one prior systemic therapy receive SBRT to selected lesion(s) followed by dual checkpoint blockade with botensilimab (Fc‑enhanced anti–CTLA‑4) plus balstilimab (anti–PD‑1). Eligible patients require ECOG 0–1, measurable disease, adequate organ function, ≤25% liver tumor burden, and no active CNS metastases or significant autoimmune/immunosuppression.
ClinicalTrials.gov ID: NCT06843551
HealthScout AI summary: This trial enrolls adults with microsatellite stable, KRAS-mutant metastatic colorectal cancer who have progressed on or are intolerant of standard chemotherapy, and excludes those with diabetes or prior anti-PD1/CTLA-4 therapy. Patients receive combination therapy with botensilimab (Fc-engineered anti-CTLA-4 antibody), balstilimab (anti-PD-1 antibody), a fasting-mimicking diet, and high-dose intravenous vitamin C.
ClinicalTrials.gov ID: NCT06336902
HealthScout AI summary: Previously untreated, metastatic pancreatic ductal adenocarcinoma (ECOG 0–1) receiving triplet chemotherapy (nab-paclitaxel/gemcitabine/cisplatin) plus chloroquine and celecoxib, combined with dual checkpoint blockade: botensilimab (Fc‑engineered anti–CTLA‑4 designed to enhance T-cell priming/Treg depletion) and balstilimab (anti–PD‑1). Key exclusions include prior metastatic therapy, CNS mets, active autoimmune disease or prior checkpoint inhibitors, significant CV/GI disease, uncontrolled infections, retinal disease/G6PD deficiency, and warfarin/digoxin use.
ClinicalTrials.gov ID: NCT06076837
HealthScout AI summary: Adults with metastatic CRPC, pancreatic cancer, or HPV-negative SCCHN lacking effective options receive triplet therapy with evofosfamide (hypoxia-activated DNA crosslinking prodrug) plus zalifrelimab (anti–CTLA-4) and balstilimab (anti–PD-1). Open-label dose-escalation followed by disease-specific expansions; key exclusions include significant prior immune toxicity, active autoimmune disease, QTc ≥470 msec/TdP risk, uncontrolled CNS disease/infections, and use of strong/moderate CYP3A4 modulators or QT-prolonging drugs.
ClinicalTrials.gov ID: NCT06782555
HealthScout AI summary: This trial enrolls adults with newly diagnosed, metastatic or unresectable, microsatellite stable colorectal cancer (no liver, bone, or brain metastases, ECOG 0-1, and no prior systemic therapy for metastatic disease), testing combination immunotherapy with botensilimab (Fc-enhanced anti-CTLA-4) and balstilimab (PD-1 inhibitor), with mFOLFOX6 plus bevacizumab or panitumumab added if disease progresses.
ClinicalTrials.gov ID: NCT06268015
HealthScout AI summary: This trial enrolls adults with unresectable or metastatic, mismatch repair-proficient colorectal cancer or pancreatic ductal adenocarcinoma harboring vaccine-covered KRAS mutations who have progressed after first-line chemotherapy, and treats them with a mutant KRAS-targeted peptide vaccine plus balstilimab (anti-PD-1) and botensilimab (Fc-enhanced anti-CTLA-4). Immunotherapy-naive patients with measurable disease and good performance status are eligible.
ClinicalTrials.gov ID: NCT06411691
HealthScout AI summary: Adults with unresectable/metastatic esophageal, gastric, or GEJ adenocarcinoma after one prior line (or relapse ≤6 months after perioperative therapy), ECOG 0–1, receive ramucirumab plus paclitaxel combined with investigational immunotherapies: agenT‑797 (allogeneic invariant NKT cell therapy targeting CD1d-presented glycolipids), botensilimab (Fc‑enhanced CTLA‑4 inhibitor), and balstilimab (PD‑1 inhibitor). Excludes prior ramucirumab, recent taxane, severe prior irAEs from PD‑(L)1/CTLA‑4, active CNS mets, significant neuropathy, or active viral infections.
ClinicalTrials.gov ID: NCT06251973
HealthScout AI summary: Adults with newly diagnosed, IDH-wild type, MGMT-unmethylated GBM post-radiotherapy (ECOG 0–2) receive Sonocloud-9–mediated blood–brain barrier opening every 3 weeks synchronized with liposomal doxorubicin plus balstilimab (anti–PD-1) and botensilimab (Fc‑enhanced anti–CTLA‑4). Excludes prior immunotherapy, multifocal/not-coverable or posterior fossa disease, active autoimmune disease, and other major comorbidities.
ClinicalTrials.gov ID: NCT05864534
HealthScout AI summary: Previously untreated adults with unresectable/metastatic clear cell RCC (all IMDC risk groups; ECOG 0–2; treated/stable brain mets allowed) are randomized to botensilimab (Fc‑enhanced anti‑CTLA‑4) plus balstilimab (anti‑PD‑1) versus standard ipilimumab/nivolumab. The trial compares objective response and durability/safety, with early efficacy focus on intermediate/poor risk disease.
ClinicalTrials.gov ID: NCT05928806
HealthScout AI summary: Adults with advanced or metastatic soft tissue sarcoma (multiple histologies; ECOG 0–1) eligible for doxorubicin and without prior anthracycline or checkpoint inhibitor receive doxorubicin plus dual checkpoint blockade. Part 1 uses balstilimab (anti–PD‑1) with zalifrelimab (anti–CTLA‑4); Part 2 explores botensilimab (Fc‑enhanced anti–CTLA‑4) ± balstilimab with doxorubicin.
ClinicalTrials.gov ID: NCT04028063