NCT06843434 · Memorial Sloan Kettering Cancer Center
A Study of Botensilimab and Balstilimab for Rectal Adenocarcinoma
What this study is about
The purpose of this study is to find out whether the combination of botensilimab and balstilimab (BOT/BAL) is a safe and effective treatment that causes few or mild side effects for people with mismatch repair proficient (MMRp)/microsatellite stable (MSS) locally advanced rectal adenocarcinoma.
View original scientific description
The purpose of this study is to find out whether the combination of botensilimab and balstilimab (BOT/BAL) is a safe and effective treatment that causes few or mild side effects for people with mismatch repair proficient (MMRp)/microsatellite stable (MSS) locally advanced rectal adenocarcinoma. The investigators will also find out whether BOT/BAL is an effective treatment when given in combination with standard chemotherapy.
Interventions
DRUG
Balstilimab
Balstilimab is a fully human monoclonal IgG4 antibody designed to block PD-1 binding to PD-L1 and PD-L2
DRUG
Botensilimab
Botensilimab is a novel fully human fragment crystallizable (Fc)-engineered immunoglobulin 1 kappa (IgG1κ) anti-CTLA-4 immunoglobulin G1 (IgG1) antagonist antibody that is designed to optimally promote fragment-crystallizable gamma receptor (FcγR) effector functions that are important for enhancing T cell priming and regulatory T cell (Treg) depletion.
Primary outcome measures
Best Overall Response Rate
Time frame: 1 year
The primary objective of this study is to determine the best overall response rate (ORR) after initial neoadjuvant combination botensilimab and balstilimab in subjects with MMRp/MSS locally advanced (stage II or III) rectal adenocarcinoma. ORR is defined by rectal MRI and endoscopic exam and graded as progressive disease (PD), stable disease (SD) (sustained for 3 months), partial response (PR), near complete response (nCR) and clinical complete response (cCR). Patients with PR, nCR, or cCR will be considered responders, while the rest will be non-responders.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Willing and able to provide written informed consent for trial. a. If participant is unable to provide written informed consent, the legally authorized representative (LAR) of the person who is being asked to participate in this research study may give consent on the participant's behalf.
- Be ≥18 years of age on the date of signing informed consent.
- ECOG performance status of 0 or 1.
- Histologically confirmed rectal adenocarcinoma.
- Adenocarcinoma with distal margin of 15 cm or less from the anal verge on endoscopy, staged with endorectal ultrasound (ERUS) or magnetic resonance imaging (MRI) as cT3/cT4 N0 or cT(any) cN1/2.
- No evidence of distant metastases
- Radiologically measurable or clinically evaluable disease per Protocol Section 13.0.
- Tumor specimen that demonstrates intact mismatch repair enzymes by immunohistochemistry or microsatellite stability as demonstrated by NGS or PCR.
- Negative pregnancy test done within 14 days prior to beginning t
Where
- Basking Ridge, New Jersey
- Middletown, New Jersey
- Montvale, New Jersey
- Commack, New York
- Harrison, New York
- New York, New York
- Uniondale, New York
Collaborators
Agenus Inc.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 16, 2026 · Source of record for eligibility and locations