Phase 2 Study of SR-8541A in Combination With Botensilimab and Balstilimab in Subjects With Refractory Metastatic Microsatellite Stable Colorectal Cancer (MSS-CRC)

January 13, 2026 updated by: Stingray Therapeutics
This is an open-label, dose escalation and expansion, multi-center phase 2 study evaluating the safety and efficacy of SR-8541A administered orally in combination with intravenous botensilimab and balstilimab in subjects with MSS-CRC with and without active liver metastases.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

70

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • New Jersey
      • Morristown, New Jersey, United States, 07960
    • Texas
      • Austin, Texas, United States, 78745
      • Dallas, Texas, United States, 75246
      • Houston, Texas, United States, 77030
        • Recruiting
        • The University of Texas M.D. Anderson Cancer Center GI Medical Oncology Dept
        • Contact:
      • Tyler, Texas, United States, 75702
    • Washington
      • Seattle, Washington, United States, 98104

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Written informed consent from subject
  2. Age ≥ 18 years old on the date of consent
  3. Histologically confirmed diagnosis of unresectable and metastatic adenocarcinoma of the colon or rectum
  4. Non-microsatellite instability high or non-deficient mismatch repair (non-MSI-H/non-dMMR) tumor status per a standard local testing method
  5. Must have received at least 1 prior chemotherapy regimen for metastatic or recurrent CRC
  6. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
  7. Measurable disease per RECIST v1.1 (Eisenhauer et al., 2009)
  8. Able to provide archival or fresh tumor tissue during screening (required) and post-treatment (optional)
  9. Adequate renal function defined as creatinine clearance ≥ 60mL/min
  10. Adequate liver function
  11. Adequate hematologic function
  12. No growth factor support, transfusions, or albumin administration within 14 days of first dose of study treatment
  13. Willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures
  14. Male and female subjects of childbearing potential must agree to use a highly medically effective method of contraception and refrain from sperm/egg donation throughout the study starting with the first dose of study treatment (or 14 days prior to the first dose of study treatment for oral contraception) and for at least 3 months after the last dose of study treatment

Exclusion Criteria:

  1. Hypersensitivity or allergy to any of the study drugs or their excipients.
  2. In Part 2, Cohort A, active liver metastases by computed topography (CT) or magnetic resonance imaging (MRI).

  3. Treatment with one of the following classes of drugs within the delineated time window prior to first dose:

    1. Small molecule/tyrosine kinase inhibitors within 2 weeks
    2. Any other systemic therapy for CRC within 3 weeks
    3. Received another investigational drug within 30 days or active participation in another clinical trial (follow-up is permitted)
    4. Medications/products which are known strong inhibitors or inducers of the CYP enzymes within 5 x T1/2
  4. Received programmed cell death protein 1, PD-(L)1, or CTLA-4 therapies including any immune checkpoint inhibitor or experimental immunologic agents.
  5. Partial or complete bowel obstruction within the last 3 months, signs/symptoms of bowel obstruction, or known radiologic evidence of impending obstruction.
  6. Refractory ascites.
  7. Current evidence of interstitial lung disease (ILD) or pneumonitis, or prior history of ILD or non-infectious pneumonitis requiring glucocorticoids.
  8. Continuous systemic treatment with either corticosteroids (>10 mg daily prednisone equivalents) or other immunosuppressive medications within 28 days prior to Day 1.
  9. Active autoimmune disease that has required systemic treatment in past 2 years
  10. Patients with adrenal / pituitary insufficiency
  11. History of documented congestive heart failure; unstable angina; poorly controlled hypertension; clinically significant valvular heart disease; high-risk uncontrolled arrhythmias (including sustained ventricular tachycardia); myocardial infarction, unstable angina, cerebrovascular accident, or transient ischemic attack within the last 6 months, or Canadian Cardiovascular Society angina class > 2
  12. History of allogeneic organ transplant, stem cell transplant, or bone marrow transplant
  13. Previous SARS-CoV-2 infection within 10 days for mild or asymptomatic infections or 20 days for severe/critical illness prior to first dose
  14. Requirement for treatment with strong cytochrome P450 3A4 inducers or inhibitors
  15. Presence of gastrointestinal condition, for example, malabsorption, that might affect the absorption of Investigational Product(s).
  16. Troponin I > ULN
  17. Uncontrolled hypertension
  18. Corrected QT interval by Fridericia (QTcF) ≥ 470 ms per the central mean average of triplicate electrocardiograms (ECGs)
  19. Left Ventricular Ejection Fraction (LVEF) < 50% using echocardiogram or multigated acquisition (MUGA)
  20. Symptomatic uncontrolled central nervous system (CNS) disease requiring treatment with steroids or anti-seizure medications within 2 months prior to Day 1. However, subjects with brain metastases that have been previously treated and are stable based on imaging performed within 2 months of Day 1 following completion of any CNS-directed therapy are allowed
  21. Leptomeningeal disease
  22. Spinal cord compression not definitively treated with surgery and/or radiation
  23. Bleeding diathesis due to underlying medical condition or anticoagulation medication which is unable to be promptly reversed by medical treatment
  24. Prior additional malignancy that is progressing or has received treatment the previous 3 years prior to first dose except for locally curable cancers that have been apparently cured, such as basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast
  25. History of uncontrolled seizures, central nervous disorders, substance abuse disorder or psychiatric disability judged by the Investigator to be clinically significant and would interfere with cooperation with requirements of the study
  26. Active infection requiring systemic treatment at time of first dose
  27. Positive for human immunodeficiency virus (HIV) (HIV antibodies) or active hepatitis B (e.g., HbsAg reactive) or active hepatitis C (e.g., HCV ribonucleic acid [RNA] qualitative) infection with detectable viral load
  28. Pregnant or lactating females who plan to nurse a child during or within 3 months of the last dose of study treatment
  29. Major surgery within 28 days prior to first dose and/or minor surgery (excluding biopsy) within 7 days prior to first dose. Note: If the subject had major surgery, the subject must have recovered adequately from the procedure and/or any complications from the surgery prior to starting study intervention
  30. Prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, or laboratory abnormality that, in the Investigator's opinion, could affect the safety of the subject or impair the assessment of study results
  31. Planned use of any of the prohibited concomitant medications

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: MSS-CRC subject with no active liver metastases
Drug: SR-8541A
SR-8541A administered orally in combination with intravenous botensilimab and balstilimab
Other Names:
  • Balstilimab
  • Botensilimab
Experimental: MSS-CRC subject with active liver metastases
Drug: SR-8541A
SR-8541A administered orally in combination with intravenous botensilimab and balstilimab
Other Names:
  • Balstilimab
  • Botensilimab

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To evaluate the safety, tolerability, efficacy, and define the optimal dose for expansion of SR-8541A in combination with botensilimab and balstilimab
Time Frame: Approximately 3 dose levels (DL) will be investigated in 28-day cycles
Part 1 of the study is to establish the recommended dose of SR-8541A in combination with botensilimab and balstilimab.
Approximately 3 dose levels (DL) will be investigated in 28-day cycles

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Stingray Therapeutics

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 20, 2024

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

September 5, 2024

First Submitted That Met QC Criteria

September 5, 2024

First Posted (Actual)

September 19, 2024

Study Record Updates

Last Update Posted (Actual)

January 15, 2026

Last Update Submitted That Met QC Criteria

January 13, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SR-8541A-002

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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