Testing a new immunotherapy for advanced colorectal cancer

A Phase IIa, Non-Randomized, Open-Label Dose Expansion Trial of Isunakinra in Combination With Pembrolizumab in Patients With Metastatic or Unresectable, Locally Advanced Colorectal Cancer

Phase 2 Interventional Buzzard Pharmaceuticals · NCT06634875

This study is testing a new immunotherapy treatment for patients with advanced colorectal cancer to see if a combination of two drugs can help those whose cancer hasn't responded to standard treatments.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment20 (estimated)
Ages18 Years and up
SexAll
SponsorBuzzard Pharmaceuticals Industry-sponsored
Drugs / interventionspembrolizumab, chemotherapy, immunotherapy, radiation
Locations2 sites (Los Angeles, California and 1 other locations)
Trial IDNCT06634875 on ClinicalTrials.gov

What this trial studies

This study enrolls patients with locally advanced or metastatic colorectal cancer that is microsatellite stable (MSS) and has a high tumor mutational burden (TMB-H) with KRAS mutations. The trial investigates the efficacy of isunakinra, a potent IL-1 inhibitor, when used alone and in combination with pembrolizumab, a PD-1 inhibitor, in patients who have already undergone standard treatments. The goal is to explore whether this combination can improve outcomes in treatment-resistant tumors.

Who should consider this trial

Good fit: Ideal candidates are adults with KRAS-mutated, microsatellite stable metastatic colorectal cancer who have progressed on prior therapies.

Not a fit: Patients with colorectal cancer that is not KRAS-mutated or those who have not received prior treatments may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with difficult-to-treat colorectal cancer.

How similar studies have performed: While this approach is novel, other studies have shown promise in using immunotherapy for colorectal cancer, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 1\. Subjects must have:

  * Histologically or cytologically confirmed adenocarcinoma of the colon or the rectum

    * Tumor is determined to be RAS-mutated (KRAS, NRAS or HRAS) and microsatellite stable/proficient in mismatch repair, as assessed by immunohistochemistry (IHC) and/or polymerase chain reaction (PCR)/next generation sequencing (NGS) in a Clinical Laboratory Improvement Act (CLIA) environment and with a tumor mutational burden (TMB) of 10 MB or more.

      2\. The study patients are required to have measurable disease by radiographic criteria (RECIST 1.1 and iRECIST).

      3\. Prior therapy: Patients must have completed or had disease progression on at least one prior line of disease-appropriate therapy for metastatic disease (with or without PD-1 inhibitors), with no available therapy likely to convey clinical benefit, or not be candidates for therapy of proven efficacy for their disease.

      4\. There should be a minimum of 4 weeks from any prior chemotherapy (except for the nitrosoureas and mitomycin C, requiring a minimum of 6 weeks), immunotherapy and/or radiation. Patients with prostate cancer on hormone deprivation therapy may continue that therapy while on study.

      5\. Patients must have recovered (grade 1 or baseline) from any clinically significant toxicity associated with prior therapy (for example, alopecia is not clinically significant).

      6\. ECOG performance status ≤ 1 7. Patients must have normal organ and hematologic function as defined below:
    * Serum creatinine ≤ 1.5 x upper limit of normal OR creatinine clearance and a 24-h urine collection of ≥ 60 mL/min.
    * ALT and AST ≤ 3x the upper limits of normal.
    * Total bilirubin ≤ 1.5 x upper limit of normal OR in patients with Gilbert's syndrome, a total bilirubin ≤ 3.0.
    * Hematological eligibility parameters (within 16 days of starting therapy):

      * Granulocyte count ≥ 1,500/mm3
      * Platelet count ≥ 75.000/mm3 8. Patients must have baseline pulse oximetry \> 90% on room air at rest.

Exclusion Criteria:

1. Subjects must have:

   ⦁ Histologically or cytologically confirmed adenocarcinoma of the colon or the rectum

   • Tumor is determined to be RAS-mutated (KRAS, NRAS or HRAS) and microsatellite stable/proficient in mismatch repair, as assessed by immunohistochemistry (IHC) and/or polymerase chain reaction (PCR)/next generation sequencing (NGS) in a Clinical Laboratory Improvement Act (CLIA) environment and with a tumor mutational burden (TMB) of 10 MB or more.
2. The study patients are required to have measurable disease by radiographic criteria (RECIST 1.1 and iRECIST).
3. Prior therapy: Patients must have completed or had disease progression on at least one prior line of disease-appropriate therapy for metastatic disease (with or without PD-1 inhibitors), with no available therapy likely to convey clinical benefit, or not be candidates for therapy of proven efficacy for their disease.
4. There should be a minimum of 2 weeks wash out period from chemotherapy and/or radiation therapy, and 4 weeks wash out period for immunotherapy.
5. Patients must have recovered (grade 1 or baseline) from any clinically significant toxicity associated with prior therapy (for example, alopecia is not clinically significant).
6. ECOG performance status ≤ 1
7. Patients must have normal organ and hematologic function as defined below:

   * Serum creatinine ≤ 1.5 x upper limit of normal OR creatinine clearance and a 24-h urine collection of ≥ 60 mL/min.
   * ALT and AST ≤ 3x the upper limits of normal.
   * Total bilirubin ≤ 1.5 x upper limit of normal OR in patients with Gilbert's syndrome, a total bilirubin ≤ 3.0.
   * Hematological eligibility parameters (within 16 days of starting therapy):

     * Granulocyte count ≥ 1,500/mm3
     * Platelet count ≥ 75.000/mm3
8. Patients must have baseline pulse oximetry \> 90% on room air at rest.

Exclusion criteria

1. Pregnant women or women presently breast-feeding their children are excluded due to unknown risks to a developing fetus or infant, confirmed by negative pre-treatment serum pregnancy test.
2. Concurrent treatment for cancer, with specific exceptions noted in inclusion criteria.
3. Any significant disease that, in the opinion of the investigator, may impair the patient's tolerance of study treatment.
4. Dementia, altered mental status, or any psychiatric condition that would prohibit the understanding or rendering of informed consent.
5. Active autoimmune diseases requiring treatment. However, patients with vitiligo, alopecia, or clinically stable autoimmune endocrine disease who are on stable dosing of appropriate replacement therapy (if such therapy is indicated) are eligible.
6. Concurrent use of systemic steroids, except for physiologic doses of systemic steroid replacement or local (topical, nasal, or inhaled) steroid use. Limited pharmacologic doses of systemic steroids (e.g., in patients with exacerbations of reactive airway disease or to prevent iv contrast allergic reaction or anaphylaxis in patients who have known contrast allergies) are allowed.
7. Patients who are receiving any other investigational agents within 28 days before start of study treatment.
8. Patients with untreated central nervous system metastases or local treatment of brain metastases within the last 2 months. Patients with stable brain metastasis for 2 months post-intervention are eligible.
9. Has severe hypersensitivity (≥Grade 3) to pembrolizumab or any of its excipients or a history of allergic reactions attributed to compounds of similar chemical or biologic composition to the agents used in study.
10. Serious or uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements.
11. HIV-positive patients are ineligible because of the potential for decreased immune response.
12. Patients unwilling to use adequate contraception (defined as hormonal or barrier method or abstinence) prior to study entry are excluded. If the patient needs to be on adequate contraception, contraception must start before study entry and continue for 3 months after completion of study therapy.

Where this trial is running

Los Angeles, California and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Colorectal Cancer Metastaticcolorectal cancermicrosatellite stableMSSkras mutatedTMB-Hmetastatic
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.