Using a radiotracer to detect granzyme B in advanced cancers

A First-in-Human, Phase I/II PET Imaging Study of 64Cu-GRIP B, a Radiotracer Targeting Granzyme B, in Patients With Advanced Malignancies

Phase1; Phase2 Interventional University of California, San Francisco · NCT05888532

This study is testing a new imaging tool to see if it can help find specific markers in advanced cancers, especially in patients with kidney and prostate cancer, to better understand how their tumors respond to treatment.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment91 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of California, San Francisco Academic / other
Drugs / interventionsimmunotherapy
Locations1 site (San Francisco, California)
Trial IDNCT05888532 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates the safety and effectiveness of a radiotracer called 64Cu-GRIP B in detecting granzyme B in patients with advanced malignancies, particularly focusing on genitourinary cancers such as renal cell carcinoma and metastatic castration-resistant prostate cancer. The study involves multiple cohorts, with participants undergoing positron emission tomography (PET) imaging to assess tumor response to immunotherapy. The trial aims to gather data on the pharmacokinetics, dosimetry, and patterns of tumor uptake of the radiotracer, which may help in identifying tumors likely to respond to treatment. By understanding these dynamics, the study hopes to pave the way for future trials utilizing 64Cu-GRIP B as a biomarker.

Who should consider this trial

Good fit: Ideal candidates include patients with histologically-confirmed metastatic renal cell carcinoma, urothelial carcinoma, or metastatic castration-resistant prostate cancer who are planning to receive immune checkpoint inhibitors.

Not a fit: Patients with non-metastatic cancers or those not eligible for immune checkpoint inhibitors may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance the ability to identify tumors that are more likely to respond to immunotherapy, potentially improving treatment outcomes for patients with advanced cancers.

How similar studies have performed: Other studies have shown promise in using imaging biomarkers for cancer treatment response, but the specific use of 64Cu-GRIP B is a novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Disease characteristics by cohort, as defined by:

   Cohort A:
   * Histologically-confirmed metastatic solid tumor malignancy (3 Male, 3 Female)
   * Locally advanced or metastatic disease on conventional imaging

   Cohort B:
   * Histologically-confirmed metastatic renal cell carcinoma (any histologic sub-type) or urothelial carcinoma
   * Locally advanced or metastatic disease on conventional imaging

   Cohort C:
   * Histologically-confirmed prostate adenocarcinoma
   * Metastatic castration resistant prostate cancer by Prostate Cancer Clinical Trials Working Group 3 (PCWG3) criteria
2. Planned treatment with immune checkpoint inhibitor (Cohorts B and C only)
3. Willing to undergo paired tumor biopsies and has safely accessible bone or soft tissue lesion (Cohorts B and C only)
4. The subject is able and willing to comply with study procedures and provide signed and dated informed consent.
5. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
6. Age 18 years or older at the time of study entry.
7. Adequate organ function, as defined by:

   * Serum creatinine \<= 1.5 x upper limit of normal (ULN) or estimated creatinine clearance \> 60 mL/min
   * Total bilirubin \<= 1.5 x ULN (\< 3 x ULN in patients with documented or suspected Gilbert's).
   * Hemoglobin \>= 8.0 g/dL
   * Platelet count \>= 75,000/microliter
   * Absolute neutrophil count ≥ 1000/microliter
8. Patients must not be pregnant or breast feeding. Women of childbearing potential are required to obtain a negative pregnancy test within 14 days of PET Imaging scan. Effective contraception (men and women) must be used in subjects of child-bearing potential.

Exclusion Criteria:

1. Patients who because of age, general medical or psychiatric condition, or physiologic status cannot give valid informed consent.
2. Any condition that, in the opinion of the Principal Investigator, would impair the patient's ability to comply with study procedures.
3. Is currently pregnant or breastfeeding.

Where this trial is running

San Francisco, California

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 Prostate CancerRenal CancerUrethral CancerAdvanced Solid TumorMetastatic Castration-resistant Prostate CancerSolid Tumor, AdultImaging StudyRadiotracer
Last reviewed 2026-06-09 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.