Using a PET Imaging Agent, 18F-Clofarabine (CFA), to Measure Deoxycytidine Kinase Activity in Metastatic Cancer

18F-Clofarabine (CFA) as a PET Imaging Agent to Measure Deoxycytidine Kinase (DCK) Activity in Metastatic Cancer, as a Candidate Predictive Biomarker for Response to DCK-dependent Drugs Such as Gemcitabine

The purpose of this study is to evaluate whether a new type of imaging study, called 18F-Clofarabine (CFA) PET/CT, can be used to image cancer pyrimidine metabolism in participants.

PET (positron emission tomography) imaging is a way of looking at cancers that can reveal cancer metabolism. Presently, however, there are no imaging agents in routine use to look at an aspect of cancer metabolism (pyrimidine metabolism) that dictates whether certain cancer drugs, e.g., gemcitabine, are likely to be taken into the cancer cells. This clinical trial will be testing whether 18F-Clofarabine (CFA) could be an imaging agent to measure this aspect of cancer metabolism.

Study Overview

• Status: Recruiting
• Conditions: Adenocarcinoma; Carcinoma; Metastatic Cancer
• Intervention / Treatment: Drug: 18F-Clofarabine

Detailed Description

The participants will receive a CFA injection into a vein in their arm. The imaging drug is attracted to and taken into certain cells in the body, including cancer cells. 18F-Clofarabine (CFA) is experimental because it is not approved by the Food and Drug Administration (FDA).

The participants will be observed for side effects, and about 1 hour later, they will receive a PET/CT scan. Additionally, they will be contacted the next day to inquire again about any side effects. If the participant's routine care involves repeat imaging of cancer, then the CFA PET/CT scan will be repeated at that time, which could be up to 365 days after the first CFA PET/CT scan.

• Study Type: Interventional
• Enrollment (Estimated): 4
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Roberto Vargas, MD; Phone Number: 866-223 8100; Email: TaussigResearch@ccf.org

Study Locations

• United States
  • Ohio
    • Cleveland, Ohio, United States, 44106
      • Recruiting
      • Cleveland Clinic, Case Comprehensive Cancer Center
      • Contact: Roberto Vargas, MD; Phone Number: 866-223-8100; Email: taussigresearch@ccf.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Histologically or cytologically proven metastatic cancer (including carcinoma, adenocarcinoma, sarcoma, or neuroendocrine cancer).
• Subjects must have metastatic disease, confirmed by imaging, typically a CT scan of the chest/abdomen/pelvis.
• Subjects must have measurable disease per RECIST 1.1
• Over 18 years of age
• ECOG performance status 0-1

• Adequate organ function as defined by the following criteria (labs may be no more than 4 weeks prior to the screening date):

  • Serum aspartate transaminase (AST; serum glutamic oxaloacetic transaminase [SGOT]) and serum alanine transaminase (ALT; serum glutamic pyruvic transaminase [SGPT]) <= 2.5 x laboratory upper limit of normal (ULN)
  • Total serum bilirubin <= 2.0 x ULN
  • Absolute neutrophil count (ANC) >= 1500/uL
  • Platelets >= 75,000/uL
  • Hemoglobin >= 8.0 g/dL
  • Serum calcium <= 12.0 mg/dL
  • Serum creatinine <= 2.9 mg/dL
• Subjects must have the ability to understand and the willingness to sign a written informed consent document
• Patient is able to remain still for the duration of the imaging procedure (up to one hour).

Exclusion Criteria:

• Within 6 months prior to enrollment on this study: myocardial infarction, severe/unstable angina, severe peripheral vascular disease (claudication) or procedure on peripheral vasculature, coronary/peripheral artery bypass graft, New York Heart Association grade II or greater congestive heart failure, cerebrovascular accident or transient ischemic attack, clinically significant bleeding or pulmonary embolism.
• Pregnancy or breastfeeding (pregnant or breastfeeding women are excluded from this study because study drugs have the potential for teratogenic or abortifacient effects.
• Other severe acute or chronic medical or psychiatric conditions or laboratory abnormalities that may increase the risk associated with study participation or study drug administration, or may interfere with the interpretation of study results, and in the judgment of the investigator would make the patient inappropriate for entry into this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: 18F-Clofarabine; 18F-Clofarabine as PET imaging agent for measuring the activity of deoxycytidine kinase (DCK) in various normal and abnormal tissues in cancer participants before and after therapy

Drug: 18F-Clofarabine; The participants enrolled will receive a baseline CFA PET/CT evaluation. Then, the participants will undergo the routine follow up would normally occur for their cancer and its treatment. If this routine follow up and care involves repeat imaging of the cancer, then the CFA PET/CT scan will be repeated at that time (timed according to standard-of-care follow-up imaging), which is expected between a month to about 4 months after the first CFA PET/CT scan. The study period will end 24 hours after this repeat PET/CT scan.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluate CFA as a PET imaging agent	Establish the image-based biodistribution of CFA, a new tracer for imaging DCK enzyme activity. DCK converts the inactive prodrug clofarabine into its active form. Thus, the degree of DCK expression in normal and abnormal tissues may predict drug effects and effectiveness. The uptake of the radiotracer (SUVs) will be measured quantitatively from PET images taken at 60 min post-injection of [18F]CFA.	up to 60 minutes after CFA PET

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlate CFA uptake with conventional imaging	Correlate CFA uptake with conventional anatomic imaging using RECIST criteria to establish change over time and differences from participants' baseline scans.	up to 3 months after CFA PET
Correlate CFA uptake with PFS	Correlate changes in CFA uptake (SUV) with disease progression as determined by standard of care surveillance imaging.	up to 12 months after CFA PET
Correlate CFA uptake with OS	Correlate changes in CFA uptake with participant outcomes as measured by all cause mortality/overall survival (OS).	up to 12 months after CFA PET
Adverse Events	Proportion of participants who develop any side effects/adverse events associated with radiotracer infusions.	within 48 hrs of radiotracer administration

Collaborators and Investigators

• Sponsor: Roberto Vargas
• Investigators: Principal Investigator: Roberto Vargas, MD, Cleveland Clinic, Case Comprehensive Cancer Center

Study record dates

Study Major Dates

• Study Start (Actual): March 6, 2023
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: September 23, 2021
• First Submitted That Met QC Criteria: September 23, 2021
• First Posted (Actual): October 4, 2021

Study Record Updates

• Last Update Posted (Actual): March 19, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Cancer; Diagnostic Imaging; 18F-Clofarabine
• Additional Relevant MeSH Terms: Pathologic Processes; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Neoplastic Processes; Pathological Conditions, Signs and Symptoms; Neoplasms; Carcinoma; Neoplasm Metastasis; Adenocarcinoma; Antineoplastic Agents; Molecular Mechanisms of Pharmacological Action; Antimetabolites, Antineoplastic; Antimetabolites; Clofarabine
• Other Study ID Numbers: CASE4Y21

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: This is a feasibility study of a novel PET-scan imaging agent and IPD is not needed for interpretation of the data

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