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

March 17, 2026 updated by: Roberto Vargas

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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
4

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Ohio
      • Cleveland, Ohio, United States, 44106
        • Recruiting
        • Cleveland Clinic, Case Comprehensive Cancer Center
        • Contact:

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Evaluate CFA as a PET imaging agent
Time Frame: up to 60 minutes after CFA PET

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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Correlate CFA uptake with conventional imaging
Time Frame: up to 3 months after CFA PET
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
Time Frame: up to 12 months after CFA PET
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
Time Frame: up to 12 months after CFA PET
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
Time Frame: within 48 hrs of radiotracer administration
Proportion of participants who develop any side effects/adverse events associated with radiotracer infusions.
within 48 hrs of radiotracer administration

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Roberto Vargas

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Roberto Vargas, MD, Cleveland Clinic, Case Comprehensive Cancer Center

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 6, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 23, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 23, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 4, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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

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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Conditions

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