An Experimental Study of Belzutifan Impact on Catecholamine Metabolism

June 29, 2026 updated by: Ruth Casey, Cambridge University Hospitals NHS Foundation Trust

An Experimental Pilot Study to Investigate Changes in Catecholamine Synthesis and Metabolism in Patients With Molecularly Profiled Phaeochromocytoma and Paraganglioma Taking Belzutifan

To investigate the impact of a medication called Belzutifan on the production and subsequent metabolism of adrenaline and noradrenaline collectively termed 'catecholamines'. The study aims to identify changes in the production and metabolism of catecholamines by measuring the substance which starts the chain of catecholamine metabolism called tyrosine in patients before, during and after 5 days of taking Belzutifan 120mg daily.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a single centre, single arm, pilot interventional study aimed at identifying alterations in catecholamine synthesis and metabolism in 12 patients taking Belzutifan 120mg daily for five days. As this is a pilot and experimental study of a rare disease, sample size was not calculated. A study recruitment target of 12 patients was established based on the annual incidence of patients with catecholamine secreting PPGL attending our national referral centre.

There is an estimated annual incidence of 100-150 patients across all of England and an annual incidence of 15-20 patients attending Cambridge University Hospital per year.

The study protocol is 14 days. All patients will be recruited by the PI after informed consent and review of the study inclusion and exclusion criteria.

Germline genetic results performed as part of routine clinical care will be recorded for all patients. For those patients with negative germline genetic test results, tumour sequencing of available tissue or tumour tissue later removed (after the end of the study protocol) during surgery will be performed to investigate for somatic variants (genetic changes unique to the tumour cells) in specific genes which may influence how Belzutifan impacts catecholamine synthesis and metabolism.

The study protocol is 14 days including five days of intervention with Belzutifan 120mg daily for all patients. Baseline plasma tyrosine and plasma metanephrines will be performed on all patients (day 0) and at several time points after starting Belzutifan 120mg daily to examine for alterations in catecholamine metabolism. Recruited patients will attend daily for seven days and again on day 10 and day 14 and will be reviewed by the PI.

Plasma tyrosine and metanephrines will be performed using specific published research methods (liquid chromatography mass spectroscopy) and a percentage reduction in catecholamine metabolites and a percentage increase in tyrosine will be calculated for every patient at the end of the 14-day protocol.

Safety measures will include monitoring of full blood count, liver function tests and by measuring blood pressure and heart rate at baseline and at day 1-7, day 10 and day 14 in all patients recruited to the study.

Any changes in blood pressure during the study protocol will be reviewed by the PI and all changes to existing medications will be performed by the PI and recorded.

All recruited patients will be interviewed daily from day 0 to day 7 and again on day 10 and day 14 and all symptoms reported will be recorded by the PI.

Study Type

Interventional

Enrollment (Estimated)

12

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

  • Name: August Palma Senior Research Nurse - Endocrinology
  • Phone Number: 01223 217 848
  • Email: august.palma@nhs.net

Study Locations

  • United Kingdom
    • Cambridgeshire
      • Cambridge, Cambridgeshire, United Kingdom, CB2 0QQ
        • Recruiting
        • Cambridge University Hospitals NHS Foundation Trust

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult patients > 18 years
  • Patients must have a biochemically confirmed diagnosis of a phaeochromocytoma or paraganglioma using plasma metanephrines or 24- hour urinary metanephrines and plasma or urinary metanephrines should be at least 1.5 times the upper limit of the normal reference range.
  • Female patients of child-bearing potential must have a negative serum pregnancy test result within 3 days before first administration of study drug
  • Able to provide informed consent

Exclusion Criteria:

  • Has hypoxia, or requires intermittent supplemental oxygen, or requires chronic supplemental oxygen.
  • Has clinically significant cardiac disease, including unstable angina, acute myocardial infarction, percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass graft surgery (CABG) ≤6 months from Day 1 of study drug administration, or New York Heart Association Class III or IV congestive heart failure. Medically controlled arrhythmia stable on medication is permitted.
  • Has a co-existing malignancy (in addition to PPGL)
  • Has a Hb < 100g/dL
  • Is on medications which may interfere with belzutifan pharmacokinetics and that cannot be stopped for the duration of the study and for 7 days after the study period (everolimus, omeprazole, esomeprazole, Fluconazole, fluoxetine, Voriconazole, Sirolimus)
  • Has a known diagnosis of HIV, hepatitis B or hepatitis C

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Intervention
For 14 day study protocol, including five days of intervention with Belzutifan
Drug: Belzutifan
Belzutifan 120mg daily for 5 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tyrosine measurements
Time Frame: Baseline, day 5 and day 14
The quantitative change in the amino acid tyrosine from baseline to the end of the study intervention (day 5) and to the end of the study (day 14).
Baseline, day 5 and day 14

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma metanephrine measurements
Time Frame: Baseline, day 5 and day 15
Quantitative changes in serial plasma metanephrines measured at baseline, at the end of the study intervention (day 5) and at the end of the study (day 14).
Baseline, day 5 and day 15

Collaborators and Investigators

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

Sponsor

Cambridge University Hospitals NHS Foundation Trust

Collaborators

University of Cambridge

Investigators

  • Principal Investigator: Ruth T Casey, MD PhD, Cambridge University Hospital and University of Cambridge

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

April 27, 2026

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

June 23, 2026

First Submitted That Met QC Criteria

June 29, 2026

First Posted (Actual)

July 2, 2026

Study Record Updates

Last Update Posted (Actual)

July 2, 2026

Last Update Submitted That Met QC Criteria

June 29, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • A097464
  • REC reference: 25/PR/1644 (Other Identifier: London - Camden & Kings Cross Research Ethics Committee)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

Yes

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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