Study of 203Pb-RMX-VH-PIB Dosimetry and Biodistribution in Patients With Glioblastoma Multiform (GBM) and Pancreatic Ductal Adenocarcinoma (PDAC) (RMX-VH)

August 4, 2026 updated by: Radiomedix, Inc.

Dosimetry and Bio-distribution of 203Pb-RMX-VH-PIB in Newly Diagnosed or Recurrent Patients With Solid Tumors: A Phase I Exploratory Study

The goal of this Phase I clinical trial is to evaluate how the imaging drug 203Pb- RMX-VH-PIB distributes in the body and how much radiation different organs receive in patients with glioblastoma multiforme (GBM) or pancreatic ductal adenocarcinoma (PDAC).

The main questions it aims to answer are:

How does 203Pb-RMX-VH-PIB spread in the body (biodistribution)? What is the radiation dose delivered to organs (dosimetry)?

Participants will:

Receive a single intravenous (IV) injection of 203Pb-RMX-VH-PIB. Undergo multiple single-photon emission computed tomography/computed tomography (SPECT/CT) imaging scans.

Have blood, urine, vital signs, and electrocardiogram (ECG) monitored for safety.

Be followed for any side effects for up to 30 days.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is an early-stage clinical trial designed to test a new imaging drug called 203Pb-RMX-VH-PIB. The study will use SPECT/CT scans to see how the drug spreads through the body and how much radiation is delivered to different organs. The trial will enroll 20 patients who have either glioblastoma multiforme (GBM), an aggressive brain tumor, or pancreatic ductal adenocarcinoma (PDAC), a type of pancreatic cancer. Patients may be newly diagnosed, have recurrent disease, or have stable tumors. For GBM patients, the drug's distribution will be compared with MRI scans to see if it highlights the tumor areas effectively. For PDAC patients, the study will track how the drug behaves in pancreatic tumors. Participants will be divided into four groups to study both biodistribution and dosimetry in each cancer type. Each participant will receive a single intravenous injection of the drug, followed by several whole-body SPECT/CT scans. To ensure safety, vital signs will be measured before and after the injection, and blood and urine samples will be collected at multiple time points. A 12-lead ECG will also be performed to monitor heart rhythm, and results will be reviewed by the investigator. Any side effects or health changes will be closely monitored and recorded for 30 days after administration. The goal of this exploratory study is to better understand how 203Pb-RMXVH- PIB works in the body and to gather important safety and radiation data in patients with GBM and PDAC.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • 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 Backup

Study Locations

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Signed informed consent.
  2. Subjects aged ≥18 years.
  3. Karnofsky status ≥60.
  4. Negative urine pregnancy test in women of childbearing potential.

  5. Histologically confirmed and /or highly suspicious GBM (Adult type Astrocytoma grade IV both IDH-Mutant and IDH-Wild Type) including primary, recurrent or stable enhancing residual or primary, recurrent or stable enhancing residual PDAC.

    a. GBM group i. Contrast enhanced Brain MRI image with results compatible with GBM within the 2 weeks of dosing day.

    ii. Tumor size of ≥ 1.0 cm in any dimension by MRI. iii. No antiangiogenic therapy within 4 weeks of the day of dosing. iv. No chemotherapy within 2 weeks of the day of dosing. v. Subjects receiving corticosteroids must be on a stable or decreasing dose regimen prior to enrollment b. PDAC group i. No chemotherapy within 2 weeks of the day of dosing ii. Tumor size of ≥ 1.0 cm in any dimension by MRI or CT

  6. Recent blood test results (within 4 weeks pre-dose) as follows:

    1. WBC: ≥ 2 x 109/L
    2. Haemoglobin: ≥ 8 g/dL
    3. Platelets: ≥75 x 109/L
    4. ALT, AST, AP ≤ 5 times ULN
    5. Bilirubin: ≤ 2 times ULN
    6. Creatinine clearance ≥ 60 mL/min, calculated by the Cockcroft-Gault equation

Exclusion Criteria:

  1. Known hypersensitivity to RMX-VH peptide analogue, 203Pb-RMX-VH-PIB, 203Pb (Lead) , or any of the excipients of 203Pb-RMX-VH-PIB.
  2. Inability to undergo MRI or CT/SPECT/CT scans
  3. Current somatic or psychiatric disease/condition that may interfere with consent or the objectives and assessments of the study.
  4. Pregnancy or plans to conceive during the course of study participation.
  5. In GBM groups participants requiring MRI: History of hypersensitivity or contraindication to gadolinium-based contrast agents, including prior allergic or anaphylactoid reactions to gadolinium contrast media, or any condition (e.g., severe renal impairment, acute kidney injury) that, in the investigator's judgment, increases the risk associated with gadolinium administration.
  6. In PDAC groups participants requiring CT scans: Any contraindications to iodinated contrast agents include a history of severe hypersensitivity or allergic reaction to iodinated contrast media, significant renal impairment (e.g., eGFR < 30 mL/min/1.73 m² or acute kidney injury), uncontrolled hyperthyroidism or other thyroid disorders that may worsen with iodine exposure, prior contrast-induced nephropathy, pregnancy, and any unstable medical condition such as severe heart failure or hemodynamic instability that, in the investigator's judgment, increases the risk of contrast administration.
  7. Male and female participants of childbearing potential who are unwilling or unable to use an acceptable method of contraception for the duration of the study.
  8. Women who are breastfeeding
  9. Participants who are currently receiving treatment with statins (HMG-CoA reductase inhibitors), including but not limited to atorvastatin, rosuvastatin, pitavastatin, simvastatin, lovastatin, pravastatin, or fluvastatin, are excluded unless the medication has been discontinued for at least four (4) drug half-lives prior to administration of the investigational product

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
Intervention / Treatment
Experimental: 203Pb-RMX-VH-PIB Imaging
All participants will receive a single intravenous injection of 203Pb-RMX-VH-PIB (5.0 ± 10% mCi). Following administration, participants will undergo multiple SPECT/CT scans to evaluate the biodistribution and radiation dosimetry of the investigational radiopharmaceutical. Safety assessments will include monitoring of vital signs, blood exams, and electrocardiograms (ECGs) before and after dosing, with adverse events recorded for up to 30 days.
Drug: 203Pb-RMX-VHPIB injection
A single intravenous (IV) injection of the investigational radiopharmaceutical 203Pb-RMX-VHPIB administered to eligible patients.
Other Names:
  • Radiotracer Injection
Diagnostic test: SPECT/CT Imaging
Serial whole-body and region-specific SPECT/CT scans performed after IP administration to assess biodistribution and dosimetry
Other Names:
  • Single-Photon Emission Computed Tomography/Computed Tomography Imaging

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Whole-body and organ-specific absorbed radiation dose for 203Pb-RMX-VH-PIB
Time Frame: From injection to up to 144 hours post-injection, multi-time-point SPECT/CT, approximately 1-2 hours, 4-6 hours, 24 hours, 48 hours, 120 hours, and, if needed, 144 hours after injection.
Whole-body and organ-specific absorbed radiation doses will be estimated using serial quantitative SPECT/CT imaging and available blood and urine radioactivity data following a single intravenous administration of 203Pb-RMX-VH-PIB. Absorbed radiation doses will be summarized per unit of administered activity, such as mGy/MBq.
From injection to up to 144 hours post-injection, multi-time-point SPECT/CT, approximately 1-2 hours, 4-6 hours, 24 hours, 48 hours, 120 hours, and, if needed, 144 hours after injection.
Organ-Specific Absorbed Dose of 203Pb-RMX-VH-PIB
Time Frame: From injection to up to144 hours post-injection, multi-time-point SPECT/CT, approximately 1-2 hours, 4-6 hours, 24 hours, 48 hours, 120 hours, and, if needed, 144 hours after injection.
For each participant, volumes of interest (VOIs) will be delineated over critical organs, including the kidneys, liver, spleen, red marrow, pancreas, brain, thyroid, and salivary glands, as well as target lesions. Time-activity curves will be fitted, and residence times will be derived. The absorbed dose per unit of injected activity will be calculated using the standard Medical Internal Radiation Dose (MIRD) schema with Organ Level Internal Dose Assessment/Exponential Modeling (OLINDA/EXM) software or an equivalent method.
From injection to up to144 hours post-injection, multi-time-point SPECT/CT, approximately 1-2 hours, 4-6 hours, 24 hours, 48 hours, 120 hours, and, if needed, 144 hours after injection.

Collaborators and Investigators

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

Sponsor

Radiomedix, Inc.

Investigators

  • Study Chair: Ebrahim Delpassand, MD, FACNM, Radiomedix, Inc.

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 (Estimated)

August 15, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

June 30, 2027

Study Registration Dates

First Submitted

July 24, 2026

First Submitted That Met QC Criteria

July 24, 2026

First Posted (Actual)

July 29, 2026

Study Record Updates

Last Update Posted (Actual)

August 7, 2026

Last Update Submitted That Met QC Criteria

August 4, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RMX-VH-02

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

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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