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Somatostatin-Receptors (SSTR)-Agonist [212Pb]VMT-alpha-NET in Metastatic or Inoperable SSTR+ Gastrointestinal Neuroendocrine Tumor and Pheochromocytoma/Paraganglioma Previously Treated With Systemic Targeted Radioligand Therapy

Phase I/II Trial of Systemic Targeted Radioligand Therapy (TRT) With Somatostatin-Receptors (SSTR)-Agonist [212Pb]VMT-alpha-NET in Metastatic or Inoperable SSTR Positive (SSTR+) Gastrointestinal (GI) Neuroendocrine Tumors (NET) and Pheochromocytoma/Paragangliomas Previously Treated With Systemic Radioligand Therapy

Status
Recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06427798
Enrollment
66
Registered
2024-05-24
Start date
2025-02-07
Completion date
2039-07-01
Last updated
2026-03-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Somatostatin Receptor Positive, Gastrointestinal Neuroendocrine Tumors, Pheochromocytoma, Paragangliomas

Keywords

212Pb, Targeted Therapy, Image-Guided Dosimetry, VMT- -NET

Brief summary

Background: Gastrointestinal neuroendocrine tumors (GI NET) are a type of cancer that affects the stomach and intestines; pheochromocytoma/paragangliomas (PPGL) are tumors that grow in or near the adrenal glands. Both of these types of tumor have high levels of a protein called somatostatin receptors (SSTR) on their surfaces. Researchers want to test a treatment that targets SSTR. Objective: To test a drug (\[212Pb\]VMT-alpha-NET) in people with GI NET or PPGL. The drug has 2 components: a protein to bind to SSTR and a radioactive agent to kill the cancer cells. Eligibility: Adults aged 18 years or older with GI NET or PPGL tumors that have spread and cannot be removed with surgery. Design: Participants will be screened. They will have a physical exam, with imaging scans, blood tests, and tests of their heart function. \[212Pb\]VMT-alpha-NET is given through a tube attached to a needle inserted into a vein (infusion). Treatment will be given in four 8 week cycles. Participants will receive the drug on the first day of each cycle. They will remain in the clinic at least 4 hours after each infusion and may need to stay in the hospital for up to 48 hour for monitoring and testing. They will have blood tests every week of each cycle. Some participants will also get a related study drug (\[203Pb\]VMT-alpha-NET). They will receive this drug a few days before the first 2 cycles. At 4, 24, and 48 hours after each infusion, they will have whole body scans. These scans will show where the study drug went in their body. Follow-up visits will continue for 10 years....

Detailed description

Background: * Somatostatin receptors (SSTR) have been shown to be over-expressed in a number of human tumors, including gastrointestinal (GI) neuroendocrine tumors (NET) and pheochromocytoma/paragangliomas (PPGL). * Targeted radioligand therapy (TRT) is a class of cancer therapeutic agents formed by attaching a radioactive isotope to a ligand that can target specific surface receptors such as SSTR on a tumor cell membrane. Efficacy is typically determined by the radiation dose deposited onto a tumor, which is determined by the radioactive isotope being used as well as the binding characteristics of the ligand-receptor/transporter pair. * While there have been clinical successes with treating gastrointestinal neuroendocrine tumors (GI NET) and PPGL with SSTR-targeting beta-emitting TRTs, tumors will invariably start to progress after some time. Re-treatment using the same beta-emitting agents at the time of progression can be done but has decreased efficacy compared to the TRT-naive setting. * Alpha emitters such as 212Pb emit alpha particles that are more damaging to tumor cells than beta emitters such as 177Lu. Therefore, TRT agents using alpha emitters are considered to be more potent and could be better than betas in the re-treatment setting. * VMT-alpha-NET is a peptide that binds to SSTR, which when attached to 212Pb becomes an alpha particle-emitting TRT that can be used to treat tumors that have SSTR surface expression. * \[203Pb\]VMT-alpha-NET is the chemically identical imaging surrogate for \[212Pb\]VMT-alpha-NET and has the same mechanism of action via binding to SSTR2. The nuclide 203Pb contained in \[203Pb\]VMT-alpha-NET emits gamma radiation suitable for single-photon emission computerized tomography (SPECT) imaging. These images can be used to assess drug product biodistribution throughout the body. Objectives: * Phase I: To determine the maximal tolerated dose (MTD) of \[212Pb\]VMT-alpha-NET using a 3+3 dose escalation design in GI NET and PPGL in a re-treatment setting. * Phase II: To determine the Overall Response Rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 of participants treated with \[212Pb\]VMT-alpha-NET at the MTD at the completion of 4 cycles of treatment, reported by disease groups. Eligibility: * Age \>= 18 years. * Histopathologically confirmed GI NET or PPGL that are metastatic or inoperable. * At least 1 prior systemic radioligand therapy. * Eastern Cooperative Oncology Group (ECOG) Performance Status \<= 1. Design: * This is an open-label, single-arm, single-center, phase I/II study evaluating the safety, preliminary efficacy, and pharmacokinetic properties of \[212Pb\]VMT-alpha-NET in GI NET and PPGL in a re-treatment setting. * Phase I participants will be accrued using a 3+3 dose escalation design with 3 dose levels to estimate MTD of \[212Pb\]VMT-alpha-NET. Once MTD is estimated, Phase II participants with GI NET and PPGL will be accrued in separate cohorts and treated at MTD of \[212Pb\]VMT-alpha-NET. * \[212Pb\]VMT-alpha-NET will be given IV every 8 weeks for a total of 4 administrations. * A subset of participants (Dosimetry Arm 1) will have \[203Pb\]VMT-alpha-NET administration followed by whole-body gamma scans combined with dosimetry SPECT/ Computed Tomography (CT) scans and collection of blood and urine samples prior to each cycle. * Participants will have timed clinical laboratory evaluations, imaging studies, and research blood, and urine samples while on the study therapy for safety and efficacy evaluations. * Following completion of treatment, participants will be seen at the NIH Clinical Center approximately 30 days later, every 12 weeks for years 1-3, every 6 months for years 4-6 for safety and efficacy assessments. Beyond 6 years, participants will be contacted annually through any NIH-approved platform to assess for overall survival and health status.

Interventions

68Ga-DOTATATE PET/CT whole-body scanning will be done at target dose of 5 mCi. The whole-body PET/CT scan will be started approximately 60 minutes after the tracer injection and will take up to 2 hours.

\[203Pb\]VMT-alpha-NET (6 mCi) will be given IV at 7 days prior.

\[212Pb\]VMT-alpha-NET will be given IV on Day 1 of every cycle for 4 cycles total at escalating doses in Phase I and at MTD during Phase II. One cycle is 8 weeks.

Sponsors

National Cancer Institute (NCI)
Lead SponsorNIH

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 120 Years
Healthy volunteers
No

Inclusion criteria

* INCLUSION CRITERIA: * Participants must have histopathologically confirmed gastrointestinal neuroendocrine tumors (GI NET) or pheochromocytoma/paraganglioma (PPGL) cancers that are metastatic or inoperable per Standard of Care. * Have received at least 1 prior systemic radioligand therapy for definitive therapeutic purposes. Note: Participants with prior external beam radiation treatment (EBRT) will also be eligible as long as they have had at least 1 prior administration of a systemic radioligand therapy. * Must have at least 1 measurable lesion by RECIST 1.1 (phase II only). * History of progression by imaging (e.g., RECIST 1.1) or clinically (defined as increase in severity or frequency of symptoms related to disease) within the past 36 months prior to the first dose of \[203Pb\]VMT-alpha-NET. * Evidence of somatostatin receptors (SSTR) expression on at least 50 percent of the radiographically identifiable (i.e., visible on an anatomic scan such as CT or magnetic resonance imaging \[MRI\]) tumor, as indicated by a positive (uptake qualitatively identifiable as above the local background) on SSTR PET scan. * Age \>= 18 years. * ECOG performance status \<= 1. * Participants must have adequate organ and marrow function as defined below: * Leukocytes: 3,000/microliter * Absolute Neutrophil Count: 1,500/microliter * Platelets: 100,000/miroliter * Hemoglobin: \>= 9.0 g/dL * Total bilirubin: within normal institutional limits. Note: \<= 5 X institutional upper limit of normal (ULN) if bilirubin elevation is due to a benign process such as Gilbert syndrome * AST: \<= 2.5 X institutional ULN * ALT: \<= 2.5 X institutional ULN * Creatinine: within normal institutional limits OR * Calculated creatinine clearance (glomerular filtration rate (eGFR): \>= 60 mL/min/1.73 m\^2 for participants with creatinine levels above institutional normal * Participants with treated brain metastases are eligible if follow-up brain imaging after central nervous system (CNS)-directed therapy shows no evidence of progression at screening. * Participants with new or progressive brain metastases or leptomeningeal disease are eligible as long as the participant is asymptomatic and not requiring medication for symptom control from the brain lesions at screening. * Participants seropositive for human immunodeficiency virus (HIV) must: * be on effective anti-retroviral therapy; and * have an undetectable viral load at screening. * Participants seropositive for hepatitis B virus (HBV), must have HBV viral load undetectable at screening. -Participants seropositive for hepatitis C virus (HCV) must: * received curative treatment; and * have an undetectable HCV viral load at screening. * Participants may enroll in this study while on another therapeutic trial in order to start the screening process. However, all other investigational agents should be stopped at least 28 days prior to receiving \[203Pb\]VMT-alpha-NET. * Individuals of child-bearing potential (IOCBP) and individuals who can father children must agree to use an effective method of contraception (barrier, hormonal, intrauterine device \[IUD\], surgical sterilization, abstinence) at study entry and at least 6 months after the last dose of the study agent(s). * Nursing participants must be willing to discontinue nursing from study treatment initiation through 6 months after the last dose of the study agents. * The ability of the participant to understand and the willingness to sign a written informed consent document.

Exclusion criteria

* History of allergic reactions attributed to compounds of similar chemical or biologic composition to VMT-alpha-NET. * Positive Beta human chorionic gonadotropin (Beta-HCG) serum or urine pregnancy test performed in i IOCBP at screening. * QTc \> 450 ms on electrocardiogram (EKG) at screening. Note: Framingham correction for QTc will be used * History of or detection at screening of active/untreated secondary malignancy except nonmelanoma skin cancer and carcinoma in situ of the uterine cervix. * Uncontrolled intercurrent illness, factors, evaluated by medical history and physical exam which would potentially increase in the risk of the participant.

Design outcomes

Primary

MeasureTime frameDescription
Phase I: MTD of [212Pb]VMT-alpha-NET using a 3+3 dose escalation design in GI NET and PPGL in a re-treatment settingDLT period (through 12 weeks after initial 212Pb]VMT-alpha-NET administration).The MTD will be presented as a recommended dose to be used as the recommended phase II dose (RP2D) for the combined participant population, as well as for each disease group being studied (GI-NET, PPGL).
Phase II: ORR by RECIST 1.1 of participants treated with [212Pb]VMT-alpha-NET at the MTD at the completion of 4 cycles of treatment, reported by disease groupsBaseline until progression or 6 years after receiving the first infusion of study drug.The overall response rate will be presented as a percentage along with 95% confidence intervals. Only evaluable participants will be included.

Secondary

MeasureTime frameDescription
Progression Free SurvivalBaseline until progression or 10 years after receiving the first infusion of study drugPFS is defined as the duration of time from start of treatment to time of progression or death, whichever occurs first. Kaplan-Meier curves of PFS will be constructed. Median PFS will be reported with 95% confidence intervals.
Safety of [203Pb]VMT-alpha-NET and [212Pb]VMT-alpha-NETStudy durationDescriptive tabulations of toxicity will be provided, along with the agent attribution determination and CTCAE grade for each toxicity event. The data will be presented as an absolute count of the event at a participant level as well as a percentage of total evaluable participants.
Overall SurvivalBaseline until progression or 10 years after receiving the first infusion of study drugKaplan-Meier curves of OS, will be constructed. Median OS will be reported with 95% confidence intervals.
PK properties of [212Pb]VMT-alpha-NET via blood and urine samplingAfter every infusion of [212Pb]VMT-alpha-NETPK data will be represented as a scatter plot graphing time vs. the amount of radioactivity found in blood and urine samples.
Dosimetry properties of [212Pb]VMT-alpha-NET via SPECT/CT, using [203Pb]VMT-alpha-NET as a surrogate with and without the administration of amino acids (Dosimetry Arm 1 only)In Dosimetry Arm 1 after every [203Pb]VMT-alpha-NET infusionBiodistribution and dosimetry data will be represented in a tabular format which indicates the percentage of the injected dose calculated to be in each of the major organs using gamma scan results. Radiation dose calculations will be performed using OLINDA/EXM software. Absorbed doses in organs and the whole body will be determined using the appropriate adult phantom (e.g., adult male, adult female). Tumor lesion absorbed doses will be determined using the sphere model in OLINDA.

Countries

United States

Contacts

CONTACTJoy H Zou, R.N.
joy.zou@nih.gov(240) 760-6153
CONTACTFrank I Lin, M.D.
frank.lin2@nih.gov(240) 760-6166
PRINCIPAL_INVESTIGATORFrank I Lin, M.D.

National Cancer Institute (NCI)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 11, 2026