211At-MABG in Adults With Advanced Neuroendocrine Cancers

NCT07661420 | Not Yet Recruiting Phase 1 DMC FDA Drug

• 2 other identifiers: 26-64031R01CA300202
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Phase I dose escalation study of 211At-MABG in adults with advanced pheochromocytoma / paraganglioma (PPGL) or other NET-overexpressing cancers (as evidenced by positive MIBG imaging) who are refractory to, lacking, or ineligible for approved treatments. Phase 1 dose-escalation will follow a standard 3+3 design with an expansion cohort at the recommended phase two dose (RP2D).

Conditions

Pheochromocytoma; Paraganglioma; Neuroendocrine Tumors; Medullary Thyroid Cancer; Bronchial Carcinoid; Gastroenteropancreatic Neuroendocrine Neoplasm

Outcome Measures

Primary Outcomes (2)

• Evaluate overall study feasibility

  Proportion of intended 211At-MABG fractionated doses that are successfully administered within the protocol-defined window (at the overall study level).

  4 weeks

• Evaluate study feasibility overall study feasibility assessed for operational issues versus treatment-related adverse events.

  Proportion of fractionated dose administrations either delayed and/or omitted due to operational issues (i.e. insufficient/delayed synthesis) versus treatment-related adverse events (at the overall study level).

  4 weeks

Secondary Outcomes (10)

• Safety of fractionated dosing of 211At-MABG in adults with advanced (PPGL) or other NET-overexpressing cancers per patient level

  4 weeks

• Safety of fractionated dosing of 211At-MABG in adults with advanced (PPGL) or other NET-overexpressing cancers per 'dose level'.

  4 weeks

• The maximum tolerated dose (MTD) and/or Recommended Phase II Dose (RP2D) of 211At-MABG

  8 weeks

• Incidence of Adverse Events

  72 months

• The objective response rate (ORR) per RECIST 1.1 following a single cycle of fractionated dosing of 211At-MABG

  72 months

Study Arms (3)

Dose Level -1: Fractionated 211At-MABG

EXPERIMENTAL

One treatment cycle (1 MBq/k) of 211At-MABG administered by IV administration in 4 fractionated (0.25 MBq/kg) weekly doses (+ 7 days) (one treatment cycle = 4 weekly fractionated doses).

Drug: 1 MBq/k of 211At-MABG Fractionated

Dose Level 1: Fractionated 211At-MABG

EXPERIMENTAL

One treatment cycle (2 MBq/k) of 211At-MABG administered by IV administration in 4 fractionated (0.5 MBq/kg) weekly doses (+ 7 days) (one treatment cycle = 4 weekly fractionated doses).

Drug: 2 MBq/k1 of 211At-MABG Fractionated

Dose Level 2: Fractionated 211At-MABG

EXPERIMENTAL

One treatment cycle (4 MBq/k) of 211At-MABG administered by IV administration in 4 fractionated (1 MBq/kg) weekly doses (+ 7 days) (one treatment cycle = 4 weekly fractionated doses).

Drug: 4 MBq/k of 211At-MABG Fractionated

Interventions

1 MBq/k of 211At-MABG Fractionated DRUG

Astatine-211 \[211At\] is a short-lived α emitter conjugated onto meta-astatobenzylguanidine (\[211At\]MABG)

Dose Level -1: Fractionated 211At-MABG

2 MBq/k1 of 211At-MABG Fractionated DRUG

Astatine-211 \[211At\] is a short-lived α emitter conjugated onto meta-astatobenzylguanidine (\[211At\]MABG)

Dose Level 1: Fractionated 211At-MABG

4 MBq/k of 211At-MABG Fractionated DRUG

Astatine-211 \[211At\] is a short-lived α emitter conjugated onto meta-astatobenzylguanidine (\[211At\]MABG)

Dose Level 2: Fractionated 211At-MABG

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients, at least 18 years of age
• Advanced neuroendocrine cancers requiring systemic therapy and refractory to, ineligible for, declining, or lacking standard treatments.
• I MIBG imaging indicating MIBG-avid disease (radiotracer uptake above background in at least one tumor site) per Investigator/Sub-Investigator assessment.
• Participants must provide written informed consent prior to study-specific procedures.
• ECOG performance status ≤ 2.
• Adequate organ function including:
• Hemoglobin ≥ 9 g/dL
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 75,000/mm³
• Measured or estimated GFR ≥ 60 mL/min
• Serum bilirubin ≤ 1.5x upper limit of normal
• ALT/AST each ≤ 2.5x upper limit of normal
• Life expectancy at least 3 months as judged by treating physician

You may not qualify if:

• Women who are pregnant or breast-feeding will not be eligible for this study.
• Inability to tolerate study procedures in the opinion of the investigator or treating physician.
• Serious or unstable medical, psychological, or social conditions that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study.
• Uncontrolled brain metastasis (Participant must be at least 4 weeks since CNS-directed therapy and no longer requiring corticosteroid therapy).
• Anticancer therapy, except hormonal therapy or bone supportive therapies, within 14 days of cycle 1 day 1.
• Has a known additional malignancy (other than the disease under study) that has required active systemic treatment within the past 2 years AND for which the natural history or recent/ongoing treatment could likely interfere with study endpoints or safety of the study treatment per Investigator and Medical Director assessment.

Sponsors & Collaborators

• University of Pennsylvania: lead
• National Institutes of Health (NIH): collaborator
• National Cancer Institute (NCI): collaborator

Study Sites (1)

University of Pennsylvania - Abramson Cancer Center

Philadelphia, Pennsylvania, 19104, United States

Location

MeSH Terms

Conditions

Pheochromocytoma; Paraganglioma; Neuroendocrine Tumors; Carcinoma, Medullary

Condition Hierarchy (Ancestors)

Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms by Histologic Type; Neoplasms; Neoplasms, Nerve Tissue; Carcinoma, Neuroendocrine; Adenocarcinoma; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms, Ductal, Lobular, and Medullary

Study Officials

• Vivek Narayan, MD, MS

  University of Pennsylvania

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Abramson Cancer Center

CONTACT

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 16, 2026
• First Posted: June 22, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): August 1, 2029
• Study Completion (Estimated): August 1, 2032
• Last Updated: June 22, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)