Imaging of Solid Tumors Using DLL3 SPECT

Not Applicable

Not yet recruiting

• Conditions: Solid Tumor Cancer; Castration Resistant Prostate Cancer (CRPC); Neuroendocrine (NE) Tumors; Castration Resistant Prostate Cancer
• Interventions: Drug: 111In-ABD147; Procedure: Single-photon emission computed tomography (SPECT)/Computerized tomography (CT)

• Registration Number: NCT07052760
• Lead Sponsor: Thomas Hope

Brief Summary

This is a single arm, pilot trial that evaluates the ability of a novel imaging agent (111In-ABD147) to detect metastatic cancer in participants with solid tumors. 111In-ABD147 is a high affinity Delta-like ligand 3 (DLL3) antigen binding domain fused to an engineered humanized Fc to create an antibody (VHH-Fc) that is bio-conjugated with a DOTA linker-chelator to a 111In radiometal. DLL3 is expressed on a variety of tumors, particularly those with neuroendocrine features.

Detailed Description

PRIMARY OBJECTIVE:

1) Determine the feasibility of detecting tumor uptake using 111In-ABD147.

SECONDARY OBJECTIVE:

1) Safety of 111In-ABD147.

EXPLORATORY OBJECTIVES:

1. Correlation of 111In-ABD147 uptake with DLL3 expression determined by immunohistochemistry.

2. Compare 111In-ABD147 scan results to archival Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET) images when available.

OUTLINE:

Participants will be assigned to cohorts based on solid tumor diagnosis. All participants will receive 1 dose of study drug followed by single-photon emission computed tomography (SPECT)/Computerized tomography (CT) imaging. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after last dose for safety.

Study Timeline

• Status Verified: 2025-06
• Study First Submitted: 2025-06-28
• Study First Submitted QC: 2025-06-28
• Last Update Submitted: 2025-06-28
• Study First Posted: 2025-07-07
• Last Update Posted: 2025-07-07
• Study Start: 2025-07-31
• Primary Completion: 2027-08-30
• Study Completion: 2027-08-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 45

Inclusion Criteria

1. Age ≥ 18 years

2. Histopathologically confirmed solid tumors in one of the following cohorts:

   1. Cohort 1 (n=15): Histologically confirmed prostate cancer, with castration resistant disease per Prostate Cancer Clinical Trials Working Group 3 (PCWG3) criteria.
   2. Cohort 2 (n=15): Histologically confirmed high grade neuroendocrine tumor, with a Ki-67 over 20.
   3. Cohort 3 (n=15): Agnostic to tumor type.

3. Metastatic disease present on conventional imaging defined as having Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 measurable disease or multiple bone metastases.

4. Ability to understand a written informed consent document, and the willingness to sign it.

Exclusion Criteria

1. Unlikely to comply with protocol procedures, restrictions and requirements and judged by the Investigator to be unsuitable for participation.
2. Has known hypersensitivity to Chinese hamster ovary cell products.
3. Has a history of severe allergic anaphylactic reactions to chimeric or humanized antibodies or fusion proteins.
4. Known pregnancy.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Cohort 1: Castration resistant prostate cancer	111In-ABD147	Participants will receive a single administration of 185 megabecquerels (MBq) (5 millicurie (mCi)) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.
Cohort 1: Castration resistant prostate cancer	Single-photon emission computed tomography (SPECT)/Computerized tomography (CT)	Participants will receive a single administration of 185 megabecquerels (MBq) (5 millicurie (mCi)) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.
Cohort 2: High grade neuroendocrine tumor	Single-photon emission computed tomography (SPECT)/Computerized tomography (CT)	Participants will receive a single administration of 185 MBq (5 mCi) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.
Cohort 2: High grade neuroendocrine tumor	111In-ABD147	Participants will receive a single administration of 185 MBq (5 mCi) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.
Cohort 3: Agnostic solid tumors	111In-ABD147	Participants will receive a single administration of 185 MBq (5 mCi) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.
Cohort 3: Agnostic solid tumors	Single-photon emission computed tomography (SPECT)/Computerized tomography (CT)	Participants will receive a single administration of 185 MBq (5 mCi) +/- 10% of 111In-ABD147 prior to SPECT/CT imaging 48 hours after injection. Repeat administration of 111In-ABD147 and SPECT/CT imaging may be performed. Participants will be followed for up to 7 days after the injection of 111In-ABD147 for evaluation of adverse events.

Primary Outcome Measures

Name	Time	Method
Standardized Uptake Values (SUVs)	2 days	Standardized Uptake Values (SUVs) will be calculated for up to five lesions in each patient, with mediastinal blood pool being used as background activity. The median and range will be reported across all Response Evaluation Criteria in Solid Tumors (RECIST) measurable lesions broken down by location (organ metastases, nodal metastases and bone metastases).
Tumor-to-background ratio (TBR)	2 days	Tumor-to-background ratios (TBR) ratios will be calculated for up to five lesions in each patient, with mediastinal blood pool being used as background activity. The median and range of the measured TBRs will be reported across all RECIST measurable lesions broken down by location (organ metastases, nodal metastases and bone metastases).

Secondary Outcome Measures

Name	Time	Method
Percentage of participants with treatment-emergent adverse events	Up to 7 days	The percentage of participants with reported treatment-emergent adverse events and the 95% confidence interval following 111In-ABD147 injection will be descriptively reported, using NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

Trial Locations

Locations (1)

University of California, San Francisco; 🇺🇸 San Francisco, California, United States