Testing the Safety of the Anti-cancer Drug, Sn-117m-DTPA, for Advanced Cancers That Have Spread to Bones
A First-in-Human Dose-Finding Phase I Study of Bone-targeted High Specific Activity Stannic-117m Pentatate (Sn-117m-DTPA) in Solid Tumors With Skeletal Metastases
3 other identifiers
interventional
24
0 countries
N/A
Brief Summary
This phase I trial tests the safety, side effects and best dose of tin (Sn)-177m-diethylenetriaminepentaacetic acid (DTPA) and how well it works in treating prostate, breast or non-small cell lung cancer that has spread from where it first started (primary site) to the bones (bone metastases). Sn-117m-DTPA was originally tested in tumors that had spread to the bones to help reduce bone pain. The drug has been improved and is designed to send low-level radiation to tumors in the bone while being gentler on the bone marrow, where blood cells are made. Sn-117m-DTPA may be safe and tolerable, and may slow down or shrink tumors in patients with metastatic prostate, breast, or non-small cell lung cancer that has spread to the bones.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for phase_1
Started Oct 2026
Shorter than P25 for phase_1
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
May 20, 2025
CompletedFirst Posted
Study publicly available on registry
May 21, 2025
CompletedStudy Start
First participant enrolled
October 1, 2026
ExpectedPrimary Completion
Last participant's last visit for primary outcome
February 12, 2027
Study Completion
Last participant's last visit for all outcomes
February 12, 2027
April 13, 2026
April 1, 2026
4 months
May 20, 2025
April 9, 2026
Conditions
Outcome Measures
Primary Outcomes (2)
Frequency of dose-limiting toxicities
Will be graded using National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version (v) 5.0. Will be summarized by severity grade, system organ class, and their relation to study treatment.
Up to completion of 1 cycle (cycle length = 56 days)
Frequency of adverse events
Will be graded using NCI CTCAE v 5.0. Will be summarized by severity grade, system organ class, and their relation to study treatment.
Up to 30 days after last dose of study treatment
Secondary Outcomes (8)
Tumor response
Up to 2 years
Time to first symptomatic skeletal event
Up to 2 years
Changes in serum PSA (prostate cancer patients only)
At baseline, days 44-56 of cycle 1, and days 30-56 of cycle 2
Time to progression in serum PSA (prostate cancer patients only)
At baseline, days 44-56 of cycle 1, and days 30-56 of cycle 2
Changes in bone-specific alkaline phosphatase levels (all patients)
At baseline, days 44-56 of cycle 1, and days 30-56 of cycle 2
- +3 more secondary outcomes
Study Arms (1)
Treatment (Sn-117m-DTPA)
EXPERIMENTALPatients receive Sn-117m-DTPA IV over 10 minutes on day 1 of each cycle. Cycles repeat every 56 days for up to 4 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo urine and blood sample collection, PET/CT and SPECT/CT throughout the study. Additionally, prostate cancer patients undergo Tc-99m bone scan at baseline and PSMA PET/CT throughout the study.
Interventions
Undergo technetium TC-99m bone scan
Undergo urine and blood sample collection
Undergo PET/CT, SPECT/CT and PSMA PET/CT
Undergo PET/CT
Undergo PSMA PET/CT
Undergo SPECT/CT
Undergo technetium TC-99m bone scan
Given IV
Eligibility Criteria
You may qualify if:
- Histologically documented prostate, breast, or non-small cell lung cancer (NSCLC)
- Metastatic disease in bone only (patients with visceral disease, cutaneous disease or malignant lymph nodes \> 3 cm in largest diameter are not eligible)
- Documented disease progression (1 or more new bone lesion or enlargement of existing bone lesion, identified by Tc-99m bone scintigraphy or CT scan, magnetic resonance imaging \[MRI\], fludeoxyglucose F-18 \[FDG\] PET CT scan or PSMA PET CT scan)
- Must have progression on at least one line of standard of care systemic therapy. There are no maximum number of prior therapies
- Patients with prostate cancer
- Patients with prostate adenocarcinoma, their disease must be characterized as: must have prior bilateral orchiectomy or ongoing androgen-deprivation therapy and a castrate level of serum testosterone (\< 50 ng/dL or \< 1.7 nmol/L)
- Serum PSA progression, defined as two consecutive increases in PSA over a previous reference value, each measurement at least one week apart or, PSA progression ≥ 25% after 12 weeks of current standard of care (SOC) therapy (Scher et al., 2016)
- Patients must have a baseline positive PSMA-PET scan. Patients must have progressed on at least one line of hormone therapy: Androgen receptor signaling inhibitors (ARSIs) therapy such as enzalutamide, apalutamide, darolutamide, or androgen synthesis blockers (abiraterone acetate). There are no minimum number of prior hormone therapies
- Progression after chemotherapy (docetaxel or cabazitaxel) in patients who were chemotherapy candidates is allowed. However, prior chemotherapy is not required
- Progression after a prostate-specific membrane antigen (PSMA)-targeted radiopharmaceutical therapy (for example: lutetium-177 vipivotide tetraxetan \[Pluvicto\]) is allowed but not required
- Allowed to have received one prior cytotoxic chemotherapy treatment and one radiopharmaceutical therapy treatment OR no more than two cytotoxic chemotherapy treatments (for patients who have not received a prior radiopharmaceutical therapy treatment)
- Patients with breast cancer
- Patients with any estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2) receptor status are eligible
- Patients with hormone-receptor positive disease should have progressed on at least one or more prior line(s) of SOC anti-estrogen therapy and a cyclin-dependent kinase (CDK)4/6 inhibitor (except if patient had a contraindication or intolerable toxicity with the use of these agents)
- Patients with HER2 positive disease should have progressed on at least one or more line(s) of SOC anti-HER2 therapy.
- +21 more criteria
You may not qualify if:
- Patients who have not recovered from reversible adverse events due to prior anti-cancer therapy (i.e., have residual toxicities \> grade 1) with the exception of alopecia
- Patients must not have received any investigational agents within 4 weeks or 5 half-lives, whichever is shorter, before starting study treatment, nor be scheduled to receive one during the planned treatment period
- Patients must not have a history of allergic reactions attributed to compounds of similar chemical or biologic composition to Sn-117m-DTPA
- Patients must not have imminent or established spinal cord compression, pathological fracture in weight bearing bones, or bone lesion with soft tissue component unless treated as appropriate with radiation and/or surgery before starting on this study
- Patients must not have received prior systemic radiotherapy with strontium-89, samarium-153, rhenium-186, rhenium-188, or radium-223 dichloride (Xofigo) for the treatment of bony metastases. Prior systemic radiopharmaceutical therapy with lutetium Lu 177 vipivotide tetraxetan (Pluvicto) is permitted, but last treatment must be at least six weeks prior to starting study treatment due to the concern of bone marrow suppression
- Patients must not have unmanageable urinary incontinence
- Pregnant women are excluded from this study because Sn-117m-DTPA is a radionucleotide with the potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with Sn-117m-DTPA, breastfeeding should be discontinued if the mother is treated with Sn-117m-DTPA
Contact the study team to confirm eligibility.
Sponsors & Collaborators
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Zin W Myint
Ohio State University Comprehensive Cancer Center LAO
Study Design
- Study Type
- interventional
- Phase
- phase 1
- Allocation
- NA
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- NIH
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
May 20, 2025
First Posted
May 21, 2025
Study Start (Estimated)
October 1, 2026
Primary Completion (Estimated)
February 12, 2027
Study Completion (Estimated)
February 12, 2027
Last Updated
April 13, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
NCI is committed to sharing data in accordance with NIH policy. For more details on how clinical trial data is shared, access the link to the NIH data sharing policy page.