Study of 68Ga-R10602

Phase 1

Recruiting

• Conditions: Locoregionally Recurrent Hormone-receptor Positive Breast Cancer; Metastatic Hormone Receptor Positive Breast Cancer
• Interventions: Drug: 68Ga-R10602 injection

• Registration Number: NCT06745804
• Lead Sponsor: Radionetics Oncology

Brief Summary

A phase 1 imaging study of 68Ga-R10602 in hormone-receptor positive breast cancer.

Detailed Description

There are two eligible disease populations for the study. Population 1 are patients with metastatic or locoregionally recurrent, endocrine-resistant, ER+ and/or PR+ breast cancer who have received at least one line of chemotherapy or ADC. Population 2 are patients with ER+ and HER2- locoregional or metastatic non-resectable breast adenocarcinoma with progression on at least one line of prior endocrine therapy in the adjuvant or metastatic setting and starting next line of therapy that will include tamoxifen, fulvestrant, aromatase inhibitor, or elacestrant with or without ovarian suppression. Both disease populations are eligible for both cohorts.

Cohort 1 will consist of twelve patients. Three dose levels will be evaluated, with each patient receiving a single dose, followed by imaging at five timepoints and blood dosimetry at seven timepoints.

In Cohort 2, ten patients will receive a single dose determined based on the results from Cohort 1. These patients will undergo imaging at a single timepoint, also selected based on findings from Cohort 1, and no dosimetry will be performed.

Study Timeline

• Study First Submitted: 2024-12-09
• Study Start: 2024-12-10
• Study First Submitted QC: 2024-12-17
• Study First Posted: 2024-12-20
• Status Verified: 2025-04
• Last Update Submitted: 2025-05-15
• Last Update Posted: 2025-05-20
• Primary Completion: 2025-08
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 22

Inclusion Criteria

1. Breast Cancer Eligibility:

   • Population 1: Pathologically confirmed ER and/or PR positive, locoregionally recurrent or metastatic breast cancer that is refractory to endocrine therapy (progression on at least one line of endocrine therapy and determined by the investigator that Study Participant would not benefit from additional endocrine therapy) who have received at least one line of chemotherapy or antibody drug conjugate in the metastatic setting (recurrence within 6 months of adjuvant chemotherapy counts as one line of therapy). There is no limit on prior number of lines of endocrine therapy. Prior treatment with CDK4/6, AKT, PI3K and/or mTOR inhibitors is permitted.
   • Population 2: Pathologically confirmed ER positive and HER2 negative locoregional or metastatic breast adenocarcinoma that is not amenable to resection, with progression on at least one line of prior endocrine therapy in the adjuvant or metastatic setting and starting next line of therapy that will include tamoxifen, fulvestrant, aromatase inhibitor, or elacestrant with or without ovarian suppression. Study Participants who will receive combination therapy (with alpelisib, capiversitib, everolimus or a CDK4/6 inhibitor) as their next line of treatment must be imaged while receiving only single agent endocrine therapy, and before starting the targeted therapy. Targeted therapy can be started after imaging.

2. Male or non-pregnant, non-lactating female Study Participant age ≥18 years. Female Study Participant of child-bearing potential and male Study Participant (if sexually active) must agree to use adequate method(s) of effective contraception during their participation in the study.

   1. Medically acceptable adequate contraception for sexually active females with child-bearing potential include: 1) surgical sterilization (such as tubal ligation or hysterectomy), 2) approved hormonal contraceptives, 3) barrier method (such as condom or diaphragm) used with a spermicide, or 4) intrauterine device (IUD).
   2. Medically acceptable adequate contraception for sexually active males include: 1) surgical sterilization (such as vasectomy), 2) a condom used with a spermicide.

3. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤2.

4. Adequate hepatic function as defined below (within 28 days of dosing with 68Ga R10602):

   1. Serum alanine aminotransaminase (ALT)/ aspartate aminotransaminase (AST) ≤3 × upper limit of normal (ULN) or ≤5 × ULN if liver metastases are present, and
   2. Serum bilirubin: total ≤1.5 × ULN (unless due to Gilbert's syndrome or hemolysis in which case total ≤3.0 × ULN).

5. Adequate renal function as measured by creatinine clearance calculated by the Cockcroft-Gault formula (≥60 mL/minute), determined within 28 days of dosing with 68Ga-R10602.

6. Able to understand and willing to sign an informed consent form (ICF).

Exclusion Criteria

1. Received a radionuclide within a period of less than 10 physical half-lives of the administered radionuclide prior to dosing with 68Ga-R10602.
2. Radiotherapy ≤14 days prior to dosing with 68Ga-R10602.
3. Major surgery ≤21 days prior to dosing with 68Ga-R10602 or has not recovered from adverse effects of such procedure.
4. Severe or unstable medical condition, such as congestive heart failure (New York Heart Association [NYHA] Class III or IV), ischemic heart disease, uncontrolled hypertension, uncontrolled diabetes mellitus, as well as an uncontrolled cardiac arrhythmia requiring medication (≥Grade 2, according to NCI-CTCAE Version 5.0), myocardial infarction within 6 months prior to starting Investigational Product, or any other significant or unstable concurrent cardiac illness. Note: Stable chronic atrial fibrillation is allowed.
5. History of cerebrovascular accident within 6 months or that resulted in ongoing neurologic instability.
6. Major active infection requiring antibiotics.
7. Known active human immunodeficiency virus infection or active infection with Hepatitis B or C.
8. Acute illness within 14 days prior to dosing with 68Ga-R10602 unless mild in severity, as assessed by the Investigator.
9. Any other condition that in the opinion of the Investigator would place the Study Participant at an unacceptable risk or cause the Study Participant to be unlikely to fully participate or comply with study procedures.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SEQUENTIAL

Arm && Interventions

Group	Intervention	Description
68Ga-R10602 Imaging Optimization Portion (Cohort 1)	68Ga-R10602 injection	68Ga-R10602 injection at pre-defined dose levels. PET/CT imaging at pre-defined timepoints.
68Ga-R10602 Imaging Confirmation Portion (Cohort 2)	68Ga-R10602 injection	68Ga-R10602 injection at the selected dose level. PET/CT imaging at a single timepoint.

Primary Outcome Measures

Name	Time	Method
Incidence of adverse events	Day 1 to Day 7	Number of participants with adverse events as assessed by NCI-CTCAE v5.0, including grade
Incidence of Serious Adverse Events	Day 1 to Day 7	Number of participants with serious adverse events
Incidence of Clinically Significant Lab Changes	Day 1 to Day 7	Number of participants with clinically significant change in clinical laboratory parameters

Secondary Outcome Measures

Name	Time	Method
Number and location of tumors identified by 68Ga-R10602 PET/CT	1 Day	Ratio of tumor SUV over reference regions SUV
Number and location of tumor lesions identified by 68Ga-R10602 PET/CT versus standard of care imaging	1 day	Number and location of tumor lesions identified by 68Ga-R10602 PET/CT and by standard of care imaging (e.g. contrast enhanced diagnostic CT) and concordance rate between 68Ga-R10602 PET/CT and standard of care images.
Image quality	1 day	Image quality as assessed by a 5-point Likert scale by central review
Absorbed dose coefficients and total body effective dose	1 Day	The total body effective dose (milliSievert \[mSv\]/MBq).
PK parameters	1 Day	Other pharmacokinetic (PK) parameters may also be evaluated as needed to support the outcome measure.

Trial Locations

Locations (3)

University of Utah, Huntsman Cancer Institute; 🇺🇸 Salt Lake City, Utah, United States

Indiana University Melvin and Bren Simon Cancer Center; 🇺🇸 Indianapolis, Indiana, United States

University of Michigan Medicine; 🇺🇸 Ann Arbor, Michigan, United States