Phase IB Study to Evaluate RAD1901 on the Availability of Estrogen Receptor Binding Sites in Metastatic Breast Cancer

Phase 1

Completed

• Conditions: Metastatic Breast Cancer
• Interventions: Drug: RAD1901

• Registration Number: NCT02650817
• Lead Sponsor: Stemline Therapeutics, Inc.

Brief Summary

The purpose of this study is to visualize and quantify ER-binding sites during treatment with Elacestrant (RAD1901)

Detailed Description

The purpose of this study is to visualize and quantify ER-binding sites during treatment with Elacestrant (RAD1901) using 16α-18F-Fluoro-17β-estradiol (FES) positron emission tomography (PET) imaging

Study Timeline

• Study First Submitted: 2016-01-06
• Study First Submitted QC: 2016-01-07
• Study First Posted: 2016-01-08
• Study Start: 2016-04-01
• Primary Completion: 2018-08-30
• Study Completion: 2019-10-18
• Status Verified: 2022-08
• Last Update Submitted: 2022-08-16
• Last Update Posted: 2022-08-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 16

Inclusion Criteria

1. Patients with histologically-proven, ER-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced, inoperative, and/or mBC
2. Tumor progression after ≥ 6 months of at least 1 line of hormonal systemic treatment (SERM, SERD, or aromatase inhibitor) in the metastatic setting
3. Measurable disease according to Response Evaluation Criteria in Solid Tumours (RECIST) criteria v1.1 or clinically evaluable disease
4. Greater than or equal to 18 years of age
5. Patients must be post-menopausal
6. Life expectancy >3 months

Key

Exclusion Criteria

1. Greater than 3 lines of endocrine therapy for metastatic disease.

2. Prior anti-cancer treatment or investigational drug therapy within the following windows:

   1. Tamoxifen or fulvestrant therapy < 42 days before 1st 18FES-PET scan
   2. Any other anti-cancer endocrine therapy < 14 days before 1st dose of study drug
   3. Any chemotherapy < 28 days before 1st dose of study drug
   4. Any investigational drug therapy < 28 days or 3 half-lives (whichever is longer) prior to the 1st dose of study drug 2. Patients with untreated or symptomatic central nervous system (brain) metastases 3. Patients with known endometrial disorders, including evidence of endometrial hyperplasia, dysfunctional uterine bleeding, or cysts

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Elacestrant (formerly RAD1901)	RAD1901	To receive daily oral elacestrant

Primary Outcome Measures

Name	Time	Method
Effect of ER Binding after RAD1901 treatment	14 Days after the first dose	To determine the effect of RAD1901 treatment on the estrogen receptor (ER) expression and estradiol binding to the ER in lesions from patients with metastatic breast cancer (mBC)

Secondary Outcome Measures

Name	Time	Method
Tumor response will be evaluated in patients with measurable or evaluable disease, using RECISTv1.1 guidelines	Every 8 weeks for to up 12 months of treatment	To determine if there is a tumor response to RAD1901 treatment
Correlation of FES uptake after RAD1901 treatment to clinical response	Every 8 weeks for to up 12 months of treatment	To determine if any changes in ER binding, as observed through FES uptake, correlate with clinical response
Safety and Tolerability assessed in terms of adverse events, serious adverse events, ECG, physical examination, ECOG performance status, vital signs, and laboratory values	Up to 30 days after the end of treatment	Characterization of the safety of RAD1901 in this patient population
Plasma concentrations of RAD1901 will be assessed at predefined intervals	Every 28 days for up to 3 cycles	Pharmacokinetic data will be collected.

Trial Locations

Locations (5)

UZ Leuven Campus Gasthuisberg; 🇧🇪 Leuven, Belgium

Erasmus Medical Center; 🇳🇱 Rotterdam, Netherlands

Institut Jules Bordet; 🇧🇪 Bruxelles, Belgium

Vrije Universiteit Medisch Centrum (VUMC); 🇳🇱 Amsterdam, Netherlands

Universitair Medisch Centrum Groningen (UMCG); 🇳🇱 Groningen, Netherlands