FIH Study of RGT-419B Alone and With Endocrine Therapy in HR-Positive, HER2-Negative Advanced/Metastatic Breast Cancer

Phase 1RecruitingNCT05304962

Regor Pharmaceuticals Inc.64 enrolled

Overview

This is a phase I, First-in-Human (FIH), open-label study to evaluate the safety, tolerability, pharmacokinetic (PK) profile, and preliminary efficacy of RGT-419B administered orally as monotherapy OR in combination with Hormonal Therapy in subjects with HR+, HER2- locally advanced and unresectable (Stage III) or metastatic (Stage IV) breast cancer whose disease has progressed during prior therapy with an approved CDK4/6i plus hormonal therapy.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Breast Cancer

Interventions

RGT-419BDRUG

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Male or female \>/= 18 years old 2. ECOG Performance Status 0 to 1 3. Subjects must have histologically or cytologically confirmed diagnosis of ER+, HER2- ABC consistent with ASCO CAP guidelines that is locally advanced and unresectable (Stage III) or metastatic (Stage IV) BC. 4. Measurable AND evaluable lesions at baseline per RECIST v1.1. 5. Eligible subjects must meet all of the following criteria: * Progression after receiving 1 line of prior cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) therapy combined with HT in the MBC setting (up to 1 additional line of CDK4/6i is permitted in the post-surgical adjuvant setting); * Subjects must have received therapy for ≥3 months in the MBC setting, or for ≥6 months in the adjuvant setting, prior to progression * Progression after ≤3 lines of prior HT therapy (regardless of whether it is HT alone or in combination with other therapies) * Prior HT combination agents, including SERD, SERM or AI, must have received formal approval by regulatory agency. * ≤ 1 prior line of chemotherapy in the metastatic setting 6. Adequate organ function 7. Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: 1. Presence of visceral metastases with severe organ dysfunction as evidence by signs and symptoms, laboratory studies, lymphangitic spread and/or rapid progression of disease 2. Pregnant or planning to become pregnant 3. Prior irradiation to \>25% of the bone marrow and/or inadequate bone marrow function or evidence of clinically significant end-organ damage 4. Major surgery, chemotherapy, targeted therapy, experimental agents, or radiation within 14-28 days prior to Cycle 1, Day 1 5. Active, serious medical condition that is not well controlled with locally approved medications allowed by the protocol 6. History of allergic reactions attributed to compounds of similar chemical or biologic composition to the drugs used in the study

Locations (8)

University of California, San Diego

La Jolla, California, United States

RECRUITING

University California, Los Angeles

Los Angeles, California, United States

RECRUITING

Hem-Onc Associates of the Treasure Coast

Port Saint Lucie, Florida, United States

ACTIVE_NOT_RECRUITING

Moffitt Cancer Center

Tampa, Florida, United States

RECRUITING

Emory University

Atlanta, Georgia, United States

RECRUITING

Massachusetts General Hospital

Boston, Massachusetts, United States

RECRUITING

Washington University School of Medicine

St Louis, Missouri, United States

RECRUITING

New York Cancer and Blood Specialists

Port Jefferson Station, New York, United States

RECRUITING

Outcomes

Primary Outcomes

Safety & Tolerability - Number of subjects with Dose-Limiting Toxicities (DLTs) at each cohort dose level in singlet and doublet therapy

Number of subjects who have a confirmed DLT at each cohort dose level in singlet and doublet study arms during the first 28-day cycle of RGT-419B treatment.

Time frame: 4 weeks (1 cycle)

Secondary Outcomes

Safety & Tolerability - Incidence, Severity, and Causality of all Treatment Emergent Adverse Events (TEAEs)

Incidence, severity, and causality of all TEAEs will be assessed for all patient participating from Day 1 dosing through end of study.