NCT05304962

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

First-in-Human, Escalating Oral Dose Study of RGT-419B Given Alone and With Endocrine Therapy in Subjects With Hormone Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Advanced/Metastatic Breast Cancer

• Status: Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 64 (estimated)
• Sponsor: Regor Pharmaceuticals Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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.

Conditions

• Breast Cancer

Interventions

Type	Name	Description
DRUG	RGT-419B	oral capsules
DRUG	RGT-419B in combination with hormonal therapy	RGT-419B in combination with hormonal therapy (Selective Estrogen Receptor Degrader, Selective Estrogen Receptor Modulator, or Aromatase Inhibitor)

Timeline

• Start date: 2022-03-04
• Primary completion: 2026-09-30
• Completion: 2026-12-30
• First posted: 2022-03-31
• Last updated: 2026-04-02

Locations

8 sites across 1 country: United States

Regulatory

• FDA-regulated drug study