OncoMatch/Clinical Trials/NCT05304962
FIH Study of RGT-419B Alone and With Endocrine Therapy in HR-Positive, HER2-Negative Advanced/Metastatic Breast Cancer
Is NCT05304962 recruiting? Yes, currently enrolling (May 2026). This Phase 1 trial studies multiple treatments including RGT-419B and RGT-419B in combination with hormonal therapy for breast cancer.
Treatment: RGT-419B · RGT-419B in combination with hormonal therapy — 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.
Check if I qualifyExtracted eligibility criteria
Cancer type
Breast Carcinoma
Biomarker criteria
Required: ESR1 overexpression (ER+)
ER+ ABC consistent with ASCO CAP guidelines
Required: HER2 (ERBB2) wild-type (HER2-)
HER2- ABC consistent with ASCO CAP guidelines
Disease stage
Required: Stage III, IV
Performance status
ECOG 0–1(Restricted strenuous activity)
Prior therapy
Must have received: CDK4/6 inhibitor — metastatic and/or adjuvant
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
Structured fields extracted by AI. May contain errors — verify against the official protocol.
US trial sites
- University of California, San Diego · La Jolla, California
- University California, Los Angeles · Los Angeles, California
- Hem-Onc Associates of the Treasure Coast · Port Saint Lucie, Florida
- Moffitt Cancer Center · Tampa, Florida
- Emory University · Atlanta, Georgia
Showing up to 5 US sites. See all sites on ClinicalTrials.gov →
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