A Phase I Study of RGT-419B in Patients With HR-Positive, HER2-Negative Advanced Breast Cancer or Other Solid Tumors

A Phase I Study Evaluating Safety and Tolerability of RGT-419B Monotherapy in Chinese Patients With Hormone Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Advanced/Metastatic Breast Cancer or Other Solid Tumors

This is a Phase 1 dose escalation and dose expansion phase I study to evaluate the safety, tolerability, pharmacokinetic profile and preliminary efficacy of RGT-419B as monotherapy in Chinese patients with HR+/HER2- advanced/metastatic breast cancer and other advanced solid tumors.

Inclusion Criteria:

• Male or female ≥ 18 years of age
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1
• Subjects with pathologically confirmed advanced solid tumors who have failed standard-of-care therapy, or have no standard-of-care therapy available, or are currently not eligible for standard-of-care therapy; Subjects with HR+/ HER2- advanced or metastatic breast cancer are preferred.
• Estimated life expectancy of at least 12 weeks

Exclusion Criteria:

• Presence of visceral metastases with severe organ dysfunction
• Known active hepatitis B or C infection
• Prior irradiation to >25% of the bone marrow and/or inadequate bone marrow function or evidence of clinicallysignificant end-organ damage
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to the drugs usedin the study