ACE-Breast03: This Phase II trial is trying to understand the effectiveness of a new targeted therapy (ARX788) in people with HER2-positive metastatic breast cancer who have not responded to other targeted therapies (T-DM1, T-DXd, Tucatinib)A Global, Phase 2 Study of ARX788 in HER2-positive, Metastatic Breast Cancer Patients Whose Disease is Resistant or Refractory to T-DM-1 or T-DXd, and/or Tucatinib-containing Regimens

Exclusion

Any subject who meets any of the following criteria is excluded from the study:

• History of allergic reactions to any component of ARX788.
• Prior history of interstitial lung disease, pneumonitis, or other clinically significant lung disease
• Any active ocular infections or chronic corneal disorders
• History of congestive heart failure, unstable angina pectoris, unstable atrial fibrillation, or cardiac arrhythmia within 12 months prior to enrollment
• Grade 3 to 4 peripheral neuropathy (NCI CTCAE v 5.0). Patients with Grade 2 neuropathy can be enrolled at investigator's discretion
• History of unstable central nervous system (CNS) metastases
• Current severe, uncontrolled systemic disease (eg, clinically significant cardiovascular, pulmonary, or metabolic diseases)
• Any uncontrollable intercurrent illness, infection (including subjects with active, symptomatic Covid-19 infections), or other conditions that could limit study compliance or interfere with assessments
• Exposure to any other investigational or commercial anticancer agents or therapies administered with the intention to treat malignancy within 14 days before the first dose of ARX788