Study of PF-07248144 in Advanced or Metastatic Solid Tumors

Required: ESR1 positive (≥1% positive stained cells)

documentation of ER-positive tumor (≥1% positive stained cells) based on most recent tumor biopsy utilizing an assay consistent with local standards

Required: HER2 (ERBB2) wild-type (IHC 0/1+ or negative by in situ hybridization (FISH/CISH/SISH/DISH) defined as a HER2/CEP17 ratio <2 or for single probe assessment a HER2 copy number <4)

documentation of HER2-negative tumor: HER2-negative tumor is determined as immunohistochemistry score 0/1+ or negative by in situ hybridization (FISH/CISH/SISH/DISH) defined as a HER2/CEP17 ratio <2 or for single probe assessment a HER2 copy number <4

Must have received: endocrine therapy — advanced or metastatic

must have progressed after at least 1 prior line of endocrine therapy

Must have received: CDK4/6 inhibitor — advanced or metastatic

must have progressed after at least 1 prior line of treatment with an endocrine therapy and CDK4/6 inhibitor in the advanced or metastatic setting

Cannot have received: systemic anti-cancer therapy

Exception: within 3 weeks prior to study entry

systemic anti-cancer therapy within 3 weeks prior to study entry

Cannot have received: cytotoxic chemotherapy

Exception: no more than 1 line for visceral disease in advanced or metastatic setting

not received more than 3 lines of systemic therapies including up to 1 line of cytotoxic chemotherapy for visceral disease in advanced or metastatic setting