A Safety, Pharmacokinetic, Pharmacodynamic and Anti-Tumor Study of PF-06873600 as a Single Agent and in Combination With Endocrine Therapy

Open to people ages 18 years and up

• Have a diagnosis of Hormone Receptor Positive (HR+), Human Epidermal Growth Factor Receptor 2 Negative (HER2-) breast cancer

• Prior combined CDK 4/6 inhibitor and endocrine therapy and 1 or 2 prior lines of chemotherapy

• Have a diagnosis of metastatic triple negative breast cancer (TNBC)

• Up to 1-2 prior lines of chemotherapy

• Have a diagnosis of advanced platinum resistant epithelial ovarian cancer (EOC)/fallopian tube cancer/primary peritoneal cancer (PPC)

• Up to 2-3 prior lines of therapy

• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1
• Measurable disease or non-measurable disease and refractory to or intolerant of existing therapies (Part 1)
• Measurable disease as defined by RECIST 1.1 is required (Part 1B and Part 2 only)

• Known active uncontrolled or symptomatic Central Nervous System (CNS) metastases
• Other active malignancy within 3 years prior to randomization, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ
• Major surgery or radiation within 4 weeks prior to study entry
• Last anti-cancer treatment within 2 weeks prior to study entry
• Participation in other studies involving investigational drug(s) within 4 weeks prior to study entry
• Pregnant or breastfeeding female patients
• Active inflammatory gastrointestinal (GI) disease, known diverticular disease or previous gastric resection or lap band surgery including impairment of gastro intestinal function or GI disease