PF-07104091 as a Single Agent and in Combination Therapy

Inclusion Criteria:

• Participants with HR-positive HER2-negative advanced or metastatic breast cancer (received at least two prior lines in the advanced or metastatic setting includingone prior line of combined CDK4/6 inhibitor and endocrine therapy and no more thantwo prior lines of cytotoxic chemotherapy)

• Participants with locally recurrent/advanced or metastatic TNBC who have received upto 2 prior lines of chemotherapy in the advanced or metastatic setting

• Participants with advanced platinum resistant epithelial ovarian cancer (EOC)/fallopian tube cancer/primary peritoneal cancer (PPC) (histologically orcytologically proven) who have received at least 1 systemic anti-cancer therapycontaining a platinum analog

• Participants with cytological diagnosis of advanced/metastatic SCLC

• Participants with or cytological diagnosis of advanced/metastatic NSCLC

• Participants with HR-positive HER2-negative advanced or metastatic breast cancer (second line plus setting) (histologically or cytologically proven).

• Participants entering the study in the expansion cohort have at least one measurablelesion as defined by RECIST version 1.1 that has not been previously irradiated

• Performance Status 0 or 1

• Adequate bone marrow, hematological, kidney and liver function

• Resolved acute effects of any prior therapy to baseline severity

Exclusion Criteria:

• Participants with known symptomatic brain metastases requiring steroids

• Participants with any other active malignancy within 3 years prior to enrollment

• Major surgery within 3 weeks prior to study entry

• Radiation therapy within 3 weeks prior to study entry.

• Systemic anti cancer therapy within 4 weeks prior to study

• Prior irradiation to >25% of the bone marrow

• Participants with active, uncontrolled bacterial, fungal, or viral infection,including HBV, HCV, and known HIV or AIDS related illness

• Active COVID-19/SARS-CoV2 infection

• Baseline 12 lead ECG that demonstrates clinically relevant abnormalities that mayaffect participant safety or interpretation of study results

• Any of the following in the previous 6 months: myocardial infarction, long QTsyndrome, Torsade de Pointes, arrhythmias, serious conduction system abnormalities,unstable angina, coronary/peripheral artery bypass graft, symptomatic CHF, New YorkHeart Association class III or IV, cerebrovascular accident, transient ischemicattack, symptomatic pulmonary embolism, and/or other clinical significant episode ofthrombo embolic disease.

• Anticoagulation with vitamin K antagonists or factor Xa inhibitors is not allowed.

• Hypertension that cannot be controlled by medications

• Participation in other studies involving investigational drug(s) within 2 weeksprior to study entry.

• Known or suspected hypersensitivity to active ingredient/excipients in PF 07104091.

• Active inflammatory gastrointestinal disease, chronic diarrhea, known diverticulardisease or previous gastric resection or lap band surgery.

• Participants with advanced/metastatic, symptomatic, visceral spread, that are atrisk of life threatening complications in the short

• Participants with an indwelling catheter that has an external component such asthose used for drainage of effusion(s) or central venous catheter that is externally

• Previous high dose chemotherapy requiring stem cell rescue

• Known abnormalities in coagulation such as bleeding diathesis, or treatment withanticoagulants precluding intramuscular injections of goserelin (if applicable).

• Current use or anticipated need for food or drugs that are known strong CYP3A4/5 orUGT1A9 inhibitors or inducers

• Current use or anticipated need for drugs that are known sensitive UGT1A1 substrateswith narrow therapeutic

• Serum pregnancy test positive at screening

• Other medical or psychiatric condition