Study of NUV-422 in Combination With Fulvestrant in Patients With HR+HER2- aBC

Inclusion Criteria:

Men and women with diagnosis of locally advanced inoperable or metastatic HR+HER2- breast cancer
Evidence of disease progression on immediate prior therapy as determined by the Investigator per standard criteria

Patients must have received standard of care treatments for their breast cancer and be eligible to receive fulvestrant

Prior standard of care treatments must include treatment with hormonal therapy in combination with an approved CDK4/6 inhibitor
Patients must have endocrine-resistant disease
Have no known active or symptomatic central nervous system (CNS) disease
Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤ 1
Life expectancy of > 6 months
Eligible to receive fulvestrant
Adequate bone marrow and organ function

Exclusion Criteria:

Have received chemotherapy, hormonal therapy (with the exception of ongoing LHRH analogs in male patients and premenopausal women), radiation, or biological anti-cancer therapy within 14 days prior to the first dose of NUV-422 and fulvestrant
Received treatment with an investigational agent for any indication within 14 days for non-myelosuppressive agent or 21 days (of < 5 half-lives) for myelosuppressive agent prior to first dose of NUV-422 and fulvestrant
Moderate liver impairment which would require a reduced dose of fulvestrant

Requires medications that are known to be strong inducers and/or inhibitors of CYP3A4/5 enzymes

For Phase 1b only: requires medications that are known to be moderate inducers and/or inhibitors of CYP3A4/5 enzymes
Known allergy or hypersensitivity to fulvestrant
For Phase 2 only: prior therapy with fulvestrant and/or investigational ER targeted agent
Females who are pregnant or breast feeding