Monotherapy Fulvestrant injection is indicated for the treatment of: Hormone receptor -positive, human epidermal growth factor receptor 2 -negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy, or HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy. Combination Therapy Fulvestrant injection is indicated for the treatment of: HR-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal women in combination with ribociclib as initial endocrine based therapy or following disease progression on endocrine therapy. HR-positive, HER2-negative advanced or metastatic breast cancer in combination with palbociclib or abemaciclib in women with disease progression after endocrine therapy. Fulvestrant injection is an estrogen receptor antagonist indicated for the treatment of: Hormone receptor -positive, human epidermal growth factor receptor 2 -negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy. HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy. HR-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal women in combination with ribociclib, as initial endocrine based therapy or following disease progression on endocrine therapy. HR-positive, HER2-negative advanced or metastatic breast cancer in combination with palbociclib or abemaciclib in women with disease progression after endocrine therapy.