Estrogen receptor modulator for the treatment of locally advanced or metastatic estrogen receptor positive breast cancer

1. A method of treating locally advanced or metastatic estrogen receptor positive (ER+) breast cancer in a postmenopausal woman in need thereof, the method comprising orally administering a therapeutically effective amount of (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid, or a pharmaceutically acceptable salt thereof, to the postmenopausal woman, wherein the postmenopausal woman has been previously treated with (i) one or more endocrine therapies, (ii) fulvestrant or (iii) one or more aromatase inhibitors.

2. The method of claim 1 , wherein the breast cancer is locally advanced or metastatic estrogen receptor positive, human epidermal growth factor receptor 2 negative (HER2−) breast cancer.

3. The method of claim 1 , wherein the breast cancer in the postmenopausal woman had previously progressed in the presence of hormonal therapy.

4. The method of claim 1 , wherein the breast cancer is not amenable to resection or radiation therapy with curative intent.

5. The method of claim 1 , wherein the breast cancer has progressed after at least 6 months of endocrine therapy for estrogen receptor positive breast cancer.

6. The method of claim 1 , wherein the breast cancer in the postmenopausal woman had previously progressed in the presence of therapy with fulvestrant.

7. The method of claim 1 , wherein the breast cancer in the postmenopausal woman had previously progressed in the presence of therapy with an aromatase inhibitor.

8. The method of claim 1 , wherein the therapeutically effective amount of (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid, or a pharmaceutically acceptable salt thereof, is administered daily to the postmenopausal woman.

9. The method of claim 1 , wherein the therapeutically effective amount of (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid, or a pharmaceutically acceptable salt thereof, is administered orally to the postmenopausal woman on a continuous daily dosing schedule.

10. The method of claim 1 , wherein the therapeutically effective amount of (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid, or a pharmaceutically acceptable salt thereof, is about 50 mg per day to about 2000 mg per day.

11. The method of claim 1 , wherein the therapeutically effective amount of (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid, or a pharmaceutically acceptable salt thereof, is administered once a day to the postmenopausal woman.

12. The method of claim 1 , wherein the (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl)phenyl)acrylic acid is administered to the postmenopausal woman in a fed state.