Estradiol Plus Olaparib for Breast Cancer (PHOEBE)

• Status: Not yet recruiting
• Trial end date: 2028-09-01
• Target enrollment: 0
• Participant gender: Female

Summary

Determine the safety and recommended Phase II dose of olaparib in combination with 17b-estradiol in post-menopausal patients with advanced ER+/HER2- breast cancer.

• Phase: Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Gary Schwartz
• Collaborator: Dartmouth-Hitchcock Medical Center
• Treatments: Estradiol; Olaparib

Criteria

Inclusion Criteria:

• Post-menopausal women with ER+/HER2- breast cancer.

• Metastatic or locoregional recurrence not amenable to treatment with curative intent.

• Received ≥1 prior line of endocrine-based therapy in the advanced/metastatic setting.

Exclusion Criteria:

• During study treatment, no concurrent anti-cancer therapies are allowed with the following exceptions:

o Anti-resorptive bone therapies (e.g., bisphosphonates, denosumab) permitted.

• Any investigational cancer therapy or systemic chemotherapy in the last 3 weeks.

• Any radiation therapy in the last 2 weeks.

• Known CNS disease, unless clinically stable for ≥ 3 months.

• Concomitant use of known strong or moderate CYP3A inhibitors.

• Persistent toxicities (≥CTCAE grade 2) caused by previous cancer therapy.

• History of any of the following:

• Deep venous thrombosis

• Pulmonary embolism

• Stroke

• Acute myocardial infarction

• Congestive heart failure

• Previous malignancy not treated with curative intent, or with an estimated recurrence risk ≥30%

• Severe renal impairment (creatinine clearance ≤ 30 mL/min).