NCT05900895 · Mary D Chamberlin
Estradiol Plus Olaparib for Breast Cancer (PHOEBE)
(PHOEBE)
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- 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).
Where
- Lebanon, New Hampshire
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 20, 2025 · Source of record for eligibility and locations