NCT05900895RecruitingPhase 1
Estradiol Plus Olaparib for Breast Cancer (PHOEBE)
Phase 1b Study of Olaparib and Estradiol in Advanced ER+ Breast Cancer (PHOEBE)
Source: ClinicalTrials.gov · Last updated 20 Nov 2025
Brief summary (registry, in English)
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.
- Status (registry)
- Recruiting
- Phase (registry)
- Phase 1
- Study type
- Interventional
- Enrollment
- 6 (estimated)
- First submitted
- 24 May 2023
- Start date
- 15 Jul 2024
- Primary completion date
- Dec 2027
- Lead sponsor
- Mary D Chamberlin
- Diseases
- Metastatic breast cancer
- NCT number
- NCT05900895
What you commit to
- Study type: Interventional · Phase 1
- Planned participants: 6
- From 15 Jul 2024 to the primary completion date, Dec 2027
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- 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 radiation therapy in the last 2 weeks.
- Concomitant use of known strong or moderate CYP3A inhibitors.
Other illness
- Any investigational cancer therapy or systemic chemotherapy in the last 3 weeks.
- Known CNS disease, unless clinically stable for ≥ 3 months.
- Persistent toxicities (≥CTCAE grade 2) caused by previous cancer therapy.
Lab values
- 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).
Who the study is looking for
- 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.
Age in the registry: 18 years to - · Sex: Female · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Dartmouth Cancer Center Coordinator of this site? Confirm its status | Lebanon | United States | Recruiting |
This page is information, not medical advice. Discuss any trial with your doctor.