Clinical trial · Interventional
Estradiol Plus Olaparib for Breast Cancer (PHOEBE)
Phase 1b Study of Olaparib and Estradiol in Advanced ER+ Breast Cancer (PHOEBE)
NCT05900895CI-TRIAL-00097554PHOEBErecruitingPhase 1ClinicalTrials.gov clinicaltrialsProvenance
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
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.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Metastatic Breast Cancer | Malignant Breast Neoplasm | CURATED_BROADER | 0.78 |
Interventions
Interventions (2)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| 17b-estradiol | Drug | — | UNRESOLVED |
| Olaparib | Drug | Olaparib | ALIAS |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Treatment Arm
- description
- Participants receive 2 cycles of olaparib in combination with 17b-estradiol and then continue to be treated with single-agent 17b-estradiol until disease progression.
- interventionNames
- Drug: Olaparib
- Drug: 17b-estradiol
Primary outcomes (1)
- measure
- Determine the Phase II dose of olaparib in combination with 17b-estradiol
- timeFrame
- 8 weeks
- 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.
Secondary outcomes (5)
- measure
- Clinical benefit rate
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 18 Years
Show eligibility criteria text
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).
References
Publications (0)
Data not yet available
No reference posted for this study.