Estradiol Plus Olaparib for Breast Cancer (PHOEBE)
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Olaparib, 17b-estradiol.
- Who it may be relevant to
- Registry conditions: Metastatic Breast Cancer. Basic parameters: from 18 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Phase 1b Study of Olaparib and Estradiol in Advanced ER+ Breast Cancer (PHOEBE)
Overview
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.
Detailed description
Patients with endocrine-resistant ER+/HER2- breast cancer are eligible. Patients will be treated with the combination of 17b-estradiol and olaparib for 2 cycles, and then treated with single-agent 17b-estradiol until disease progression. Clinical benefit, progression-free survival, objective response, tumor metabolic response, and toxicity will be determined.
Interventions
- Drug Olaparib
Participants will be treated with olaparib at the approved doses for the treatment of subtypes of breast cancer or at reduced dose/frequency for participants with moderate renal impairment. - Drug 17b-estradiol
17b-estradiol will be taken orally three times per day.
Primary outcome measures
- Determine the Phase II dose of olaparib in combination with 17b-estradiol [Time frame: 8 weeks]
Secondary outcome measures (5)
- Clinical benefit rate [Time frame: 6 months]
- Objective response rate [Time frame: 6 months]
- Progression-free survival [Time frame: 12 months]
- Plasma Olaparib concentration [Time frame: 6 hours]
- Plasma 17b-Estradiol/Estrone concentration [Time frame: 6 hours]
Eligibility 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).
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- N/A
- Model
- Sequential
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
United States · 1 center
- Dartmouth Cancer Center — Lebanon
Identifiers
NCT: NCT05900895 · STUDY02002007