Recruiting
Phase 1

Estradiol & Olaparib

Sponsor:

Mary D Chamberlin

Code:

NCT05900895

Conditions

Metastatic Breast Cancer

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Olaparib

17b-estradiol

Study Details

Brief 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.

Conditions

Metastatic Breast Cancer

Study ID

NCT05900895

Start date

Jul 15, 2024

Status verified date

Oct, 2025

Completion date

Dec, 2028

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

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).

Study Design

Enrollment

6 participants

Anticipated

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Treatment Arm

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.

Interventions

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.

17b-estradiol

17b-estradiol will be taken orally three times per day.

Primary outcome measure

  • Determine the Phase II dose of olaparib in combination with 17b-estradiol [ Time Frame: 8 weeks ]

Central Contacts and Locations

Central contacts

Research Nurse

1-800-639-6918Cancer.Research.Nurse@dartmouth.edu

Locations

Dartmouth Cancer Center

Recruiting

Lebanon, New Hampshire, United States, 03756

Contacts

Mary D Chamberlin, MD

603-653-6181mary.d.chamberlin@hitchcock.org

Ashley E Gaughan-Maher, MA

603-653-0628ashley.e.gaughan-maher@hitchcock.org

Principal Investigator:

Mary D Chamberlin, MD

More Information

Sponsor

Mary D Chamberlin

Last update posted

Nov 20, 2025

Last verified

Oct, 2025

Keywords

  • metastatic
  • locally advanced
  • estradiol therapy
  • olaparib

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Mary D Chamberlin on 2025-11-20.