OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer

Purpose

This phase 3 clinical trial compares the safety and efficacy of palazestrant (OP-1250) to the standard-of-care options of fulvestrant or an aromatase inhibitor in women and men with breast cancer whose disease has advanced on one endocrine therapy in combination with a CDK4/6 inhibitor.

Conditions

  • Breast Cancer
  • Advanced Breast Cancer
  • Metastatic Breast Cancer
  • ER Positive Breast Cancer
  • HER2 Negative Breast Carcinoma

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • Adult female or male participants. - ER+, HER2- locally advanced or metastatic breast cancer that is not amenable to curative therapy. - Evaluable disease (measurable disease or bone-only disease). - Previously received a CDK4/6 inhibitor in combination with an endocrine therapy in the advanced setting. One additional line of ET as a monotherapy is allowed. Duration of the most recent prior ET must be at least 6 months. - Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. - Adequate hematologic, hepatic, and renal functions. - Female participants can be pre-, peri- or postmenopausal. - Male and pre- or peri-menopausal female participants must be willing to take a GnRH (or LHRH) agonist.

Exclusion Criteria

  • Symptomatic visceral disease, imminent organ failure, or any other reason that makes the participant ineligible for endocrine monotherapy. - Previously received chemotherapy in the advanced/metastatic setting. - Previously received treatment with elacestrant or an investigational estrogen receptor-directed therapy. - History of allergic reactions to study treatment. - Any contraindications to the selected standard-of-care endocrine therapy in the local prescribing information. - Symptomatic central nervous system metastases, carcinomatous meningitis, leptomeningeal disease, or a spinal cord compression that require immediate treatment. - Clinically significant comorbidities such as significant cardiac or cerebrovascular disease, gastrointestinal disorders that could affect absorption of study treatment.

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Palazestrant (OP-1250)
Participants will receive Palazestrant
  • Drug: Palazestrant
    Participants will be treated with palazestrant once daily on a 4 week (28 day) cycle. Doses evaluated in the dose-selection part will be 120 mg once daily and 90 mg once daily.
    Other names:
    • OP-1250
Active Comparator
Standard of Care Endocrine Therapy
Participants will receive Investigator's choice of one of the Standard of Care drugs (fulvestrant, anastrozole, letrozole, or exemestane)
  • Drug: Fulvestrant
    Participants will be treated with fulvestrant on C1D1, C1D15, and then on Day 1 of every subsequent 4 week (28 day) cycle
  • Drug: Anastrozole
    Participants will be treated with anastrozole once daily on a 4 week (28 day) cycle
  • Drug: Letrozole
    Participants will be treated with letrozole once daily on a 4 week (28 day) cycle
  • Drug: Exemestane
    Participants will be treated with exemestane once daily on a 4 week (28 day) cycle

Recruiting Locations

Clinical Trial Site
Nashville, Tennessee 37232

More Details

Status
Recruiting
Sponsor
Olema Pharmaceuticals, Inc.

Study Contact

Olema Pharmaceuticals, Inc.
415-651-7206
OPERA-01@olema.com

Detailed Description

This is an international, multicenter, randomized, open-label, active-controlled, phase 3 clinical trial. The purpose of this trial is to compare the safety and efficacy of palazestrant (OP-1250) as a single agent to the standard of care endocrine therapy: either fulvestrant or an aromatase inhibitor (anastrozole, letrozole, or exemestane). This trial is seeking adult participants with ER+, HER2- advanced or metastatic breast cancer whose disease has relapsed or progressed on 1 or 2 prior lines of standard-of-care endocrine therapy for metastatic breast cancer. Prior lines of therapy must include one line of endocrine therapy in combination with a CDK 4/6 inhibitor. In the dose-selection part of the trial, approximately 120 participants will be randomized to one of the two doses of palazestrant or to the standard-of-care endocrine therapy. Thereafter, approximately 390 participants will be randomized to palazestrant at the selected dose or to the standard-of-care endocrine therapy.