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

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.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.