Active — Not RecruitingPhase 3

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

United States, Argentina, Australia510 participantsStarted 2023-11-16

Plain-language summary

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.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Key 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. Key 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 cerebrovascula…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Dose-Selection Part: Incidence of adverse events

Timeframe: From Date of Randomization up to 16 weeks

Dose-Selection Part: Incidence of dose reduction

Timeframe: From Date of Randomization up to 16 weeks

Dose-Selection Part: Incidence of drug discontinuation

Timeframe: From Date of Randomization up to 16 weeks

Trial: Progression-Free Survival (PFS)

Timeframe: From Date of Randomization until Disease Progression or Death Due to Any Cause (estimated as up to 2 years)

Trial details

NCT IDNCT06016738

SponsorOlema Pharmaceuticals, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2026-10-31

View on ClinicalTrials.gov More Breast Cancer trials

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Dose-Selection Part: Incidence of adverse events

Timeframe: From Date of Randomization up to 16 weeks

Dose-Selection Part: Incidence of dose reduction

Timeframe: From Date of Randomization up to 16 weeks

Dose-Selection Part: Incidence of drug discontinuation

Timeframe: From Date of Randomization up to 16 weeks

Trial: Progression-Free Survival (PFS)

Timeframe: From Date of Randomization until Disease Progression or Death Due to Any Cause (estimated as up to 2 years)