OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer
OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer
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.
Not Available
Phase III
Adults
Hormonal Therapy
Anastrozole,
Exemestane,
Fulvestrant,
Letrozole (Femara),
OP-1250
Abramson, Vandana
International
Vanderbilt University
11-28-2025
Eligibility
18 Years and older
ALL
false
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.
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.
