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.
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.
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.
Participants will be treated with fulvestrant on C1D1, C1D15, and then on Day 1 of every subsequent 4 week (28 day) cycle
Participants will be treated with anastrozole once daily on a 4 week (28 day) cycle
Participants will be treated with letrozole once daily on a 4 week (28 day) cycle
Participants will be treated with exemestane once daily on a 4 week (28 day) cycle
Bahía Blanca, Buenos Aires, Argentina
Mar del Plata, Buenos Aires, Argentina
Mar del Plata, Buenos Aires, Argentina
Córdoba, Córdoba Province, Argentina
Córdoba, Córdoba Province, Argentina
San Salvador de Jujuy, Jujuy Province, Argentina
La Rioja, La Rioja Province, Argentina
Viedma, Río Negro Province, Argentina
Rosario, Santa Fe Province, Argentina
Rosario, Santa Fe Province, Argentina
San Miguel de Tucumán, Tucumán Province, Argentina
Buenos Aires, Argentina