NCT06016738

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

A Phase 3 Randomized, Open-Label Study of OP-1250 Monotherapy vs Standard of Care for the Treatment of ER+, HER2- Advanced or Metastatic Breast Cancer Following Endocrine and CDK 4/6 Inhibitor Therapy (OPERA-01)

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 510 (estimated)
• Sponsor: Olema Pharmaceuticals, Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

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.

Conditions

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

Interventions

Type	Name	Description
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.
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

Timeline

• Start date: 2023-11-16
• Primary completion: 2026-06-30
• Completion: 2027-09-30
• First posted: 2023-08-30
• Last updated: 2026-03-13

Locations

233 sites across 26 countries: United States, Argentina, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, Czechia, France, Germany, Hong Kong, Hungary, Italy, Malaysia, Mexico, Netherlands, Poland, Portugal, Puerto Rico, Romania, South Korea, Spain, Taiwan, Thailand, United Kingdom

Regulatory

• FDA-regulated drug study