RecruitingPhase 3NCT07085767

Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer

A Phase 3 Randomized, Double-Blind, Active-Controlled Study of Palazestrant With Ribociclib Versus Letrozole With Ribociclib for the First-Line Treatment of ER+, HER2- Advanced Breast Cancer (OPERA-02)


Sponsor

Olema Pharmaceuticals, Inc.

Enrollment

1,000 participants

Start Date

Nov 3, 2025

Study Type

INTERVENTIONAL

Conditions

Summary

This phase 3 clinical trial compares the efficacy and safety of palazestrant with ribociclib to letrozole and ribociclib in women and men who have not received prior systemic anti-cancer treatment for advanced breast cancer.


Eligibility

Min Age: 18 Years

Plain Language Summary

Simplified for easier understanding

This study is testing a combination of two drugs — palazestrant (a next-generation hormone blocker) and ribociclib (a drug that slows cancer cell growth by targeting a protein called CDK4/6) — as a first-line treatment for hormone receptor-positive, HER2-negative advanced or metastatic breast cancer. **You may be eligible if...** - You are an adult (any gender) - You have been diagnosed with ER-positive, HER2-negative locally advanced or metastatic breast cancer that cannot be cured with surgery - Your cancer is either newly diagnosed at an advanced stage, or has returned more than 12 months after completing hormonal therapy - Your overall health is good (ECOG 0 or 1) and blood counts and organ function are adequate **You may NOT be eligible if...** - You have received prior treatment for advanced or metastatic disease - You have previously used a CDK4/6 inhibitor - You have uncontrolled heart problems or significant liver disease - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

DRUGPalazestrant

Participants will be treated with palazestrant 90 mg once daily on a 4-week (28-day) cycle.

DRUGLetrozole-matching placebo

Participants will be treated with letrozole-matching placebo once daily on a 4-week (28 day) cycle

DRUGRibociclib

Participants will be treated with ribociclib 600 mg once daily on Days 1-21 of a 4-week (28 day) cycle.

DRUGLetrozole

Participants will be treated with letrozole 2.5 mg once daily on a 4-week (28-day) cycle

DRUGPalazestrant matching-placebo

Participants will be treated with palazestrant-matching placebo once daily on a 4-week (28-day) cycle


Locations(85)

Clinical Trial Site

Hot Springs, Arkansas, United States

Clinical Trial Site

Santa Barbara, California, United States

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Denver, Colorado, United States

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Peoria, Illinois, United States

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Ames, Iowa, United States

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Scarborough, Maine, United States

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Annapolis, Maryland, United States

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Kansas City, Missouri, United States

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Santa Fe, New Mexico, United States

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Columbus, Ohio, United States

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Horsham, Pennsylvania, United States

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Sayre, Pennsylvania, United States

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Knoxville, Tennessee, United States

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Tennessee City, Tennessee, United States

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Denton, Texas, United States

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El Paso, Texas, United States

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Houston, Texas, United States

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San Antonio, Texas, United States

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Salt Lake City, Utah, United States

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Olympia, Washington, United States

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Vancouver, Washington, United States

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Sydney, New South Wales, Australia

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Waratah, New South Wales, Australia

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South Brisbane, Queensland, Australia

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Adelaide, South Australia, Australia

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Clayton, Victoria, Australia

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Geelong, Victoria, Australia

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Heidelberg, Victoria, Australia

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Nedlands, Western Australia, Australia

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Toronto, Ontario, Canada

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Bobigny, France

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Athens, Pireas, Greece

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Thessaloniki, Thessaloniki, Greece

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Hong Kong, Hong Kong, Hong Kong

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Hong Kong, Kowloon, Hong Kong

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Hong Kong, Pok Fu Lam, Hong Kong

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Milan, Milano, Italy

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Ipoh, Ipoh Perak, Malaysia

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Kuala Lumpur, Kuala Lumpur, Malaysia

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Kuala Lumpur, Kuala Lumpur, Malaysia

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George Town, Pulau Pinang, Malaysia

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Kota Kinabalu, Sabah, Malaysia

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Kuching, Sarawak, Malaysia

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Petaling Jaya, Selangor, Malaysia

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Putrajaya, Wilayah PE, Malaysia

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Apeldoorn, Gelderland, Netherlands

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Rzeszów, Podkarpackie Voivodeship, Poland

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Rzeszów, Podkarpackie Voivodeship, Poland

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Brzozów, Woj Podkarpackie, Poland

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Cluj-Napoca, Cluj, Romania

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Iași, Iaşi, Romania

Clinical Trial Site

Timișoara, Timiș County, Romania

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Busan, Busan Metropolitan City, South Korea

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Daegu, Daegu Metropolitan City, South Korea

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Goyang-si, Gyeonggi-do, South Korea

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Seongnam-si, Gyeonggi-do, South Korea

Clinical Trial Site

Suwon, Gyeonggi-do, South Korea

Clinical Trial Site

Yongin-si, Gyeonggi-do, South Korea

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Seoul, Seoul, South Korea

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Seoul, Seoul, South Korea

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Seoul, Seoul, South Korea

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Seoul, Seoul Special City, South Korea

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Seoul, Seoul Special City, South Korea

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Alicante, Alicante, Spain

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Barcelona, Barcelona, Spain

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Barcelona, Barcelona, Spain

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Granada, Granada, Spain

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Madrid, Madrid, Spain

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Murcia, Murcia, Spain

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Valencia, Valencia, Spain

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Chang-hua, Chang Hua, Taiwan

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Kaohsiung City, Sanmin, Taiwan

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Taipei, Special Municipality, Taiwan

Clinical Trial Site

Taipei, Special Municipality, Taiwan

Clinical Trial Site

Taipei, Taipei City, Taiwan

Clinical Trial Site

Taipei, Taipei City, Taiwan

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Bangkok, Bangkok, Thailand

Clinical Trial Site

Dusit, Bangkok, Thailand

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Ban Phaeo, Changwat Samut Sakhon, Thailand

Clinical Trial Site

Hat Yai, Changwat Songkhla, Thailand

Clinical Trial Site

Chiang Mai, Chiang Mai, Thailand

Clinical Trial Site

Brighton, England, United Kingdom

Clinical Trial Site

London, England, United Kingdom

Clinical Trial Site

London, Greater London, United Kingdom

Clinical Trial Site

Guildford, Surrey, United Kingdom

View Full Details on ClinicalTrials.gov

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NCT07085767


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