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

NCT ID: NCT07085767

Last Updated: 2026-02-09

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

1000 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-11-03

Study Completion Date

2032-01-31

Brief Summary

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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.

Detailed Description

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This is an international, multicenter, randomized, double-blind, active-controlled, phase 3 clinical trial. The purpose of this trial is to compare the efficacy and safety of palazestrant in combination with ribociclib +letrozole -matching placebo (Arm A: investigational arm) with letrozole in combination with ribociclib + palazestrant-matching placebo (Arm B: control arm).

This trial is seeking adult participants with ER+, HER2- advanced breast cancer who have not received prior systemic anti-cancer treatment for advanced disease. Approximately 1,000 participants will be randomized in a 1:1 ratio to one of the two study arms.

Conditions

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

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

TRIPLE

Participants Caregivers Investigators

Study Groups

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Palazestrant

Participants will receive palazestrant, ribociclib and letrozole-matching placebo

Group Type EXPERIMENTAL

Palazestrant

Intervention Type DRUG

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

Letrozole-matching placebo

Intervention Type DRUG

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

Ribociclib

Intervention Type DRUG

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

Letrozole

Participants will receive letrozole, ribociclib and palazestrant-matching placebo

Group Type ACTIVE_COMPARATOR

Ribociclib

Intervention Type DRUG

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

Letrozole

Intervention Type DRUG

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

Palazestrant matching-placebo

Intervention Type DRUG

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

Interventions

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Palazestrant

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

Intervention Type DRUG

Letrozole-matching placebo

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

Intervention Type DRUG

Ribociclib

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

Intervention Type DRUG

Letrozole

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

Intervention Type DRUG

Palazestrant matching-placebo

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

Intervention Type DRUG

Other Intervention Names

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OP-1250

Eligibility Criteria

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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 per RECIST 1.1 or bone-only disease).
* De novo advanced breast cancer or with disease recurrence occurring after 12 months of completing adjuvant endocrine therapy (with or without CDK4/6 inhibitors)
* 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

* Disease recurrence during adjuvant endocrine therapy
* Currently receiving or previously received systemic anti-cancer therapy for ER+, HER2- advanced breast cancer.
* Previously received treatment with fulvestrant, elacestrant or an investigational endocrine therapy in any setting.
* History of allergic reactions to study treatment.
* Any contraindications to letrozole and ribociclib.
* Symptomatic central nervous system metastases, carcinomatous meningitis, leptomeningeal disease, or a spinal cord compression that require immediate treatment.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Novartis Pharmaceuticals

INDUSTRY

Sponsor Role collaborator

Olema Pharmaceuticals, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Medical Director, MD

Role: STUDY_DIRECTOR

Olema Pharmaceuticals, Inc.

Locations

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Clinical Trial Site

Ames, Iowa, United States

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Scarborough, Maine, United States

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Kansas City, Missouri, United States

Site Status RECRUITING

Clinical Trial Site

Santa Fe, New Mexico, United States

Site Status RECRUITING

Clinical Trial Site

Columbus, Ohio, United States

Site Status RECRUITING

Clinical Trial Site

Sayre, Pennsylvania, United States

Site Status RECRUITING

Clinical Trial Site

Tennessee City, Tennessee, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Sydney, New South Wales, Australia

Site Status RECRUITING

Clinical Trial Site

Waratah, New South Wales, Australia

Site Status RECRUITING

Clinical Trial Site

South Brisbane, Queensland, Australia

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Adelaide, South Australia, Australia

Site Status RECRUITING

Clinical Trial Site

Clayton, Victoria, Australia

Site Status RECRUITING

Clinical Trial Site

Geelong, Victoria, Australia

Site Status RECRUITING

Clinical Trial Site

Nedlands, Western Australia, Australia

Site Status RECRUITING

Clinical Trial Site

Hong Kong, Kowloon, Hong Kong

Site Status RECRUITING

Clinical Trial Site

Hong Kong, Pok Fu Lam, Hong Kong

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Kaohsiung City, Sanmin, Taiwan

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Chang-hua, , Taiwan

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Dusit, Bangkok, Thailand

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Ban Phaeo, Changwat Samut Sakhon, Thailand

Site Status ACTIVE_NOT_RECRUITING

Clinical Trial Site

Hat Yai, Changwat Songkhla, Thailand

Site Status ACTIVE_NOT_RECRUITING

Countries

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United States Australia Hong Kong Taiwan Thailand

Central Contacts

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Olema Pharmaceuticals, Inc.

Role: CONTACT

415-651-7206

Related Links

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Other Identifiers

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OPERA-02

Identifier Type: OTHER

Identifier Source: secondary_id

OP-1250-302

Identifier Type: -

Identifier Source: org_study_id

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