Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer

ClinicalTrials.gov ID: NCT05508906

Public ClinicalTrials.gov record NCT05508906. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

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ClinicalTrials.gov public records Last synced May 19, 2026, 6:22 AM EDT

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Official title

A Phase 1b Open-Label Multicenter Study of OP-1250 (Palazestrant) in Combination With the CDK4/6 Inhibitor Ribociclib, With the PI3K Inhibitor Alpelisib, With the mTOR Inhibitor Everolimus, or With CDK4 Inhibitor Atirmociclib in Adult Subjects With Advanced and/or Metastatic ER Positive, HER2 Negative Breast Cancer

Study identification

NCT ID: NCT05508906
Recruitment status: Recruiting
Study type: Interventional
Phase: Phase 1
Lead sponsor: Olema Pharmaceuticals, Inc.; Industry
Enrollment: 190 participants

Conditions and interventions

Conditions

Interventions

Alpelisib Drug
Atirmociclib Drug
Everolimus Drug
Palazestrant Drug
Ribociclib Drug

Drug

Eligibility (public fields only)

Age range: 18 Years and older
Sex: All
Healthy volunteers: Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date: Aug 30, 2022
Primary completion: Dec 30, 2027
Completion: Jan 30, 2028
Last update posted: Oct 21, 2025

2022 – 2028

United States locations

U.S. sites: 14
U.S. states: 14
U.S. cities: 14

Facility	City	State	ZIP	Site status
Banner MD Anderson Cancer Center	Gilbert	Arizona	85234	Recruiting
University of California San Francisco Health	San Francisco	California	94158	Recruiting
University of Colorado Cancer Center	Aurora	Colorado	80045	Recruiting
Advent Health Hematology and Oncology	Orlando	Florida	32804	Recruiting
University of Iowa	Iowa City	Iowa	52242	Recruiting
Dana Farber Cancer Institute	Boston	Massachusetts	02215	Recruiting
Henry Ford Health	Detroit	Michigan	48126	Recruiting
Regents of the University of Minnesota	Minneapolis	Minnesota	55455	Recruiting
Washington University, School of Medicine	St Louis	Missouri	63110	Recruiting
Ichan School of Medicine at Mount Sinai	New York	New York	10029	Recruiting
Atrium Health Levine Cancer Institute	Charlotte	North Carolina	28204	Recruiting
Henry-Joyce Cancer Clinic, The Vanderbilt Clinic	Nashville	Tennessee	37232	Recruiting
MD Anderson Cancer Center	Houston	Texas	77030	Recruiting
Northwest Medical Specialties	Tacoma	Washington	98405	Recruiting

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 2 non-U.S. sites.

About this trial record page

What this page shows: Public field values for ClinicalTrials.gov record NCT05508906, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do: No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from: Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh: Last update posted Oct 21, 2025 · Synced May 19, 2026

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The complete protocol, eligibility criteria, and contact information for NCT05508906 live on ClinicalTrials.gov.

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