OncoMatch/Clinical Trials/NCT05508906
Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer
Is NCT05508906 recruiting? Yes, currently enrolling (Jun 2026). This Phase 1 trial studies multiple treatments for metastatic breast cancer.
Treatment: Palazestrant · Ribociclib · Alpelisib · Everolimus · Atirmociclib — This is a Phase 1b open-label, 2-part study in 3 treatment groups. The 3 treatment groups are as follows: Treatment Group 1: Palazestrant (OP-1250) in combination with ribociclib (KISQALI®, Novartis Pharmaceuticals Corporation). Treatment Group 2: Palazestrant (OP-1250) in combination with alpelisib (PIQRAY®, Novartis Pharmaceuticals Corporation). Treatment Group 3: Palazestrant (OP-1250) in combination with everolimus. Treatment Group 4: Palazestrant (OP-1250) in combination with atirmociclib.
Check if I qualifyExtracted eligibility criteria
Treatments studied
Targeted therapy
Endocrine / hormonal
Other
Cancer type
Breast Carcinoma
Biomarker criteria
Required: ESR1 overexpression (ER+)
ER+/HER2- disease, as determined in the most recently obtained archival tumor tissue sample from a metastatic site, using locally accepted criteria by the local pathology report.
Required: HER2 (ERBB2) wild-type (HER2-)
ER+/HER2- disease, as determined in the most recently obtained archival tumor tissue sample from a metastatic site, using locally accepted criteria by the local pathology report.
Disease stage
Metastatic disease required
advanced or metastatic Breast Cancer (mBC). Evaluable disease with one of the following: Measurable disease, ie, at least 1 measurable lesion as per RECIST 1.1 ... OR patients with predominantly bone disease ... are allowed if it is possible to evaluate on radiological examinations ... even if lesions are non-measurable according to RECIST 1.1.
Performance status
ECOG 0–1(Restricted strenuous activity)
Prior therapy
Cannot have received: OP-1250 (OP-1250)
Have received prior treatment with OP-1250.
Cannot have received: PI3K inhibitor
Exception: Treatment Group 2 only
Have received prior treatment with approved or investigational PI3K inhibitor (Treatment Group 2).
Cannot have received: mTOR inhibitor
Exception: Treatment Group 3 only
Have received prior treatment with approved or investigational ... mTOR inhibitor (Treatment Group 3).
Lab requirements
Liver function
No clinically significant history of liver disease consistent with Child-Pugh Class B or C, including active viral or other hepatitis (eg, hepatitis B or hepatitis C virus), current alcohol abuse, or cirrhosis.
Cardiac function
No clinically significant, uncontrolled heart disease and/or cardiac repolarization abnormality.
Clinically significant, uncontrolled heart disease and/or cardiac repolarization abnormality. Known clinically significant history of liver disease consistent with Child-Pugh Class B or C, including active viral or other hepatitis (eg, hepatitis B or hepatitis C virus), current alcohol abuse, or cirrhosis.
Structured fields extracted by AI. May contain errors — verify against the official protocol.
US trial sites
- Banner MD Anderson Cancer Center · Gilbert, Arizona
- University of California San Francisco Health · San Francisco, California
- University of Colorado Cancer Center · Aurora, Colorado
- Advent Health Hematology and Oncology · Orlando, Florida
- University of Iowa · Iowa City, Iowa
Showing up to 5 US sites.
See all sites on ClinicalTrials.gov →Frequently asked questions
Is NCT05508906 currently recruiting?
Yes, this trial is currently recruiting patients.
Are there prior therapy exclusions?
Yes. Prior OP-1250, PI3K inhibitor, mTOR inhibitor disqualifies patients from enrollment.
Does this trial require ESR1?
Yes, ESR1 overexpression is a required biomarker for enrollment.
Does this trial require ERBB2?
Yes, ERBB2 wild-type is a required biomarker for enrollment.
Could you qualify for this trial?
Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.
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