NCT06016738Phase 3Active not recruiting

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

Study sponsor: Olema Pharmaceuticals, Inc. · OLMA

Compare the available registry edits below. Primary completion is the date data collection ends for the main study measures; it does not tell you when results will be published.

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Primary completion2026-10-31Estimated

Enrollment · participants510Estimated

Source updated2026-08-13Last update listed in the registry record

Version history

Changes to this trial

Last 12 months

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Posted 2026-08-13 · 2 fields changed

Primary completion date changed

− Before

~~30 Jun 2026~~

+ After

31 Oct 2026

Recruitment status changed

− Before

~~Recruiting~~

+ After

Active not recruiting

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Study details

Conditions studied

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

Treatments or interventions studied

PalazestrantDrugAlso known as OP-1250
FulvestrantDrug
AnastrozoleDrug
LetrozoleDrug
ExemestaneDrug

Primary outcomes · main study measures

Read the study measures

measure: Dose-Selection Part: Incidence of adverse events; description: To evaluate the number of participants with adverse events; timeFrame: From Date of Randomization up to 16 weeks; measure: Dose-Selection Part: Incidence of dose reduction; description: To evaluate the number of participants reducing the dose of palazestrant; timeFrame: From Date of Randomization up to 16 weeks; measure: Dose-Selection Part: Incidence of drug discontinuation; description: To evaluate the number of participants discontinuing palazestrant; timeFrame: From Date of Randomization up to 16 weeks; measure: Trial: Progression-Free Survival (PFS); description: To compare PFS, based on a Blinded Independent Review Committee (BIRC) assessment, between arms of OP-1250 and standard-of-care treatment. This will be assessed separately in populations of ESR1-mutation detected and ESR1-mutation not detected participants.; timeFrame: From Date of Randomization until Disease Progression or Death Due to Any Cause (estimated as up to 2 years)

History coverage

Research sample: selected versions from May 2023 onward plus a preceding baseline where available. Only selected fields were retained; endpoint measures were truncated to 300 characters. This is not complete trial or sponsor history. Daily snapshots begin when collection starts.

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