Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer
← catalyst calendarNCT05508906 · readout in 499 d
Sponsored by Olema Pharmaceuticals, Inc. (industry) · OLMA — their whole pipeline →. With Novartis, Pfizer.
Phase
Phase 1
Status
Recruiting
Study type
Interventional
Design
Non randomized · None · Treatment
Enrollment
190estimated
Sites
16
Countries
Australia, United States
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2022-08-31 | actual | When the study began enrolling |
| Primary completion | 2027-12-31 | estimated | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2028-01-31 | estimated | The whole study's end, after follow-up |
| First posted | 2022-08-19 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2025-10-22 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Conditions
- Metastatic Breast Cancer
- ER-positive Breast Cancer
- HER2-negative Breast Cancer
- Breast Cancer
- Locally Advanced Breast Cancer
Interventions
- Drug: Palazestrant
- Drug: Ribociclib — also filed as KISQALI®, CDK4/6 inhibitor
- Drug: Alpelisib — also filed as PIQRAY®, PI3K Inhibitor
- Drug: Everolimus — also filed as mTOR inhibitor
- Drug: Atirmociclib — also filed as CDK4i
Primary outcomes
what the primary-completion date above is the date OFDose Limiting Toxicities (DLTs)
measured The first 28 days of treatment
Characterize the incidence, nature and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs) of palazestrant when administered with ribociclib, alpelisib, everolimus, or atirmociclib.
measured Up to 30 days after last dose of study drug(s) treatment
Pharmacokinetics (PK) of palazestrant when administered with ribociclib (Treatment Group 1) or alpelisib (Treatment Group 2), everolimus (Treatment Group 3), or atirmociclib (Treatment Group 4) .
measured Every 28 days
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