# A Phase 1 Study of Oral OP-1250 in Combination With Palbociclib in HR+/HER2- Breast Cancer Patients

> **NCT05266105** · PHASE1 · ACTIVE_NOT_RECRUITING · sponsor: **Olema Pharmaceuticals, Inc.** · enrollment: 60 (actual)

## Conditions studied

- Breast Cancer

## Interventions

- **DRUG:** Palazestrant
- **DRUG:** Palbociclib

## Key facts

- **NCT ID:** NCT05266105
- **Lead sponsor:** Olema Pharmaceuticals, Inc.
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE1
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2021-12-10
- **Primary completion:** 2026-03
- **Final completion:** 2026-03
- **Target enrollment:** 60 (ACTUAL)
- **Last updated:** 2025-11-24

## Collaborators

- [object Object]

## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT05266105

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT05266105, "A Phase 1 Study of Oral OP-1250 in Combination With Palbociclib in HR+/HER2- Breast Cancer Patients". Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/clinical/NCT05266105. Licensed CC0.

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*[Clinical trials dataset](/datasets/clinical-trials) · CC0 1.0*