# A Study of H3B-6545 in Combination With Palbociclib in Women With Advanced or Metastatic Estrogen Receptor-Positive Human Epidermal Growth Factor Receptor-2 (HER2)-Negative Breast Cancer

> **NCT04288089** · PHASE1 · ACTIVE_NOT_RECRUITING · sponsor: **Eisai Inc.** · enrollment: 31 (actual)

## Conditions studied

- Receptors, Estrogen
- Genes, Erbb-2
- Breast Neoplasms

## Interventions

- **DRUG:** Palbociclib (75, 100, 125 milligram [mg])
- **DRUG:** H3B-6545 (150, 300, 450 mg)

## Key facts

- **NCT ID:** NCT04288089
- **Lead sponsor:** Eisai Inc.
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE1
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2020-04-01
- **Primary completion:** 2022-09-16
- **Final completion:** 2027-03-31
- **Target enrollment:** 31 (ACTUAL)
- **Last updated:** 2026-02-27


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT04288089

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT04288089, "A Study of H3B-6545 in Combination With Palbociclib in Women With Advanced or Metastatic Estrogen Receptor-Positive Human Epidermal Growth Factor Receptor-2 (HER2)-Negative Breast Cancer". Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/clinical/NCT04288089. Licensed CC0.

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