# Study to Evaluate Overall Survival in Japanese Patients With HR+/HER2- Advanced Breast Cancer Treated With Palbociclib Plus Letrozole

> **NCT04735367** · — · COMPLETED · sponsor: **Pfizer** · enrollment: 42 (actual)

## Conditions studied

- Breast Cancer

## Interventions

- **DRUG:** palbociclib plus letrozole

## Key facts

- **NCT ID:** NCT04735367
- **Lead sponsor:** Pfizer
- **Sponsor class:** INDUSTRY
- **Phase:** —
- **Study type:** OBSERVATIONAL
- **Status:** COMPLETED
- **Start date:** 2021-02-03
- **Primary completion:** 2023-09-29
- **Final completion:** 2023-09-29
- **Target enrollment:** 42 (ACTUAL)
- **Last updated:** 2025-12-09


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT04735367

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT04735367, "Study to Evaluate Overall Survival in Japanese Patients With HR+/HER2- Advanced Breast Cancer Treated With Palbociclib Plus Letrozole". Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/clinical/NCT04735367. Licensed CC0.

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