# Study to Evaluate Real-world Effectiveness With Palbociclib Plus Endocrine Therapy as First-line/Second-line Treatment for HR+/HER2- Advanced Breast Cancer in Japan

> **NCT05399329** · — · COMPLETED · sponsor: **Pfizer** · enrollment: 693 (actual)

## Conditions studied

- Breast Cancer

## Interventions

- **DRUG:** Palbociclib
- **DRUG:** Endocrine therapy

## Key facts

- **NCT ID:** NCT05399329
- **Lead sponsor:** Pfizer
- **Sponsor class:** INDUSTRY
- **Phase:** —
- **Study type:** OBSERVATIONAL
- **Status:** COMPLETED
- **Start date:** 2022-04-20
- **Primary completion:** 2025-06-27
- **Final completion:** 2025-06-27
- **Target enrollment:** 693 (ACTUAL)
- **Last updated:** 2026-04-09


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT05399329

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT05399329, "Study to Evaluate Real-world Effectiveness With Palbociclib Plus Endocrine Therapy as First-line/Second-line Treatment for HR+/HER2- Advanced Breast Cancer in Japan". Retrieved via AI Analytics 2026-07-10 from https://api.ai-analytics.org/clinical/NCT05399329. Licensed CC0.

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