Real-world treatment patterns and blood test frequency for palbociclib in patients with hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced breast cancer in Japan were posted on ClinicalTrials.gov on 2026-04-21. The observational study included 1170 participants.
Background
Hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced breast cancer represents a significant proportion of breast cancer cases. Endocrine-based therapies, including palbociclib, are crucial in managing this subtype. Understanding real-world treatment patterns, patient demographics, and the duration of these therapies, as well as subsequent treatments, is vital for optimizing patient care and informing clinical guidelines. This retrospective observational study utilized administrative claims data from Japan to provide insights into these aspects of care.
Trial design
This was a completed retrospective observational study that enrolled 1170 participants with advanced breast cancer in Japan. The study focused on patients diagnosed with Breast Cancer, specifically the HR+/HER2- subtype. The primary objective was to describe patient demographics, treatment patterns, and treatment duration of palbociclib-based therapy, as well as subsequent treatment patterns and durations after palbociclib-based therapy among these patients.
Key results
The study collected key measurements regarding the frequency of blood tests among participants receiving palbociclib treatment:
- Percentage of Participants According to Number of Blood Tests at 1 to 4 Weeks From Palbociclib Treatment Initiation
- Less than 1 test: 17.4% of participants
- 1 test: 12.9% of participants
- 2 tests: 28.4% of participants
- 3 tests: 29.7% of participants
- 4 tests: 8.3% of participants
- More than 4 tests: 3.3% of participants
- Percentage of Participants According to Number of Blood Tests at 5 to 8 Weeks From Palbociclib Treatment Initiation
- Less than 1 test: 23.6% of participants
- 1 test: 25.5% of participants
- 2 tests: 38.5% of participants
- 3 tests: 9.3% of participants
- 4 tests: 2.1% of participants
- More than 4 tests: 1.0% of participants
What this means
The results of this real-world observational study provide valuable data on the practical aspects of managing HR+/HER2- advanced breast cancer patients treated with palbociclib in Japan. The detailed breakdown of blood test frequencies during the initial weeks of treatment offers insights into monitoring practices in a real-world setting. This information can help clinicians and healthcare systems understand current patterns of care and potentially identify areas for optimizing patient monitoring and resource allocation for individuals receiving palbociclib.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the observational study NCT05153187, titled "Real-world Treatment Patterns of Endocrine Based Therapy Among Patients With Hormone Receptor-positive/Human Epidermal Growth Factor Receptor-2-negative (HR+/HER2-) Advanced Breast Cancer: An Analysis of Administrative Claims Data in Japan", were posted on 2026-04-21 on clinicaltrials.gov.