Editor’s Note: The PATINA (AFT-38) trial is a randomized, open-label, phase III study designed to evaluate the efficacy and safety of palbociclib + HER2-targeted therapy + endocrine therapy versus HER2-targeted therapy + endocrine therapy alone in patients with HR+/HER2+ metastatic breast cancer following induction therapy. Previous data from PATINA demonstrated that the addition of palbociclib significantly prolonged median progression-free survival (mPFS) in this patient population. 

At the 2025 ESMO Annual Congress, the patient-reported outcomes (PRO) results were presented, showing that the palbociclib combination did not adversely affect health-related quality of life (HRQoL) as measured by FACT-B and EQ-5D-5L scores. This finding indicates that palbociclib improves clinical outcomes while maintaining quality of life—a critical consideration for long-term treatment in HR+/HER2+ metastatic breast cancer. Oncology Frontier invited Professor Zhao Yanxia from Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, to provide expert commentary on this study.

Study Overview

Title: 485MO – Health-related quality of life (HRQoL) from the PATINA trial (AFT-38): Impact of adding palbociclib to HER2 and endocrine therapy after induction in HR+/HER2+ metastatic breast cancer (MBC)

Background

The phase III PATINA trial (AFT-38; NCT02947685) evaluated whether adding palbociclib to HER2-targeted therapy plus endocrine therapy (ET) after induction chemotherapy could improve outcomes in patients with HR+/HER2+ metastatic breast cancer.

The trial previously demonstrated that palbociclib addition improved median PFS by 15.2 months (HR = 0.74), with manageable toxicity. The 2025 ESMO presentation focused on pre-specified HRQoL endpoints from this study.

Methods

Patients completed FACT-B and EQ-5D-5L assessments at baseline, every three cycles until disease progression or end of treatment.

The time to symptom deterioration (TTSD)—defined as a ≥5-point decline from baseline in the FACT-B Trial Outcome Index (TOI) or death from any cause—was compared between groups using a two-sided log-rank test (α = 0.05). Mixed-effects models for repeated measures (MMRM) were used to estimate mean HRQoL trajectories at cycle 13 (Y1) and cycle 37 (Y3) and to assess between-group differences.

Results

A total of 230/261 patients in the palbociclib arm and 220/257 patients in the control arm were included in the HRQoL analysis. Completion rates for PRO assessments at baseline, cycle 13, and cycle 37 exceeded 93%, 84%, and 81%, respectively.

• Time to symptom progression or death: HR = 0.89 (95% CI: 0.70–1.14); P = 0.37

• HRQoL scores (FACT-B and EQ-5D-5L): remained stable throughout treatment

• No significant differences were observed between the two groups at Y1 or Y3 across global or functional domains

Conclusion

Adding palbociclib to HER2-targeted therapy and endocrine therapy maintained patients’ health-related quality of life throughout treatment. This finding complements the previously reported significant improvement in PFS and supports a favorable benefit–risk profile for the palbociclib-based regimen as a first-line maintenance option for HR+/HER2+ metastatic breast cancer.

For patients expected to receive long-term systemic therapy (median PFS > 44 months), maintaining HRQoL while extending survival is both clinically meaningful and highly encouraging.

Expert Commentary — Professor Zhao Yanxia

This study, based on the phase III PATINA trial, investigated the impact of adding palbociclib to HER2-targeted therapy and endocrine therapy in patients with HR+/HER2+ metastatic breast cancer after induction chemotherapy.

The results showed excellent PRO completion rates (>81%) at baseline, cycle 13, and cycle 37, and no significant differences between the palbociclib and control groups in FACT-B and EQ-5D-5L scores across time points.

Combined with prior evidence that the regimen extended median PFS by 15.2 months with manageable toxicity, the study provides robust confirmation that the addition of palbociclib does not compromise quality of life, further supporting its role as an optimal maintenance therapy in this patient population.

From a clinical perspective, this trial addresses a critical question—does improved efficacy come at the cost of reduced quality of life? For patients with HR+/HER2+ metastatic breast cancer, who often require prolonged treatment, the palbociclib-based combination not only extends survival but also preserves patient well-being.

This provides clinicians with comprehensive, evidence-based support encompassing efficacy, safety, and quality of life, reinforcing palbociclib as a standard component of modern maintenance therapy strategies.

Professor Zhao Yanxia Department of Breast Oncology Union Hospital, Tongji Medical College, Huazhong University of Science and Technology