PALOMA-3: Phase III Trial of Fulvestrant With or Without Palbociclib in Premenopausal and Postmenopausal Women With Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer That Progressed on Prior Endocrine Therapy-Safety and Efficacy in Asian Patients.

Abstract

PURPOSE:

To assess efficacy and safety of palbociclib plus fulvestrant in Asians with endocrine therapy-resistant metastatic breast cancer.

PATIENTS AND METHODS:

The Palbociclib Ongoing Trials in the Management of Breast Cancer 3 (PALOMA-3) trial, a double-blind phase III study, included 521 patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer with disease progression on endocrine therapy. Patient-reported outcomes (PROs) were assessed on study treatment and at the end of treatment.

RESULTS:

This preplanned subgroup analysis of the PALOMA-3 study included premenopausal and postmenopausal Asians taking palbociclib plus fulvestrant (n = 71) or placebo plus fulvestrant (n = 31). Palbociclib plus fulvestrant improved progression-free survival (PFS) compared with fulvestrant alone. Median PFS was not reached with palbociclib plus fulvestrant (95% CI, 9.2 months to not reached) but was 5.8 months with placebo plus fulvestrant (95% CI, 3.5 to 9.2 months; hazard ratio, 0.485; 95% CI, 0.270 to 0.869; P = .0065). The most common all-cause grade 3 or 4 adverse events in the palbociclib arm were neutropenia (92%) and leukopenia (29%); febrile neutropenia occurred in 4.1% of patients. Within-patient mean trough concentration comparisons across subgroups indicated similar palbociclib exposure between Asians and non-Asians. Global quality of life was maintained; no statistically significant changes from baseline were observed for patient-reported outcome scores with palbociclib plus fulvestrant.

CONCLUSION:

This is the first report, to our knowledge, showing that palbociclib plus fulvestrant improves PFS in asian patients. Palbociclib plus fulvestrant was well tolerated in this study.

• Authors: Hiroji Iwata, Seock-Ah Im, Norikazu Masuda, Young-Hyuck Im, Kenichi Inoue, Yoshiaki Rai, Rikiya Nakamura, Jee Hyun Kim, Justin T Hoffman, Ke Zhang, Carla Giorgetti, Shrividya Iyer, Patrick T Schnell, Cynthia Huang Bartlett, Jungsil Ro
• Journal: Journal of global oncology (J Glob Oncol) Vol. 3 Issue 4 Pg. 289-303 (Aug 2017) ISSN: 2378-9506 [Print] United States
• PMID: 28831437 (Publication Type: Journal Article)