Safety Results Of The Canadian Expanded Access Program (Eap) Of Palbociclib (Pal) Plus Letrozole (L) In Postmenopausal Patients (Pts) With Hormone Receptor-Positive (Hr Plus )/Human Epidermal Growth Factor Receptor 2-Negative (Her2-) Advanced Breast Cancer (Abc) Deemed Appropriate Candidates For First-Line (1l) Endocrine Therapy (Et) With L.

e12534Background: In the PALOMA-2 study, 1L PAL+L prolonged progression-free survival in women with estrogen receptor-positive/HER2- ABC vs placebo + L (hazard ratio 0.58; Pu003c 0.001). Here we assess a cohort of Canadian pts treated with 1L PAL+L for ABC in an EAP study (NCT02142868). Methods: This was an open-label, single-arm study of US and Canadian postmenopausal women (N = 337) with HR+/HER2- ABC for whom 1L ET with L was deemed appropriate. The primary objective was to allow pt access to PAL in combination with L. PAL (125 mg/d orally [3 wk on, 1 wk off]) was administered with L (2.5 mg orally QD) until PAL was commercially available. Secondary objectives included safety and patient-reported outcomes (PROs). Results: 96/97 (99%) treated/enrolled Canadian pts were assessed for safety and PROs (treated pt characteristics: median age 62.5 y, white/Asian [89%/7%], metastatic sites bone/lung/liver [71%/25%/17%], ECOG PS 0-1/2 [93%/7%], 89% with prior systemic anticancer treatment [tx]). Median exposure was...