Abstract 4401
Background
In Feb 2015, palbociclib plus letrozole (P+L) became the first cyclin-dependent-kinase 4/6 inhibitor approved for mBC/aBC in the US. Until now, long-term outcomes studies have included a limited number of patients receiving P+L. The objective of this study is to describe real-world patient characteristics and clinical effectiveness associated with P+L as initial endocrine-based therapy use 4 years post approval.
Methods
Adult postmenopausal women diagnosed with metastatic HR+/HER2- breast cancer who initiated P+L as first-line therapy on or after 2/3/2015 were identified by providers in the Cardinal Health Oncology Provider Extended Network, including 1800 oncologists/hematologists in the US. A subset of providers abstracted data related to patient characteristics and clinical outcomes including disease response and disease progression into an electronic case report from (eCRF). Data were abstracted from the time of initiation of P+L through Feb 2019 (or end of follow up/death). Providers were shown response classification schema corresponding to RECIST v1.1 and asked to indicate the patient’s best response if recorded. The objective response rates (ORR – incl. complete response [CR] and partial response [PR]), clinical benefit rates (CBR – incl. CR+PR+stable disease [SD] >24 wks), and progression-free survival (PFS) rate at 12-month were reported. Each eCRF was reviewed by independent clinical staff; source data was verified on 10% of the patients.
Results
31 providers submitted 202 eCRFs, of which, 193 were eligible. Median follow-up from 1L P+L initiation was 15.4 months, 45.6% of patients had discontinued P+L at data cut-off. Table shows key patient characteristics and ORR, CBR, and PFS rate at 12-month, each showing benefit of 1L P+L in the real-world.Table:
338P
N = 193 | All |
---|---|
Mean age at diagnosis, yrs | 62.7 |
Non-Hispanic white, % | 74.6 |
Black/African-American, % | 17.1 |
ECOG-PS 0/1, % | 89.6 |
N0, % | 22.8 |
Visceral mets, % | 51.3 |
Bone only mets, % | 25.4 |
ORR, % | 65.8 |
CR | 9.8 |
PR | 56.0 |
CBR†, % | 88.0 |
CR | 12.7 |
PR | 61.3 |
SD† | 14.0 |
12-month PFS, % | 74.5 |
†Excluding 43 patients with duration of treatment <24 wks
Conclusions
These real-world data demonstrate the benefit of 1L P+L 4 years post approval in the US and support the clinical benefit of 1L P+L reported in randomized clinical trials.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Pfizer Inc.
Funding
Pfizer Inc.
Disclosure
J. Kish: Full / Part-time employment: Cardinal Health; Advisory / Consultancy, Paid consultant in connection with the development of this abstract: Pfizer Inc. J. Trocio: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. T. Miller: Full / Part-time employment: Cardinal Health; Advisory / Consultancy, Paid consultant in connection with the development of this abstract: Pfizer Inc. D. Nero: Full / Part-time employment: Cardinal Health; Advisory / Consultancy, Paid consultant in connection with the development of this abstract: Pfizer Inc. D. Liassou: Full / Part-time employment: Cardinal Health; Advisory / Consultancy, Paid consultant in connection with the development of this abstract: Pfizer Inc. X. Liu: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. L. McRoy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. B. Feinberg: Full / Part-time employment: Cardinal Health; Advisory / Consultancy, Paid consultant in connection with the development of this abstract: Pfizer Inc.
Resources from the same session
4317 - Prognostic factors analysis of 343 patients with adenocarcinoma of esophagogastric junction
Presenter: Yixun Lu
Session: Poster Display session 2
Resources:
Abstract
4099 - Effects of preoperative preparation time on efficacy of neoadjuvant chemotherapy (SOX) in patients with advanced gastric cancer
Presenter: Xinxin Wang
Session: Poster Display session 2
Resources:
Abstract
3769 - The prognostic value of higher absolute lymphocyte counts for patients with surgically resected non-advanced gastric cancer
Presenter: Se Jun Park
Session: Poster Display session 2
Resources:
Abstract
1718 - Trastuzumab and pertuzumab added to neoadjuvant chemoradiotherapy in resectable HER2+ esophageal adenocarcinoma patients: an update on survival and predictive biomarkers in the TRAP study
Presenter: Charlotte Stroes
Session: Poster Display session 2
Resources:
Abstract
5403 - Interim analysis of a phase II trial of perioperative chemotherapy plus avelumab in esophagogastric and gastric adenocarcinoma
Presenter: Thierry Alcindor
Session: Poster Display session 2
Resources:
Abstract
591 - Evaluation of the introduction of primary G-CSF prophylaxis to the FLOT chemotherapy regimen.
Presenter: Kelly-Marie Crampton
Session: Poster Display session 2
Resources:
Abstract
1402 - Subgroup analyses of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with 2 and 4 courses of cisplatin/S-1 (CS) and docetaxel/cisplatin/S-1 (DCS) as neoadjuvant chemotherapy for locally advanced gastric cancer
Presenter: Tsutomu Hayashi
Session: Poster Display session 2
Resources:
Abstract
3743 - HER2 Copy Number as Predictor of Disease-Free Survival in HER2-Positive Resectable Gastric Cancer
Presenter: Zimin Liu
Session: Poster Display session 2
Resources:
Abstract
2032 - Effect of neoadjuvant chemotherapy on the Programmed Death-1 pathway in esophageal and gastric cancer
Presenter: Maria Svensson
Session: Poster Display session 2
Resources:
Abstract
4304 - A user-friendly nomogram to predict relapse-free survival (RFS) in western patients with resected gastric cancer (GC)
Presenter: Massimiliano Salati
Session: Poster Display session 2
Resources:
Abstract