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
2037 - Updated survival analysis of the randomized phase III trial comparing S-1 versus capecitabine in the first-line treatment of metastatic colorectal cancer (SALTO) by the Dutch Colorectal Cancer Group.
Presenter: Johannes Kwakman
Session: Poster Display session 2
Resources:
Abstract
3053 - JFMC51-1702-C7: Phase II study investigating efficacy and safety of trifluridine/tipiracil (FTD/TPI) plus bevacizumab (BEV) in patients (pts) with metastatic colorectal cancer (mCRC) refractory or intolerant to standard chemotherapies.
Presenter: Keisuke Kazama
Session: Poster Display session 2
Resources:
Abstract
3183 - Bevacizumab plus trifluridine/tipiracil in elderly patients with previously untreated metastatic colorectal cancer (KSCC 1602): A single-arm, Phase 2 study
Presenter: Akitaka Makiyama
Session: Poster Display session 2
Resources:
Abstract
3233 - Biweekly TAS-102 and Bevacizumab as a Third-Line Chemotherapy for metastatic colorectal cancer: A Phase II Multicenter Clinical Trial (TAS-CC4 study)
Presenter: Yoichiro Yoshida
Session: Poster Display session 2
Resources:
Abstract
5907 - Liquid biopsy concordance based on clonality and timing of testing in patients with metastatic colorectal cancer
Presenter: Pashtoon Kasi
Session: Poster Display session 2
Resources:
Abstract
1866 - Plasma clearance of RAS mutation under therapeutic pressure is a rare event in metastatic colorectal cancer
Presenter: Emilie Moati
Session: Poster Display session 2
Resources:
Abstract
2312 - High Circulating miR-1247 is a marker for poor prognosis in patients with metastatic colorectal cancer treated with chemotherapy and cetuximab
Presenter: Jakob Schou
Session: Poster Display session 2
Resources:
Abstract
5602 - Clinical relevance of circulating tumor (ct)DNA genotyping for first line cetuximab-based treatment monitoring in metastatic colorectal cancer (mCRC): a prospective multicentric study
Presenter: JOANA Vidal Barrull
Session: Poster Display session 2
Resources:
Abstract
3182 - Clonal hematopoiesis mutations in plasma cfDNA RAS/BRAF genotyping of metastatic colorectal cancer
Presenter: Beili Wang
Session: Poster Display session 2
Resources:
Abstract
5205 - Immune status of patients with different stages of colorectal cancer with and without circulating tumor cells
Presenter: Anastasia Sitkovskaya
Session: Poster Display session 2
Resources:
Abstract