Abstract 3011
Background
Neratinib (NER) is an irreversible pan-HER kinase inhibitor with demonstrated clinical activity for HER2-positive and HER2-mutated breast cancers (BC). Mechanisms of resistance to NER are poorly understood. The Src/Abl inhibitor dasatinib (DAS) has shown ability to overcome resistance to HER2-targeted agents such as lapatinib (LAP) and TRAS in vitro. This pre-clinical study investigated the efficacy of DAS in combination with NER to overcome or prevent NER resistance in BC models.
Methods
Anti-proliferative effects of NER, LAP, TRAS, DAS, and NER plus DAS were assessed in five NER-resistant HER2+ BC cell lines (HCC1954-N, HCC1569-N, EFM192A-N, BT474-N, and SKBR3-N) by acid phosphatase assay. IC50values and Combination index (CI) values were calculated to determine synergy (CI < 0.8) using Calcusyn. Neratinib resistance was defined as an IC50value > 150 nM NER. Apoptosis induction was assessed by Caspase 3/7-Glo assay. Reverse phase protein array was used to determine changes in key signalling pathways in HCC1954-N cells. BC cells were treated twice weekly with NER and/or DAS and crystal violet stained when confluent to examine resistance development.
Results
All NER resistant cell lines examined had significantly reduced response to NER (11-83 fold increase in IC50values versus parental cells), as well as LAP and TRAS, compared to their parental cells.The combination of NER and DAS displayed synergy in all five NER resistant cell lines (CI = 0.1-0.6). NER plus DAS caused a strong induction of apoptosis in the HCC1954-N cells (p = 0.015). NER/DAS treatment caused changes in 23 phospho- or total protein levels, including suppression of Akt, MAPK, Src, p38 and AMPK signalling. NER alone (9 phospho- and 1 total proteins) and DAS alone (3 phospho- and 3 total proteins) altered fewer targets. The addition of DAS to NER prevented the emergence of NER resistance in parental HCC1954 and HCC1569 cells.
Conclusions
This study provides pre-clinical rationale for the combination of NER and DAS in NER-resistant HER2+ BC and shows that this combination warrants further investigation.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Puma Biotechnology.
Disclosure
N. Conlon: Research grant/Funding (institution): Puma Biotechnology. J. Crown: Full/Part-time employment: OncoMark; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (institution): Eisai; Honoraria (self): Amgen; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Puma Biotechnology; Honoraria (self): Seattle Genetics; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony, Travel/Accommodation/Expenses: Pfizer; Honoraria (self), Advisory/Consultancy: Vertex; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution), Travel/Accommodation/Expenses: Roche; Honoraria (self), Travel/Accommodation/Expenses: MSD Oncology; Travel/Accommodation/Expenses: AstraZeneca; Travel/Accommodation/Expenses: Abbvie; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Boehringer Ingelheim; Honoraria (self), Speaker Bureau/Expert testimony: Genomic Health. D.M. Collins: Research grant/Funding (institution): Puma Biotechnology; Research grant/Funding (institution): Roche. All other authors have declared no conflicts of interest.
Resources from the same session
5255 - [18F]-FDG PET/CT in predicting PD-L1 status in nasopharyngeal carcinoma
Presenter: Liang Zhao
Session: Poster Display session 1
Resources:
Abstract
4910 - Expression of PD-L1 in Chinese Patients with Common Cancers
Presenter: Min Zheng
Session: Poster Display session 1
Resources:
Abstract
4227 - The clearance of EGF by tumor-associated macrophages is suppressed by chemotherapeutic agent cisplatin
Presenter: Irina Larionova
Session: Poster Display session 1
Resources:
Abstract
5222 - VHIO-300 and a thousand one nights, a tale of Precision Medicine
Presenter: Ginevra Caratù
Session: Poster Display session 1
Resources:
Abstract
5668 - Matched Whole-Genome Sequencing and Whole-Exome Sequencing with Circulating Tumor DNA (ctDNA) Analysis are complementary modalities in clinical practice
Presenter: Robin Imperial
Session: Poster Display session 1
Resources:
Abstract
5772 - Exploring the role of genes associated with familial cancer syndromes on the development of multiple primary tumors
Presenter: Atanaska Mitkova
Session: Poster Display session 1
Resources:
Abstract
4784 - Doxorubicin resistance: early and advanced tumors can use two different strategies based on initial and profound abnormalities in microRNA expression signature
Presenter: Volodymyr Halytskiy
Session: Poster Display session 1
Resources:
Abstract
3456 - From tumor transcriptomes to underlying cell type proportions to better predict prognosis and response to treatments
Presenter: Yuna Blum
Session: Poster Display session 1
Resources:
Abstract
4976 - Optimization of automated germline DNA extraction from non-tumoral formalin-fixed paraffin embedded (FFPE) tissues
Presenter: Omar Youssef
Session: Poster Display session 1
Resources:
Abstract
4242 - HIV, HBV and HCV screening practices in oncology: a cross-sectional interregional survey
Presenter: Isabelle Poizot-Martin
Session: Poster Display session 1
Resources:
Abstract