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
1269 - One-year follow-up results of eribulin for soft-tissue sarcoma including rare subtypes in a real-world observational study in Japan
Presenter: Shunji Takahashi
Session: Poster Display session 1
Resources:
Abstract
2868 - Prevalence of chemotherapy use and its impact on overall survival in patients with bone- and soft tissue sarcomas -A population-based analysis of 3746 patients
Presenter: Herbert Loong
Session: Poster Display session 1
Resources:
Abstract
3042 - Clinical course and therapeutic management of classical and endemic Kaposi’s Sarcoma (C/E KS)
Presenter: Lina Benajiba
Session: Poster Display session 1
Resources:
Abstract
3141 - The final outcomes of study on combined therapy of adult patients with localized synovial sarcoma
Presenter: Katarzyna Kozak
Session: Poster Display session 1
Resources:
Abstract
5449 - Real-world Outcomes of Patients with Locally Advanced or Metastatic Epithelioid Sarcoma
Presenter: Mrinal Gounder
Session: Poster Display session 1
Resources:
Abstract
4465 - SAKK 57/16 Nab-Paclitaxel And Gemcitabine in soft tissue sarcoma (NAPAGE): results from the phase I part of a phase I/II trial
Presenter: Antonia Digklia
Session: Poster Display session 1
Resources:
Abstract
5013 - Outcome of 98 patients with epithelioid sarcoma treated in curative intent: a retrospective study from the French Sarcoma Group (GSF-GETO)
Presenter: Maud Pedrono
Session: Poster Display session 1
Resources:
Abstract
5614 - Comparison of filgrastim and pegfilgrastim prophylaxis in sarcoma patients receiving highly myelosuppressive chemotherapy.
Presenter: Paolo Tarantino
Session: Poster Display session 1
Resources:
Abstract
1033 - Access to clinical trials for soft tissue sarcoma patients in Western and Eastern Europe
Presenter: Vasilii Ostafiichuk
Session: Poster Display session 1
Resources:
Abstract
4094 - Treatment outcomes for adult patients with localized osteosarcoma treated with chemotherapy without methotrexate
Presenter: Marília Silva
Session: Poster Display session 1
Resources:
Abstract