Abstract 342: In vivo response and molecular characterisation of a NSCLC squamous cell carcinoma PDX model exhibiting reproducible sensitivity to FGFR inhibitors.
Authors: Mckenzie Andrew , Cranston Aaron , Mallinder Phil , Papadopoulou Nektaria , Jiang Simon , Moakes Kerry , Yin Yinfei , Onion David , Grabowska Anna , Page Martin , Kumari Rajendra 
Published: August 2014

BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer cases, carries a poor prognosis and remains an area of high unmet need. Despite recent advances in treating NSCLC adenocarcinomas with targeted agents such as Erlotinib (Tarceva©) and Crizotinib (Xalkori©) few advances have been made in the treatment of squamous cell carcinoma (SCC), which accounts for 25% of all NSCLC. Although the incidence of fibroblast growth factor receptor (FGFR) mutations in SCC is modest, amplification of FGFR is well documented and there are several first generation FGFR inhibitors currently in clinical trial. It is therefore essential to develop relevant in vivo patient-derived xenograft (PDX) models for the development and characterisation of new FGFR agents and/or combination strategies which may prolong benefit and delay the emergence of resistance.

METHODS: LION137 is a novel NSCLC SCC patient-derived xenograft (PDX) model which is maintained subcutaneously in vivo admixed with a human stromal cell component. Cohorts of mice were dosed with AZD4547 alone or in combination with chemotherapy (CTx; parallel or serial dosing regimens). The extent of inhibition was measured over several in vivo passages and following cryopreservation/resuscitation. Response to treatment was evaluated by tumour growth inhibition and waterfall plots. Tumour material was characterised for 50 key oncogenes and mutations by Ion Torrent sequencing and FGFR1-4 expression and genomic amplification by quantitative PCR. Immunohistochemistry (IHC) was used to confirm SCC subtype, EMT status and FGFR expression.

RESULTS: LION137 PDX tumours (SCC confirmed by IHC) exhibited reproducible sensitivity to AZD4547 alone (P&lt;0.001) which was maintained both in continuous serial passage and following cryopreservation (at -196°C). FGFR expression and amplification and mutational analysis were assessed in naïve tumour material, following 10 weeks of continuous dosing and following outgrowth from CTX treatment and correlated with treatment response.

CONCLUSIONS: LION137 is a novel patient-derived NSCLC SCC xenograft model with reproducible FGFRi-sensitivity which is directly relevant to the clinical setting. This model could be invaluable in assessing novel agents targeting the FGFR pathway and in the development of new combination strategies which may prevent or overcome resistance.

Citation Format: Andrew Mckenzie, Aaron Cranston, Phil Mallinder, Nektaria Papadopoulou, Simon Jiang, Kerry Moakes, Yinfei Yin, David Onion, Anna Grabowska, Martin Page, Rajendra Kumari. In vivo response and molecular characterisation of a NSCLC squamous cell carcinoma PDX model exhibiting reproducible sensitivity to FGFR inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 342. doi:10.1158/1538-7445.AM2013-342