[Preclinical models to establish innovative therapy strategies : Ex‑vivo assessment of head and neck tumor chemo- and immune responses]

Reduced Cytokine Release in Ex Vivo Response to Cilengitide and Cetuximab Is a Marker for Improved Survival of Head and Neck Cancer Patients

Targeting of α_Vβ3 and α_Vβ5 integrins by cilengitide may reduce growth of solid tumors including head and neck squamous cell carcinoma (HNSCC). Preclinical investigations suggest increased activity of cilengitide in combination with other treatment modalities. The only published trial in HNSCC (ADVANTAGE) investigated cisplatin, 5-fluorouracil, and cetuximab (PFE) without or with once (PFE+CIL1W) or twice weekly cilengitide (PFE+CIL2W) in recurrent/metastatic HNSCC. ADVANTAGE showed good tolerability of the cilengitide arms and even lower adverse events (AEs) compared to PFE but not the benefit in overall survival expected based on preclinical data. As we found in the FLAVINO assay, a short-time ex vivo assay for prediction of chemosensitivity, only a subgroup of HNSCC had an increased suppressive effect of cilengitide containing combination therapies on colony formation of epithelial cells (CF_ec) and release of pro-angiogenetic and pro-inflammatory cytokines, whereas other HNSCC failed to respond. Response to α_Vβ3 and α_Vβ5 integrin targeting by cilengitide classifies HNSCC regarding outcome. We present FLAVINO data arguing for further development of cilengitide plus cetuximab in treatment of a subgroup of HNSCC potentially identified by the FLAVINO assay using a set of biomarkers for response evaluation.

[Preclinical models in head and neck tumors : Evaluation of cellular and molecular resistance mechanisms in the tumor microenvironment]

Because head and neck squamous cell carcinomas (HNSCC) are characterized by a distinct intertumorigenic and intratumorigenic heterogeneity, they often show substantial differences in the response to established therapy strategies. At present, a multitude of biologics and new pharmacological compounds for targeted therapies are available that allow more efficient and less toxic treatment. There is increasing pressure to establish predictive assays not only for ex ante analysis of the individual patient response to combined chemoradiotherapy and targeted therapies but also for investigation of the efficacy of new drugs. In this respect it is essential to maintain the pathophysiological tissue composition as it is known that paracrine tumor-stroma cell interactions may influence tumor reactivity to treatment. More complex models for individualized sensitivity testing have recently been described and the results are promising to pave the way for personalized cancer therapy. This review article focuses on different systems for maintaining the tumor microenvironment and hence the individual cellular composition, such as 3D organotypic models, organotypic multicellular spheroids, patient-derived xenografts and ex vivo tissue cultures and discusses the advantages and disadvantages in terms of translation into clinical application.