Despite intensive treatment efforts combining surgery, radio- and chemotherapy, the prognosis of patients suffering from glioblastoma (GBM) remains poor. Virtually all GBMs progress despite therapy. Patients receiving the standard therapy at primary disease have a median overall survival of 12-15 months. There is currently no defined standard treatment regimen for recurrent GBM. Tyrosine kinase receptor-targeted therapy is widely used in preclinical and clinical experimental brain tumor research. Increased tyrosine kinase activity has been asssociated with GBM oncogenesis and several tyrosine kinase receptors, e.g. VEGFR, FGFR, PDGFR are upregulated in malignant glioma. In the past and in the present, targeting of VEGF- and PDGF-signaling (amongst others) has shown promising preclinical and clinical results in human glioblasto-ma.~In that context our own in vitro studies lead to the assumption that application of a multi-targeted tyrosine kinase inhibitor could be a most effective treatment approach for GBM patients. We were able to demonstrate that GBM cells from different tumor regions express different set of tyrosine kinase receptors that all could be targeted by the multi-targeted tyrosine kinase inhibitor TKI258, including PDGFRß, CSF 1R, KIT, FLT3, VEGFR, TrkA, RET and FGFRs. In combination with its ability to cross the blood-brain-barrier (BBB), the exploration of TKI258 for patients with recurrent GBM appears very promising.~Recently, safety and feasibility of TKI258 was demonstrated in adult patients with advanced solid malignan-cies. The maximum tolerated dose (MTD) was determined and a recommended dose for phase II trials was established. Meanwhile, TKI258 is in phase III development in renal cell carcinoma, and in phase II devel-opment in advanced breast cancer, relapsed multiple myeloma and urothelial cancer.~Since the toxicity profile for compounds that could cross the BBB might be different in patients with CNS diseases/disorders (e.g. brain tumors) compared to patients with malignancies outside the CNS, we here propose a phase I trial exploring TKI258 in patients with recurrent glioblastoma.~In this study with a modified 3+3 dose finding design, a safe and tolerable dose of TKI258 in patients with relapsed glioblastoma should be established.
In this study with a modified 3+3 dose finding design, a safe and tolerable dose of TKI258 in patients with relapsed glioblastoma should be established.