A phase I dose-escalation study of regorafenib (BAY 73-4506), an inhibitor of oncogenic, angiogenic, and stromal kinases, in patients with advanced solid tumors.

PURPOSE: Regorafenib is a novel oral multikinase inhibitor of angiogenic (VEGFR1-3, TIE2), stromal (PDGFR-ß, FGFR), and oncogenic kinases (KIT, RET, and RAF). This first-in-man, phase I dose-escalation study assessed the safety, pharmacokinetic, pharmacodynamic, and efficacy profiles of regorafenib in patients with advanced solid tumors. PATIENTS AND METHODS: Patients aged 18 years or older with advanced solid tumors refractory to standard treatment were recruited. Regorafenib was administered orally for 21 days on/seven days off in repeating cycles, until discontinuation due to toxicity or tumor progression. Adverse events (AE) were assessed using National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. Pharmacokinetic profiles were measured after a single dose and on day 21. Pharmacodynamic and efficacy evaluations included tumor perfusion assessment using dynamic contrast-enhanced MRI, plasma cytokines, and tumor response using RECIST (v1.0). RESULTS: Fifty-three patients were enrolled into eight cohorts at dose levels from 10 to 220 mg daily. The recommended dose for future studies was determined to be 160 mg daily, with a treatment schedule of 21 days on/seven days off in repeating 28-day cycles. The most common drug-related grade 3 or 4 AEs were dermatologic AEs (hand-foot skin reaction, rash), hypertension, and diarrhea. Pharmacokinetic analysis revealed a similar exposure at steady state for the parent compound and two pharmacologically active metabolites. Tumor perfusion and plasma cytokine analysis showed biologic activity of regorafenib. Three of 47 evaluable patients achieved a partial response (renal cell carcinoma, colorectal carcinoma, and osteosarcoma). CONCLUSION: Regorafenib showed an acceptable safety profile and preliminary evidence of antitumor activity in patients with solid tumors.

Phase I study of telatinib (BAY 57-9352): analysis of safety, pharmacokinetics, tumor efficacy, and biomarkers in patients with colorectal cancer.

BACKGROUND: Telatinib (BAY 57-9352) is an orally available, small-molecule inhibitor of vascular endothelial growth factor receptors 2 and 3 (VEGFR-2/-3) and platelet-derived growth factor receptor ß tyrosine kinases. METHODS: In this multicenter phase I dose-escalation study including a phase II like expansion part, 39 patients with refractory colorectal cancer (CRC) were enrolled into 14 days on / 7 days off in repeating cycles of 28 days (n = 11) or continuous dosing groups (n = 28) to receive ≥ 600 mg telatinib twice-daily (bid). RESULTS: Hypertension (28%) and diarrhoea (15%) were the most frequent study drug-related adverse events of CTC grade 3. In this population, no clear relationship between telatinib dose and individual Cmax and AUC was apparent in the 600 mg bid to 1500 mg bid dose range. No partial remission according to RECIST was reached, but 41% of the patients reached some tumour shrinkage during treatment. Tumour blood flow measured by dynamic contrast-enhanced magnetic resonance imaging and sVEGFR-2 plasma levels decreased with increasing telatinib AUC(0-12). CONCLUSION: Telatinib treatment was well tolerated. The observed single agent antitumor activity in heavily pretreated CRC patients was limited. Pharmacodynamic results are suggestive for the biological activity of telatinib justifying a further evaluation of telatinib bid in combination with standard chemotherapy regimens in CRC patients.

DCE-MRI assessment of the effect of vandetanib on tumor vasculature in patients with advanced colorectal cancer and liver metastases: a randomized phase I study.

BACKGROUND: Vandetanib is a once-daily oral inhibitor of VEGFR, EGFR and RET signaling pathways. In patients with advanced colorectal cancer and liver metastases, the effect of vandetanib on tumor vasculature was assessed using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). METHODS: Eligible patients received vandetanib 100 or 300 mg/day. DCE-MRI (iAUC(60 )and K(trans)) was used to quantify the primary endpoints of tumor perfusion and vascular permeability. An exploratory assessment of tumor oxygenation was performed using MRI/T2*. All MRI parameters were measured at baseline (twice) and on days 2, 8, 29 and 57. RESULTS: Twenty-two patients received vandetanib (n = 10, 100 mg; n = 12, 300 mg). Baseline measurements of iAUC(60 )and K(trans )were reproducible, with low intrapatient coefficients of variation (11% and 24%, respectively). Estimates of mean % changes from baseline were -3.4% (100 mg) and -4.6% (300 mg) for iAUC(60), and -4.6% (100 mg) and -2.7% (300 mg) for K(trans); these changes were not significantly different between doses. The exploratory T2* measurement showed a significant increase at 300 mg versus 100 mg (P = 0.006). Both doses of vandetanib were generally well tolerated; common toxicities were fatigue, rash and diarrhea (majority CTC grade 1 or 2). The pharmacokinetic profile of vandetanib was similar to that observed previously. There were no RECIST-defined objective responses; five patients experienced stable disease >/=8 weeks. CONCLUSION: In this study in patients with advanced colorectal cancer, vandetanib did not modulate gadolinium uptake in tumor vasculature and tissue measured by the DCE-MRI parameters iAUC(60 )and K(trans). TRIAL REGISTRATION: NCT00496509 (ClinicalTrials.gov); D4200C00050 (AstraZeneca).

Onset and maintenance of angiogenesis in biomaterials: in vivo assessment by dynamic contrast-enhanced MRI.

OBJECTIVE: To describe dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a practical tool for longitudinal assessment of angiogenesis in biomaterials. BACKGROUND: There is a lack of suitable methods for in vivo evaluation of the integration of biomaterials in a clinical setting. In oncology, DCE-MRI is used for the longitudinal monitoring of altered tumor angiogenesis during therapy. Thus, we investigated whether DCE-MRI enables to assess the integration of biomaterials over time. METHODS: The tested material was bovine bone matrix applied in a bilateral sinus lift procedure in combination with concentrated mononuclear cells, including mesenchymal stem cells and autologous thrombin. To assess the development of new blood vessels inside the biomaterial, DCE-MRI was carried out before and 11, 25, 53, and 104 days after surgery. Perfusionparameters were calculated according to the model of Tofts. RESULTS: Analysis of the data revealed increasing parameters for perfusion and blood supply within the transplant over time. It was possible to determine the values for each transplantation site and each point of time separately. CONCLUSION: DCE-MRI is appropriate to repetitively survey angiogenesis and integration of biomaterials in patients. It seems appropriate as a valuable indicator of treatment response or failure, with consecutive adaption of the therapy regime.