Phase I evaluation of telatinib, a vascular endothelial growth factor receptor tyrosine kinase inhibitor, in combination with irinotecan and capecitabine in patients with advanced solid tumors.

Purpose: We studied the safety and tolerability of telatinib, an orally available, small-molecule tyrosine kinase inhibitor of the vascular endothelial growth factor receptor (VEGFR-2/VEGFR-3), platelet-derived growth factor receptor beta, and c-Kit in combination with capecitabine and irinotecan.

Experimental Design: Telatinib twice daily continuously, irinotecan once every 3 weeks, and capecitabine oral twice daily on day 1 to 14 were administered in cycles of 21 days in escalating doses in successive cohorts. Toxicity was evaluated to conform to the Common Terminology Criteria for Adverse Events version 3.0. Pharmacokinetic and (circulating) endothelial (progenitor) cell measurements were done. Tumor efficacy was evaluated using the Response Evaluation Criteria in Solid Tumors.

Results: Twenty-three patients were included in this phase I trial. Most frequently (>25%) reported adverse events of any grade were vomiting, nausea, fatigue, diarrhea, alopecia, and hand-foot syndrome. A silent myocardial infarction and two cases of decreased left ventricular ejection fraction were reported; both were reversible. Cardiac monitoring of the subsequent patients did not reveal other abnormalities. The study was terminated when the recommended single agent phase II doses of telatinib (900 mg twice daily) and capecitabine/irinotecan was reached. Pharmacokinetic profiles showed no clinically relevant changes upon coadministration of the three drugs. (Circulating) endothelial (progenitor) cell levels stabilized during treatment. Five of 23 patients had partial remission and 9 of 23 patients showed stable disease.

Conclusions: Continuous administration of 900 mg telatinib twice daily can be safely combined with irinotecan (180 mg/m(2)) and capecitabine (1,000 mg/m(2) twice daily, day 1-14) and is the recommended schedule for further phase II studies. Tumor shrinkage and disease stabilization was observed. Cardiac toxicity needs further investigation in following studies.