This study will enroll patients with non-metastatic nasopharyngeal carcinoma (NPC) that have
residual Epstein-Barr virus (EBV) DNA after curative radiotherapy or chemoradiotherapy. The
purpose is to evaluate the survival in these patients treated with apatinib (YN968D1), an
inhibitor of vascular endothelial growth factor receptor (phase IIa) and to compare the
survival in these patients treated with apatinib versus placebo (phase IIb).