Famitinib in combination with concurrent chemoradiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma: a phase 1, open-label, dose-escalation Study

Background:Famitinib is a tyrosine kinase inhibitor against multiple targets,including vascular endothelial growth factor receptor 2/3,platelet-derived growth factor receptor,and stem cell factor receptor(c-kit).Previous studies have demonstrated anti-tumour activities of famitinib against a wide variety of advanced-stage solid cancers.We aimed to determine the safety and efficacy of famitinib with concurrent chemoradiotherapy(CCRT)in patients with locoregionally advanced nasopharyngeal carcinoma(NPC).We also evaluated the feasibility of contrast-enhanced ultrasound(D-CEUS)as a predictor of early tumour response to famitinib and to correlate functional parameters with clinical efficacy.Methods:The trial was conducted in subjects with stage III or IVa-b NPC using a 3+3 design of escalating fami-tinib doses.Briefly,subjects received 2 weeks of famitinib monotherapy followed by 7 weeks of famitinib plus CCRT.D-CEUS of the neck lymph nodes was performed at day 0,8 and 15 after famitinib was administered before starting concurrent chemoradiotherapy.End points included safety,tolerability and anti-tumour activity.Results:Twenty patients were enrolled(six each for 12.5,16.5 and 20 mg and two for 25 mg).Two patients in the 25 mg cohort developed dose-limiting toxicities,including grade 4 thrombocytopenia and grade 3 hypertension.The most common grade 3/4 adverse events were leukopenia,neutropenia and radiation mucositis.D-CEUS tests showed that more than 60%of patients achieved a perfusion parameter response after 2 weeks taking famitinib alone,and the parameter response was associated with disease improvement.In the famitinib monotherapy stage,three patients(15%)showed partial responses.The complete response rate was 65%at the completion of treatment and 95%3 months after the treatment ended.After a median follow-up of 44 months,the 3-year progression-free survival(PFS)and distant metastasis-free survival were 70%and 75%,respectively.Subjects with a decrease of perfusion parameter response,such as peak intensity decreased at least 30%after 1 week of famitinib treatment,had higher 3-year PFS(90.9%vs.44.4%,95%CI 73.7%-100%vs.11.9%-76.9%,P<0.001)than those with an increase or a reduction of less than 30%.Conclusions:The recommended famitinib dose for phase II trial is 20 mg with CCRT for patients with local advanced NPC.D-CEUS is a reliable and early measure of efficacy for famitinib therapies.Further investigation is required to confirm the effects of famitinib plus chemoradiotherapy.