Abstract
BACKGROUND: To investigate the maximum tolerated dose (MTD) of apatinib delivered during and after intensity-modulated radiotherapy (IMRT) for unresectable hepatocellular carcinoma (HCC). METHODS: Patients with unresectable HCC who were not eligible for radiofrequency ablation (RFA), transcatheter arterial chemoembolization (TACE), or residual/ recurrent after the prior local treatment were enrolled. Patients were scheduled to be treated with IMRT at 50-60 Gy/25-30 fractions. Oral apatinib tablets were administered concurrently with IMRT and continued thereafter. We used a 3 + 3 dose-escalation design, with three dose levels of apatinib (250, 500, and 750 mg). Grade 3 or more severe adverse events (AEs) were defined as dose-limiting toxicities (DLTs). The treatment response was calculated using the Modified Response Evaluation Criteria in Solid Tumours. RESULTS: Nine patients with Barcelona Clinic Liver Cancer Stage C were included. One patient withdrew from the apatinib 250 mg group and another patient was added. No DLTs occurred in the apatinib 250 mg group. Five patients were included in the apatinib 500 mg group, and 2 cases of DLT (grade 3 leukopenia) were found among them. Dose escalation was terminated and the MTD was determined to be 250 mg. Common grade 1-2 AEs included fatigue, hypertension, dizziness, bone marrow suppression, and hyperbilirubinemia. The median follow-up time for all patients was 16.0 months. Three patients achieved complete response and another three achieved partial response. The objective response rate was 6/9 (66.7%), and the disease control rate was 9/9 (100%). Three patients relapsed out of the radiation field. The median progression-free survival was 17.0 months, and the median overall survival was 16.7 months. CONCLUSIONS: When combined with IMRT, apatinib 250 mg daily was recommended for a phase 2 study of unresectable HCC. The antitumor activity of the combination treatment was encouraging. The safety and efficacy of apatinib combined with IMRT for unresectable HCC should be further investigated in future studies. TRIAL REGISTRATION: Registration No. ChiCTR1800018309 . Registered 11 September 2018. Retrospectively registered, https://www.chictr.org.cn/showproj.aspx?proj=30461 .