Dose-escalation trial of lobaplatin weekly plus concurrent radiotherapy for local-regionally advanced nasopharyngeal carcinoma

Objective To define the maximum-tolerated dose (MTD) of lobaplatin (LBP) in a weekly regimen combined with concurrent radiotherapy in the treatment of locally advanced nasopharyngeal carcinoma (NPC). Methods A total of 18 cases with stage Ⅲ/IV A NPC were enrolled. Concurrent chemoradiotherapy was given to all the patients with a dose escalation of LBP. The initial dose of LBP was 15 mg/m2 with an escalating dose of 5 mg/m2. At least 3 patients were assigned into each group. Patients were proceeded into the next dose group if no dose-limiting toxicity (DLT) occurred until the MTD was achieved. Efficacy and toxicity were evaluated regularly. Results Three patients were assigned into the 10 mg/m2, 3 into the 15 mg/m2, and 6 into the 20 mg/m2 and 25 mg/m2 groups, respectively. Two patients experienced DLT in the 25 mg/m2 group. Hence, the MTD was determined as 20 mg/m2. At 3 months after corresponding treatment, the remission rate of nasopharyngeal tumors and neck-positive lymph nodes of the patients was 100%. The most common toxicity was reversible bone marrow suppression. Conclusions The MTD of weekly lobaplatin plus concurrent IMRT is 20 mg/m2 for locally advanced NPC. This regimen is reliable and safe, which is worthy of further clinical study. Key words: Nasopharyngeal neoplasm/concurrent chemoradiotherapy; Lobaplatin; Dose-limiting toxicity; Maximum tolerated dose