Dose Escalation of Lobaplatin Concurrent With Intensity-modulated Radiotherapy for the Treatment of Stage III-IVb Nasopharyngeal Carcinoma: A Phase I Clinical Trial in an Asian Population

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in Southern China area, which is characterized by obvious regional characteristics and "Guangdong cancer". Radiotherapy is the main treatment for locally advanced nasopharyngeal carcinoma. In recent years, chemotherapy has improved the short-term and long-term survival of patients with locally advanced nasopharyngeal carcinoma.

Lobaplatin is the third generation platinum anticancer drugs, mechanism of action and traditional cisplatin is similar, mainly formed by the Pt-GG and Pt-AG chain cross connect, replication and transcription process blocks of deoxyribonucleic acid(DNA), thereby interfering with tumor cell cycle. The damage of DNA induced by lobaplatin can influence the expression of tumor cell specific genes. Due to the different structure of lobaplatin and no cross resistance to cisplatin in the study showed that, compared with cisplatin with gastrointestinal reaction more mild, and no cisplatin common liver and kidney toxicity, neurotoxicity and ototoxicity, in some tumors have a better adaptability; but compared with cisplatin had more severe bone marrow suppression this, offset some of the advantages of lobaplatin in a certain extent. At present, the clinical indications for the treatment of such diseases include head and neck cancer, breast cancer, gastrointestinal cancer, gynecologic malignant tumor and non small cell lung cancer. Tian Ying confirmed that lobaplatin has obvious cytotoxic effect on nasopharyngeal carcinoma cells, in a concentration dependent manner, the mechanism for the dual role, namely block at lower concentration of cells in G2 phase and induce apoptosis at higher concentration, provide the possibility for clinical treatment of nasopharyngeal carcinoma for lobaplatin; there are a number of clinical study confirmed that lobaplatin chemoradiotherapy for locally advanced nasopharyngeal carcinoma with cisplatin approximation. But at present, there is no report on the dose and tolerability of concurrent radiotherapy for nasopharyngeal carcinoma.

Therefore, a dose escalation trial was conducted to determine maximum tolerated dose of lobaplat in as a single agent combined with concurrent intensity-modulated radiotherapy in a Chinese population with locoregionally advanced NPC.