Study protocol for a prospective observational study to evaluate the efficacy of fosnetupitant for long-delayed chemotherapy-induced nausea and vomiting in patients receiving platinum- based chemotherapy (LODEC-N)

Abstract Background The efficacy of fosnetupitant (FosNTP) in combination with palonosetron and dexamethasone for preventing highly emetogenic chemotherapy-induced nausea and vomiting (CINV) was demonstrated in a phase III study (CONSOLE study). Although the exploratory analysis of the CONSOLE study suggested the efficacy of triplet antiemetic therapy, including FosNTP, in the extended overall phase (0–168 h), its efficacy in the long-delayed phase (> 168 h) has not been evaluated. Additionally, the efficacy of FosNTPs in moderately emetogenic chemotherapy has not yet been elucidated. Therefore, this study aims to prospectively assess the efficacy of FosNTP for CINV in the long-delayed phase (> 168 h) in patients receiving platinum-based chemotherapy (cisplatin, carboplatin, and oxaliplatin). Methods This is a single-center, single-arm, prospective observational study. Patients scheduled to receive platinum-based chemotherapy will be enrolled. Clinical pharmacists and attending physicians will evaluate all adverse events. The primary endpoint is a long-delayed (120–336 h) complete control (CC) rate, defined as the proportion of patients experiencing no emetic episodes and no moderate or severe nausea without rescue medication. The main secondary endpoints include a long-delayed complete response (CR) rate, defined as the proportion of patients experiencing no emesis without rescue medication, and an overall (0–336 h) CC, CR, and total control rates, defined as the proportion of patients experiencing no vomiting and nausea without rescue medication in the extended overall phase (0–336 h). A subset analysis is planned according to the CINV risk of chemotherapy for each endpoint and time-to-treatment failure for each agent. Discussion This study aims to elucidate the efficacy of triplet antiemetic therapy, including FosNTP, and identify risk factors for CINV in the long-delayed phase in patients receiving platinum-based chemotherapy. Trial Registration: This trial was registered in the Japan Registry of Clinical Trials (jRCT) as jRCT1030230130. Protocol version V.1.0, March 19, 2023.