NET-02: A multi-centre, randomised, phase II trial of liposomal irinotecan (nal-IRI) and 5-fluorouracil (5-FU)/folinic acid or docetaxel as second-line therapy in patients (pts) with progressive poorly differentiated extra-pulmonary neuroendocrine carcinoma (PD-EP-NEC)

Background: The prognosis for pts with PD-EP-NEC is poor. First-line treatment for advanced disease is etoposide/platinum-based chemotherapy, analogous to that of high grade lung NEC, with no standard second-line treatment, and is an area of unmet need. Methods: This is a multi-centre, randomised, phase II trial of nal-IRI; 80mg/m2 intravenously (IV) over 90 mins, prior to 5-FU; 2400 mg/m2 infusion over 46 hrs and folinic acid, Q14 days, or docetaxel; 75mg/m2 IV over 60 mins, Q21 days, as second-line therapy in pts with progressive PD-EP-NEC (Ki-67>20%), with the overall aim of selecting a treatment for continuation to a phase III trial. The standard arm is that used in high-grade lung NEC, of which docetaxel is a second-line therapy option (NCCN guidelines) and combination regimens such as Irinotecan/5-FU are a second-line therapy option currently used without trial evidence for this subset of pts. Pts must have had prior treatment with first-line platinum-based chemotherapy, have documented disease progression and have an ECOG performance status of ≤2. This study plans to recruit 102 pts from 16 UK centres (over 37 mths). Primary endpoint is 6-mth progression-free survival (PFS) rate; trial is designed to have an 80% chance of demonstrating that the one-sided 95% confidence interval of the 6 mth PFS rate excludes 15%, if the true rate is at least 30%, where 30% is the required level of efficacy, and a rate of <15% would give grounds for rejection. If both treatment arms exceed the required level of efficacy to warrant further evaluation in a phase III trial, treatment with the higher PFS rate at 6 mths will be selected. Secondary endpoints include overall survival, objective response rate, toxicity, quality of life, serum neuron-specific enolase. Exploratory endpoints include quantification of circulating tumour cells (CTCs), circulating tumour deoxyribonucleic acid (ctDNA) and molecular profiling of CTCs, ctDNA and tumour tissue, and generation of CTC-derived xenografts. This trial is open and has enrolled 6 pts at time of submission.