Conditions: Neuroendocrine Tumors
Keywords: Neuroendocrine sorafenib cyclophosphamide pharmacodynamic
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 22
Healthy volunteers: no

Brief summary:
This is a phase II clinical trial to assess the efficacy of the combination of metronomic cyclophosphamide and tailored sorafenib dosing in advanced, progressive NET. NET are highly vascular tumors, and high VEGF expression has been correlated with worse clinical and pathological characteristics as well as poor prognosis. A novel antiangiogenic approach relies on targeting not only the endothelial cells but also rendering them more sensitive to VEGFR blockade by achieving pericyte detachment. In this study, the dose of sorafenib will be titrated up to a maximum of 800mg BID based on patients' toxicity and on a novel pharmacodynamic assay that measures inhibition of molecular target(PDGFR) in patients' peripheral blood mononuclear cells. Dual VEGFR targeting is achieved by administering sorafenib plus metronomic low dose cyclophosphamide.

Detailed description:

Arms:
arm 1: Patients will receive sorafenib and cyclophosphamide.

Interventions: intervention 1: Sorafenib intervention 2: Cyclophosphamide
Intervention descriptions: intervention 1: During a run-in period, patient will start taking 50 mg QD of oral cyclophosphamide and 200 mg BID of sorafenib. On day 8 of run-in the patient will be evaluated for toxicity. In the absence of toxicity, the patient will be escalated to sorafenib 400 mg BID and continue on daily 50 mg of cyclophosphamide, or the patient will be informed to continue on sorafenib 200 mg BID and cyclophosphamide 50 mg QD. Dose escalation procedure will be repeated every 2 weeks until unable to tolerate the study drug, or a maximum of 800 mg BID is reached, or achievement of \> 90% inhibition of phosphorylation of PDGFR/Raf axis in PBMC. After "run-in" period, patient begins cycle 1, each cycle will last 28 days. Both cyclophosphamide and sorafenib will be taken orally. intervention 2: During a run-in period, patient will start taking 50 mg QD of oral cyclophosphamide and 200 mg BID of sorafenib. On day 8 of run-in the patient will be evaluated for toxicity. In the absence of toxicity, the patient will be escalated to sorafenib 400 mg BID and continue on daily 50 mg of cyclophosphamide, or the patient will be informed to continue on sorafenib 200 mg BID and cyclophosphamide 50 mg QD. Dose escalation procedure will be repeated every 2 weeks until unable to tolerate the study drug, or a maximum of 800 mg BID is reached, or achievement of \> 90% inhibition of phosphorylation of PDGFR/Raf axis in PBMC. After "run-in" period, patient begins cycle 1, each cycle will last 28 days. Both cyclophosphamide and sorafenib will be taken orally.

Protocol document: