Multicenter, open label, single arm, phase II study to assess the efficay and safety of enfortumab-vedotin (EV) as a single agent in patients with advanced Neuroendocrine Carcinomas (NEC).

Prior treatment

• Prior systemic treatment with any antimicrotubule agent such as taxanes or Enfortumab Vedotin, or more than two lines of chemotherapy-based systemic therapy, excluding adjuvant or neoadjuvant treatments.
• Patients with a history of other active malignancies within three years prior to study start, with the exception of: adequately treated carcinoma in situ of the cervix, basal or squamous cell carcinoma of the skin, or prior confined malignancy surgically resected with curative intent.
• Patients having received any anticancer therapy within 14 days prior to the first dose of study drug.
• Patients undergoing major surgery in the four weeks prior to the first dose of study drug.

Other illness

• Patients with known hypersensitivity to EV or any excipient contained in the EV pharmaceutical formulation (including histidine, trehalose dihydrate, and polysorbate 20).
• Patients with evidence of other severe uncontrolled disease as judged by the investigator.
• Patients with a significant history of uncontrolled cardiovascular disease or renal, neurological, psychiatric, endocrine, metabolic, immunological, or hepatic disease.

Lab values

• Patients with poorly controlled diabetes (glycated haemoglobin ≥ 10%).
• Patients with active immune thrombocytopenic purpura, autoimmune haemolytic anaemia, or a history of being refractory to platelet transfusions (within 1 year prior to the 1st dose of study drug).

Other

• Grade 2 or higher peripheral neuropathy.
• Women who are pregnant or breastfeeding.

• Patients 18 years of age or older.
• Women who are not surgically sterile or post-menopausal (for at least one year) and men who have not had a vasectomy must use highly effective contraception measures. (Please see section 13.3.8 of protocol for further details).
• Patients who give informed consent to participate in the study.
• Patients with histologically documented poorly-differentiated neuroendocrine carcinoma of any origin, excluding the lung, or histologically documented well-differentiated neuroendocrine tumours of grade 3 histology with a Ki-67 index >20%, of any origin, excluding the lung, who have failed at least one prior line of platinum-based systemic therapy or are considered ineligible for platinum-based chemotherapy
• Patients with radiologically documented metastatic or locally advanced disease at the start of the study. Subjects with brain metastases must have clinically controlled neurological symptoms and must have completed radiotherapy at least 21 days prior to administration of the first dose of study drug.
• Patients with ECOG score 0-2.
• Evaluable and/or measurable disease by CT scan according to RECIST v1.1.
• Patients must have adequate renal and hepatic function according to the local laboratory reference ranges at the time of screening: - Absolute neutrophil count ≥ 1500/µcL - Platelets ≥ 80,000/mm3 - Haemoglobin ≥ 9.0 g/dL - Serum creatinine ≤ 1.5 mg/dL or calculated creatinine clearance ≥ 30 mL/min - Sodium > 130 mmol/L - Alkaline phosphatase, AST and ALT ≤ 2.5 x ULN - Bilirubin ≤ 1.5 x ULN - Patients with liver metastases may have ALP, AST and ALT ≤ 5.0 x ULN - Patients with bone metastases may have alkaline phosphatase ≤ 5.0 x ULN - Patients with Gilbert’s syndrome may have bilirubin > 1.5 x ULN - Coagulation: activated partial thromboplastin time (aPTT), prothrombin time (PT) ≤ 1.2 x ULN.
• Life expectancy of at least 12 weeks.
• Women must be surgically sterile, post-menopausal (for at least 1 year), or have a negative pregnancy test.