43P Outcomes for metastatic paraganglioma and pheochromocytoma treated with chemotherapy

undergone chemotherapy and mitotane treatment.Cisplatin, 25 mg/m2 on day 1 and nivolumab 240 mg on day 2, every two weeks, were administered to advanced/ metastatic ACC with disease progression to EDP-M regimen plus/minus other chemotherapeutic regimens.Primary endpoint was the disease control rate (DCR), defined as proportion of objective response or disease stabilization lasting at least 6 months.Secondary endpoints were disease response rate, overall survival (OS), progression free survival (PFS) and safety.Results: Nineteen patients were enrolled between January 2023 and October 2024.The median follow-up was of 9.7 months.The DCR was obtained in the 42.1% of patients [95%CI,.Six patients obtained a partial response and 8 patients a stable disease.The median PFS was of 4.31 months [95%CI,] and the median OS was not reached.Chemo-immunotherapy combination was well-tolerated, and most toxicities were limited to grade G1-2 according to WHO criteria.The most common treatment-related adverse events were asthenia, nausea, and paresthesia.Only one patient discontinued treatment after 1 cycle, due to grade 3 immune-related hepatitis.Conclusions: Cisplatin and nivolumab showed to active in advanced, previously treated, ACC patients.The survival achieved in this setting of patients known to have a poor prognosis is promising.