TY - JOUR T1 - Response to combined peptide receptor radionuclide therapy and checkpoint immunotherapy with ipilimumab plus nivolumab in metastatic Merkel cell carcinoma JF - Journal of Nuclear Medicine JO - J Nucl Med DO - 10.2967/jnumed.121.262344 SP - jnumed.121.262344 AU - Justin Ferdinandus AU - Wolfgang Peter Fendler AU - Katharina Lueckerath AU - Christoph Berliner AU - Sabine Kurzidem AU - Eva Hadaschik AU - Joachim Klode AU - Lisa Zimmer AU - Elisabeth Livingstone AU - Dirk Schadendorf AU - Ken Herrmann AU - Juergen Christian Becker AU - Selma Ugurel Y1 - 2021/09/01 UR - http://jnm.snmjournals.org/content/early/2021/09/02/jnumed.121.262344.abstract N2 - Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine cancer of the skin. For patients who are refractory to immune checkpoint inhibition (ICI), treatment options are limited. Few cases of MCCs with high somatostatin receptor (SSTR) expression were reported to show responses upon SSTR-directed peptide receptor radionuclide therapy (PRRT). A combination of PRRT and ICI has not been reported in MCC to date. A 60-year old man with metastatic MCC, who was primarily resistant to the anti-PD-L1 ICI with avelumab and secondarily resistant to the anti-CTLA4 plus anti-PD-1 ICI therapy with ipilimumab plus nivolumab (IPI/NIVO) with additional RT, presented with multiple bone and lymph node metastases. After confirmation of SSTR expression, the patient was treated with a salvage therapy of additional four doses of IPI/NIVO combined with two cycles of PRRT. Treatment was well tolerated with transient hematoxicity and mild nausea. Re-staging three months after therapy start showed an exceptional good response. This case report demonstrates the feasibility of a combined treatment with IPI/NIVO and PRRT as a salvage option for MCC patients progressing under ICI therapy. Prospective evidence confirming the additive value of combining ICI and radionuclide therapy in a larger cohort is needed. ER -