Agnostic Therapy in Rare Solid Tumors

"The intervention consists of administering Nivolumab 480 mg intravenously every 4 weeks, with a +5 day window for postponement but not for advancement of treatment. Treatment will continue until limiting toxicity, disease progression, or for a maximum period of 12 months (13 cycles) as maintenance therapy, provided the patient maintains stable disease, a partial response, or a complete response. Patients who are off treatment for more than 56 days (2 cycles) due to Nivolumab-related toxicities or other clinical issues will be discontinued from the protocol.~After 12 months of treatment or in the event of study discontinuation for any reason, patients will be followed by the research team via telephone every 60 days, with a +/- 7 day window, until death."