RecruitingPhase 1Drug trialSafety of SBRT With Anti-PD1 and Anti-IL-8 for the Treatment of Multiple Metastases in Advanced Solid Tumors and MelanomaNivolumab (and other agents affecting the anti-programmed death-1 \[anti-PD-1\] pathway) have demonstrated anti-tumor activity in multiple tumor types. Combinations of immune-oncology (IO) agents with complimentary mechanisms as well as radiation represent a promising strategy to improve response rates to immunotherapy and overcome resistance. In this phase I/Ib study, radiation will be used in combination with IO agents nivolumab and anti-IL-8 (BMS-986253) to assess toxicity by organ system and then assess the preliminary efficacy of the treatment regimen. In Part 1, the study will determine the safe doses of radiation by organ site in conjunction with nivolumab and BMS-986253. In Part 2, the treatment regimen will be investigated in melanoma, prioritizing acral melanoma, to describe the response rate to treatment as well as other clinical and safety outcomes. The study will also provide the opportunity to evaluate changes in the tumor microenvironment induced by the treatment.