A Study of Surufatinib Combined With Serplulimab in the Treatment of Advanced Solid Tumors With Neuroendocrine Differentiation That Failed Standard Therapy

"surufatinib:~250 mg (5 capsules) once a day, Q3W, continued until the patient developed disease progression or met other protocol criteria for discontinuation of study treatment; If the patient vomits after taking the medicine, there is no need to take the supplement; The missed dose should not be added the next day, and the next prescribed dose should be taken as usual.~serplulimab:~300mg fixed dose, intravenous infusion, d1, Q3W; Continued administration until the patient developed disease progression or met other protocol criteria for discontinuation of study therapy.~Imaging was used every 6 weeks (±7 days) to evaluate tumor status until disease progression (RECIST 1.1) or death (during patient treatment), and tumor treatment and survival status after disease progression were recorded. The changes of neuroendocrine tumor markers were detected after treatment."