Adriamycin and Ifosfamide Combined With Sintilimab

This study tests two chemotherapy drugs (adriamycin and ifosfamide) combined with an immunotherapy drug called sintilimab for people with advanced or inoperable soft tissue sarcomas — cancers of the body's connective tissues like fat, muscle, or blood vessels — that have not responded to standard treatments or where no standard treatment exists. **You may be eligible if...** - You have advanced or inoperable soft tissue sarcoma confirmed by biopsy - Standard treatment has failed, does not exist, or you cannot tolerate it for your subtype - You have at least one measurable tumor on imaging (CT or MRI) - You are in reasonable overall health and able to tolerate treatment - You are willing to participate and sign the consent form **You may NOT be eligible if...** - Your sarcoma type is specifically excluded (such as chondrosarcoma, osteosarcoma, gastrointestinal stromal tumor, or malignant mesothelioma) - You have no measurable disease on imaging - You have significant heart, liver, or kidney problems that would make chemotherapy unsafe - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.