Testing the Addition of Cemiplimab to Palbociclib for the Treatment of Advanced Dedifferentiated Liposarcoma

This phase II trial compares the effect of treatment with palbociclib alone to treatment with palbociclib plus cemiplimab for treating patients with dedifferentiated liposarcoma that may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body (advanced). Palbociclib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Cemiplimab is a monoclonal antibody that may interfere with the ability of cancer cells to grow and spread. The combination of these two drugs may be more effective in shrinking or stabilizing advanced dedifferentiated liposarcoma compared to palbociclib alone.