A Randomized Phase 2 Trial with a Safety Lead-In to Evaluate Palbociclib Versus Palbociclib and Cemiplimab for the Treatment of Advanced Dedifferentiated Liposarcoma

This study is being done to answer the following question:
Is the combination of palbociclib plus cemiplimab better than palbociclib alone to treat of advanced dedifferentiated liposarcoma that cannot be removed by surgery?
We are doing this study because we want to find out if the combination of palbociclib plus cemiplimab is better or worse than the usual approach for your dedifferentiated liposarcoma. The usual approach is defined as care most people get for dedifferentiated liposarcoma.