This phase II trial tests how well itacitinib works in in patients with immune related adverse events (irAEs) arising from immune checkpoint inhibitors (ICI) that do not respond to steroids (steroid refractory). Steroids are the usual treatment for these side effects. However, sometimes steroids do not improve or fix the side effects. Giving itacitinib may be effective in treating patients with known or suspected problems coming from ICIs, that do not resolve or improve with steroids, by reducing the patient's immune system response that can cause the irAEs.

This phase III trial studies how well lenalidomide and dexamethasone works with or without daratumumab-hyaluronidase in treating patients with high-risk smoldering myeloma. Drugs used in chemotherapy, such as lenalidomide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Anti-inflammatory drugs, such as dexamethasone lower the bodys immune response and are used with other drugs in the treatment of some types of cancer. Daratumumab-hyaluronidase is a monoclonal antibody, daratumumab, that may interfere with the ability of cancer cells to grow and spread, and hyaluronidase, which may help daratumumab work better by making cancer cells more sensitive to the drug. Giving lenalidomide and dexamethasone with daratumumab-hyaluronidase may work better in treating patients with smoldering myeloma.