This study is investigating how a drug called iberdomide works alone or with another drug named dexamethasone to treat a type of blood cancer called smoldering multiple myeloma. Smoldering multiple myeloma is an early stage of multiple myeloma, where cancer cells are present, but not causing symptoms. Iberdomide is a form of immunotherapy which means it helps the body’s immune system fight cancer. Dexamethasone is a synthetic steroid used to reduce inflammation and help other medicines work better. The study aims to see if these drugs together can help delay the cancer from getting worse.

• The study involves random assignment to one of two groups - one group receives both drugs, and the other receives only iberdomide.
• Treatment cycles last 28 days and may continue as long as the disease does not get worse or side effects are not severe.
• Participants will be followed up for 4 weeks after treatment, then checked every 6 months.