This is a clinical trial for adults diagnosed with relapsed and/or refractory multiple myeloma (RRMM). 

The purpose of this study is to test the safety of the study drug TAK-981 when given with mezagitamab or daratumumab and hyaluronidase-fihj. This study will also determine the recommended dose of TAK-981 and see how well cancer responds when given this drug combination.

TAK-981 and mezagitamab are investigational drugs. “Investigational” means that TAK-981 and mezagitamab are not yet approved by the US Food and Drug Administration (FDA). Daratumumab and hyaluronidase-fihj are approved by the FDA.
   
TAK-981 blocks the attachment of a protein in cells, called Small Ubiquitin-like Modifier (SUMO), to other proteins in cells. When SUMO is blocked in the cells of the immune system (the part of the body that fights disease or cancer), the body’s ability to act against the cancer is improved. Blocking of SUMO may also directly make it harder for the tumor cells to grow. TAK-981 is given as an intravenous (IV) infusion over a period of 50 to 70 minutes.
   
Mezagitamab is an anti-CD38 monoclonal antibody. A monoclonal antibody is a type of protein made in the laboratory that can bind to substances in the body, including cancer cells and multiple myeloma cells. Mezagitamab is given as a subcutaneous injection (given under the skin). The injection will be given in the stomach, thighs, arms, or the upper buttock area. 
   
Participants might be in the study for approximately 36 to 48 months, but the total amount of time will vary depending on how they are feeling, how well they tolerate the study drugs, and how their disease responds to the study drugs. If the study doctor believes that participants would benefit by continuing to take the study drugs after initial treatment, then study treatment may continue longer.