The study is testing a new treatment called AZD0120 for people with a type of blood cancer known as relapsed/refractory multiple myeloma. This is a disease where abnormal cells in the bone marrow grow uncontrollably. The treatment involves using special cells called CAR T-cells, which are modified to attack the cancer. The trial has two parts: Phase 1b to check if the treatment is safe and Phase 2 to see if it works well. To join, participants need to have tried at least three other treatments and be 18 or older. They also need to be in good general health. However, you cannot join if you have other serious health problems or if your cancer has spread to the brain.

• The study requires participants to be adults with at least three prior treatments for multiple myeloma.
• Participants should expect to undergo evaluations for safety and effectiveness of the treatment.
• People with serious heart, brain, or mental health conditions cannot participate.