We are doing this study to find out if an experimental drug called AbbV-383 (the study drug) is safe and effective for patients with relapsed/refractory multiple myeloma.

Relapsed/Refractory Multiple Myeloma (RRMM)

Adults ages 18+ who:

• Are diagnosed with multiple myeloma
• Have failed at least 2 previous lines of therapy that included the following drugs: a proteasome inhibitor (PI), an immunomodulatory imide (IMiD), and an anti-CD38 monoclonal antibody (mAb)

For more information about who can join this study, please contact the study team at quinna.marshburn@duke.edu.

If you choose to join the study, you will go through a screening period that lasts for about 3 weeks. During this period, you will:

• Have a bone marrow biopsy
• Have a skeletal survey and a CT scan or MRI
• Have blood and urine tests, an EKG, and physical exams

If you are eligible based on screening, you will proceed to the study drug dosing period. During this period, you will get a random assignment (like a coin flip) to Arm A or Arm B.

Arm A
If you are in this arm of the study dosing period, you will:

• Get the study drug as an intravenous (IV) infusion every 28 days
• Stay in the hospital for at least 24 hours following your first dose of the study drug so we can monitor your tolerance

Arm B
If you are in this arm of the study dosing period, you will get treatment with a standard, available option for RRMM. The study doctor will choose the regimen that they believe is best for you from the following options:

• Carfilzomib + Dexamethasone (Kd)
• Elotuzumab + Pomalidomide + Dexamethasone (EloPd)
• Selinexor + Bortezomib + Dexamethasone (SVd)