Subcutaneous Daratumumab Administration in the Thigh Vs Abdomen in Plasma Cell Disorders

The purpose of this study is to look at the safety, tolerability, and serum concentration of daratumumab administered subcutaneously in the thigh versus the abdomen in patients with plasma cell disorders. Daratumumab is a monoclonal antibody that can attach itself to the CD38 protein on the surface of abnormal plasma cells. Daratumumab can kill the abnormal plasma cells and/or help your immune system find and destroy them. Due to the way daratumumab works, normal cells may also be affected. All reference to the words "study drug" in this consent form will mean Daratumumab. Daratumumab has been approved by the U.S. Food and Drug Administration (FDA) alone or in combination with other standard of care drugs for treatment of multiple myeloma in both subcutaneous (DARZALEX FASPRO®) and intravenous (DARZALEX®) ways of being delivered. The FDA has also approved the subcutaneous administration of daratumumab combined with other standard of care drugs for patients with light chain (AL) amyloidosis. Subcutaneous means the drug is given by an injection just beneath the skin. Intravenous (IV) means the drug is given as an injection directly into a vein. Usually when given subcutaneously, the study drug is given by an injection in the abdomen. Having the drug given by subcutaneous injection (underneath the skin of the abdomen) has lessened the IV related side effects and the drug administration by injection is quicker. However, some patients cannot receive the study drug injections in their abdomen because they find them very painful or have other medical reasons making it difficult to get these injections. The goal of this study is to see if getting the study drug subcutaneously, injected under the skin by a needle, in the patient's upper thigh will have the same results, or better results, as getting the injection in the abdomen. This would therefore, improve patients access to the drug and provide an alternative place to receive the injection of the drug. This study will take place at University of Maryland Medical Center and there will be about 30 people who will take place in this study here. Dr. Badros is the Sponsor-Investigator of the study. Funding to conduct the study and study drug are being provided by Johnson \& Johnson Innovative Medicine (J\&J IM).