Autologous stem cell transplant is beneficial to patients who are diagnosed with multiple myeloma or systemic amyloidosis. However, undesired symptoms such as weakness, fatigue, nausea, pain and sleep disturbance after transplant can contribute to complications and increase the how long the patient is in the hospital, especially in patients age 60-75. Research has shown that the development and the intensity of these symptoms are closely associated with an increase in a protein called a cytokine which is involved in the inflammatory response in the human body. One of the cytokines is called Interleukin-6 or IL-6.Therefore, this study will investigate if blocking IL-6 with an agent called siltuximab, administered before and after transplant, will decrease the symptom burden after transplant to improve quality of life and recovery in the immediate post-transplant period.