Patients with light-chain (AL) amyloidosis who are treated with high-dose chemotherapy (melphalan) and autologous stem cell transplantation (HDM/SCT) have the greatest success for long-term survival. These findings, which appeared as a “Letter” in the journal Blood, (2015; doi:10.1182/blood-2015-08-662726), reported on the largest number of patients in the world receiving high dose chemotherapy and stem cell transplantation for this rare disease.
AL amyloidosis is the most common form of systemic amyloidosis in the United States. The disease is caused when a person’s antibody-producing plasma cells produce abnormal light chains, which are components of antibodies. These light chains misfold and form amyloid deposits, a starch-like protein. These amyloid deposits accumulate in the liver, kidneys, spleen, or other tissues and can cause serious damage to these organs.
HDM/SCT was considered an innovative treatment approach when it was first developed at Boston University School of Medicine (BUSM) and Boston Medical Center (BMC) in Massachusetts in 1994. Since that time, 629 patients with AL amyloidosis have undergone this treatment at BMC.
Hematologic responses were assessed in 543 patients at 6 to 12 months following HDM/SCT treatment. Forty percent achieved a hematologic complete response (CR) after stem cell transplantation. Hematologic relapse occurred in 18.2% at a median of 3.97 years post treatment. Long-term survival, up to 20 years, was achieved in nearly one-third of patients.
“While survival is strongly dependent upon achieving hematologic complete response (CR), the survival of patients who did not achieve a CR and of those who relapsed after CR is notable, suggesting a benefit of aggressive treatment,” explained corresponding and lead author Vaishali Sanchorawala, MD, professor of medicine and associate director of the Amyloidosis Center at BUSM and director of the stem cell transplant program in the section of Hematology and Oncology at BMC.
“Strategies to better understand which patients may benefit the most from this treatment and reducing treatment-related mortality, as well as using combination therapies with novel agents to increase the CR rate, will likely improve outcomes in the future for patients who just a few years ago were considered to have a rapidly fatal diagnosis,” added Sanchorawala.