Survival increases among patients with amyloidosis treated with high-dose melphalan and autologous stem cell transplantation

FDA Highlights – by Bruce Sylvester – Patients with selected immunoglobulin light chain amyloidosis who are treated with high-dose melphalan and autologous stem cell transplantation (HDM/SCT) have a high organ response rate and increased overall survival, even among those who did not achieve a haematologic complete response. Researchers reported this finding in the October 2011 issue of Blood.

“This study provides the longest outcome data on AL patients treated with HDM/SCT, including OS [overall survival], EFS [event-free survival], and long-term mortality,” said lead author Martha Skinner, MD, Boston University Medical Center, in Boston, Massachusetts. “Our results demonstrate that, with careful patient selection and experienced management, low rates of treatment related mortality can be achieved.”

As background, the authors noted that untreated patients have poor outcomes, with a median survival of 10 to 14 months after diagnosis. Less than 5% of patients survived for 10 years prior to the introduction of HDM/SCT treatment.

The investigators analysed data on 421 subjects treated with HDM/SCT and compared outcomes for patients with and without a complete response.

Treatment related mortality was 11.4% overall (5.6% in the last five years). The complete response rate was 34% and the median event-free survival and overall survival was 2.6 and 6.3 years, respectively.

Eighty-one subjects died within one year of HDM/SCT and were not evaluable for haematologic and organ response.

Of the 340 evaluable subjects, 43% achieved haematologic complete and 78% achieved an organ response. For complete response subjects, median event-free survival and overall survival were 8.3 and 13.2 years, respectively. Among the 195 subjects who did not achieve a complete response, 52% achieved an organ response, and their median event-free survival and overall survival were two and 5.9 years, respectively.

Despite the importance of attaining complete response, the authors noted that  achievement of partial response often resulted in a long period of stable or improved diseases.

“We pioneered HDM/SCT treatment for AL amyloidosis in 1994,” added Dr. Skinner. “This long-term review shows durable haematologic and organ responses for most patients with an overall survival greatly exceeding what it was prior to HDM/SCT treatment.”