NEW YORK (Reuters Health) – Autologous or allogeneic stem-cell transplants (SCT) were effective consolidation therapies for some patients with Richter’s syndrome (transformed chronic lymphocytic leukemia) in a retrospective study from Europe.
Researchers in the European Group for Blood and Marrow Transplantation studied 34 patients who had autoSCT and 25 who had alloSCT for Richter’s syndrome.
“Richter’s syndrome is a rare disease, so it has been difficult to assess the impact of different treatment strategies from single center studies,” lead investigator Dr. Kate Cwynarski from Royal Free Hospital, London, UK, told Reuters Health by email. “We are grateful for the involvement of patients and medical colleagues who have participated in our EBMT multicenter study that is the largest recorded to date.”
While the results show that patients with chemosensitive Richter’s syndrome appear to benefit from consolidation with stem-cell transplant strategies, she said, “Presently it is unclear which patients benefit from autoSCT versus alloSCT.”
“Prolonged survival is seen in a proportion of patients, and studies are ongoing to identify biological factors in the disease that may predict for improved outcome,” Dr. Cwynarski said.
More than 90% of both transplant groups had sustained engraftment (92% after alloSCT; 97% after autoSCT). Primary nonengraftment occurred only once, after alloSCT.
Estimated three-year overall survival was 36% after alloSCT, and nonrelapse mortality was 26%. The relapse rate was 47%, and relapse-free survival was 27% at three years.
After autoSCT, overall survival was 59% at three years. Nonrelapse mortality at three years was 12%, 43% of patients relapsed, and the relapse-free survival was 45% at three years.
This 59% overall survival compares favorably with a previously reported survival of less than 25% among chemotherapy-sensitive patients without SCT consolidation in a series from MD Anderson Cancer Center, the researchers note.
Their new findings appeared online April 30 in the Journal of Clinical Oncology.
Seven patients (28%) developed grade 2 to 4 acute graft-versus-host disease (GVHD) after alloSCT. Six of 19 evaluable patients developed chronic GVHD.
In the alloSCT group, overall survival was significantly higher when patients underwent transplantation in complete or partial remission than when they were transplanted with progressive disease (41% vs 17%; p=0.047).Only age of 60 years and above had an unfavorable effect on relapse after alloSCT.
In the autoSCT group, there were no significant prognostic factors for overall survival, nonrelapse mortality, relapse risk, and relapse-free survival.
“Presently a number of different chemoimmunotherapeutic strategies are used to treat patients with Richter’s syndrome,” Dr. Cwynarski said. “The decision regarding the intensity of the regimen utilized is affected by a number of factors including the performance status, age, and prior therapies used to treat the CLL if diagnosed prior to Richter’s syndrome.”
But the long-term outcomes of chemoimmunotherapeutic strategies is generally poor, she said, which is why doctors consider consolidation with high dose procedures.
She continued, “The addition of radioimmunotherapy to conditioning of autoSCT has been adopted for patients with transformed B-cell non Hodgkin lymphoma and may improve the outcome for patients undergoing autoSCT for Richter’s syndrome. The use of reduced intensity conditioning approaches is presently being explored and has increased the proportion of patients who may be considered for alloSCT.”
J Clin Oncol 2012.