Reduced Intensity Allogeneic Stem Cell Transplantation For Follicular Lymphoma Relapsing After An Autologous Transplantation. An Analysis From The EBMT

This was a retrospective analysis from the Lymphoma Working Party of the EBMT. Eligible patients had a diagnosis of FL, were aged 18-70 and had relapsed after a prior autoSCT. Tandem transplants, cord blood transplants and mismatched unrelated transplants were excluded. Data analyses was performed using Kaplan Meier estimates and cumulative incidence analyses.

309 patients were identified with a median age at diagnoses of 44 (range 21-69). 209 were male and 100 female and the stage at diagnoses was stage I 5%, stage II 8%, stage III 22% and stage IV n=62% and 24% of patients had B symptoms at diagnosis. The median time from diagnosis to RICalloSCT was 62 months (range 11-253 months). All patients had undergone a prior autoSCT at a median of 23 months (range 4-158 months) prior to the RICalloSCT. The patients had received a median of 4 lines (range 3-10) of therapy prior to the RICalloSCT. At the time of transplant 77.5% of patients had chemosensitive disease and 16% had chemoresistant disease, 2% were in untested relapse. All patients received a reduced intensity conditioned allogeneic SCT from either a sibling 42%, matched unrelated donor 53% or mismatched sibling donor 5%. The performance status at transplant was good in 96% of patients. 95% of patients engrafted and 4% of patients died prior to engraftment. The cumulative incidence of acute GVHD was 29.5% and chronic GVHD 51.9%. With a median follow up of 33.5 months for surviving patients the non-relapse mortality (NRM) was 9% at 100 days, 19% at 1 year and 25% at 5 years. The NRM was significantly higher in patients over the age of 50 (hazard ratio (HR) 1.8, CI 1.1-3.1, p=0.03) and in those receiving an unrelated donor transplant (HR 1.7, CI 1.0-3.0, p=0.05). The relapse/progression rate was 20% at 2 years and 30% at 5 years and was significantly lower in patients with chemosensitive disease at transplantation (HR 0.46, CI 0.26-0.78, p=0.005). The 2 year and 5 year progression free survival (PFS) was 57% and 45% respectively and was significantly better in patients with chemosensitive disease at transplant (HR 0.56, CI 0.38-0.81 p=0.002). Older patients (>50) had a significantly worse PFS (HR1.62, CI 1.11-2.36, p=0.012). The 2 and 5 year overall survival was 62% and 53% respectively and was significantly worse in patients over the age of 50 (HR 2.01, CI 1.34-3.03, p=0.001).

This is the largest cohort of patients with follicular lymphoma undergoing a RICalloSCT following failure of a prior autologous SCT. This data suggests that a RICalloSCT is an effective salvage strategy in this setting particularly in younger patients with chemosensitive disease at transplant.

No relevant conflicts of interest to declare.