Waldenström's macroglobulinemia (WM) is an indolent lym phomaand is responsive to therapy regimens containing alkylating agents, purine analogs and rituximab if treatment becomes necessary. We initiated a multicenter phase II trial to determine the safety and efficacy of a regimen containing pentostatin, cyclophosphamide and rituximab (PER) in patients with WM. Between May 2005 and December 2010, 25 patients with WM were included in the study. Twenty-one patients received PER as first-line therapy. In these patients, 2-year progression-free survival was 83.6% and 2-year overall survival was 100%. Thirteen patients (52%) received R maintenance therapy. In these patients, the 2-year progression-free survival was 91.67% and 2-year overall survival was 100%. We have provided evidence that PER is a safe and effective regimen for WM. Although R maintenance therapy after PER seemed to induce a better long-term outcome, this study was not powered to address this issue.

The aim of this registry-based retrospective study was to analyze the outcome of second allogeneic hematopoietic SCT (alloHSCT_2) performed in patients with lymphoma who had relapsed after a first allogeneic transplant (alloHSCT_1). Patients ⩾ 18 years who had received an alloHSCT_2 for lymphoma relapse between 2000 and 2011 were eligible. One hundred and forty patients were identified. The diagnosis was Hodgkin lymphoma (HL) in 31%, diffuse large B-cell lymphoma in 14%, T-cell lymphoma in 12%, indolent lymphoma in 19%, mantle cell lymphoma in 16% and other lymphomas in 8% of the patients. The median interval from alloHSCT_1 to alloHSCT_2 was 19 (range 4-116) months. Disease status at alloHSCT_2 was chemosensitive in 46%, refractory in 43% and unknown in 11% of the patients. Three-year PFS, OS, relapse incidence and nonrelapse mortality were 19%, 29%, 58% and 23%, respectively. PFS and OS were significantly affected by refractory disease at alloHSCT_2 and a short interval between alloHSCT_1 and alloHSCT_2. Long-term PFS was observed across all lymphoma subsets except for aggressive B-cell lymphoma. In conclusion, alloHSCT_2 is feasible and can result in long-term disease control in patients with lymphoma recurrence after alloHSCT_1, in particular if relapse occurs late and is chemosensitive.

The aim of this registry-based retrospective study was to analyze the outcome of second alloSCT (alloSCT2) performed in patients with malignant lymphoma who had relapsed after a first alloSCT (alloSCT1).Another purpose was to identify prognostic factors which might influence outcome after alloSCT2. Primary endpoint was disease-free survival (DFS) measured from alloSCT2; secondary endpoints were overall survival (OS), non-relapse mortality (NRM), and incidence of relapse (REL). Eligible were patients >=18 years who were registered within the EBMT and had received an alloSCT2 for relapse of lymphoma between 2000-2011 with a minimum interval of 3 months between alloSCT1 and alloSCT2. Centers with eligible patients were contacted to provide additional treatment and follow-up information. Statistical analysis was descriptive and employed log rank comparisons for univariate assessment of the impact of baseline characteristics on survival endpoints. Results 229 patients were identified who fulfilled the inclusion criteria. Additional information upon center request was provided for 84 them, resulting in exclusion of 19 patients who had been re-grafted for reasons other than relapse. The final study sample of 65 patients had a median age of 39 (18-67) years, a median interval from diagnosis to alloSCT1 of 21 (4-107) months, and a median interval from alloSCT1 to alloSCT2 of 18 (3-169) months. Diagnosis was Hodgkin's lymphoma (HL) in 29%, diffuse large B cell lymphoma (DLCL) in 14%, T cell lymphoma (TCL) in 12%, lymphoblastic lymphoma in 12%, follicular lymphoma (FL) in 11%, mantle cell lymphoma (MCL) in 11%, and other lymphoma in 11% of the patients. Remission status at alloSCT2 was CR/PR in 28% and more advanced in 72%. The same donor was used in 55% of the second allotransplants, whereas an alternative donor was used in 45%. Conditioning was myeloablative in 32% and less intensive in 68% of the alloSCT2 procedures. With a median observation time after alloSCT2 of 73 (13-73) months, DFS, OS, REL, and NRM were 26%, 37%, 55%, and 19% at 2 years; and 19%, 27%, 61%, and 19% at 5 years after alloSCT2. 45 patients died (26 from relapse and 19 from other reasons, mainly multi organ failure due to GVHD, infectious complications or toxicity). 15% of the patients suffered from grade 3/4 acute GVHD. The cumulative incidence of chronic GVHD was 34% at 2 years. Whilst DFS and OS were adversely affected by non-remission at alloSCT2 (p=0.017 and p=0.004) and interval between alloSCT1 and alloSCT2<12 months (p=0.011 and p=0.001; Fig. 1), underlying diagnosis (HL vs. DLCL/FL/MCL vs. TCL) and donor (same vs. alternative donor) had no significant impact. Conclusions Although disease recurrence remains a problem, second allogeneic transplantation is a reasonable option in patients with lymphoma relapse after a first allogeneic transplantation, resulting in long-term remission in a substantial proportion of patients – in particular if the interval between alloSCT1 and alloSCT2 is 12 months or longer. Disclosures: No relevant conflicts of interest to declare.