Donor Lymphocyte Infusions for the Treatment of Relapsed Non-Hodgkin Lymphoma Following Allogeneic Stem Cell Transplantation: A LWP-EBMT Study

Introduction

Relapse of non-Hodgkin lymphoma (NHL) following allogeneic stem cell transplantation (alloSCT) is a common occurrence associated with a poor outcome with limited treatment options. Donor lymphocyte infusions (DLI) are commonly employed in this setting in an attempt to exploit the allogeneic graft versus lymphoma (GVL) effect to induce remissions. There is however a paucity of data describing the efficacy of DLIs in inducing remissions in NHL subtypes and the risk of subsequently developing graft versus host disease (GVHD). We report here the largest series of patients with NHL receiving DLI for relapse after alloSCT.

Methods

Patients relapsing after an alloSCT for NHL and receiving DLI were identified on the EBMT database. Centres were invited to contribute additional data. 118 patients [follicular lymphoma (FL) n=28, diffuse large B cell lymphoma (DLBCL) n=28, T cell lymphoma (TCL) n=52 and mantle cell lymphoma (MCL) n=10] from 39 centres who received DLI as the only treatment for relapse were identified. Patients receiving DLI in combination with other therapy were excluded from this analysis. The median age at alloSCT was 50 (range 18-73) years. There were 81 male and 37 female patients who underwent an alloSCT with reduced intensity (RIC) (n=90) or myeloablative conditioning (MAC) (n=28) at a median of 2.4 (range 0.3-26.3) years from diagnosis. Allogeneic cells were provided from matched sibling (n=63), unrelated (n=47) or mismatched family (n=8) donors and 85 patients received either ATG/ALG or CAMPATH as part of GVHD prophylaxis. The median time from alloSCT to relapse was 3.8 months (range 18 days-67 months).

Results

Patients received a median of 1 (range 1-19) DLI at a median starting dose of 1.5 x10⁶ CD3/kg (range 0.01-120x10⁶ CD3/kg) at a median of 152 days (range 18-2136) post alloSCT. The median last dose of DLI was 10x10⁶/kg (range 0.1-180x10⁶/kg) given at a median of 353 days (range 41-2725) post alloSCT. The median time from relapse to the first DLI was 35 days (range 0-168). Acute GVHD and chronic GVHD prior to DLI was reported in 29% and 14% of patients, respectively. Of 93 evaluable patients 47 (51%) patients achieved a complete remission, 10 (11%) a partial remission, 13 (14%) stable disease and 23 (25%) had progressive disease following DLI. The median duration of response was 36 months (range 1-168). When analysed according to histology the overall response rate (ORR) (CR+PR) for FL was 84% (CR 68%), DLBCL 41% (32% CR), TCL 54% (46% CR) and MCL 86% (CR 71%). The median duration of responses for FL, DLBCL, TCL and MCL were 30 (range 2-150), 38 (4-76), 37 (range 1-168) and 50 months (13-116) respectively. With a median follow up of 77 months after the 1st DLI 36 (31%) patients remain in complete remission, 29 (25%) without any further therapy. 37 (35%) went on to receive additional antilymphoma therapy after the DLI. Of 17 patients with FL achieving a CR post DLI 12 (71%) remain in remission without further therapy at a median of 78 (9-158) months after DLI. Of 18 patients with TCL that achieved a CR with DLI, 15 (83%) remain in remission without further therapy at a median of 95 (range 42-161) months after DLI. Following the DLI 43 (36%) patients developed aGVHD (6 grade I, 13 grade II, 11 grade III, 9 grade IV, 4 grade unknown) and 33 (28%) developed cGVHD (11 limited, 20 extensive, 2 unknown). Following the first DLI the cumulative incidence of relapse was 31% (CI 22-41) at 4 years and of NRM 28% (CI 20-37). The 4-year PFS after 1^st DLI was 39% (CI 30-50) and the OS, 44% (CI 35-54).

Conclusions

DLI induce significant rates of disease response in patients with NHL relapsing after alloSCT providing clear proof of principle of the allogeneic GVL effect. The rates of response are most impressive in FL and MCL. The majority of patients with TCL and FL that achieve a CR post DLI remain in remission with long term follow up. Acute and chronic GVHD is a significant complication of DLI.