Post Donor Lymphocyte Infusion Research Articles

Donor Lymphocyte Infusion (DLI) post allogeneic stem cell transplant (allo-SCT) in Acute Myeloid Leukemia (AML) and High-Grade Myelodysplastic Syndrome (MDS). A longitudinal retrospective study using peripheral blood (PB) CD34+ and CD3+ donor chimerism (DC) monitoring

IntroductionThis longitudinal study was based on the outcomes of Donor Lymphocyte Infusion (DLI) for falling peripheral blood (PB) CD34+ and CD3+ donor chimerism (DC). MethodsFrom 2012 to 2018, data was collected from the BMT database and electronic medical records (EMR). The primary objective was to compare the indication for DLI based on falling PB CD34+ or CD3+ DC in patients post allo-SCT for AML and MDS and their overall survival (OS). Results18/70 patients met the inclusion criteria. Indications for DLI were i) falling PB CD34+ DC ≤ 80 % with morphological relapse, ii) falling PB CD34+ DC ≤ 80 % without morphological relapse and iii) falling PB CD3+ DC ≤ 80 % without falling PB CD34+ DC. Log rank analysis showed falling PB CD34+ DC and morphological relapse had significantly lower OS. Linear regression demonstrated better OS post DLI if there was PB CD34+ and CD3+ chimerism response at 30 days (p = 0.029), GVHD (p = 0.032) and tapering immunosuppression at the time of falling DC (p = 0.042). ConclusionDLI for PB CD34+ DC values ≤ 80 % and morphological relapse had the lowest OS. In this study, full DC was achieved after DLI even with a PB CD3+DC value as low as 13 %, provided the PB CD34+ DC remained > 80 %. Further research is vital in CD34+ DC as a biomarker for disease relapse and loss of engraftment.

Fractionated Gemtuzumab Ozogamicin Followed By Non-Engraftment Donor Leukocyte Infusions for Relapsed/Refractory Acute Myeloid Leukemia

Background: Previous studies have shown durable AML patient responses following donor lymphocyte infusions (DLI) in the absence of engraftment in both the frontline and relapsed setting (Dey et al, BJH 2005, Colvin et al, BBMT 2009, Ai et al, Blood 2010). Herein we report results from the completed dose-escalation phase from our trial of fractionated dosing of gemtuzumab ozogamicin (GO) followed by non-engraftment mismatched allogeneic donor cells infusion in patients with relapsed/refractory (R/R) AML. In this trial, instead of engraftment, it is postulated that donor cells serve as a potent immune stimulator. Study Design and Methods: In this phase I/II study, GO 6-9mg/m 2 total dose was administered as a fractionated 2-3mg/m 2 dose (capped at 4.5mg) on days 1, 4, and 7, followed by infusion of HLA-mismatched (0-3/6 antigens) related donor cells on day 8 [NCT03374332]. The dose-escalation phase 1 cohort used a 3+3 design combining GO with donor leucocyte infusion (DLI) at dose 1-2x10 7 CD3+ cells/kg (Dose Level 1) or 1-2x10 8 CD3+ cells/kg (Dose Level 2). Patients enrolled in the phase II portion were treated at the maximum tolerated dose (MTD) level. Lab correlative studies were drawn pre and post DLI to assess immune effector cells and leukemic blast surface expression as well as cytokine release profiles. Patients 18 years of age and older with histologically confirmed R/R AML who had recurrence or progression after at least 1 prior standard treatment were eligible. Enrollees must have had no active systemic infections and adequate lung, liver, cardiac, and renal function with an ECOG PS 0-1. Patients in CR or CRi after initial treatment could receive up to 2 additional treatments with GO+DLI. Results: Eleven patients (7 men and 4 women) were enrolled into the study. The median age was 72 years (54-81 years) and patients had received 1-4 previous lines of treatment. All patients were refractory to hypomethylating agents and venetoclax. No patient was a candidate for allogeneic stem cell transplant at the time of study enrollment. Ten patients received 3/6 and one patient received 1/6 HLA mismatched donor cells from a first- or second-degree relative. The MTD was determined to be 2x10 8 CD3+ cells/kg. Three patients were enrolled on dose level 1 and eight patients were enrolled on dose level 2. Treatment was well tolerated with minimal Grade 3 or 4 non-hematologic adverse events attributable to the study ( Table 1). One patient at dose level 2 developed septic shock and died prior to DLI while another patient at dose level 2 developed cryptococcal fungemia and died within one week of DLI. No donor experienced a Grade 3 or 4 adverse event. All patients had fever post DLI that fit criteria for Grade 1 or 2 CRS while one patient developed Grade 3 CR. Two patients with Grade 2 CRS and one patient with Grade 3 CRS received tociluzimab. One patient attained a CR after one cycle of GO+DLI. All other patients had progressive disease. Ultimately the study was stopped early due to futility. Median IL-6 and IL-8 levels were higher in the first 3 patients at dose level 2 (605.5pg/mL and 218.5 pg/mL) compared to the three patients in dose level 1 (79pg/mL and 57.8 pg/mL) but the difference was not statistically significant. IL-10 levels were significantly higher in dose level 2 than dose level 1(125 vs 14.8 pg/mL, p=0.05) Conclusions: The MTD of DLI in combination with GO for relapsed/refractory AML patients is 2x10 8 CD3+ cells/kg. Treatment in an older relapsed/refractory population was well tolerated. Patients reliably developed fevers post DLI with Grade1 or 2 CRS. However, there was no evidence that fever development corresponded to a clinical benefit or that the addition of non-engraftment DLI augmented the effect of single agent gemtuzumab. Additional analysis of cytokine release profiles for the remaining patients as well as immune checkpoint inhibition on leukemic blasts for all patients will be presented at the meeting.

Anti α4β7 Integrin Monoclonal Antibody (Vedolizumab) for the Treatment of Steroid-Resistant Severe Intestinal Acute Graft Versus Host Disease

Background: Steroid resistant (SR) acute Graft versus Host Disease (aGvHD) is a life-threating complication of allogeneic- stem cell transplantation (SCT); outcomes in grade III-IV are poor with mortality rates as high as 90%. Vedolizumab (Vd) is a monoclonal antibody inhibiting the binding of integrin α4β7 to Mad CAM -1, consequently impairing homing of T cells to the gastrointestinal (GI) endothelium. It is an approved therapy for inflammatory bowel disease (IBD). Encouraging results were recently reported by Floisand et al., in 6 patients (pts) with SR GI aGvHD (BBMT, 2017). We report a single center experience with the use of Vd in pts with severe SR GI GvHD.Methods: Medical records of 8 pts treated with Vd for SR GI aGvHD were reviewed. SR GI aGvHD was defined as progressive or refractory disease after receiving cyclosporine (CSA) and methylprednisolone (MP) at a dose of 2 mg/kg. Vd was administered at a dose of 300 mg IV, with planned repeated infusion after 2 and 6 weeks. Complete response (CR) was defined as complete resolution of GI aGvHD symptoms , including stopping of analgesics, total parenteral nutrition (TPN), and steroids. Partial response (PR) was defined as improvement in GI GvHD from grade III-IV to grade I-II.Results: Overall, 8 pts were included with a median age of 54 years (range, 21-66). AML was the leading diagnosis (50%). Graft source was peripheral blood in all patients. The majority of pts had HLA matched unrelated donor (5), followed by matched sibling donor (2), and a mismatched unrelated donor (1). Most pts received myeloablative conditioning regimens (6); GvHD prophylaxis included CSA (8) and Methotrexate (MTX) (6) or Mycophenolate Mofetil (MMF) (2). Anti Thyomoctye Globulin (ATG) was given to 7 pts.All pts were diagnosed with GI aGvHD according to clinical manifestations. Colonic biopsies, supporting the diagnosis, were performed in 4 pts. Liver and skin aGvHD was noted in 3 and 4 pts, respectively. Prior to Vd all patients had received IV MP 2mg/kg/day, CSA, oral non-absorbable steroids and MMF. TPN was given to 7 pts. Two patients had developed posterior reversible encephalopathy syndrome and were put off CSA (1 before and 1 after Vd).Five pts developed aGvHD at median of 30 days post SCT, 2 pts at 30 days post-donor lymphocyte infusion (DLI) and 1 pt at 9 months post SCT (30 days following CSA cessation). The majority of pts received only 2 of the 3 doses of Vd (5/8 pts). Two pts experienced multi-organ failure prior to Vd initiation, and died soon after the intervention. Six pts had a clinical GvHD response within a median of 10 days (range, 7-24 days) from Vd first administration. Two pts had CR and 4 PR of the GI aGvHD. Two CR pts were able to be taken off immunosuppression (Table). However, 3/6 pts succumbed to infection complications at median of 7.5 months (range, 2-10 months) post transplantation. Of the two patients in achieving CR of aGvHD, one developed severe neurologic dysfunction with features of Guillain-Barré syndrome and the other succumbed to AML relapse. Following Vd, 5 patients had a CMV reactivation, although 4 had experienced prior reactivations. No other viral infections (EBV, HHV6, HSV, JCV) were observed. Three pts had probable invasive aspergillosis infection and 7 patients had signs consistent with bacterial infections with or without bacteremia.Conclusions: Our data suggest that targeting integrin a4b7 can ameliorate severe SR GI aGvHD. Whether the high infection rates observed following administration are related to Vd or to prolonged immunosuppression is inconclusive. The timing, role and safety of Vedolizumab administration should be further explored in a clinical trial setting. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Elimination of Acute GvHD with Three Doses of Abatacept Prophylaxis Combined with Post-Transplant Cyclophosphamide after Myeloablative Treosulfan-Based Conditioning in the HLA Identical Sibling and Unrelated (10-12/12) Peripheral Blood Stem Cell Donor Setting: Improved Safety and Efficacy Compared to Alemtuzumab Prophylaxis

Background. Acute graft versus host disease (GvHD) remains a major cause of treatment failure post allogeneic stem cell transplantation (HSCT). CD28-CD80/CD86 axis T cell co-stimulation blockade with CTLA4-Ig using abatacept (AB) is an emerging acute GvHD prophylaxis strategy1. After myeloablative conditioning (MAC), together with methotrexate and calcineurin inhibition, four doses of AB commencing day (d)-1 is being investigated in the unrelated HLA 7/8 and 8/8 mismatched/matched donor settings, mostly in children2. It is unknown if AB can be de-escalated in adults to three doses for HLA matched sibling (SIB) or unrelated 10-12/12 donors (MUD), or combined with post-transplant cyclophosphamide (PT-CY) GvHD prophylaxis3, or combined with treosulfan (TREO)-based MAC4, which are other emerging transplant strategies. We investigated the safety and efficacy of this combination, and compared outcomes to a standard anti-CD52 directed IgG1 alemtuzumab (CH) prophylaxis regimen5 in a reduced intensity conditioning (RIC). Methods. We report a single centre consecutive cohort study using peripheral blood stem cells from SIB or HLA 10-12/12 MUDs, for HSCT in adults with blood cancer indications (intuitional registration: 1920-31). One group received AB GvHD prophylaxis while the other group received CH. During 2018-2019, the AB cohort received MAC with IV fludarabine 150 mg/m2, IV TREO 42 mg/m2, and 2 Gy total body irradiation (TBI). GvHD prophylaxis comprised three doses of IV AB 10 mg/kg on d+5, +14, and +28. This was combined with IV PT-CY 50 mg/kg on d+3 and +4, IV tacrolimus 0.03 mg/kg/d infusion from d+5, and IV mycophenolate mofetil 15 mg/kg tds from d+53. The MAC AB cohort was compared to a RIC CH cohort, chosen to be biased against AB. During 2017-2018 the CH cohort received RIC with IV fludarabine 150 mg/m2and IV melphalan 140 mg/m2. GvHD prophylaxis comprised IV CH 10 mg on d-7 to d-3, and IV ciclosporin 1.5 mg/kg bd from d-1. The primary outcome measure was the incidence of acute GvHD6 at d100 and 180 post HSCT. Secondary outcomes measures were the incidence of graft failure, mixed donor chimerism, donor lymphocyte infusion (DLI), CMV reactivation, relapse, overall survival, at d100 and 180. The AB and CH cohorts were indirectly compared. Results. A total of 39 patients were included in this study, with 15 consecutive patients in the AB group (Table). The AB group had a median Karnofsky score of 70% and HCT-CI of 6; significant comorbidity greater than other reports1,2. The major cancer indications were acute leukaemia and myelodysplastic syndrome (MDS). The AB and CH groups were largely balanced. There were no AB related infusion reactions. As expected for MAC, the AB group had a numerically but not clinically significantly slower time to engraftment relative to the RIC CH group. There was no AB group graft failure. Remarkably, the AB group did not experience acute GvHD compared to the CH group by d100 (P=0.03) and d180 (P<0.01). In contrast, by d100, 29% in the CH group experienced acute GvHD after a median of 59 days post HSCT. No AB group patients experienced mixed donor chimerism (P<0.01), nor required a DLI (P<0.01) compared to the CH group, where all had <99% T cell or whole blood values at d100. Consequently, 45% of the CH cohort without acute GvHD were treated with DLI, with all patients experiencing acute GvHD at a median of 39 days post DLI (Table). Other secondary outcomes were similar. The AB group experienced a CMV reactivation rate of 67% in IgG seropositive patients. Unfortunately, 93% of CMV IgG positive patients in the CH group experienced CMV reactivation. No relapses were observed by d180 in the AB group, whereas in the CH group, 8% of patients experienced relapse. Mortality at d180 was 20% in the MAC AB group, and 21% in the RIC CH group. Conclusions. Acute GvHD prophylaxis with only three doses of AB and PT-CY post TREO-based MAC appears to be safe and efficacious in the SIB and MUD settings, in a highly co-morbid adult blood cancer population. This AB approach seems favourable compared to CH despite RIC, where acute GvHD without DLI or post DLI remains significant. A prospective multicentre clinical trial with AB in this setting seems warranted to confirm these remarkable findings of patient benefit. References. 1. Biol Blood Marrow Transplant (BBMT) 2013;19:1638-49. 2. NCT01743131. 3. Lancet Haematol 2019;6:e132-43. 4. Cancer 2017;123:2671‐79. 5. BBMT 2017;23:805-12. 6. BBMT 2016;22:4-10. Table Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Abatacept, alemtuzumab, cyclophosphamide all the for the indication of graft versus host disease (GvHD) prophylaxis.

A High Dose of Naïve CD8+ T-Cells Increases the Incidence of Graft-Versus-Host Disease (GvHD) after Donor Lymphocyte Infusions (DLIs) from HLA Identical Sibling Donors

Introduction DLIs represent a major therapeutic approach for relapse and mixed chimerism (MC) after allogeneic hematopoietic cell transplant (AlloHCT). DLI studies have identified several variables with impact on response and GvHD. Despite some studies having explored the role of T-cells and other cell subsets, such as mononuclear cells (MNCs), comprehensive data regarding the cellular composition of DLI and its role in GvHD remains incomplete, as the development of GvHD post DLI is often unpredictable. Herein we analyzed the cellular composition of DLI from fully human leukocyte antigen (HLA) identical sibling (HLA Id Sib) donors and its impact on the development of GvHD in patients who underwent AlloHCT for hematological malignancy, and its impact on the development of GvHD. Methods Inclusion criteria were as follows: 1) Patients ≥ 18 years-old, 2) AlloHCT, 3) HLA Id Sib donor; 4) treatment with DLI; and 5) signed informed consent of patient and donor. Exclusion criteria were: 1) unrelated or mismatched related donors, 2) HCT2 prior to DLI, or 3) GvHD at DLI. For the purpose of avoiding bias, only the cell composition of the first DLI (DLI1) was analyzed. The following cell subsets of the DLI were studied: CD3+, CD4+, CD8+, CD16+CD56+CD3+ (NKT-cell), CD3+CD45RA+CCR7+ (TN), CD3+CD45RA+CCR7+CD31+ (TRTE), CD3+CD45RA+CD95+CD27+ (TSCM), CD3+CD45RA-CCR7+ (TCM), CD3+CD45RA-CCR7- (TEM), CD3+CD45RA+CCR7- (TTE), CD3+CD4+CD25brightCD127dim (TREG), CD3+CD4+CD25brightCD45RA+CD127dim (naïve TREG). The TN, TCM, TEM and TEM compartment was analyzed for both CD4+ and CD8+. We also analyzed the MNCs, CD19+ (B-cell), CD27+CD19+ (mature B-cell), CD16+CD56+CD27- (natural killer (NK+) cell) and CD16+CD56+CD27+ (CD27+NK+cell). Results Fifty-six DLIs were infused in 36 patients; the median number of DLI was 1 per patient (range, 1-3). Diagnoses were as follows: 13 AML/MDS, 6 HL, 5 MPN, 4 NHL, 4 CLL, 3 MM and 1 B-ALL. For the study, a landmark analysis was performed from the DLI date. The median follow up from DLI was 282 days (range, 9-5,560 days). Overall response rate in relapsed patients was 29% (9 of 31 patients; 6 CR and 3 PR, most responses being observed after DLI1. Further, five patients had DLI for MC and full donor chimerism was achieved in all patients. Thirteen patients (36%) developed GvHD post DLI. Two patients had GvHD before DLI, but there was no case of GvHD at DLI. The median time interval form DLI to GvHD was 76 days (range, 7-261). As per clinical presentation, 10 patients (27%) had acute GvHD, whereas eight patients (22%) had chronic GvHD. The 6-month and 1-year cumulative incidence (CI) of GvHD was 33% and 46%, respectively. When the risk of GvHD was analyzed according to DLI cell subsets, we observed that a DLI1 containing >3x106 CD8+TN correlated with an increased incidence of GvHD (Figure 1a). Also, a DLI1 with >0.8x108 MNCs/Kg (Figure 1b), >2.6x106 mature B-cell/Kg, or >0.35x106 CD27+NK+cells/Kg were linked to the development of GvHD (Table 1). Noteworthy, CD3+, TN (both CD4+ and CD8+ combined) or CD4+TN had no impact on the development of GvHD; and a high proportion of TREG was not protective for the development of GvHD (Table 2). Finally, there was no statistically significant association between any clinical variable and GvHD. Conclusion In conclusion, in this cohort of AlloHCT patients from HLA Id Sib donors, a DLI1 containing a high proportion of CD8+TN, but not CD4+TN, increased the probability of developing GvHD. Further, a DLI1 containing a high dose of MNCs, CD27+NK+cells and mature B-cell also associated with GvHD. These data provide novel insight for the understanding of GvHD post DLI. A DLI1 containing a lower dose of CD8+TN could reduce the risk of GvHD, but this asset warrants further validation in larger cohorts, and within a controlled randomized trial setting. Disclosures Bosch: F. Hoffmann-La Roche Ltd/Genentech, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Efficacy and Toxicity of Donor Lymphocyte Infusions in the Management of Mixed Donor-Recipient Chimerism Following Allogeneic Stem Cell Transplantation for Lymphoid Malignancies:- a Study of the LWP-EBMT

Efficacy and Toxicity of Donor Lymphocyte Infusions in the Management of Mixed Donor-Recipient Chimerism Following Allogeneic Stem Cell Transplantation for Lymphoid Malignancies:- a Study of the LWP-EBMT

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

IntroductionRelapse 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.MethodsPatients 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).ResultsPatients 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 1st DLI was 39% (CI 30-50) and the OS, 44% (CI 35-54).ConclusionsDLI 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. DisclosuresRobinson:Sandoz: Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau. Chalandon:Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel costs. Beelen:Medac: Consultancy, Other: Travel Support. Finke:Neovii: Consultancy, Honoraria, Other: travel grants, Research Funding; Medac: Consultancy, Honoraria, Other: travel grants, Research Funding; Riemser: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Other: travel grants, Research Funding. Tischer:Jazz Pharmaceuticals: Other: Jazz Advisory Board. Corradini:Amgen: Honoraria, Other: Advisory Board & Lecturer; Novartis: Honoraria, Other: Advisory Board & Lecturer; Abbvie: Honoraria, Other: Advisory Board & Lecturer; Sandoz: Other: Advisory Board; Sanofi: Honoraria, Other: Advisory Board & Lecturer; Gilead: Honoraria, Other: Advisory Board & Lecturer; Takeda: Honoraria, Other: Advisory Board & Lecturer; Roche: Honoraria, Other: Advisory Board & Lecturer; Janssen: Honoraria, Other: Lecturer; Celgene: Honoraria, Other: Advisory Board & Lecturer.

Donor-lymphocyte infusion following haploidentical hematopoietic cell transplantation with peripheral blood stem cell grafts and PTCy.

Donor-lymphocyte infusion (DLI) for relapse following haploidentical hematopoietic cell transplantation (haploHCT) with post-transplant cyclophosphamide (PTCy) has been described in recipients of bone marrow grafts, but not recipients of G-CSF mobilized peripheral blood (PB) grafts. We retrospectively identified patients who underwent DLI following PB-haploHCT with PTCy for relapse, or loss of chimerism (LOC). Twelve patients (57%) received DLI for hematologic relapse/persistent disease, seven (33%) for extramedullary relapse and two (10%) for LOC. Sixteen (76%) received chemotherapy prior to DLI, which did not correlate with response. The most common first dose was 1 × 106 CD3+ cells/kg. Two patients developed grade I aGvHD post DLI, one had grade II and two had grade III. One developed mild skin cGvHD 1361 days post DLI. Pre-DLI aGvHD predicted post-DLI aGvHD (P=0.025). Six patients achieved CR after DLI for overt relapse, one achieved full donor chimerism after LOC. Patients with LOC or EM relapse had superior relapse-free survival following DLI (P=0.029). DLI following PB-haploHCT with PTCy is a viable salvage therapy for overt relapse or LOC without a substantial increase in GvHD, and donor lymphocytes may be collected simultaneously with graft collection to facilitate availability in patients at high risk of relapse.

Donor Lymphocyte Infusions for Haematological Malignancy Relapse

Donor lymphocyte infusions (DLI) are a therapeutic approach broadly used in relapse post Allogeneic Hematopoietic Cell Transplant (Allo-HCT). In CML relapse, DLI have proven very effective, but in other hematological malignancies its effectiveness has been reported rather erratic and poor; hence the need of a better understanding of factors influencing outcomes. Questions regarding the CD3 dose, the use of G-CSF mobilized DLI or the potential toxicity associated to the use of DLI from mismatched donors remain open.We report a cohort of 66 patients who, within a cell therapy program (Banc de Sang i Teixits, Barcelona), consecutively underwent allo-HCT and received DLI for relapse. Disease diagnosis was as follows: Lymphoproliferative malignancy (LPD) 29 patients AML and high-risk MDS 24 patients and ALL 13 patients (CML patients were not included). Median age at allo-HCT was 48 years (5-68). The combination female-donor and male-patient was 21%. 27% allo-HCT were T-cell depleted and 29% received a myeloablative conditioning regimen. Immunosupression was CsA-based in 83% of the allo-HCT. Transplants from HLA fully match donors were 54 (81%) and 19% were from mismatch donors. Indication for DLI was morphological relapse in 61 patients (92%) and disease detected by flow cytometer or at a molecular level in 5 patients (8%). 32 (48%) DLI were obtained at stem cell collection day (G-CSF mobilized) and cryopreserved, whereas 34 (52%) DLI were obtained by lymphapheresis.The median follow-up was 198 days (9-4246). The estimated 1-year OS was 60%. A total of 100 DLI were infused, with a median of 1.5 DLI/patient and a median time from allo-HCT to DLI of 303 days (70-5153). Median CD3+ total dose was 2x107 CD3+/Kg (first DLI median dose was 1x107 CD3+/Kg). The time interval from allo-HCT to DLI ≥10 months (Log-Rank 3.64, p=0.056) was associated to better survival. In line with this, there was a trend in patients relapsing ≥ 9 months post allo-HCT (median relapse date) for better survival (Log-Rank 3.33, p=0.068). Twenty-six patients (42%) developed GvHD post-DLI. In 17 patients overall grade was 2-4, which was not associated to poorer outcome. Lately, 8 patients developed extensive chronic GvHD. The development of chronic GvHD was associated to a better survival (Log-Rank 6.07, p=0.014). A total dose ≥1x107CD3+/Kg was associated to a better survival (Log-Rank 4.78, p=0.029) compared to total lower doses. The achievement of complete remission post DLI was also associated to better OS (Log-Rank 4.54, p=0.33). Ten patients died due to non-relapse mortality causes and twenty-seven due to disease progression. Of interest, we found a trend on outcomes when using non G-CSF mobilized DLI compared to-G-GCF mobilized DLI (Log-Rank 2.65, p= 0.104). However, the administration of a pre DLI debulky therapy was not associated with better outcomes. Variables with p<0.1 were included in the multivariate analysis, which identified the achievement of CR post DLI (p=025), chronic GvHD (p=0.026), total dose ≥1x107CD3+/Kg (p=0.026) and time from allo-HCT to DLI ≥10 months (p=0.026) associated to a better OS.Overall, this study reports a poor prognostic cohort, in which the vast majority had a post allo-HCT morphological relapse. In this group, patients treated with DLI can have a prolonged survival by achieving CR. Additionally, the survival appeared to be DLI dose-dependent, since patients receiving doses ≥1x107CD3+/Kg had better OS. Additionally, the development of chronic GvHD was associated to a better OS.Fig 1. OS according to the total CD3 dose infusedFig 2. OS according to the development of chronic GvHDFig 3. OS according to the response post DLI. DisclosuresNo relevant conflicts of interest to declare.

Efficacy and Toxicity of Donor Lymphocyte Infusions in Relapsed Acute Myeloid Leukemia Post Allogeneic Hematopoietic Cell Transplantation: Single-Center Experience

Introduction: Allogeneic hematopoietic cell transplantation (alloHCT) is a potentially curative treatment in acute myeloid leukemia (AML) and is pursued as a means to decrease the hazard of relapse. However, relapse of the underlying disease following both conventional and reduced intensity HCT still remains an unresolved problem highlighting the necessity to investigate novel and different approaches to target it. Over the last decades, Donor Lymphocyte Infusions (DLIs) have been proposed as a major immunotherapeutic strategy in relapsed patients. In the era of emerging modified immunological approaches, efficacy and toxicity of DLIs remain to be clarified. The present retrospective analysis aimed to assess efficacy and toxicity of DLIs in relapsed AML patients post alloHCT.Methods: We retrospectively studied relapsed patients undergone alloHCT for AML between January 1990 and June 2016. Until 2007, our center’s immunotherapeutic strategy consisted of immediate cessation of immunosuppression, administration of IL-2/ΙFNa-2β if chimerism reduction was evident and escalated doses of DLIs depending on the time period and the donor type (sibling or unrelated). Since then, we have stopped the administration of immunomodulatory agents due to inefficacy and complications shown in interim analysis.Results: In total, 266 AML patients underwent transplantation from 162 identical sibling, 8 relative, 8 haploidentical, 88 matched unrelated donors; 89 patients relapsed. Fifty two patients aged 40 (range 7-63) years old received DLIs. They had received peripheral (47) or bone marrow (5) grafts, post myeloablative (44) or reduced intensity (8) regimens. Twenty out of 52 patients were transplanted in complete remission and 32 in relapsed or refractory disease. Their donors were identical siblings (42), matched unrelated(5), non-identical siblings (3) and haploidentical donors (2). With a median follow-up of 11.8 (2.6-181) months, relapse was documented 4.6 months (0.4-28.5) post alloHCT. The majority of patients (45) received induction and/or salvage chemotherapy or azacytidine because of morphological remission (blasts ≥ 20 %). Twenty four patients received chemotherapy and cryopreserved graft infusion, with a dose of CD34+>1×106/kg body weight, to prevent neutropenia. Median DLIs were 2 (1-6) and CD3+ were 1.9 (0.5-4.5) x108/kg in sibling and 0.9 (0.5-1.43) x106/kg in unrelated transplants. Second transplant from the original relative donor (1 bone marrow /2 peripheral blood grafts) was performed in 3 patients early after first HCT (5-9 months) but it failed due to disease progression. Complete remission was observed in 17 patients (34%); whereas acute graft-versus-host-disease (GVHD) in 27 patients (52%) and chronic in 13 patients (25%). In total, 43 patients died; 35 of disease, 6 of DLI-related mortality and 2 of other causes. One-year Disease-free survival (DFS) post DLIs was 50% and 2-year 34.4%. The presence of GVHD was associated with higher DFS (74% vs 4%, p=0.015). In multivariate analysis, independent favorable factors for higher DFS were the presence of GVHD (p<0.001/beta=4.086), the myeloablative conditioning (p=0.011/beta=3.087) and the longer time to relapse (p=0.004/beta=0.921). No association with survival was found for the other factors studied (age, gender, disease phase, type of transplant and donor, HLA histocompatibility).Conclusion: Our experience of more than 2 decades with DLIs aiming at improving disease free survival and lowering relapse has shown acceptable toxicity and efficacy of immunotherapy in relapsed AML patients. We have also demonstrated the favorable impact of the graft-versus-leukemia effect that was shown to be stronger with myeloablative conditioning and the presence of GVHD. Despite encouraging results, there is an emerging need of alternative strategies. Systematic prophylactic use of DLIs may be useful, but should be balanced against the risk of severe or fatal GVHD. Furthermore, early administration of biologically targeted therapies, may be an attractive treatment in certain specifically defined subgroups of patients. In this context, the innovative strategies would be ideally more effective and less toxic in treatment of relapse. DisclosuresNo relevant conflicts of interest to declare.

Outcomes and Impact of Donor Lymphocyte Infusion after Reduced Intensity Conditioned-Alemtuzumab Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Mature Lymphoid Malignancies

Allogeneic hematopoetic stem cell transplantation (allo-HSCT) offers long-term remission for patients with lymphoid malignancies. In particular, reduced intensity conditioned (RIC) protocols with Alemtuzumab T-cell depletion lead to durable engraftment and reduced graft versus host disease (GvHD). However, such regimens may be associated with reduced graft-versus-lymphoma (GvL) effect and higher incidence of disease progression, leading to increased use of donor lymphocyte infusion (DLI). This study examined transplant outcomes and use of DLI in a large UK RIC-Alemtuzumab conditioned HSCT cohort.288 consecutive adult patients from three UK transplant centres (Birmingham, Glasgow, Oxford) undergoing first Alemtuzumab-based RIC HSCT for Hodgkin's lymphoma (57%), Non-Hodgkin's lymphoma (24%) and chronic lymphocytic leukemia (19%) between 2000 and 2012 were included. Overall survival (OS), current progression-free survival (CPFS), relapse incidence (RI), transplant-related mortality (TRM), incidence of GvHD and effects of DLI were analyzed.Median age was 49y (range 17-68) and 60% were male. Patients were heavily pre-treated with 58% having received ≥3 prior lines of treatment and 49% having failed a previous autograft. 55% received stem cells from an HLA-matched unrelated donor and 94% received a peripheral blood stem cell harvest. The most frequent conditioning regimen was Fludarabine, Melphalan and Alemtuzumab (FMC) (70%) and the median total Alemtuzumab dose was 50mg (range 30-100). Median duration of follow-up for survivors was 64 months.3y OS and CPFS were 53% and 50%, respectively. Factors negatively associated with OS in univariate (UV) analysis were previous autograft (p=0.01), no requirement for DLI (p=0.05), disease status not CR (p=0.05), previous treatment number ≥3 (p=0.007) and failure to engraft plts (p=0.001). On multivariate (MV) analysis, only previous autograft (HR 1.58 p=0.01) and failure to engraft plts (HR 2.3 p=0.0001) retained significance. Factors negatively associated with CPFS on UV analysis were no requirement for DLI (p=0.006), failure to engraft plts (p=0.0003) and previous treatment lines ≥3 (p=0.04). On MV analysis, no DLI remained a significant predictor of adverse CPFS (HR 1.8 p=0.01), as did failure to engraft plts (HR 1.77 p=0.005) and ≥3 treatment lines (HR 1.46 p=0.04).At 3y, the cumulative incidence of relapse and TRM was both 27%. The incidence of grade 2-4 acute GvHD (aGvHD) and extensive chronic GvHD (cGvHD) was 22% and 18%, respectively. UV predictors of RI were unrelated donor (p=0.0009), HLA mismatch (p=0.04), age > median (p=0.04) and lack of aGvHD (p=0.04). The presence of cGvHD may have been protective against relapse (p=0.08). No variables retained significance on MV modelling. UV predictors of TRM were failure to engraft plts (p=0.001), HLA mismatch (p=0.005), age > median (p=0.004), previous autograft (p=0.02), FMC conditioning (p=0.03), ≥3 previous lines of treatment (p=0.001) and development of aGvHD (p=0.04). On MV modelling, failure to engraft plt (p=0.001), HLA mismatch (p=0.03), age > median (p=0.003) and treatment number ≥3 (p=0.04) retained significance.62/288 patients received DLI; 37 receiving prophylactic DLI (pDLI) for mixed chimerism and 25 receiving therapeutic DLI (tDLI) for disease relapse. The median dose of DLI was 1x 10^6 CD3+ cells/kg (range 0.1 - 10 x 10^6). Median time from HSCT to first DLI was 10.5 months (range 3-30), to 2nd DLI 15 months (6-51) and to 3rd DLI 19 months (9-30). At 3y, OS after pDLI was 75% and after tDLI was 29%. 29/37 (78%) of pDLI and 14/25 (56%) of tDLI recipients achieved full or stable mixed chimerism. 3y RI after pDLI was 29% and after tDLI was 59% (p=0.02). Overall, the incidence of GvHD post-DLI was 32% (48% tDLI, 22% pDLI, p=ns). Median time to GvHD after last DLI was 46 days (range 17-249). There was no significant impact of post-DLI GvHD on RI (RI at 1y post DLI 18% in GvHD cohort vs 21% with no GvHD, p=ns), but GvHD increased TRM at 1y post DLI (17% in the GvHD cohort vs 3% with no GvHD, p=0.05).This is the largest series to date with long-term follow-up examining outcomes after Alemtuzumab-based RIC HSCT for mature lymphoid malignancy. Our data indicate that allo-HSCT is effective and is associated with good long term outcomes. Use of pDLI for was associated with excellent outcomes and supports use of DLI in patients developing mixed chimerism following allo-HSCT for lymphoid malignancies. DisclosuresNo relevant conflicts of interest to declare.

Phase I study of azacitidine following donor lymphocyte infusion for relapsed acute myeloid leukemia post allogeneic stem cell transplantation

Donor lymphocyte infusion (DLI) without prophylactic immunosuppression has been used for relapsed AML after allogeneic stem cell transplant (allo-SCT). However DLI is associated with an increased incidence of acute Graft vs. Host Disease (aGVHD). In mice, administration of azacitidine (AzaC) on days 4, 6, 8, and 10 post DLI increases regulatory T cell (Treg) numbers and prevents GVHD without hindering Graft vs. Leukemia (GVL). Based on these findings, we conducted a phase 1 study of AzaC post DLI for AML relapse post allo-SCT. AzaC was administered on days 4, 6, 8 and 10 post-DLI. Dose escalation was done using a 3+3 design with three AzaC dose levels: 30mg/m2 (level −1), 45mg/m2 (level 1) and 75mg/m2 (level 2). Three patients were treated in the 45mg/m2 dose level and 5 patients were treated in the 75mg/m2 dose level; no DLTs or grade 3–5 treatment related toxicities were observed. After a median follow-up of 5.2 months, no patients developed grade III–IV aGVHD and no patients died of aGVHD. Six out of 8 patients in the treatment group responded to treatment including two cytogenetic complete remissions, one hematologic complete remission, and three complete remissions with incomplete count recovery. In conclusion, administration of AzaC early post DLI is well tolerated and can potentially prevent GVHD after DLI. Further studies are required to evaluate the effect of azacitidine early post DLI on GVHD and GVL.

Extracorporeal Photopheresis As Second Line Therapy for Steroid Refractory Acute Gvhd: Retrospective Study of Long-Term Outcomes

IntroductionUp to 50% of patients with acute GVHD (aGVHD) have a suboptimal response to first line therapy with corticosteroids. Extracorporeal photopheresis (ECP) is one of the recommended second line options. Overall response rates of 60-77% have been reported with ECP as second line therapy for aGVHD. Factors associated with lower response and survival were Grade >II at onset and number of organs involved. In a large retrospective study of ECP as second line therapy, 19.5% of patients developed chronic GVHD (cGVHD). Previous studies have included small numbers of patients with aGVHD post T cell depleted transplants or Donor Lymphocyte Infusion (DLI).MethodsWe conducted a retrospective analysis of outcomes in 40 patients treated with ECP for steroid refractory or steroid dependent aGVHD at 2 UK transplant centres. The aim was to analyse overall survival and long-term outcomes. All patients received 2-3 treatments per week for 8 weeks after which schedules differed according to centre, cessation or gradual taper.ResultsBetween 2006 and 2014, 44 patients had received ECP as second line therapy, 4 were excluded from analysis as they had received less than 4 treatments. The median age was 51years (21-67years). Table 1 illustrates details of conditioning and GVHD prophylaxis. Thirty percent of patients were post DLI: 5 (12.5%) for disease relapse and 7 (17.5%) for mixed chimerism. Transplant conditioning included T cell depletion in 24 (60%): alemtuzumab n=17, ATG n=7. The median duration of steroids pre-starting ECP was 18 days (range 5-56). Using Modified Glucksberg crtieria at the onset of ECP, 5 patients (12.5%) had Grade II, 30 (75%) Grade III (including 6 with stage 4 gut) and 5 (12.5%) Grade IV aGVHD. Nine patients (22.5%) had 1 organ involvement and 31 (77.5%) had 2 or more organs involved. The dominant organ was gut in 21 (52.5%), liver in 10 (25%)and skin in 9 (22.5%). Maximal response rates were CR 57.5%, PR 27.5% and NR 15%. A number of patients received additional immunosuppressive therapy, predominantly anti-TNF antibodies: 14 patients (35%) (etanercept n=11, infliximab n=3).Using Kaplan-Meier analysis, censoring at last follow up, the overall survival from start of ECP at 5 years was 45.1% (95% CI 31.85-63.04%) Figure 1. The median survival was 2 years (27days-7.8yrs). In the DLI group, the 5 year overall survival was 59.8%. In a subgroup log rank Mantel-Cox analysis no significant difference was observed in the 5 year overall survival according to dominant organ involved: 53% skin, 40.6% gut and 50% liver (p=0.77) Figure 2.The cumulative incidence of death was 57.5% (23patients). The leading cause of death was infection 13/23 deaths (56.5%) followed by 5 deaths due to GVHD, 4 due to relapse, 1 from unrelated causes.The incidence of chronic GVHD was 55%. Treatment for cGVHD varied with 8 patients continuing ECP >12 weeks on a tapering schedule, 2 patients restarting ECP for cGVHD and the others receiving a variety of therapies including MMF, tacrolimus, Rituximab and imatinib. At last follow up, 17 patients were alive, 9 were off immunosuppression (2 of whom had not developed cGVHD) and 8 were still on immunosuppression. The performance status in the 17 surviving patients was ECOG 0= 8, 1=8 and 2=1.DiscussionOur study shows an encouraging 5 year overall survival of 45.1% in a cohort with predominantly severe Grade III aGVHD. The 5 year survival was higher in the DLI group at 59.8%. Fifty three percent had stage 3-4 gut involvement, which is a recognised poor risk feature. Infection was the leading cause of death, which is of particular relevance in the T deplete setting. Whilst 55% developed cGVHD, over a long follow up period (median of 4years), the cGVHD resolved and performance status was preserved in most of the surviving patients. The incidence of cGVHD was higher than in other studies but the patients had higher grade of aGVHD at onset, were older and had multi-organ involvement. These findings need to be confirmed in prospective studies.Table 1Pretransplant CharacteristicsNo. of patients (%)Conditioning RegimesMyeloablative10 (25%)Non-myeloablative18 (45%)Total post DLI12 (30%)T cell depletion24 (60%)Alemtuzumab17 (42.5%)ATG7 (17.5%)GVHD prophylaxisCsA20 (50%)CsA/MTX9 (22.5%)CsA/MMF Tacro/MMF8 (20%) 3 (7.5%)Donor SourceMatched sibling Matched unrelated donor 10/10 9/10 8/10 Double Cord9 (22.5%) 21 (52.5%) 3 (7.5%) 1 (2.5%) 6 (15%) [Display omitted] [Display omitted] DisclosuresRadia:Therakos: Other: ASH travel expense, Speakers Bureau. Off Label Use: Extracorporeal Photopheresis (ECP) is not licensed for use in GVHD but is recommended in international guidelines as a therapeutic option.. McLornan:Novartis: Research Funding, Speakers Bureau. Russell:Therakos: Other: shares.

Brentuximab Vedotin in Combination with Donor Lymphocyte Infusion for Patients with Hodgkin Lymphoma Relapsing after Allogeneic Stem Cell Transplantation

▪IntroductionBrentuximab Vedotin (BV) has recently received approval for treatment of Hodgkin lymphoma (HL) relapse after auto-SCT. Although BV is very effective in treating relapse of HL post auto-SCT, response is usually transient. In contrast, there is a paucity of data regarding the efficacy and safety of BV, combined or not with donor lymphocyte infusion (DLI), for the treatment of relapse occurring after allo-SCT.MethodsSearch for patients (pts) with relapsed HL post allo-SCT was performed in our transplant data set with the aim to evaluate the efficacy and safety of BV in combination with DLI for the treatment of relapsing HL post allo-SCT. Eight pts with relapsed HL after allo-SCT that were treated with BV were included in this report.ResultsPatients and treatment: There were 6 males and 2 females, with a median age of 31 years (range, 23 - 40), who had previously failed an auto-SCT. Five pts had previously received BV after auto-SCT and all but one responded to treatment. All pts had chemosensitive disease before allo-SCT and were transplanted in a state of partial remission (PR). The graft source was unmanipulated peripheral blood stem cells from a matched related or an unrelated donor in 5 and 2 pts, respectively, while 1 pt received a double umbilical cord blood graft (DUCB). Five pts achieved complete remission (CR) and one PR after allo-SCT, while 2 pts had progressive disease (PD). Disease progression occurred in a median of 11 months (range, 4 - 17) after allo-SCT. All pts received BV at a dose of 1.8mg/kg every 3 weeks for a maximum of 16 doses, till disease progression or toxicity. In two pts chemotherapy was administered before BV. A median of 4.5 (range, 3 -12) BV cycles was administered. DLI was co-administered in 5 out of 7 pts (excluding one patient who received DUCB). Decision for DLI was at the discretion of the treating physician. One pt received 4 DLIs at escalating doses (5x106, 107, 5x107, 108/kg), while another one received 2 escalating DLIs (107, 108/kg) at 3 months interval. Three pts received a single DLI (107/kg).Treatment outcome: Three and two pts achieved CR and PR respectively after treatment with BV in combination with DLI. None of the pts treated only with BV responded. Four out of 5 pts developed GVHD (3 chronic, 1 acute) post DLI administration, that resolved in all cases after a short course of low dose steroids. Disease progression was observed in 3 out of 5 responders in 4, 7 and 9 months, while 2 pts remain progression free with a median follow up of 14,5 (range, 4 - 22) months. Six out of 8 pts are alive, while 2 pts died from HL. BV/DLI treatment was well tolerated and no serious adverse effects were observed in any of the patients.ConclusionsIn our study, we observed that administration of BV with DLI for HL relapsing post allo-SCT in pts with prior failure to auto-SCT was effective while toxicity was minimal. Notably, re-administration of BV to pts previously treated for post auto-SCT relapse did not result in additional toxicity or resistance. Furthermore, BV combined with DLI, but not BV alone, yielded anti-tumor response in 5/7 of these very high risk pts suggesting a possible synergistic effect. Of notice is the observation that one pt who was refractory to BV post auto-SCT, had a PR after re-administration of BV post allo-SCT. Our observations are in accordance with the results of a previous report, showing that BV plus DLI after allo-SCT creates a vaccination like-effect against HL [1]. Finally, in our study we observed lower than expected frequency of GVHD post DLI that was of transient duration and easily manageable with low dose steroids. We assume that this may be due to an immune-modulating effect produced by BV. Indeed previous studies have shown that CD30 is expressed on the surface of activated T-cells present in inflammatory infiltrates of GVHD lesions [2]. Administration of BV plus DLI should be tested in larger group of patients at high risk of relapse after allo-SCT.

A Multicentre Retrospective UK Study Detailing Onset Of Graft Verus Host Disease, Responses To Treatment and Outcome After Donor Lymphocyte Infusion Following Haemopoietic Stem Cell Transpantation: Rates Of GVHD Are High But Death From GVHD Infrequent

A Multicentre Retrospective UK Study Detailing Onset Of Graft Verus Host Disease, Responses To Treatment and Outcome After Donor Lymphocyte Infusion Following Haemopoietic Stem Cell Transpantation: Rates Of GVHD Are High But Death From GVHD Infrequent

A Comparison Of Long-Term Outcomes Of Donor Lymphocyte Infusions and Tyrosine Kinase Inhibitors In CML Patients Relapsed After Allogeneic Hemopoietic Stem Cell Transplantation

Abstract 5501Relapse is a major cause of treatment failure of allogeneic hematopoietic cell transplantation (HCT) for Chronic Myeloid Leukemia (CML). DLI (Donor lymphocyte infusion) and TKI (Tyrosine Kinase inhibitors) are the two standard treatment options in this setting but reports comparing their long-term outcomes are scarce.Between 1993 and 2012, 28 patients underwent DLI and 18 patients received TKI for chronic or advanced phase relapse of CML at our institution. Chronic hematologic, cytogenetic and molecular relapses were considered as chronic phase relapses. Accelerated phase and blast crisis relapses were considered as advanced phase relapses. Overall survival (OS), failure free survival (FFS) and cumulative incidence of failure (CIF) were analyzed retrospectively and for these analyses, failure was defined as lack of response, relapse or intolerance requiring change in treatment. This study had Institutional Research Ethics Board approval.Among18 patients treated with TKI, 15 patients received imatinib, 2 received dasatinib and 1 received nilotinib as the first line treatment. In DLI group, number of infusions per patient ranged between 2 and 4. Patients in the DLI group were more likely to be transplanted during the 1st chronic phase of disease (86% vs. 56%, p=0.008), with bone marrow stem cells (100% vs. 56%, p=<0.0001) and less likely to have pre-HCT tyrosine kinase inhibitor treatment (0% vs. 33%, p=0.002). Patients in the TKI group are more likely to be treated during advance phases of relapse (39% vs. 7%, p=0.018). Type of donor, age at stem cell transplant or relapse and prior acute or chronic GVHD were not different between the groups. No patients received reduced intensity conditioning or T-cell depleted grafts.64% of patients treated with DLI and 83% treated with TKIs achieved complete molecular response (CMR). 21% of patients initially treated with DLI required further treatment with TKIs after a second relapse. In the TKI group, no patients were later treated with DLI, but one required a change from imatinib to dasatinib due to intolerance. The incidences of treatment failures in DLI and TKI groups were 43% and 28% respectively.At a median follow up of 146 (range, 40-220) and 70 (range, 9-139) months respectively, 9 (32%) in the DLI group and 6 (33%) in TKI group have died. when chronic phase relapses were analyzed separately 7 (21%) in the DLI group and none from the TKI treated group have died. Mortality was higher in advanced phase relapses with 2 (100%) patients in the DLI group having died without achieving any response, and in the TKI group; 4 (57%) patients achieved CMR but eventually 6 out of 7 (86%) patients have died at a median time of 9 (3-114) months.In multivariable analysis, advanced phase of relapse was associated with shorter OS (HR=109.7; 95% CI, 12.2-985.3; p= <0.0001), shorter FFS (HR = 82.3; 95% CI, 7.1-956.5; p =0.0004) and higher CIF (HR= 67.9; 95% CI, 6.9-669.8; p=0.0003). Comparing treatment with TKI, treatment with DLI was associated with an inferior OS (HR =37.4; 95% CI, 2.2-625.4; p=0.01), shorter FFS (HR =21.15; 95% CI, 1.8-251; p=0.02) and higher CIF (HR =19.5; 95% CI, 1.6-236.5; p=0.02). Prior acute GVHD grade 2-4 was associated with higher CIF (HR=3.3; 95% CI, 1.15-9.2; p= 0.03), but there was no effect on OS and FFS. Prior chronic GVHD, age at relapse treatment, and time from stem cell transplant to relapse treatment and year of relapse treatment were not found to be significant factors.New onset or worsening of GVHD was significantly higher in the DLI group (68% vs. 6%, p=0.001). Among the patients treated with DLI, development of post DLI GVHD was associated with better OS (HR=0.26; 95% CI, 0.07-0.99; p=0.048), FFS (HR=0.3, 95% CI, 0.11-0.88; p=0.027) and lower CIF (HR=0.32; 95% CI, 0.1-0.96; p=0.04). Prior history of chronic GVHD was associated with higher FFS in DLI treated patients (HR=0.3; 95% CI, 0.1-0.89; p= 0.03), but did not have significant effect on OS (HR=0.32, 95% CI, 0.08-1.3; p=0.1) or CIF (HR=0.43; 95% CI, 0.143-1.28; p=0.13).In conclusion, TKIs appears better than DLI in CML patients who had relapsed in chronic phase after myeloablative T-cell-replete HCT. Outcomes were poor in advanced phase relapses irrespective of modality and novel strategies need to be explored in this group of patients. Disclosures:No relevant conflicts of interest to declare.

Pre-Emptive Donor Lymphocyte Infusions (DLI) Lead to High Cure Rates in T-Cell Depleted Allogeneic Haemopoietic Stem Cell Transplants for MDS/AML

Abstract 660Relapse is a major cause of treatment failure following allogeneic haemopoietic stem cell transplants (HSCT). Donor lymphocyte infusions may be given pre-emptively (pDLI) to improve falling donor T cell chimerism or therapeutically (tDLI) following relapse. Herein we present results of pDLI or tDLI in patients receiving T-cell depleted allogeneic HSCT for AML, MPD or MDS at our institution.120 patients receiving DLI were identified; diagnoses included AML (60), MDS RAEB (29), RCMD (19) and MPD (12). Transplants occurred between 1999–2010; median follow-up was 1110 (132-3990) days. Median age at transplant was 54(17-72) yrs. Conditioning regimens were reduced intensity in 114 patients (T-cell depletion was with either ATG or CAMPATH) and myeloablative in 6 cases. Donor type was sibling (54) or unrelated donor (66), cell source was BM (27) or PBSC (92).pDLI was instituted for poor or declining CD3 chimerism (CD3 <50% or fall in CD3 >20% in 1 month), using an escalating dose schedule at 6–8 week intervals. pDLI continued in the absence of improvement in donor CD3% but ceased if graft-versus-host disease (GvHD) developed. Patients with morphologic/cytogenetic relapse received tDLI using a similar schedule, alone or in combination with chemotherapy.64 patients received pDLI whilst 55 received tDLI. Both cohorts were matched for age, sex, diagnosis, conditioning received, donor type, stem cell source and HLA-matching. There was no significant difference in numbers of patients in morphological/cytogenetic CR between the groups at the time of transplant (p<0.05).The median time to pDLI was 164 days (87-1304 days) with median total dose 1.5×106 CD3+cells/kg (1×105-1.66×108). Median donor CD3 chimerism prior to pDLI was 24(0-77)%. OS post pDLI was 83% at 5 years (event free survival 66% at 5 years). Response to pDLI included achievement of full donor chimerism (FDC) in 41(69.5%) patients, persistent mixed donor chimerism (MDC) in 4 patients and no improvement in chimerism in 15 patients. There was no significant difference in CD3% pre-pDLI between responders and non-responders (p<0.05).Only 4 patients who achieved FDC subsequently relapsed, at a median of 912.5 days post DLI; 3 of these patients have been successfully salvaged. All non-responders relapsed at a median 128 days (13-394) post first DLI: 5 succumbed to disease, 5 underwent second allograft and 5 stabilised with chemotherapy (median OS post DLI 1336 (415-1542) days). 3 of 5 patients who underwent second BMT are alive with median DFS 1547 (949-2389) days post second BMT.The median time to tDLI in the relapse cohort was 303 days (74-2801 days). The median total dose was 1×107 CD3+ cells/kg (5×105-1.6×108), significantly higher than the median pDLI total dose (p<0.01). The median donor CD3 chimerism prior to tDLI was 87% (0-100%), significantly higher than for pDLI CD3% (p<0.01).Patients received intensive chemotherapy (n=29), non-intensive chemotherapy (n=7) or no additional treatment (n=15) at the time of relapse (of these 15 patients, 2 had 7% and 10% blasts pre t-DLI, 13 had cytogenetic/molecular relapse).The 5yr OS post DLI for patients treated with tDLI was 41%. Of 15 patients who received tDLI only, 5 achieved CR with a median OS of 705 (85-1324) days. Of the 36 patients who received chemotherapy before tDLI; 19 (52.8%) achieved CR of whom 9 subsequently relapsed and 2 died of GvHD. The remainder have sustained disease free survival post first DLI: median 1711(292-2749) days. For both groups, time to first DLI was associated with a significantly reduced 5y OS post DLI (<6 months pDLI 72%, tDLI 14% vs >6 months pDLI 93%, tDLI 50%, p<0.01).Overall, 44 (39%) patients developed GvHD post DLI (35 chronic GvHD – 5 limited, 30 extensive). No significant association was seen between conditioning, donor type, degree of stem cell matching or source and occurrence of GvHD post DLI. Rates of GvHD were not different for pDLI/tDLI and were unrelated to the number/total dose of DLI given.Our experience demonstrates the efficacy of DLI in maintaining long term remissions in patients with myeloid malignancies following T-cell depleted HSCT. In particular, patients receiving pDLI attain a 5-yr OS and EFS of 83% and 66% respectively. Even in patients with morphologic and cytogenetic relapse, tDLI in combination with chemotherapy can effectively salvage a proportion of patients but is less effective in the context of early disease relapse. Disclosures:Ho:Bristol-Myers Squibb: Consultancy, Honoraria, Speakers Bureau. Mufti:Celgene: Consultancy, Research Funding.

Alemtuzumab-Based RIC HSCT with Pre-Emptive DLI as An Effective Strategy to Achieve Long-Term Disease Remission In Patients with High Risk Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukaemia (AML).

AbstractAbstract 1304Disease relapse following allogeneic haematopoietic stem cell transplant (HSCT) for MDS/AML remains one of the primary causes of treatment failure, particularly in the setting of T-cell depleted reduced-intensity conditioning (RIC). Pre-emptive immunotherapy such as the use of donor lymphocyte infusions (DLI) is one strategy utilized to prevent relapse, although this approach may be associated with an increased risk of GvHD. We present our experience, evaluating toxicity and efficacy of pre-emptive DLI for the treatment of mixed donor chimerism (MDC) in a cohort of high risk MDS/AML patients who received a uniform alemtuzumab-based RIC HSCT protocol.37 patients received a RIC protocol using fludarabine, busulphan and alemtuzumab. The stem cell source was BM (n=8) and PBSC (n=29) with a median cell dose of 2.40 and 5.34×106̂ CD34/kg respectively. The donor source was from HLA-matched sibling (n=20), HLA-matched unrelated (n=14) with 3 1-allele mismatched unrelated donors. Peripheral blood CD3 chimerism was monitored at day 30, 60, 100, 180 and 1 year post-HSCT. Patients with MDC (defined as CD3 <50%, or fall of CD3 of greater than 20% in a month) received pre-emptive DLI at a starting dose of 5×105̂CD3/kg or 1×106̂CD3/kg. In order to receive pre-emptive DLI, patients had to be in cytogenetic and morphological remission, to be off immunosuppression and have no evidence of active GvHD. Escalating doses of DLI were administered at 6–8 week intervals in the absence of improvement in donor chimerism (increase of <20% donor CD3).The median age of the cohort at transplant was 59 yrs (25-71). At the time of initial diagnosis 70% of the patients had an advanced stage disease (RAEBI/II (24%) or AML(46%)). Mean donor CD3 chimerism at the time of DLI was 44% (range: 0–76%) and median time to DLI was 195 days (range: 22 to 732 days). The median number of DLI doses was 3 (range:1-5) with a median total CD3 dose of 4.9×106̂ CD3/kg (range: 5×105̂ to 4.15×108̂). The majority of patients (83%) achieved full donor chimerism (FDC, >95%) at a median time of 193 days following the start of DLI (range: 47–732 days).The incidence of GVHD was 54%, however the incidence of severe (acute grade III,IV or chronic extensive) GvHD was limited at 21%. Skin was the commonest site of involvement with GvHD. The number of DLI doses, the total DLI dose infused, recipient age, donor source and disease stage all had no association with the development of GvHD or attainment of FDC post DLI. At last follow-up, 10 patients had died due to disease relapse(4), PTLD(1), GvHD/CMV(1), multi-organ failure(1), cerebral haemorrhage(1), infection(1) and encephalopathy(1). Evidence of relapsed disease was seen in 7 patients, and 3 patients proceeded to a second RIC HSCT.The 2-yr actuarial OS, TRM and DFS was 81%+/−6%, 14%+/−6%, and 68%+/−8% respectively. Encouragingly, the median OS for survivors post-DLI was 2537 days (range: 805–3287 days). Neither donor source, disease stage nor the presence of GvHD post-DLI had any impact on TRM, relapse or OS. Patients who achieved FDC post DLI had a 2-yr OS of 84%+/−7% when compared with those who failed to achieve FDC: 60%+/−21%, p=0.23. In conclusion, the use of pre-emptive DLI HSCT is associated with a low incidence of severe GvHD and a low TRM and relapse. In combination with an alemtuzumab-based RIC HSCT, this approach facilitates the attainment of durable long-term remission in patients whilst reducing the procedure related toxicity. Disclosures:No relevant conflicts of interest to declare.

Second Allogeneic Transplants for Relapsed Acute Lymphoblastic Leukemia Result in High Response Rates of Short Duration: Further Intervention Is Required to Maintain Response.

Abstract 4293▪The major cause of failure after allogeneic hematopoietic stem cell transplantation (SCT) for acute lymphoblastic leukemia (ALL) is disease relapse. Patients and MethodsWe analyzed the outcome of second SCT for treatment of disease relapse occurring within 6 months (n=10) or after 6 months (n=18) following first SCT in 28 ALL patients (12F/16M) with median age 23.5 years (range 3-50) transplanted between 1993 and 2009 at our institution. At time of SCT 43% of patients had advanced remission beyond CR1 (n=12) and 57% had active disease (n=16). High risk cytogenetic profile defined by the presence of t(9;22) or t(4;11) translocation, or hypodiploid clone was noted in 43% of patients (n=12) at time of diagnosis. A myeloablative busulfan- or TBI-based transplant preparative regimen (n=8) or reduced-intensity fludarabine-based regimen (n=20) was used followed by matched sibling (n=17), matched unrelated (n=9), or mismatched cord blood (n=2) infusion. A different donor was used in 54% of cases. GVHD prophylaxis was either tacrolimus-based (n=20) or cyclosporine-based (n=8). Only one patient in this analysis received consolidation following second SCT in the form of prophylactic donor lymphocyte infusion (DLI). Results26 patients were evaluable for response with 2 early deaths within 30 days of SCT. Overall response rate was 88% with 38% sustained (n=10) and 50% complete (n=13) response rates. Acute grades II-IV and III-IV GVHD rates were 27% (n=7) and 12% (n=3), respectively; chronic extensive GVHD was noted in 1 patient. Progression-free (PFS) and overall survival (OS) were 27% and 42%, respectively, at 1 year. However, there is only one long-term survivor at 5 years, with a median follow-up time of 6 months among 5 survivors. The primary cause of death was disease relapse (n=14), with remaining causes GVHD (n=4), infection (n=2), multi-organ failure (n=2). Disease characteristics, including WBC count and cytogenetic profile at diagnosis, time to first remission, time to progression after first SCT, time between first and second SCT, age at SCT, intensity of SCT preparative regimen, disease stage at SCT, donor relation, use of same or different donor, and development of GVHD were evaluated in a univariate analysis for PFS following second SCT without any statistically significant factors identified. There was a trend for longer PFS in patients who had a late relapse following first SCT (p=.06). At 1 year, PFS was 29% for patients whose disease progressed after 6 months following first SCT versus only 12% for those who had very early relapse (p=.06, Figure 1). ConclusionsIn summary, a second allogeneic SCT remains an effective method for achieving response in a highly refractory patient population. However, post-SCT interventions are needed to achieve sustained response, as demonstrated by the long-term remission of the only patient who received post SCT prophylactic DLI. A significant proportion of patients remain disease-free up to one year following second SCT, thereby providing a window of time to administer consolidation in the form of immunotherapy or low-dose chemotherapy maintenance. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Cryopreserved G-CSF Mobilized Donor Lymphocyte Infusion (DLI) without Withdrawal of Immunosuppression Is Safe and Highly Effective for Treating Isolated Poor Donor T-cell Chimerism Following Reduced Intensity Allogeneic Transplantation (RICT).

Abstract 3308Poster Board III-196The use of lineage-specific chimerism studies following allotransplantation has shown that low levels of donor T-cell chimerism can be seen following some preparative regimens despite good engraftment of donor myeloid-origin cells. Furthermore, low levels of early T-cell chimerism have been associated with eventual graft rejection, malignant relapse and poorer event-free survival [Maris et al Blood 102: 2021-2030 (2003); Saito et al Biol Blood Marrow Transplant 14: 1148-1155 (2008)]. There is no consensus regarding the management of such differential engraftment. Withdrawal of immunosuppression, DLI, and second transplant with repeat conditioning have all been used. We utilized a strategy of low dose DLI (initial dose 0.1-1 × 10e7 CD3+ cells/kg) without additional conditioning or withdrawal of immunosuppression in patients with donor T-cell chimerism < 50% following allotransplant who had no evidence of relapse/progression of malignancy. Nineteen consecutive patients treated this way between Nov 2005 and April 2009 were included in this analysis - median age 59 (range 36-63);15M, 4F; NHL 5, AML 5, MDS 3, CLL2, CML 2, MPS 2; donor =MRD 3, MUD 16; Preparative regimen for transplant- reduced intensity 18, myeloablative 1, and consisted of fludarabine/busulfan (11), fludarabine/cyclophosphamide (6), other (2). Alemtuzumab was used in the preparative regimen in 15 and rabbit antithymocyte globulin in 2. The first DLI was administered a median of 66 days post BMT (range 36-237). Median CD3+ and CD34+ cell dose was 1.0 ×10e7/kg (range 0.1-1) and 0.24 × 10e6 (0.02-0.74) respectively. Cryopreserved G-CSF mobilized cells collected at the time of BMT were used for the DLI in all patients. Median (range) donor chimerism in blood CD3+ cells and CD33+ cells prior to DLI was 14% (0-34%) and 100% (10-100%) respectively. Pre and post DLI donor T-cell chimerism is shown in the Figure below. Full donor CD3 chimerism (FDC) (>90% donor-derived CD3+ cells) was achieved after one DLI in 9 evaluable patients (50%) at a median 90 d post infusion (range 30-180 d). Eight patients received additional DLI (median 1 range 1-3) at a CD3+ cell dose up to 4 × 10e7/kg and 7 of these patients achieved FDC in CD3+ cells [total success rate in achieving FDC = 89%]. FDC was durable in all cases. Acute GVHD (none > gd 2 overall) developed in three evaluable patients following DLI (17% - median 43d [35-57d]) and chronic GVHD (extensive mild 1, moderate 8, severe 1) developed in ten patients (55% -median 119d [53-166d]). One patient died of chronic GVHD. With a median follow-up of 728d (135-1240d) estimated 2yr survival from DLI is 74%. ConclusionThis strategy is highly effective at correcting poor donor T-cell chimerism without inducing severe GVHD. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.