ALBERT

Description: By reducing treatment intensity allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become feasible for elderly patients. Different reduced-intensity conditioning (RIC) regimens are available, but there is little consensus about the optimal preparative regimen to use, in particular with regard to the outcomes counterbalancing the aim of feasibility and tolerability with higher rates of relapse. Here, we retrospectively evaluate the outcome of sequential therapy employing RIC with fludarabine 30 mg/m2, cytarabine 2g/m2 and amsacrine 100 mg/m2 for 4 days (FLAMSA; Schmid C et al. JCO 2005) followed by busulfan 10 x 0.8 mg/kg (FLAMSA-Bu) compared to RIC utilizing fludarabine 5 x 30 mg/m2, carmustine (BCNU) 2 x 150 mg/m2 and melphalan 110 mg/m2 (FBM; Marks R et al. Blood 2008) in elderly patients treated consecutively at our institution between July 2005 and October 2012. We analyzed the course of 114 patients (pts) with acute myeloid leukemia (AML; n=99) or myelodysplasia (MDS; n=15) aged ≥ 59 years with 59 pts aged ≥ 66 years who were treated with either FLAMSA-Bu (n=66; n=24 ≥ 66 years) or FBM (n=48; n=35 ≥ 66 years). All patients received sero-therapy with anti-thymocyteglobuline (ATG). Median patient age was 66 years for the entire cohort (68 years FBM; 64 years FLAMSA-Bu). 36 patients (75%) of the FBM and 42 patients (63 %) of the FLAMSA-Bu group suffered from high risk disease defined as relapsed or refractory AML or refractory anemia with excess of blasts in transformation (RAEB-T). The hematopoietic cell transplantation comorbidity index (HCT-CI) was higher for the patients of the FBM group than for the FLAMSA-Bu group with 26 (54 %) versus (vs) 24 patients (36 %) scoring ≥ 2 (p 0.085). Graft source after conditioning with FBM/FLAMSA-Bu was bone marrow (1/2), G-CSF mobilized peripheral blood stem cells (40/62) and double-umbilical cord-blood (7/1). In 23 pts (20 %) HLA-matched related and in 91 pts (80 %) HLA-matched unrelated donor transplantation was performed. Engraftment failure was observed in 1 patient after FLAMSA-Bu, while engraftment was achieved in all evaluable patients of the FBM group in a median of 23 days vs 18 days after FLAMSA-Bu (p 0.003), while 7 pts with double-umbilical cord-blood transplantation where included in the FBM group vs 1 pt in the FLAMSA-Bu group. Non-hematological treatment-related acute toxicity ≥ CTC III (gastrointestinal, hepatic, cardiovascular, renal, centralnervous system) occurred in 12/48 pts (25 %) after FBM and in 18/66 pts (27 %) after FLAMSA-Bu. Incidence of severe acute (III-IV) and chronic GvHD was 22.9 %/16.6 % for FBM vs 18.2 %/19.7 % for FLAMSA-Bu, respectively. After conditioning with FBM 2/48 pts vs 9/66 pts after FLAMSA-Bu were diagnosed with a secondary malignancy (p 0.08). Non-relapse mortality (NRM) after 12 months was 26.8 % for FBM versus 25.2 % for the FLAMSA-Bu group. Incidence of relapse after FBM vs FLAMSA-Bu conditioning was 22.9 % vs 15.2 % after 1 year and 31.3 % vs 16.7 % after 2 years. Occurrence of relapse was significantly related to an incomplete or mixed chimerism (donor cells ≤ 95 % in peripheral blood and/or bone marrow) at day +30 (p 0.001). After a median follow up of 31.4 months (range 4.4-97.5) estimated overall survival (OS) and relapse-free survival (RFS) after 2 years was 55.4 % and 51.4 % for the FBM vs 58 % and 56.7 % for the FLAMSA-Bu group, respectively. Analyzing different subgroups, FBM conditioning might be favorable for pts aged ≥ 66 years when suffering from high risk AML (n=26): Within this group 1-year OS after FBM vs FLAMSA-Bu was 71.4 % vs 66.7 % (p 0.58) and 1-year RFS was 71.4 % vs 58.3 % (p 0.59), respectively. Notably, for pts at highest risk (aged ≥ 66 years and suffering from secondary or therapy-related AML; n=24) the benefit of FBM conditioning becomes more pronounced: 1-year OS after FBM vs FLAMSA-Bu was 62.5 % vs 37.5 % (p 0.26) and 1-year RFS 54.2 % vs 37.5 % (p 0.17). Both conditioning regimens are feasible, and provide similar rates of acute toxicity, NRM and GvHD. There might be evidence for a benefit of conditioning with FBM for the subgroup of “the oldest patients at highest risk”. Taking into account that there is an increasing group of ‘medically fit’ elderly patients in the field of allogeneic transplantation, prospective clinical trials are needed to investigate different conditioning regimens considering their special requirements. Disclosures No relevant conflicts of interest to declare.

Description: Allogeneic hematopoietic stem cell transplantation (HSCT) is a valuable treatment option for patients with relapsed or refractory lymphoma including patients with relapse after a first autologous HSCT. However, outcome in non-remission patients is still poor. Here we report the feasibility and efficacy of a protocol using the concept of sequential therapy with clofarabine induction chemotherapy followed by a HLA-haploidentical HSCT in the treatment of patients with advanced non-remission lymphoma. 16 adults (11 male, median age: 53 years, median comorbidity index: 3) with MCL (n=7), CLL (n=1), AITL (n=2), secondary DLBCL (n=2), DLBCL (n=2), follicular lymphoma (n=1), B- lymphoblastic lymphoma (n=1) were treated between September 2010 and February 2013. After induction-chemotherapy with clofarabine (5x30 mg/m² IV), followed by 3 days of rest, a reduced intensity conditioning (RIC) consisting of fludarabine/cyclophosphamide plus melphalan 110 mg/m2 IV was performed prior to a T-cell replete HLA-haploidentical HSCT. High dose cyclophosphamide (Cy) was administered for post-grafting immuno-suppression followed by mycophenolate mofetil and tacrolimus. The median number of immuno-chemotherapy attempts prior to haploidentical HSCT was 4 including 8 autologous HSCT. None of the patients were in complete remission (CR) prior to haploidentical HSCT. After salvage therapy and prior to haploidentical HSCT, progressive disease (PD) was documented in 9 patients with one patient being primarily refractory, while in 7 patients a partial remission (PR) was observed. Neutrophil engraftment was achieved in 16 patients (100%) within a median of 21 days (range 14-36) and platelet engraftment in 14 patients (88%) within a median of 30 days (range 18-115). No primary graft rejection occured. By day +30 CR was achieved in 4 patients (25%) and PR in 11 patients (69%), whereas 1 patient (6%) showed PD. Full donor chimerism on day +30 was detected in all 16 patients. By day +100, 8 of the 14 evaluated 14 patients (57%) achieved CR, 4 (29%) PR, and only 2 (14%) had relapsed. Full donor chimerism was detected in 13 (93%) patients. The rate of acute GvHD grade II-IV was 31%, while chronic GvHD occurred in 3 of 14 (21%) evaluable patients (21%). Non hematologic regimen-related grade III-IV toxicity was observed in 9 patients (56%), and included most commonly transient elevation of liver enzymes (38%), mucositis (19%), and nausea and vomiting (19%). Creatinine elevation (6%), hand-foot syndrome (6%) and haemorrhagic cystitis (6%) were rare. After a median follow up of 14.5 months (range 5.7-35) 4 patients had relapsed, and 4 patients had died, while death was lymphoma-associated only in one patient. Causes of non-relapse mortality (NRM) were haemorrhagic cerebral bleeding in one patient (day +101), and toxicity/infection in 2 patients (day +141; day +156). Cumulative incidence of NRM was 0% on day +100 and increased up to 20% (7-50) on day +360. Estimated one-year overall survival and progression-free survival were 75% (95 CI 46-90) and 56% (95 CI 30-76), respectively. Sequential therapy combining cloforabine induction-chemotherapy and HLA-haploidentical HSCT using RIC, a T-cell replete graft and high dose Cy post-transplant is feasible, shows a favourable toxicity profile and furthermore achieves significant anti-lymphoid activity in patients with advanced non-remission lymphoma. These early results are promising, but longer follow up is needed. Disclosures: Off Label Use: Clofarabine off label use in adults. Hausmann:Sanofi: Travel support Other. Tischer:Sanofi: Travel support Other.

Description: Hematopoietic stem cell transplantation is a potent curative treatment option for patients suffering from high-risk AML and MDS. However, not in all of our patients a suitable HLA-matched donor could be identified in time. To evaluate the feasibility and outcome of T-cell-replete (TCR) HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) utilizing post-transplantation high-dose cyclophosphamide (PTCY) in the context of sequential therapy in patients with high-risk, relapsed/refractory and progressive AML and MDS, we retrospectively analyzed the course of 64 patients (AML n=61, MDS n=3; median age: 50 years; male n=30) transplanted between 2009 and 2015 at our center. Disease was advanced in 55 patients including 24 patients with relapse after a first allogeneic transplantation. 54 patients presented with active disease at time of haplo-HSCT. Donors (median age: 38 years; male n=30) were fully HLA-haplotype mismatched (5/10 HLA-loci) in 48 cases (77%). All patients received sequential therapy prior to haplo-HSCT combining cytoreductive chemotherapy (clofarabine n=34; FLAMSA n=25; FLAG-Ida n=2; others n=3) and reduced-intensity conditioning (RIC) which was started after three days of rest thereafter. Conditioning was drug-based in 42 patients receiving fludarabine, cyclophosphamide (CY) and melphalan (110 mg/m2) while it was TBI-based in the others (n=22) consisting of fludarabine and CY plus either 4 (n=20) or 2 Gy TBI (n=2). Post-grafting immunosuppression was high-dose CY given on day + 3 and +4, tacrolimus and mycophenolate mofetil (both started on day +5) in all patients. Unstimulated bone marrow was the graft source in 37 patients. One graft rejection was observed after conditioning with 2 Gy TBI. Neutrophil/platelet engraftment was achieved in 49/58 evaluable patients at a median of 16 (range: 14-27) and 20 (range: 13-74) days, respectively. Acute GvHD grade II-IV occurred in 19 patients (30 %) while it was severe (grade III-IV) in only 3 (5 %). Chronic GvHD was most frequently mild (n=9) to moderate (n=8); one severe chronic GvHD occurred. Severe (grade III-IV) mucositis, hemorrhagic cystitis and hand-foot syndrome/rash were observed in 10, 5 and 2 patients, respectively; no patient developed VOD. Kidney failure requiring hemodialysis occurred in 7 patients. CMV reactivation was observed in 28 of 47 patients at risk (59 %) and EBV in 3, while only one patient developed CMV disease (pneumonia) and no patient developed PTLD. Probable or proven (n=2) invasive aspergillosis was diagnosed in 10 patients. One-year non-relapse mortality was 27.5 % (95% CI 17-41). After a median follow up of 21 months (range: 3-64), estimated one-year overall survival (OS) was 55 % (95 % CI 41-66), and one-year disease-free survival (DFS) was 43 % (95 % CI 26-51). At two-years after sequential haplo-HSCT OS and DFS were both 39 % (95 % CI 26-51). In summary, sequential therapy in the setting of RIC-TCR haplo-HSCT using PTCY is well tolerated with low rates of GvHD and acceptable NRM in patients with high-risk AML and MDS, while providing an effective anti-leukemic activity in advanced disease. Results are comparable to data of a historical cohort of patients with high-risk AML and MDS undergoing sequential therapy using the FLAMSA-RIC protocol in a HLA-matched setting, as reported by our group previously. Thus, we suggest that donor availability can be expanded in patients with high-risk and advanced AML/MDS who lack a conventional donor or need promptly access to a donor due to aggressive disease. Disclosures Hausmann: Sanofi-Aventis: Other: advisory board. Tischer:Sanofi-Aventis: Other: advisory board. Off Label Use: clofarabine in adults; efficacy is shown in myeloid blasts;.

Description: Abstract 3071 Background: Prognosis of relapse after first allogeneic hematopoietic stem cell transplantation (allo-HSCT) is poor, and no standard treatment is available. Second HSCT (HSCT2) is a valuable treatment option for selected patients. Change of donor for HSCT2 is a frequently used strategy to enhance the graft-versus leukemia-activity, although its role for improving the outcome is still unclear. However, identification and activation of a new donor for HSCT2 is time consuming and might delay or even prevent a second transplant. In contrast, haploidentical family donors are rapidly available in the vast majority of patients and might therefore be an alternative for HSCT2, once change to a new donor is planned. Based upon these considerations, HSCT2 from haploidentical family donors was used as preferred treatment for acute leukemia relapse after allo-HSCT in our transplant center since August 2009. According to the concept of sequential therapy (as introduced by the FLAMSA-RIC regimen), patients initially received cytoreductive chemotherapy, followed, after three days of rest, by reduced intensity conditioning (RIC). Based on the Baltimore protocol for haploidentical HSCT using RIC and post-transplant cyclophosphamide for depletion of allo-reactive T-cells, individual and disease-specific modification of this regimen were used for preparation before HSCT2. Patients and Methods: Fourteen adult patients (7 male, median age: 37 years) suffering from AML (n=11) or ALL (n=3) with an ECOG score of

Description: Sequential conditioning regimens, comprising cytoreductive chemotherapy shortly applied prior to reduced intensity conditioning are successfully used for high-risk (HR) AML/MDS in matched related and unrelated donor hematopoietic stem cell transplantation. However, few data are available for sequential conditioning in the context of HLA-haploidentical transplantation (haplo-HSCT), especially in the elderly. To investigate the relative merits of sequential haplo-HSCT in the elderly we retrospectively analyzed the outcome of thirty-five patients (pts) with advanced AML/MDS (〉=50 years old). Thirty-three pts suffering from HR AML, defined by refractory, relapsed or secondary leukemia, or complete remission with adverse-risk genetics according to ELN criteria and two pts with HR MDS according to IPSS-R, who underwent T-cell-replete haplo-HSCT at our institution between January 2009 and November 2016 were included. Disease was active in 29 pts while 6 had achieved CR. Pre-transplantation risk factors were scored using the hematopoietic cell transplantation-specific comorbidity index (HCT-CI) which was ≥3 in 13 pts (median HCT-CI:2, range 0-8). A sequential therapeutic concept using either FLAMSA (n=26) or clofarabine (n=9) for cytoreduction was used prior to RIC in all pts. Bone marrow (54%) and peripheral blood stem cells (46%) were both used as graft source. Post-grafting immunosuppression consisted of high-dose cyclophosphamide, tacrolimus and MMF in all pts. Median age was 60 years (50-70). One graft rejection occurred. Three pts died early in aplasia. Neutrophil and platelet engraftment was achieved in 95% and 77% of evaluable pts, respectively at a median of 16,5 (13-89) and 31,5 (11-103) days.Acute GvHD grade I-III occurred in 25/32 of the pts (grade III n=2); no patient developed grade IV aGvHD. Chronic GvHD was observed in 13/29 pts and was most frequently assessed as mild (n=6) or moderate (n=5) while 2 pts developed severe cGvHD. No GvHD related death was observed. CI of NRM at day 100, 1-year and 3-years was 11%, 23% and 23%, respectively. CI of relapse at 1- and 3-years was 15% and 27%, with a median time to relapse of 152 days (20-413). At a median follow up of 27 months (4-74), estimated one- and three-year overall survival (OS) was 62% and 52% respectively. One- and three-year leukemia-free survival (LFS) was 59% and 52%. Our results suggest that using a sequential therapeutic concept in PTCY-based haplo-HSCT is safe and properly tolerated while it provides a favorable disease control when treating elderly HR MDS/AML pts. Thus, sequential haplo-HSCT seems to be a valuable alternative in pts who lack a conventional donor or are in urgent need for prompt transplantation. Disclosures Tischer: Jazz Pharmaceuticals: Other: Jazz Advisory Board.

Description: Posttransplantation lymphoproliferative disease (PTLD) associated with Epstein-Barr virus (EBV) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation. PTLD is efficiently prevented by adoptive transfer of EBV-specific T cells from the donor. To make EBV-specific T cells available in urgent clinical situations, we developed a rapid protocol for their isolation by overnight stimulation of donor blood cells with peptides derived from 11 EBV antigens, interferon-γ surface capture, and immunomagnetic separation. Six patients with PTLD received 1 transfusion of EBV-specific T cells. No response was seen in 3 patients who had late-stage disease with multiorgan dysfunction at the time of T-cell transfer. In 3 patients who received T cells at an earlier stage of disease, we observed complete and stable remission of PTLD. Two patients have remained free from EBV-associated disease for more than 2 years. CD8+ T cells specific for EBV early antigens rapidly expanded after T-cell transfer, temporarily constituted greater than 20% of all peripheral blood lymphocytes, and were maintained throughout the observation period. Thus, a rapid and sustained reconstitution of a protective EBV-specific T-cell memory occurred after the infusion of small numbers of directly isolated EBV-specific T cells.

Description: Transplant-associated microangiopathy (TAM) is a life-threatening complication after allogeneic transplantation, related to endothelial toxicity caused by chemoradiotherapy, infections, immunosuppressive drugs and GvHD. Clinical manifestations include severe thrombocytopenia, microangiopathic hemolysis and organ dysfunction (e.g. renal, neurological) in the absence of disseminated intravascular coagulation. The reported incidence of TAM after allogeneic hematopoietic stem cell transplantation (HSCT) varies between 0,5 to 70%. Data for TAM occurrence and outcome in the context of HLA-haploidentical transplantation (haplo-HSCT) are rare. Here, we report our experience on TAM incidence, disease manifestation, treatment and outcome in T-cell-replete haplo-HSCT using PTCY as GvHD prophylaxis. We retrospectively analyzed the treatment course of 148 adult patients undergoing haplo-HSCT with regard to the incidence of TAM at our center from January 2012 to April 2019. The diagnosis of TAM required the fulfillment of the criteria as defined by Ruutu et al., Haematologica 2007. Median age of the entire cohort was 54 years (23-74). The majority of patients was transplanted for myeloid disease (60%). Postgrafting immunosuppression consisted of PTCY, CNI and MMF in all patients. Median follow-up time upon survivors was 3 years (4 months - 7 years). Twenty of 148 patients developed TAM, with a cumulative incidence of 10% at day 100. Median interval from haplo-HSCT to TAM onset was 63 days (23-295 days), with seven patients showing TAM after day +100. Median platelet count at diagnosis was 20 x 109/L (range: 6-116), predominantly de novo or worsening thrombocytopenia. Median LDH level was 437 IU/L (305-1445 IU/L). Serum haptoglobin levels were decreased in 85% of the TAM patients. 12/20 patients had active infection at the time of TAM diagnosis, most commonly viral (10/12). All but three patients presented with concurrent active acute GvHD requiring systemic steroid treatment in 16 patients Renal function abnormalities were diagnosed in 55% of the patients affected by TAM, with 4 patients requiring hemodialysis. Nine patients developed grade III hypertension and three patients showed neurologic dysfunction. Upon diagnosis of TAM, CNI dose was reduced (7 patients) or temporarily discontinued (7 patients). No switch to another CNI was performed. FFPs were transfused in nine patients, three patients underwent plasma exchange therapy without any effect. In four patients rituximab was applied. With a CI of 18% vs 2% (p0.002) using a PBSC graft was a risk factor for TAM development when compared to BM. Neither origin of disease (myeloid/lymphoid) nor sex of patient/donor or conditioning intensity (RIC/MAC) influenced the incidence significantly. Estimated one-year and three-year overall survival did not differ between the TAM and the non-TAM cohort (61% vs 61% and 46% vs 47%, p=0.9). Only one patient died because of TAM. With an incidence of 10% at day +100 at our center TAM is a serious but not rare complication after haplo-HSCT using PTCY, CNI and MMF for GvHD prophylaxis. However, in our cohort disease course was moderate with low TAM-associated mortality. The use of a PBSC graft was the only factor influencing TAM incidence. Disclosures Hiddemann: F. Hoffmann-La Roche: Research Funding.

Description: Unmanipulated, T-cell-replete (TCR) HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using post-transplantation cyclophosphamide (PTCY) for selective in vivo T-cell depletion of allo-reactive T-cells has become a valuable treatment alternative in patients with various hematologic disorders who lack a conventional donor or need timely transplant due to aggressive disease. However, as of yet few data are available for the treatment of ALL with this approach, particularly in relapsed and refractory disease. To evaluate the outcome of TCR haplo-HSCT utilizing PTCY in the context of intensified conditioning in patients with high-risk, relapsed and refractory ALL, we retrospectively analysed 29 patients (B-ALL n=27, T-ALL n=2; 12 male; median age 42 years: range 8-68) transplanted between 2010 and 2015 in five German transplant centers including one pediatric. Disease was active (relapsed/refractory) in 14 patients (48%) while others were in first (35%) or subsequent remission (17%). Eleven patients (38%) had relapsed after a previous allogeneic transplantation. Patients not in CR received cytoreductive chemotherapy prior to the conditioning regimen, according to the "sequential therapy" concept (Schmid C et al., JCO 2005; Tischer J et al, Ann Hematol 2013). Conditioning was TBI-based in 15 adults consisting of fludarabine and +/- cyclophosphamide plus either 12 Gy TBI or 8 Gy TBI applied in patients older than 55 years; children (n=3) received 10-12 Gy TBI plus etoposide. In adults with relapse after a first allogeneic transplantation conditioning was drug-based replacing TBI with treosulfan (3 x 10-12 g/m2) and etoposide. Post-grafting immunosuppression was high-dose cyclophosphamide, tacrolimus or cyclosporine A (n=4) and MMF in all patients. 27/29 patients engrafted, while 2 patients died early in aplasia. No primary graft rejection was observed. Acute GvHD grade II-IV occurred in 7 patients (24%); no patient developed grade IV acute GvHD. Mostly mild to moderate chronic GvHD was observed in 6 patients (21%), and CI of chronic GvHD at 2 years was 25%. No patient died due to GvHD. Severe toxicity (grade III-IV) was observed in 12 patients (41%), most commonly mucositis (n=34%), diarrhoea (31%), hyperbilirubinemia and transient elevation of transaminases (28%) and hemorrhagic cystitis (21%). CMV reactivated in 11/23 patients at risk and EBV in 3 while no patient developed CMV disease or PTLD. Proven invasive aspergillosis was diagnosed in 2, probable invasive aspergillosis in 5 patients. One-year non-relapse mortality (NRM) was 10%. Patients grafted with active disease experienced a one-year NRM of 14%. One-year relapse incidence was 35%. After a median follow up of 31 months (range 7.1-53.6), estimated one-year and three-year overall and relapse-free survival was 72/49% and 55/41%, respectively. In summary, intensification of the preparative regimen is well tolerated in the setting of TCR haplo-HSCT using PTCY as GvHD prophylaxis with low GVHD rates and NRM in patients with high-risk, relapsed and refractory ALL, while providing effective anti-leukemic activity. Results are at least comparable to HLA-matched transplantation. Thus, we suggest that the donor pool can be safely expanded in patients with high-risk and advanced ALL who lack a conventional donor, and that unrelated donor transplantation might be challenged in patients suffering from aggressive disease in the future. Disclosures Albert: GSK: Research Funding.

Description: Introduction: Monitoring of minimal residual disease (MRD) is commonly used after allogeneic stem cell transplantation (SCT) in acute myeloid leukemia (AML) patients. Flow cytometry of leukemia-associated aberrant immunophenotypes (LAIP) and chimerism analyses are frequently used tools to monitor MRD. These methods have lower sensitivities and lower relapse detection rates in contrast to molecular markers monitored by quantitative RT-PCR. However, their clinical implications are still limited and only little evidence of single molecular markers is available. We report on a retrospective study of 144 patients with molecular MRD markers transplanted at the Ludwig-Maximilans-University Hospital of Munich-Grosshadern, and analyzed the prognostic values of molecular MRD Monitoring after SCT, baseline risk factors, and follow-up (FU) markers (e.g. chimerism analyses and LAIP). Patients and Methods: Between January 2000 and August 2012, 495 AML patients underwent SCT at our institution. 164 patients had molecular MRD markers and 144 patients had at least one sample with quantitative results prior and/or after SCT, and were included into the analyses. At transplantation, patients had a median age of 48 years (range, 18 -73), and 49 patients were in complete remission, while 95 patients were in a more advanced status of their disease (〉CR2). 106 patients received SCT from a HLA matched (10/10) and 38 patients from a HLA mismatched donor. Grafts were obtained either from related (n=60) or unrelated (n=84) donors. Most patients received reduced intensity conditioning (n=142). In 338 bone marrow samples MRD was monitored prior to SCT, on day +30 and on day +100. During the FU period after day +100, MRD was monitored at individual intervals in 429 peripheral blood samples. Quantitative RT-PCR was performed for NPM1 mutation (n=52), MLL-PTD (n=31), RUNX1-RUNX1T1 (n=12), CBFß-MYH11 (n=14), MLL rearrangements (n=20), MDS-EVI1/EVI1 (n=10), and DEK-CAN (n=5). Sensitivities of the different RT-PCRs assays ranged between 10-4 and 10-6. Results: After a median FU of 41 months (range, 4 – 115), 43 patients (30%) relapsed. The MRD levels monitored by RT-PCR prior to SCT and on day +30 after SCT showed no significant impact on relapse-free survival (RFS) and overall survival (OS). At day +100 after SCT, MRD positivity was strongly associated with worse RFS (HR 3.1, p=0.001) and OS (HR 3.2, p=0.004). This was also reflected in a cumulative two-year incidence of relapse of 61% for MRD positive patients versus 15% for MRD negative patients (p

Description: HLA- haploidentical stem cell transplantation (SCT) has been shown to be a suitable alternative for treatment of hematopoietic malignancies if no matched donor is available. Haploidentical family members sharing one HLA-haplotype may differ in one or more HLA-antigens of the second haplotype. The risks are rejection of the graft and severe graft-versus-host disease (GVHD). In particular unmodified grafts may cause severe GVHD, and T-cell depleted grafts may be rejected. We have designed a protocol of unmodified marrow transplantation supplemented by G-CSF mobilized blood cells (MBC) 6 days after marrow transplantation from which CD6-positive cells are depleted. These cells facilitate engraftment and modify GVHD. Patients were conditioned with 12 Gy total body irradiation (TBI), donor leukocytes, antithymocyte globulin and cyclophosphamide, unmodified marrow was given on day 0 and CD6-depleted MBC on day 6. In a first series of 53 patients CD6 cells were depleted by indirect loading and depletion with goat-anti-mouse antibody coupled to Dynabeads. The second series comprised 22 patients whose MBC were depleted using the CliniMacs system with CD6-antibody directly bound to immunomagnetic beads. Table I shows the median and the range () of the cell numbers transplanted after CD6 depletion comparing the two methods. Table II shows the number of patients with acute GVHD in relation to the median of all given transplants. Rejection of the transplant was not observed in 71 evaluable patients. GVHD 〉= 2 occurred in 47 %, GVHD 〉= 3 in 21% of 70 evaluable patients. The incidence of acute GVHD was lower in patients given less CD4 cells (p=0.06), it was significantly lower in patients given MBC separated by immunomagnetic beads charged with the specific antibody (p 〈 0.02). The content of CD8-positive, NK-, B- and CD34-positive cells had no effect on the incidence of GVHD. We conclude from these results that transfusion of CD6-depleted MBC on day 6 facilitates engraftment of marrow from HLA-haploidentical donors without T cell depletion without jeopardizing engraftment and without severe GVHD, if CD4 cells are depleted. A particular advantage is the content of NK cells and CD8 T cells maintaining a potential GVL-effect. Tab.I CD34 x 10e6/kg CD56 x 10e6/kg CD19 x 10e6/kg CD8 x 10e6/kg CD4 x 10e6/kg Indirect labelling (N=53) 7.3 (0.4–35.8) 19.8 (4.8–65.4) 36.1(5.6–117.3) 5.8 (0.75–55) 3.9 (0.12–65.4) Direct labelling (N=22) 13.4(2.5–29.1) 17.1 (1.7–57.3) 48.7 (5.1–175) 2.0 (0.12–13.2) 0.47 (0.05–2.5) Table II aGVHD 0 aGVHD I–II aGVHD III–IV total CD4 2.28 x 10e6/kg 11 16 11 38 CD8 4.61 x 10e6/kg 16 13 8 37