In the era of Bortezomib-based Induction, intensification of Melphalan-based conditioning with Bortezomib does not improve Survival Outcomes in newly diagnosed Multiple Myeloma: a study from the Chronic Malignancies Working Party of the EBMT.

Bortezomib (Vel)- Melphalan 200 mg/m2 (Mel200) (Vel-Mel) has been utilised to intensify conditioning in autologous hematopoietic stem cell transplantation (AHCT) for multiple myeloma (MM). This EBMT registry-based study compared Vel-Mel with Mel200 during upfront AHCT. Between 2010 and 2017, MM patients who received Vel-Mel (n = 292) conditioning were compared with 4,096 Mel200 patients in the same 58 centres. Pre-AHCT, compared to Mel200 patients, Vel-Mel patients had similar International Staging System (ISS) scores and cytogenetic risk profiles; a similar proportion had received bortezomib-based induction (85% and 87.3%, respectively) though they were younger with a better performance status. Vel-Mel patients were more likely to achieve CR post-induction (40.6% vs 20.3%, p < 0.001) and by day 100 of AHCT (CR/VGPR: 70.2 % vs. 57.2%, p < 0.001). There was no difference in 3-year PFS (49% vs 46%, p = 0.06) or early post-AHCT mortality. In multivariable analysis, Vel-Mel associated with inferior PFS (HR: 1.69 (1.27-2.25, p < 0.001) and OS (HR:1.46 (1.14-1.86,p = 0.002), similar to negative effects on PFS of advanced ISS (HR:1.56 (1.33-1.83, p < 0.001), high-risk cytogenetics (HR:1.43(1.18-1.74, p < 0.001) and poor post-induction response(<=PR)(HR: 1.43(1.25-1.62, p < 0.001) Overall, despite superior pre- and post-AHCT responses, there was no improvement in PFS or OS following Vel-Mel. This data supports the findings of the smaller prospective IFM study.

Favorable outcomes of allogeneic hematopoietic stem cell transplantation with fludarabine-bendamustine conditioning and posttransplantation cyclophosphamide in classical Hodgkin lymphoma.

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with relapsed and refractory classic Hodgkin lymphoma (rrHL). However, the optimal conditioning regimen and GVHD prophylaxis for rrHL remain undetermined. The aim of this study was to investigate outcomes of allo-HSCT with a fludarabine plus bendamustine (FluBe) conditioning regimen and GVHD prophylaxis with posttransplantation cyclophosphamide (PTCY) in patients with rrHL. METHODS: Allo-HSCT results in 58 adult patients with rrHL were analyzed retrospectively. RESULTS: Three-year overall survival and event-free survival were 81% (95% CI 65-91) and 55% (95% CI 38-72), respectively. The cumulative incidence of relapse (CIR) at 3 years was 33% (95% CI 13-51). The cumulative incidence of aGVHD grade II-IV and severe aGVHD grade III-IV was 36% (95% CI 22-48) and 22% (95% CI 9-33), respectively. The cumulative incidence of cGVHD was 32% (95% CI 17-45), including moderate or severe cGVHD in 17% (95% CI 4-28). Patients who developed aGVHD after allo-HSCT had significantly lower CIR (24% vs 49%, p = 0.004). The use of PBSC as a graft source also significantly reduced CIR (4% vs 61%, p = 0.002). CONCLUSIONS: FluBe-PTCY allo-HSCT facilitates favorable outcomes, low toxicity, and mortality in rrHL.

Graft-versus-Host Disease Prophylaxis with Post-Transplantation Bendamustine in Patients with Refractory Acute Leukemia: A Dose-Ranging Study.

The prognosis of acute leukemia refractory to induction chemotherapy or immunotherapy is dismal. Salvage allogeneic hematopoietic stem cell transplantation (HSCT) is widely used option for these patients, but only 10% to 15% of patients are cured by the procedure. Preclinical studies indicate that substitution of post-transplantation cyclophosphamide with bendamustine (PTB) in a prophylaxis regimen may be associated with an augmented graft-versus-leukemia (GVL) reaction. The aim of this study was to establish the optimal dose of PTB and evaluate the antileukemic effect of HSCT with this type of graft-versus-host disease (GVHD) prophylaxis. In the prospective trial (NCT02799147), PTB was administered in doses of 140, 100, and 70 mg/m2 on days +3 and +4. Myeloablative conditioning with fludarabine and oral busulfan was provided to all patients. The first 12 patients received single-agent PTB, and subsequent patients received combination therapy with tacrolimus and mycophenolate mofetil (MMF). Inclusion criteria were acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL) refractory to at least one induction course of chemotherapy or target therapy and ≥5% clonal blasts in the bone marrow. The study cohort comprised 22 patients with AML and 5 with ALL. Seven patients were enrolled in the 140 mg/m2 group (due to a stopping rule), and 10 each were enrolled in the 100 mg/m2 and 70 mg/m2 groups. Primary refractory disease was documented in 41% of the patients, and secondary refractory was documented in 59%. The median blast count in the bone marrow at the start of the conditioning was 18% (range, 6% to 97%). Transplantation was performed with a matched sibling donor in 5 patients, a matched or mismatched unrelated donor in 15, and a haploidentical donor in 7. Engraftment was documented in 93% of the patients, including 89% with complete remission and 63% without measurable residual disease. After PTB prophylaxis, we observed an unusual complication, a cytokine release syndrome (CRS), in 70% of the patients, including grade 3 to 5 CRS in 44%. The most frequent clinical symptoms included high fever in 67% of patients, abnormal liver function tests in 67%, pancreatitis in 63%, skin vasculitis in 56%, enterocolitis in 48%, inflammation of oral mucosa in 37%, disseminated intravascular coagulation in 37%, and central nervous system toxicity in 26%. The development of CRS was associated with use of an HLA-mismatched donor (75% versus 20%; P = .0043). Classic acute GVHD was documented in 44% of the patients. Grade II-IV acute GVHD was associated with grade 3 to 5 CRS (67% versus 25%; P = .031). Moderate and severe chronic GVHD in the 100-day survivors were more often observed after single-agent PTB than after the combination immunosuppression (100% versus 18%; P = .002). A relatively low relapse rate was observed for this patient population. Three-year overall survival was 28% (95% confidence interval [CI], 13% to 46%), and event-free survival was 29% (95% CI, 13% to 46%). Nonrelapse mortality was 46% (95% CI, 25% to 64%), and the cumulative incidence of relapse was 26% (95% CI, 11% to 44%). No relapses were documented after day +100. There were no statistically significant differences among the dose groups (P = .3481); however, survival was higher in the 100 mg/kg group. Survival was higher in patients with AML compared with those with ALL (35% versus 0%; P = .0157). PTB represents a promising option to augment the GVL effect in refractory AML; however, the high CRS-associated mortality necessitates additional studies to reduce the risk of this complication. Thus, routine clinical application of PTB cannot be currently recommended. Combination immunosuppression with tacrolimus and MMF partially ameliorates these complications, at least in the setting of HLA-matched allografts. Biological mechanisms of CRS and GVL after PTB require further elucidation.

High prevalence of CD3, NK, and NKT cells in the graft predicts adverse outcome after matched-related and unrelated transplantations with post transplantation cyclophosphamide.

The predictive value of graft composition and plasma biomarkers on the outcome of allogeneic HSCT is well known for conventional GVHD prophylaxis based on calcineurin inhibitors with or without antithymocyte globulin. Currently, there is limited data whether these results could be translated to post transplantation cyclophosphamide (PTCy). The prospective extension cohort of NCT02294552 trial enrolled 79 adult patients with acute leukemia in CR. Twenty-six received matched-related bone marrow (BM) grafts with single-agent PTCy and 53 received unrelated peripheral blood stem cell graft (PBSC) with PTCy, tacrolimus, and MMF. The grafts were studied by the flow cytometry, and plasma samples were analyzed by ELISA. In the cluster and major component analysis, we determined that transplantation from donors with high content of CD3, NKT, and CD16-CD56 + subpopulations in the PBSC grafts was associated with poor immunological recovery and compromised event-free survival (50% vs. 80%, HR 2.93, p = 0.015) both due to increased relapse incidence and non-relapse mortality. The significant independent predictor of moderate and severe chronic GVHD was the high prevalence of and iNKT, Vß11, and double-positive cells in the PBSC grafts from young donors (HR 2.75, p = 0.0483). No patterns could be identified for BM grafts and for plasma biomarkers.

Risk-adapted GVHD prophylaxis with post-transplantation cyclophosphamide in adults after related, unrelated, and haploidentical transplantations.

INTRODUCTION: Although a number of studies were published on the efficacy of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis, no large studies prospectively evaluated this strategy in related, unrelated, and haploidentical grafts. METHODS: In this study, GVHD prophylaxis for 57 matched bone marrow (MBM) grafts consisted of single-agent PTCy, for 88 matched PBSC grafts (MPBSC) consisted of PTCy, tacrolimus, and mycophenolate mofetil (MMF) 30 mg/kg, and for 55 mismatched grafts (MMGs) consisted of PTCy, tacrolimus and MMF 45 mg/kg. RESULTS: The study met the primary endpoint to demonstrate equivalent rates of acute GVHD grade II-IV (11%, 17%,19%, P = .46), III-IV (7%, 2%, 6%, P = .41), and moderate and severe chronic GVHD (22%, 11%, 15%, P = .23). There was also no differences in non-relapse mortality (11% vs 15% vs 17%, P = .75), overall survival (63% vs 71% vs 56%, P = .72), event-free-survival (51% vs 66% vs 48%, P = .32) for MBM, MPBSC, and MMG groups, respectively. Toxicity was comparable between groups except higher incidence of nephrotoxicity in combination arms (P = .0005) and higher incidence of graft failures in MMG group (P = .004). CONCLUSION: The suggested risk-adapted PTCy-based prophylaxis is feasible and is associated with low GVHD incidence and mortality in all types of grafts. The study was registered on clinicaltrials.gov (NCT02294552).

Pharmacokinetic comparison of cyclosporin A and tacrolimus in graft-versus-host disease prophylaxis.

A number of studies were published with contradictory results comparing tacrolimus (Tac) and cyclosporine A (CsA) for graft-versus-host disease (GVHD) prophylaxis, but there are only few that accounted for pharmacokinetic (PK) parameters. In this study, we created a model based on median concentrations, variability of concentrations, and failures to maintain target levels that distinguished patients with low, intermediate, and high risks of acute GVHD (hazard ratios (HR) 1.77, 95%CI 1.36-2.32, p < 0.0001). This model was used to compare 95 patients with CsA and 239 with Tac GVHD prophylaxis. In the multivariate analysis, incorporating PK risk, no differences were observed for grade II-IV acute GVHD (HR 0.73, 95%CI 0.48-1.10, p = 0.13), but grade III-IV acute GVHD was lower in the Tac group (HR 0.47, 95%CI 0.28-0.78, p = 0.004). The observed difference was due to patients with high PK risk (HR 0.377, 95%CI 0.19-0.75, p = 0.005), but not with low and intermediate PK risk (p > 0.05). Patients in the Tac group had better GVHD relapse-free survival (HR = 0.659, p = 0.01) and comparable overall survival (p > 0.05). In conclusion, PK risk should be accounted for in comparisons of GVHD prophylaxis regimens with calcineurin inhibitors, and Tac was superior to CsA in patients with high, but not intermediate and low PK risk.

Graft-versus-Host Disease Prophylaxis in Unrelated Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil.

Clinical efficacy of post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis has been demonstrated in haploidentical and HLA-matched bone marrow but not in unrelated peripheral blood stem cell (PBSC) transplantations. Also, no direct comparisons have been published with current standard of care, combination of antithymocyte globulin (ATG), calcineurin inhibitors, and either methotrexate or mycophenolate mofetil (MMF). Eighty-six adult patients (median age 34 years; range, 18 to 59) with acute myeloblastic and lymphoblastic leukemia underwent unrelated PBSC transplantation with PTCy, tacrolimus, and MMF as GVHD prophylaxis in the single-center trial (clinicaltrial.govNCT02294552). The control group comprised 125 consecutive historical control patients who received ATG, tacrolimus, and methotrexate or MMF. Cumulative incidences of grades II to IV acute (19% versus 45%, P = .0003), grades III to IV acute (4% versus 27%, P < .0001), and chronic GVHD (16% versus 65%, P < .0001) were significantly lower in the PTCy compared with the ATG group. PTCy-based prophylaxis was associated with reduced incidence of nonrelapse mortality (16% versus 36%, P = .005; HR, .55; 95% CI, .34 to .89) and improved overall survival (69% versus 40%, P = .0007; HR, .43; 95% CI, .26 to .70), event-free survival (65% versus 38%, P = .0006; HR, .49; 95% CI, .31 to .78), and GVHD relapse-free survival (52% versus 12%, P < .0001). PTCy-based prophylaxis also had a better safety profile compared with ATG with reduced incidence of veno-occlusive disease, cytomegalovirus reactivation, invasive mycosis, and reduced severity of mucositis. In this study we demonstrated that PTCy in combination with tacrolimus and MMF is a safe and effective GVHD prophylaxis for unrelated PBSC transplantation. Although there are several limitations of the historical control approach, this study suggests the superiority of a PTCy-based approach over an ATG-based prophylaxis.