Grade II-IV Graft-versus-host Disease Research Articles

Graft-Versus-Leukemia Effect after Haplo-Identical Stem Cell Transplantation with Post-Transplant Cyclophosphamide in Patients with AML- No Association with Graft-Versus-Host Disease: A Study on Behalf of the Acute Leukemia Working Party of EBMT

Introduction. Allogeneic stem-cell transplantation (SCT) is a curative approach in acute myeloid leukemia (AML) by providing dose-intensive chemo-radiotherapy and enhancing a graft-versus-leukemia (GVL) effect. The GVL effect is provided by alloimmune T- cells and is usually closely associated with graft-versus-host disease (GVHD). Patients with GVHD have a lower incidence of relapse, but at high grades a higher incidence of non-relapse mortality (NRM). However, GVL can also occur independently of GVHD. The use of haplo-identical SCT is rapidly increasing over the last decade due to the introduction of non-T depleted methods, in particular with post-transplant cyclophosphamide (PTCy), with expected outcomes that are similar to other donor sources. The GVL effect after T- depleted haplo-identical SCT is mostly related to natural-killer cell alloreactivity and is not necessarily associated with GVHD. However, there is no definite data whether GVL after SCT in the non-T depleted setting is similarly associated with GVHD as in the matched donor setting.Methods. We assessed the impact of acute and chronic GVHD on SCT outcomes in patients with AML following non-T depleted haplo-identical SCT with PTCy, by using a series of landmark analyses.Results. The study included 605 patients with AML in CR1 (73%) or CR2 (27%) after non-T depleted haplo-identical SCT with PTCy, given during the years 2009-2016. The median age was 53 years (range, 18-76). 71% had myeloablative conditioning and 29% had reduced-intensity conditioning . The overall rate of acute GVHD grade II-IV and III-IV was 28.4% and 8.0%, respectively. The rates of chronic GVHD all grades and extensive were 32.7% and 12.3%, respectively. The rate of relapse and NRM were 21.8% and 18.2% and the rates of leukemia-free survival (LFS) and overall survival, 2 years after SCT were 59.9% and 64.1%, respectively. 509 patients were alive and leukemia-free 100 days after transplant. 366 had no prior acute GVHD at this landmark, 107 had acute GVHD grade II and 36 had grade III-IV. The overall rate of subsequent relapse was 20.3%, 18.3% and 11.9%, respectively (P=0.60). The overall rates of subsequent NRM were 10.3%, 19.0% and 35.7%, respectively (P<0.001). The rates of LFS were 69.4%, 62.6% and 52.4%, respectively (P=0.01). Multivariate analysis showed that acute GVHD grade II before day 100 was not associated with subsequent relapse (Hazard ratio (HR) 1.02, P=0.93), had borderline association with NRM (HR 1.79, P=0.09) and no association with LFS (HR 1.28, P=0.27). Acute GVHD grade III-IV before day 100 was not associated with subsequent relapse (HR 0.92, P=0.87), while it was associated with higher NRM (HR 5.23, P<0.001) and inferior LFS (HR 2.35, P=0.003). Both acute GVHD grade II and grade III-IV were associated with subsequent extensive chronic GVHD, HR 2.02 (P=0.04) and 6.93 (P<0.001), respectively. 393 patients were alive and leukemia-free 6 months after transplant. Out of them 316 had no prior chronic GVHD at this landmark, 55 had limited and 22 extensive chronic GVHD. The overall rate of subsequent relapse was 14.3%, 9.2% and 23.9%, respectively (P=0.60). The overall rates of subsequent NRM were 7.3%, 10.4% and 31.7%, respectively (P=0.003). The rates of LFS were 78.4%, 80.4% and 44.4%, respectively (P=0.01). Multivariate analysis showed that limited grade chronic GVHD occurring before 6 months was not associated with subsequent relapse (HR 0.69, P=0.44), NRM (HR 1.43, P=0.55) or LFS (HR 0.88, P=0.74). Extensive chronic GVHD was not associated with subsequent relapse (HR 1.44, P=0.56) but was associated with higher NRM (HR 5.77, P=0.004) and inferior LFS (HR 2.75, P=0.01). Similar results were seen for prior chronic GVHD at the 1 year landmark.Conclusions. By a series of landmark analyses at 100 days, 6 months and 1 year after SCT, we did not find any association of acute GVHD grade II or III-IV or chronic GVHD (limited or extensive) with subsequent relapse. Acute GVHD grade III-IV was associated with a higher NRM and lower LFS rates after day100. All grades of acute GVHD were associated with a higher incidence of chronic GVHD. Previous extensive chronic GVHD was also associated with a higher NRM and a lower LFS. GVL is thus not associated with GVHD after non T-deleted haplo-identical SCT with PTCy. Future novel strategies for prevention of significant GVHD are warranted. DisclosuresAngelucci:Vertex Pharmaceuticals Incorporated (MA) and CRISPR CAS9 Therapeutics AG (CH): Other: Chair DMC; Roche Italy: Other: Local (national) advisory board; Novartis: Honoraria, Other: Chair Steering Comiittee TELESTO Protocol; Celgene: Honoraria, Other: Chair DMC; Jazz Pharmaceuticals Italy: Other: Local ( national) advisory board. Mohty:MaaT Pharma: Consultancy, Honoraria.

Related and Unrelated Donor Transplantation for β Thalassemia Major: Results of an International Survey

▪We studied 1110 children, adolescents and young adults with β thalassemia major transplanted with grafts from HLA-matched relative (n=677; 61%), HLA-mismatched relative (n=78; 7%), HLA-matched unrelated (n=252; 23%) and HLA-mismatched unrelated (n=103; 9%) donors in 2000 - 2016. The median age at transplantation was 6 years (range <1 - 25). Eight-five percent received ≥20 transfusions and 88% were reported as “inadequately” chelated. Most patients (73%) had hepatomegaly (2 cm or greater below the right costal margin) and 50% reported serum ferritin ≥2500 ng/mL. The Pesaro risk class could be assigned for only 526 (47%) of transplantations: Class I (39%), Class II (8%) and Class III (54%). Liver biopsies are not routinely performed in China. All patients received a myeloablative transplant conditioning regimen; 34% received busulfan (Bu; IV 8.4 - 13.2 mg/kg) + cyclophosphamide (Cy; 100-120 mg/kg) + thiotepa (TT; 5 mg/kg) + fludarabine (FLU; 200 mg/m2), 23%, Bu (IV 11-16 mg/kg) + Cy (100-120 mg/kg) + FLU (200 mg/m2), 22%, Bu (PO or IV 16 mg/kg) + Cy (200 mg/kg), 15%, treosulfan (42 mg/m2) + TT (8 mg/kg) + FLU (120 mg/m2) and the remaining 5%, Bu (PO or IV 12 or 16 mg/kg) or melphalan (140 mg/m2) + FLU (150 - 180 mg/m2) ± TT (8-10 mg/kg). Bu dosing was based on pharmacokinetic studies. In vivo T-cell depletion (anti-thymocyte globulin), graft-versus-host disease (GVHD) prophylaxis and graft type were confounded with transplant conditioning regimen. Ninety percent of transplants were in 2006-2016. The median follow-up was 48 months (range 3 - 193). The day-28 incidence of neutrophil recovery in patients aged ≤6 years, 7-15 years and 16-25 years were 92%, 93%, and 82%, respectively, p=0.28. The corresponding day-100 incidence of platelet recovery were 93%, 90%, and 70%, respectively, p<0.001. The 5-year incidence of graft failure was higher for patients aged 16-25 years at 23% compared to 8% and 10% for patients aged ≤6 and 7-15 years (p=0.01). Risk factors associated with overall mortality and treatment failure (graft failure or death from any cause) are shown in Table 1. Overall survival and disease-free survival (alive with sustained engraftment) were highest in children aged ≤6 years and received grafts from an HLA-matched sibling or HLA-matched unrelated donor. The 5-year probabilities of overall survival for patients aged ≤6 years, 7-15 years and 16-25 years were 91%, 83% and 55%, respectively, p<0.001. The corresponding probabilities for disease-free survival were 87%, 79% and 55%, p<0.001 (Figure 1). In the subset of patients for whom Pesaro risk class could be assigned, mortality and treatment failure were higher for Class II and Class III compared to Class I (Table 1). We tested for an effect of transplant center on survival and found none. Risks for acute grade II-IV GVHD were higher after HLA-mismatched related (hazard ratio [HR] 3.04, p<0.001), HLA-matched unrelated (HR 3.35, p<0.001) and HLA-mismatched unrelated (HR 2.21, p=0.003) compared to HLA-matched sibling transplants. Similarly, chronic GVHD risks were also higher after HLA-mismatched related (HR 2.64, p=0.002), HLA-matched unrelated (HR 2.13, p=0.018) and HLA-mismatched unrelated (HR 4.25, p<0.001) compared to HLA-matched sibling transplants. Nevertheless, mortality and treatment failure risks did not differ after HLA-matched sibling and HLA-matched unrelated donor transplants. In conclusion, transplantation for β thalassemia major should be offered early (aged 6 years or younger) from an HLA-matched sibling or an HLA-matched unrelated donor. Mismatched related donor transplants were associated with higher treatment failure and overall mortality. These data suggest cautious use of the following conditioning regimens: Bu + Cy, treosulfan + TT + FLU and Bu or melphalan ± TT ± FLU although identifying an optimal conditioning regimen(s) are best studied in the setting of carefully controlled clinical trials. [Display omitted] DisclosuresDvorak:Jazz Pharmaceuticals: Consultancy; Chimerix, Inc.: Membership on an entity's Board of Directors or advisory committees. Shenoy:Novartis, Vertex, Bluebird Bio: Honoraria, Membership on an entity's Board of Directors or advisory committees. Walters:Sangamo Therapeutics: Consultancy; bluebird bio: Research Funding; ViaCord Processing Lab: Other: Medical Director; AllCells Inc.: Other: Medical Director.

Peritransplantation Ruxolitinib Prevents Acute Graft-versus-Host Disease in Patients with Myelofibrosis Undergoing Allogenic Stem Cell Transplantation

JAK inhibition by ruxolitinib is approved for treating myelofibrosis and also has shown efficacy in treating steroid-resistant acute and chronic graft-versus-host disease (GVHD). In 12 patients with myelofibrosis (median age, 63 years; range, 43 to 71 years) who were treated with ruxolitinib and underwent allogeneic stem cell transplantation (ASCT), ruxolitinib was continued (2 × 5 mg daily) until stable engraftment. No graft failure was observed, and leukocyte engraftment was achieved after a median of 12 days (range, 11 to 18 days). One patient developed fever of unknown origin after discontinuation of ruxolitinib; otherwise, no withdrawal syndrome was observed. Overall, only 1 patient each experienced acute GVHD grade I or II, resulting in an 8% incidence of acute GVHD grade II-IV at day +100, with no nonrelapse mortality. Complete chimerism was achieved in 11 patients after a median of 40 days, and molecular clearance of the underlying driver mutation was noted in 10 patients after a median of 32 days. Cytomegalovirus (CMV) reactivation occurred in 5 patients (41%), 1 of whom had CMV colitis as well, but all resolved after ganciclovir treatment. In 2 patients, ruxolitinib had to be discontinued on day 17 and day 18 after ASCT due to cytopenia after engraftment. Levels of inflammatory cytokines IL-8, IL-10, IL-6, TNFR2, INF-α, and INF-β were reduced after ruxolitinib treatment. After day +100, 4 patients developed acute GVHD (1 with grade I, 2 with grade II, and 1 with grade III) after tapering of cyclosporine, and all patients were alive at a median follow-up of 17 months (range, 12 to 18 months).

Change of apheresis device decreased the incidence of severe acute graft-versus-host disease among patients after allogeneic stem cell transplantation with sibling donors.

The composition of the graft used for allogeneic hematopoietic stem cell transplantation (HSCT) is important for the treatment outcome. Different apheresis devices may yield significant differences in peripheral blood stem cell graft cellular composition. We compared stem cell grafts produced by Cobe Spectra (Cobe) and Spectra Optia (Optia) with use of the mononuclear cell (MNC) protocol, and evaluated clinical outcome parameters such as graft-versus-host disease (GvHD), transplant-related mortality (TRM), relapse, and overall survival. During 5 years, 31 Cobe Spectra and 40 Spectra Optia grafts were analyzed for CD34, CD3, CD4, CD8, CD19, and CD56 cell content. Clinical outcome parameters were correlated and compared between the two patient groups using different apheresis devices. Optia grafts contained fewer lymphocytes compared to Cobe (p < 0.001). Optia grafts had a significantly lower incidence of acute GvHD Grades II through IV (Cobe 45% vs. Optia 23%; p = 0.039) and TRM (16% vs. 2.5%; p < 0.05) but higher chronic GvHD (32% vs. 67%; p = 0.005) compared to Cobe grafts. Finally, the multivariate analysis showed a significant correlation among the different apheresis devices and both acute GvHD II through IV and severe chronic GvHD. The multivariate analysis also showed a significant correlation between the CD3+ cell dose and the incidence of severe acute GvHD. Optia-obtained grafts yielded a lower acute GvHD Grades II-IV and TRM risk, but had no impact on relapse or overall survival in this study. Understanding and further improvement of peripheral blood stem cell (PBSC) apheresis techniques may be used in the future to personalize HSCT by, for example, fine-tuning the GvHD incidence.

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

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. 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) 30mg/kg, and for 55 mismatched grafts (MMGs) consisted of PTCy, tacrolimus and MMF 45mg/kg. 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). 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).

Comparison of Different Rabbit Anti-Thymocyte Globulin Formulations in Allogeneic Stem Cell Transplantation: Systematic Literature Review and Network Meta-Analysis

Since 2000, various phase III randomized controlled trials (RCTs) have investigated the efficacy of rabbit antithymocyte globulin (ATG) in patients following allogeneic stem cell transplantation (allo-SCT). Comparisons of different ATG formulations are lacking, however. Our aim was to synthesize all published efficacy evidence to enable a comparison of all available formulations of rabbit ATG in the allo-SCT setting. We performed a systematic literature review to identify all available phase III RCT evidence. We searched the Cochrane Library, MEDLINE, MEDLINE In-Process, and the website www.ClinicalTrials.gov. In addition, a trial presented at the Annual Meeting of the American Society of Hematology 2016 was added to include the most recent evidence. We identified a total of 6 RCTs, including 2 formulations: anti–T lymphocyte globulin (ATLG; Grafalon, Neovii Biotech, Lexington, MA) and polyclonal globulin immunized with human thymocytes (Thymoglobulin [Thymo]; Genzyme-Sanofi, Cambridge, MA). The evidence was synthesized using a conventional network meta-analysis (NMA). The best treatment for preventing graft-versus-host disease (GVHD) was ATLG, which had a more favorable hazard ratio (HR) compared with standard treatment (chronic GVHD: HR, .42; 95% confidence interval [CI], .31 to .56; acute GVHD grade II-IV: HR, .54; 95% CI, .39 to .73; acute GVHD grade III-IV: HR, .50; 95% CI, .29 to .86), whereas both ATLG and Thymo were at least similarly effective in terms of transplantation-related mortality (TRM) (ATLG: HR, .90; 95% CI, .61 to 1.32; Thymo: HR, .90; 95% CI, .56 to 1.44). Thymo tended to be the better treatment option regarding overall survival (OS) (HR, .86; 95% CI, .59 to 1.26). Our NMA provides the first report of the relative efficacy of all available rabbit ATG formulations in patients undergoing allo-SCT. Until additional data from randomized head-to-head comparisons are available, based on the present analysis, ATLG seems to be the best option to prevent chronic and acute GVHD. Both formulations show similar efficacy in terms of TRM, whereas Thymo appears to be the better treatment option in terms of OS.

Bortezomib, rituximab, and risk of graft-versus-host disease (GVHD) after BEAM conditioning for allogeneic stem cell transplantation (alloSCT).

e18543 Background: GVHD remains the main limitation of alloSCT and is exacerbated by the intensity of the conditioning regimen. In a recent study, the risk of acute grade II-IV GVHD and extensive chronic GVHD (cGVHD) after a nonmyelobaltive (NMA) regimen was 11%, and 26%, respectively (Khouri I. Blood 2014 124:2306). Higher rates were previously observed (32% and 54%, respectively) with the BEAM regimen. Based on clinical data showing a reduction in GVHD with the use of rituximab or bortezomib, we conducted a phase I/II study evaluating the addition of bortezomib to rituximab+BEAM in patients (pts.) who were not eligible for NMA alloSCT. Methods: Bortezomib was administered at 1.3 mg/m2 IV on days -13, -6, -1 and +2. The dose was later reduced to 1 mg/m2 after the occurrence of C. Difficile colitis in the first 3 pts. leading to 2 deaths. Rituximab was given on day -13 at a dose of 375 mg/m2, then at 1000 mg/m2 on days -6, +1, and +8 of alloSCT. BEAM was administered between days -6 and -1. All pts. received our standard GVHD prophylaxis with tacrolimus and methotrexate. In addition, thymoglobulin 1 mg/kg IV was given on days -2, and -1 in patients receiving matched unrelated donor (MUD) or mismatched (MM) transplants. Results: Thirty-nine pts. were studied. Median age was 54 yrs. Thirteen (33%) and 26 (67%) pts. had indolent or aggressive lymphoma histologies, respectively. Sixteen (41%) pts. were refractory. Twenty-two (56%) received alloSCT from HLA-compatible siblings, 16 (41%) from MUDs and 1 (3%) from mm donors. Peripheral blood was the source of stem cells in 97% of pts. ABO and CMV-mismatch rates were 56% had 50%, respectively. Median follow up surviving patients was 65 mos. Five-year OS and PFS rates were 35% and 28%, respectively. The CI of acute grade II-IV, III-IV, and cGVHD were 55%, 34%, and 41%, respectively. No predictor for acute GVHD was identified. Instead, we found that sex-mismatched transplants were predictive of a higher risk of cGVHD ( P= 0.01). Conclusions: The current trial is the first one evaluating the safety and efficacy of bortezomib plus rituximab as a part of the BEAM regimen for alloSCT. A better prophylaxis regimen is needed to lessen the risk of GVHD in this setting. Clinical trial information: NCT00439556.

95 - Biomarkers Predict Graft-Vs-Host Disease Outcomes Better Than Clinical Response after One Week of Treatment

Graft-versus-host disease (GVHD), the primary cause of non-relapse mortality (NRM) following allogeneic hematopoietic stem cell transplantation, does not always respond to treatment with high dose systemic corticosteroids. We have recently shown that a combination of three biomarkers (TNFR1, ST2, and REG3α) measured at onset of GVHD can predict day 28 response to treatment and 6-month NRM (Levine, Lancet Haem, 2015). Our goal in the current study was to determine if the same biomarker-based Ann Arbor GVHD algorithm can alsopredict treatment response andmortality whenapplied after one week of systemic corticosteroid treatment. The study population consisted of 378 patients (pts) with acute GVHD from 11 centers in the Mount Sinai Acute GVHD International Consortium. All pts were treated with systemic steroids and provided a plasma or serum sample obtained after one week of treatment (±3 days). The median starting dose of systemic steroids for Grade II-IV GVHD was 2.0 mg/kg/day and for Grade I was 1.0 mg/kg/day, after which treatment varied. Patients were divided into test (n=236) and validation (n=142) cohorts. We applied the Ann Arbor GVHD algorithm to concentrations of TNFR1, ST2, and REG3α measured after one week of treatment to generate a predicted probability of 6-month NRM, which we term the treatment score (TS). We employed unsupervised k-medoidclustering to partition TS values from the test cohort into two groups (high and low). This unbiased approach identified a high score group made up of 25% of pts (n=58) in the test cohort. We observed that the day 28 response rate (complete, CR + partial, PR) was significantly lower in pts with high scores compared to low scores in the test cohort (24% vs 65%, p Approximately half of the pts in each cohort (test: 48%; validation: 44%) responded (CR+PR) to the first week of steroids and these ptshad significantly lower 6-month NRM than non-responders (NR) (test: 17% vs 36%, p=0.0002; validation: 13% vs 36%, p=0.0014). Yet the TS continued to stratify mortality risk independently of clinical response. In the test cohort, pts with a high score comprised 16% of all early responders and experienced more than twice the NRM of early responders with a low score (33% vs 13%, p=0.022) (Fig 2A). Conversely, test cohort pts who did not respond by day 7, but had a low score, fared much better than non-responders with a high score (NRM 21% vs 68%, p In conclusion, a treatment score based on three GVHD biomarkers measured after one week of steroids stratifies pts into two groups with distinct risks for treatment failure and 6-month NRM. It is particularly noteworthy that the TS identifies two subsets of pts with steroid refractory (SR) GVHD who have highly different outcomes (Fig 2B/D). The much larger group, approximately two thirds of all SR pts, may not need the same degree of treatment escalation as is traditional for clinical non-response, and thus overtreatment might be avoided. Because the TSis measured at a common decision making time point, it may prove useful to guide risk-adapted therapy. Disclosures Mielke:Novartis: Consultancy; MSD: Consultancy, Other: Travel grants; Celgene: Other: Travel grants, Speakers Bureau; Gilead: Other: Travel grants; JAZZ Pharma: Speakers Bureau. Kroeger:Novartis: Honoraria, Research Funding. Chen:Incyte Corporation: Consultancy, Membership on an entity9s Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Jagasia:Therakos: Consultancy. Kitko:Therakos: Honoraria, Speakers Bureau. Ferrara:Viracor: Patents & Royalties: GVHD biomarker patent. Levine:Viracor: Patents & Royalties: GVHD biomarker patent.

The combination of cyclosporine and mycophenolate mofetil is less effective than cyclosporine and methotrexate in the prevention of acute graft-versus host disease after stem-cell transplantation from unrelated donors.

Acute graft-versus-host disease (GVHD) is the major treatment-related complication after stem-cell transplantation (SCT) from unrelated-donors. Several GVHD prophylaxis regimens have been explored, but no regimen has shown superiority. We analyzed transplantation outcomes in 472 consecutive unrelated-donor SCT recipients, using cyclosporine/methotrexate (MTX, n=314) or cyclosporine/mycophenolate-mofetil (MMF, n=158) for GVHD prophylaxis. Neutrophil engraftment was faster after MMF, days 11 and 14, respectively (P=.001). Acute GVHD grade II-IV and III-IV occurred in 47% and 28% after MMF compared to 27% and 12% after MTX, respectively (P<.001). Nonrelapse mortality (NRM) was 44% and 24%, respectively (P<.001). Death associated with GVHD occurred in 25% and 8% (P<.0001), while other NRM causes occurred in 19% and 16%, respectively (P=.39). Relapse mortality was similar. Overall survival was better after MTX, 40% and 29%, respectively (P=.006). However, this difference had only borderline significance when adjusting for differences in patient characteristics (HR, 1.3, P=.08). To minimize potential selection bias we analyzed outcomes on the basis of an intention-to-treat like analysis. During the years 2008-2009, the leading GVHD prophylaxis regimen for unrelated-donor SCT included MMF (89% of transplants). During the other periods, MTX was used predominantly (82% of transplants). The two periods were otherwise well-matched. Acute GVHD occurred more often in 2008-2009. Death associated with GVHD occurred more often, while other NRM causes occurred less often resulting in similar NRM and overall survival. In conclusion, cyclosporine/MMF is associated with faster engraftment and possibly with less organ toxicity than cyclosporine/MTX. However, it is associated with increased rates of acute GVHD and GVHD-associated deaths.

Sirolimus Combined with Mycophenolate Mofetil (MMF) and Cyclosporine (CSP) Significantly Improves Prevention of Acute Graft-Versus-Host-Disease (GVHD) after Unrelated Hematopoietic Cell Transplantation (HCT): Results from a Phase III Randomized Multi-Center Trial

▪A randomized 3-arm Phase II trial involving 208 older or medically infirm patients (pts) with hematological malignancies given unrelated HCT after minimal intensity conditioning demonstrated that adding sirolimus to tacrolimus and MMF resulted in less grades II-IV GVHD, less steroid use, and less CMV reactivation (Hematologica 2014; 99(10); 1624). Based on this trial we designed a Phase III multi-site trial comparing triple therapy with sirolimus/MMF/CSP (Arm2) to the standard immunosuppressive regimen of MMF/CSP (Arm1). The primary objective of the trial was to compare the respective incidences of grades II-IV acute GVHD. Secondary objectives included comparing non-relapse mortality, survival, and progression-free survival. Pts in both Arms received CSP 5 mg/kg bid starting on day -3 through day 96 with a taper through day 150. In the first 28 days after HCT CSP was targeted to 400 and 350ng/ml in Arm1 and Arm2, respectively and 120-360ng/ml after day 28 in both arms. Arm 1: MMF was given daily at 15 mg/kg Q8 hours until day +30, reduced to 15 mg/kg Q12 hours until day 150, then tapered through day 180. Arm 2: MMF was given daily at 15 mg/kg Q8 hours until day +30, reduced to 15 mg/kg Q12 hours until day 40, then discontinued (no taper). In addition to the MMF/CSP, sirolimus was administered starting on day -3 at 2.0 mg/day through day 150 with a target level of 3-12ng/ml, with tapering off by day 180. The target enrollment was 300 pts with a built-in interim analysis for futility. At the time of the interim analysis, 158 pts ineligible for high-dose conditioning had been enrolled (Nov. 2010 to Jan. 2016: Arm1 n=74, Arm2 n=84) Their median age was 62 (range 18-79) yrs. The median HCT comorbidity index (HCT-CI) was 3 (range 0-10). Five pts had 6 previous allogeneic HCT and 32 pts (20%) had 36 previous autologous HCT. All pts were matched for HLA-DRB1 and -DQB1 at the allele level: 8 had single allele mismatches at HLA-A, -B or -C and the remainder (n=150) were fully HLA-matched. Diagnoses included AML (n=64), MDS/MPD (n=30), NHL (n=23), MM (n=13), CLL (n=13), ALL (n=11), HL (n=2), and CML (n=2). Randomization was stratified by transplant center. Unmodified PBSC grafts contained a median of 8.0 ×106 CD34 and 2.9 × 108 CD3 cells/kg. Conditioning consisted of fludarabine 90mg/m2 and 2-3 Gy TBI. Sustained donor engraftment occurred in 99% of pts. The median follow-up of surviving pts was 24 (range, 1-65) months. Table 1 and Figures 1 and 2 summarize results. The day-100 cumulative incidences of grades II-IV acute GVHD were in Arm1: 53%, and Arm2: 25% (p=0.0001) and the grades III-IV acute GVHD were in Arm1: 8%, Arm2: 2% (p=0.04). The 1-year cumulative incidence of chronic extensive GVHD was similar between Arm1: 49%, and Arm2: 48% (p=0.94). The 1-year cumulative incidence of non-relapse mortality was lower in Arm2 (Arm1: 15% and Arm2: 5%; p=0.007), while relapse/progression was similar at 1 year for Arm1: 21%, and Arm2: 19% (p=0.86). The 1-year overall and progression-free survivals for Arm1 vs. Arm2 were: 72% vs. 85% (p=0.03), and 65% vs. 77% (p=0.08); respectively. T-cell (CD3) donor chimerism was lower in Arm 2 on day 28 (median, Arm1 85%; Arm2 80%; p=0.05) with no differences seen in granulocyte (CD33: Arm1 98%, Arm2 95%) or NK cell (CD56: Arm1 96%, Arm2 97%) donor chimerisms.In summary, the interim analysis showed that adding sirolimus to MMF and CSP not only reduced the risks of grades II-IV but also of grades III-IV acute GVHD and of non-relapse mortality without increasing the risk of relapse or progressive malignancy. Based on these findings and the significantly improved survival, the DSMB recommended the trial be closed. This triple immunosuppressive regimen should, therefore, be considered in the future as the standard of care in pts given unrelated donor grafts after minimal intensity conditioning. [Display omitted] [Display omitted] [Display omitted] DisclosuresPulsipher:Novartis: Consultancy, Other: Study Steering Committee; Chimerix: Consultancy; Jazz Pharmaceutical: Consultancy; Medac: Other: Housing support for conference.

Antithymocyte Globulin-Based Prophylaxis for Graft Versus Host Disease Compared to Post-Transplant Cyclophosphamide-Based Prophylaxis in Matched Unrelated Donor Transplantation

INTRODUCTIONPost-transplant high-dose cyclophosphamide (PTCy) has shown to prevent graft versus host disease (GvHD) after haploidentical allogeneic hematopoietic cell transplantation (HSCT). Although less extended, its use after matched unrelated donor (MUD) HSCT in combination with additional immunosuppression has been encouraging. The aim of this study was to analyze and compare outcomes of antithymocyte globulin based (ATG) versus PTCy-based GvHD prophylaxis in matched unrelated donor HSCT.MATERIAL AND METHODSWe retrospectively analyzed 51 MUD (8/8 HLA-matched) transplants performed in two Spanish centers: 25 received ATG-based prophylaxis and were performed from 2010 to 2013, and 26 received PTCy-based prophylaxis and were performed from 2013 to 2016.RESULTSCharacteristics of patients and post-HSCT complications are detailed in Table 1. There were no significant differences in age, gender, diagnosis and Disease risk index. For the ATG group, conditioning regimen consisted of fludarabine combined with busulfan (80%) or melphalan (12%), and TBI plus cyclophosphamide (8%). All patients received ATG 2 mg/kg from day -4 to day -2 followed by methotrexate and cyclosporine (CsA). Conditioning regimen for patients from the PTCy group consisted of fludarabine and busulfan (85%) and thiotepa combined with busulfan and fludarabine (15%). GvHD prophylaxis consisted of PTCy 50 mg/kg on days +3 and +4, combined with: CsA plus MMF in 57%, CsA alone in 31%, or tacrolimus plus MMF or sirolimus in 8%, and tacrolimus alone in 4%.With a median follow-up of 58 months for the ATG group and 12 months for the PTCy group, there were no statistically significant differences in overall survival at 18 months (56% vs 85%, p=0.08), in event free survival (56% vs 68%, p=0.5), and in cumulative incidence of relapse (12% vs 18%, p=0.3). Non-relapse mortality at 12 months was significantly higher in the ATG group (32% vs 10%, p = 0.04). The ATG group presented more cases of hepatic toxicity grades I-IV and hemorrhagic cystitis than PTCy group (Table 1). Cumulative incidence of acute GvHD grades II-IV was higher in the ATG group as well as acute GvHD grades III-IV, with no differences in moderate/severe chronic GvHD incidence (Figure A).CONCLUSIONIn our experience, albeit differences in follow-up and limited number of patients, we conclude that PTCy combined with additional immunosuppression after MUD allogeneic HSCT offers lower rates of acute GvHD together with less toxicity and non-relapse mortality compared to ATG-based prophylaxis. Further analysis including larger series and follow-up are needed to confirm these observations. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The Impact of Antithymocyte Globulin (ATG) Dose in Allogeneic Hematopoietic Stem Cell Transplantation with HLA Mismatched Donors

Background: Antithymocyte globulin (ATG) is usually included in conditioning regimens in hematopoietic stem cell transplantation (HSCT) from HLA mismatched donors to reduce the incidence of graft versus host disease (GVHD) and rejection. In this study, we intended to assess the clinical impact of ATG dose in HSCT from HLA mismatched donors.Patients and Methods: We retrospectively analyzed 268 consecutive patients with acute myeloid leukemia (n=159), acute lymphoblastic leukemia (n=49) or myelodysplastic syndrome (n=60) receiving busulfan based conditioning and HSCT with HLA mismatched sibling, unrelated, or haplo-identical family donors in five centers of Korea between 2005 and 2015.Results: The median age was 44.5 (range, 15-75) years. Fourty-two patients were treated with myeloablative conditioning and 226 patients with reduced intensity conditioning regimen. ATG at a total dose of 0 (n=31), 2.5-7.5 mg/kg (n = 16), 9 mg/kg (n = 164) or 12mg/kg (n=57) was given to patients according to protocol. 140 patients received HSCT in complete remission and 73 patients in relapse or refractory status. The median follow up duration for surviving patients was 33.8 (range, 2.0-100.6) months. The 3-year overall survival (OS) and event free survival (EFS) rate for all patients was 44.7% and 39.2% There was no significant difference of OS according to ATG dose (P=0.153), but ATG dose of 2.5-7.5mg/kg was significantly associated with better EFS than 0, 9 mg/kg, or 12mg/kg of ATG groups (79.1% vs. 45.4%, 38.9%, and 31.7%, respectively, P=0.038) (Table 1). In addition, ATG dose significantly affected on relapse (P=0.046). The relapse incidence in patients receiving 2.5-7.5 mg/kg of ATG was lower compared to those given 0, 9, or 12 mg/kg of ATG (6.7% for 2.5-7.5mg/kg of ATG group vs. 29.5%, 34.0%, and 46.9% for 0, 9, and 12 m/kg of ATG groups, respectively). The incidences of acute GVHD grades II-IV were 32.6%, 25.0%, 29.4% and 24.6% in patients receiving 0. 2.5-7.5, 9, and 12 mg/kg of ATG, respectively. The incidence of extensive chronic GVHD tended to be lower according to the increase of ATG dose (36.8%, 34.5%, 27.4%, and 21.1% for 0. 2.5-7.5, 9, and 12 mg/kg of ATG dose, respectively).In multivariate analysis, ATG dose of 9 mg/kg (P=0.023) and 12 mg/kg (P=0.036) was associated with shorter EFS compared to 2.5-7.5 mg/kg of ATG.Conclusion: 9mg/kg of ATG dose or more in HLA mismatched busulfan based HSCT with HLA mismatch donors increased the risk for relapse and reduced the EFS. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Final Results of a Multicenter Prospective Phase II Trial of Allogeneic Transplantation for Relapsed/Refractory CD20+ B-Cell Lymphomas: Effect of Rituximab on Graft-Versus-Host Disease-Free/Relapse-Free Survival (GRFS)

Introduction: Patients with refractory and relapsed B-cell lymphomas have few curative options. Despite novel target therapies, only patients receiving allogeneic stem cell transplantation (alloSCT) can achieve a long-term disease control. A lot of effort has been done over the last years to produce strategies reducing non-relapse mortality (NRM) without damaging the graft-versus-lymphoma effect. We conducted a multicenter prospective phase II trial to evaluate the benefit of high-dose Rituximab (R) in the conditioning regimen before alloSCT. The primary end-point of the study was progression-free (PFS) survival. We evaluated also the long-term outcome with the novel composite end-point of graft-versus-host disease-free/relapse-free survival (GRFS). Methods:The study enrolled 121 adult patients who received alloSCT for relapsed/refractory B-cell lymphomas [n=35 (28%) follicular lymphomas; n=29 (24%) chronic-lymphocytic leukemia; n=35 (28%) diffuse large B-cell lymphomas; n= 22 (18%) mantle cell lymphomas]. The median age was 52 years (range, 23-65). Seventy-four pts (61%) failed a previous autograft. The conditioning regimen consisted of thiotepa (12 mg/kg), cyclophosphamide (60 mg/kg) and fludarabine (60 mg/m2) and high-dose of rituximab (500 mg/m2 on day-6),. Graft-versus-host disease (GVHD) prophylaxis was based on cyclosporine and mini-methotrexate; ATG (7 mg/kg) was given to the patients allografted from unrelated donors. Sixty-seven (55%) and fifty-four (45%) patients received grafts from related and unrelated donors, respectively. Results: At a median follow-up of 41 months (range 6-95 months), the estimated 3-years PFS and overall survival (OS) were 50% (95%CI, 41%-61%) and 61% (95%CI, 51%-71%), respectively. The 1 and 3-years GRFS were 40% (95%CI, 32%-50%) and 34% (95%CI, 26%-44%), respectively. The GRFS was significantly better in patients affected by indolent disease (43% versus 22%, long-rank test, p=0.02); in addition there was a tendency for better GRFS for those transplanted from unrelated donors (41% versus 27%, p=0.096). The 3-years GRFS were 41% and 30% in patients with complete remission (CR) and partial remission (PR) at the time of transplant, respectively (p=0.185). The multivariate analysis showed that patients affected by aggressive histotype and with bone marrow (BM) infiltration at time of transplant had a poor outcome in terms of PFS, OS and GRFS [hystotype: PFS, HR 3.30 (p=0.003); OS, HR 3.73 (p=0.007); GRFS, HR 2.02 (p=0.026); BM infiltration: PFS, HR 4.79 (p<0.001); OS, HR 6.00 (p<0.001); GRFS, HR 2.7 (p=0.004)]. The crude cumulative incidence (CCI) of NRM was 21% (95%CI, 14%-30%) at 3-years whereas the CCI of acute GVHD grade II-IV was 22% (95%CI,15%-30%). The CCI of acute GVHD was not statistically significant different in matched sibling donors and unrelated donors (21% versus 22%, respectively p=0.717). According to the modified Seattle criteria, the CCI of extensive GVHD was 17% (95%CI, 11%-27%) whereas the limited form was 27% (95%CI, 19%-39%). In the univariable Fine and Gray model, the only factor that was protective against the occurrence of chronic GVHD was the transplant from unrelated donors when R and ATG were combined together [HR 0.50 (95%CI, 0.25-0.99), p=0.05]. In fact, the CCI of chronic GVHD at 3-years from matched sibling donors was 54% (95%CI,42%-71%) as opposed to 31% from unrelated donors (95%CI, 19%-49%) (p=0.04). Conclusions: Our trial showed:1) R did not improve PFS as compared with our historical control; 2) the combination of R and ATG is synergistic and resulted protective against chronic GVHD; 3) GRFS analysis showed that 34% of the patients are alive without any complications at 3-years after allograft and this should be the standard to compare novel drug results. Future protocols should consider the use of GRFS as endpoint and inclusion of ATG also for those receiving sibling grafts. DisclosuresCascavilla:Janssen-Cilag: Honoraria.

Immune Reconstitution after Umbilical Cord Blood Versus Peripheral Blood Progenitor Cell Transplantation in Adults Following Myeloablative Conditioning

Immune Reconstitution After Umbilical Cord Blood Versus Peripheral Blood Progenitor Cell Transplantation In Adults Following Myeloablative ConditioningIntroduction: We report on the tempo of immune reconstitution after myeloablative umbilical cord blood transplantation (UCBT, n=61) compared with allogeneic peripheral blood progenitor cells transplantation (PBPCT, n=59).Methods: All patients 18 years or older who underwent first allogeneic transplantation after myeloablative conditioning for hematological malignancies between Jan, 2004 and Dec, 2013 and were alive at 1-year post transplant were included. Patients who received T-cell depletion or antithymocyte globulin were excluded.Results: Overall, the most common diagnosis was acute (83.6% vs 61%) or chronic (3.3% vs. 10.2%) leukemia in UCBT and PBPCT groups, respectively, p=0.07. Median age of UCBT group was 37.2 years vs. 45 years in PBPCT group, p<0.01. The majority of UCBT group (92%) received two units. Almost all patients in PBPCT group (97%) had 6/6- or 8/8-HLA matched sibling donor. More than half of recipients of either UCBT (54%) or PBPCT (51%) were cytomegalovirus (CMV) seropositive. About 97% in both groups received total body irradiation (TBI) for conditioning. Graft-versus-host disease (GVHD) prophylaxis was provided with cyclosporine plus either mycophenolate (UCBT) or methotrexate (PBPCT).The median time to neutrophil engraftment was notably faster in the PBPCT group (15 days, range 10-31) compared with the UCBT group (24 days, range 6-39), p<0.001. All subsets of cells analyzed were significantly lower in the UCBT group for at least first month post-transplant compared with PBPCT group [Figures 1-3]. Natural killer (NK) cells were the first cells to reconstitute in the UCBT group, especially the CD56bright subset, the absolute numbers of which were significantly higher in UCBT than in the PBPCT group from 2 months until at least one year. Similarly, although CD19+ B cells were lower in UCBT group for first month post- transplant, they reached comparable levels to that of PBPCT group at 2-3 months post-HCT and then surpassed the PBPCT group with UCB having significantly higher numbers at 6 and 12-months post-HCT (p<0.05). The absolute numbers of total T cells (CD3+CD56-), CD4+ and CD8+ T cells remain significantly lower in the UCBT group until 3 months, but were then comparable to that of PBPCT group at 6 and 12 months. "NKT" cells (CD3+CD56+) and the naïve T cells (CD4+CD45RO-CD27+) remain significantly lower in UCBT group at all time points tested. The numbers of effector memory (CD4+CD45RO+CD27-) and central memory T cells (CD4+CD45RO+CD27+) were lower for the first three months after transplant, but were then comparable to the PBPCT group thereafter. Regulatory T cells (Tregs; CD4+CD25brightCD127-) were lower in UCBT group for the first 6 months and then comparable to PBPCT group at 12 months.Clinical correlates: Infection density at 1 year (number of infection events/1000 patient days at risk) of bacterial (6.3 vs. 3.7, p<0.01) and viral (5.4 vs 2.2, p<0.01), but not fungal infections (0.27 vs. 0.34, p=0.69) was significantly higher in the UCBT group than in the PBPCT group, respectively. UCBT group had a significantly higher incidence of acute grade II-IV GVHD (75%, 95% confidence interval (CI) 61- 90%, versus 51%, 95% CI 37-65%, p<0.01) and grade III-IV GVHD (33%, 95% CI 21-45%, versus 17%, 95% 7-26%, p=0.03) than PBPCT group respectively. Incidence of chronic GVHD at 2 years was similar in two groups. In univariate analysis, risk of relapse at 3-years was significantly lower in UCBT (19%, 95% CI 9-28%) than PBPCT group (35%, 95% CI 22-48%), p=0.05. There was no difference in overall survival at 3 years (72% vs 66%, respectively, p=0.34).Conclusion: After myeloablative conditioning, UCBT group has significantly delayed neutrophil engraftment and reconstitution of all T cell subsets and NKT cells, compared to that of PBPCT group, which along with a higher incidence of acute GVHD explains higher infection density in the UCBT group. Conversely, rapid recovery of NK and B cells may partly explain lower risk of relapse in the UCBT group. Despite significantly lower numbers of Tregs in UCBT group, risk of chronic GVHD was similar to that of PBPCT group. Ongoing multivariate analysis of the impact of CMV serostatus and other cell subsets on clinical outcomes will provide further answers. [Display omitted] [Display omitted] [Display omitted] DisclosuresMiller:Oxis Biotech Scientific Advisory Board: Membership on an entity's Board of Directors or advisory committees.

Biomarkers Predict Graft-Vs-Host Disease Outcomes Better Than Clinical Response after One Week of Treatment

Graft-versus-host disease (GVHD), the primary cause of non-relapse mortality (NRM) following allogeneic hematopoietic stem cell transplantation, does not always respond to treatment with high dose systemic corticosteroids. We have recently shown that a combination of three biomarkers (TNFR1, ST2, and REG3α) measured at onset of GVHD can predict day 28 response to treatment and 6-month NRM (Levine, Lancet Haem, 2015). Our goal in the current study was to determine if the same biomarker-based Ann Arbor GVHD algorithm can alsopredict treatment response andmortality whenapplied after one week of systemic corticosteroid treatment.The study population consisted of 378 patients (pts) with acute GVHD from 11 centers in the Mount Sinai Acute GVHD International Consortium. All pts were treated with systemic steroids and provided a plasma or serum sample obtained after one week of treatment (±3 days). The median starting dose of systemic steroids for Grade II-IV GVHD was 2.0 mg/kg/day and for Grade I was 1.0 mg/kg/day, after which treatment varied. Patients were divided into test (n=236) and validation (n=142) cohorts. We applied the Ann Arbor GVHD algorithm to concentrations of TNFR1, ST2, and REG3α measured after one week of treatment to generate a predicted probability of 6-month NRM, which we term the treatment score (TS). We employed unsupervised k-medoidclustering to partition TS values from the test cohort into two groups (high and low). This unbiased approach identified a high score group made up of 25% of pts (n=58) in the test cohort.We observed that the day 28 response rate (complete, CR + partial, PR) was significantly lower in pts with high scores compared to low scores in the test cohort (24% vs 65%, p<0.0001) (Fig 1A). Analysis of the validation cohort using the same TS definitions showed similar differences in response rates (22% vs 61%, p<0.0001) (Fig 1B). Further, nearly four times as many pts with high scores in both cohorts died within 6 months from non-relapse causes compared to pts with low scores (test: 57% vs 17%, p<0.0001; validation: 57% vs 14%, p<0.0001) (Fig 1C/D). As expected, the majority of non-relapse deaths in pts treated for GVHD were directly attributable to GVHD (test: 95%; validation: 89%). Relapse rates for high and low score pts were similar (data not shown), and thus pts with a high TS experienced significantly worse overall survival in both cohorts (test: 37% vs 72%, p<0.0001; validation: 38% vs 79%, p<0.0001) (Fig 1E/F).Approximately half of the pts in each cohort (test: 48%; validation: 44%) responded (CR+PR) to the first week of steroids and these ptshad significantly lower 6-month NRM than non-responders (NR) (test: 17% vs 36%, p=0.0002; validation: 13% vs 36%, p=0.0014). Yet the TS continued to stratify mortality risk independently of clinical response. In the test cohort, pts with a high score comprised 16% of all early responders and experienced more than twice the NRM of early responders with a low score (33% vs 13%, p=0.022) (Fig 2A). Conversely, test cohort pts who did not respond by day 7, but had a low score, fared much better than non-responders with a high score (NRM 21% vs 68%, p<0.0001) (Fig 2B). Two thirds of early non-responders comprised this more favorable group. These highly significant results reproduced in the independent validation cohort in similar proportions (CR+PR: 45% vs 6%, p=0.0003; NR: 61% vs 22%, p=0.0001) (Fig 2C/D). Finally, a subset analysis revealed that pts classified as NR after one week of steroids due to isolated, yet persistent, grade I skin GVHD (24/378, 6%) overwhelmingly had low treatment scores (22/24, 92%) and experienced rates of NRM (9%) comparable to responders with low scores, thus forming a distinct, albeit small, subset of pts with non-responsive GVHD that fares particularly well (Fig 3).In conclusion, a treatment score based on three GVHD biomarkers measured after one week of steroids stratifies pts into two groups with distinct risks for treatment failure and 6-month NRM. It is particularly noteworthy that the TS identifies two subsets of pts with steroid refractory (SR) GVHD who have highly different outcomes (Fig 2B/D). The much larger group, approximately two thirds of all SR pts, may not need the same degree of treatment escalation as is traditional for clinical non-response, and thus overtreatment might be avoided. Because the TSis measured at a common decision making time point, it may prove useful to guide risk-adapted therapy. [Display omitted] [Display omitted] [Display omitted] DisclosuresMielke:Novartis: Consultancy; MSD: Consultancy, Other: Travel grants; Celgene: Other: Travel grants, Speakers Bureau; Gilead: Other: Travel grants; JAZZ Pharma: Speakers Bureau. Kroeger:Novartis: Honoraria, Research Funding. Chen:Incyte Corporation: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Jagasia:Therakos: Consultancy. Kitko:Therakos: Honoraria, Speakers Bureau. Ferrara:Viracor: Patents & Royalties: GVHD biomarker patent. Levine:Viracor: Patents & Royalties: GVHD biomarker patent.

Donor-Recipient Matching for KIR Genotypes Reduces Chronic GVHD and Missing Inhibitory KIR Ligands Protect against Relapse after Myeloablative, HLA Matched Hematopoietic Cell Transplantation

BackgroundAllogeneic hematopoietic cell transplantation (HCT) can be curative for many hematologic diseases. However, complications such as graft-versus-host disease (GVHD) and relapse of primary malignancy remain significant and are the leading causes of morbidity and mortality. Effects of killer Ig-like receptors (KIR)-influenced NK cells on HCT outcomes have been extensively pursued over the last decade. However, the relevance of the reported algorithms on HLA matched myeloablative HCT with rabbit antithymocyte globulin (ATG) is used for GVHD prophylaxis remains elusive. Here we examined the role of KIR and KIR-ligands of donor-recipient pairs in modifying the outcomes of ATG conditioned HLA matched sibling and unrelated donor HCTMethods and FindingsThe study cohort consisted of 281 HLA matched sibling and unrelated donor-recipient pairs of first allogeneic marrow or blood stem cell transplantation allocated into ‘discovery’ (135 pairs) and ‘validation’ (146 pairs) cohorts. High resolution HLA typing was obtained from the medical charts and KIR gene repertoires were obtained by a Luminex® based SSO method. All surviving patients were followed-up for a minimum of two years. KIR and HLA class I distributions of HCT pairs were stratified as per applicable definitions and were tested for their association with cause specific outcomes [acute GVHD grade II-IV (aGVHD), chronic GVHD needing systemic therapy (cGVHD) and relapse] using a multivariate competing risks regression model as well as with survival outcomes [relapse-free survival (RFS), cGVHD & relapse free survival (cGRFS) and overall survival (OS)] by multivariate Cox proportional hazards regression model. A significant association between KIR genotype mismatching (KIR-B/x donor into KIR-AA recipient or vice versa) and cGVHD was found in both discovery (p = 0.001; SHR = 2.78; 95%CI: 1.50–5.17) and validation cohorts (p = 0.005; SHR = 2.61; 95%CI: 1.33–5.11). High incidence of cGVHD associated with KIR genotype mismatching was applicable to both sibling and unrelated donors and was specific to recipients who had one or two C1 bearing HLA-C epitopes (HLA-C1/x, p = 0.001; SHR = 2.40; 95%CI: 1.42–4.06). When compared with KIR genotype mismatched transplants, HLA-C1/x patients receiving grafts from KIR genotype matched donors had a significantly improved cGRFS (p = 0.013; HR = 1.62; 95%CI: 1.11–2.39). Although there was no effect of KIR genotype matching on survival outcomes, a significantly reduced incidence of relapse (p = 0.001; SHR = 0.22; 95%CI: 0.10–0.54) and improved relapse-free survival (p = 0.038; HR = 0.40; 95%CI: 0.17–0.95) was observed with one or more missing ligands for donor inhibitory KIR among the recipients of unrelated donor transplants.ConclusionsThe present study for the first time presents the beneficial effects of KIR genotype matching in reducing cGVHD in myeloablative transplant setting using HLA matched (sibling and unrelated) donors. The findings offer a clinically applicable donor selection strategy that can help control cGVHD without affecting the risk of relapse and/or identify patients at a high risk of developing cGVHD as potential candidates for preemptive therapy. The findings also affirm the beneficial effect of one or more missing inhibitory KIR ligands in the recipient in reducing relapse and improving a relapse free survival in unrelated donor transplants.

TCR Alpha/Beta and CD19 Depletion in Transplantation from Matched Unrelated and Haploidentical Donors in Pediatric Leukemia Patients: Comparison of Two Gvhd Prophylaxis Regimens

Graft-versus-host disease (GvHD) is a major obstacle to success of transplantation from unrelated and haploidentical donors. Depletion of α/β(+) T cells and CD19+ lymphocytes is a technology of graft manipulation aiming to improve GvHD control. We retrospectively evaluated two regimens of serotherapy and pharmacological GVHD prophylaxis in recipients of TCR-alpha/beta depleted grafts. Ninety nine children, AML(49) and ALL(50), all in CR, 37 female, 62 male, median age 8,4 years, underwent HSCT between May 2012 and June 2015. Thirty eight - from haploidentical and 61 from matched unrelated donor (MUD). The backbone of conditioning included Fludarabine/ Treosulfan/Melphalan in 92, Fludarabine/TBI/VP-16 in 7. Two regimens of GVHD prophylaxis were used. Regimen 1 (n-53): ATGAM 50 mg/kg and post-transplant tacro/Mtx (n-43) or no post-transplant Rx (10); regimen 2 (n-46): thymoglobulin 5 mg/kg, rituximab 200mg/m2 and post-transplant bortezomib (n-32) or tacro/mtx (n-8) or no post-transplant Rx (n-6). PBSC were depleted of TCR-alpha/beta and CD19+ cells with CliniMACS technology. The median dose of CD34+ cells was 9,1x106/kg, TCRa/b - 9,6x103/kg. Engraftment was achieved in 97 of 98 evaluable pts, median time to neutrophil and platelet engraftment was 13 and 14 days. Acute GvHD grade II-IV incidence was 23±4%, grade III-IV – 8±2%. Regimen 2 was more effective in preventing aGVHD with CumInc of 10±4% versus 34±6%, p=0,007, and chronic GVHD with CumInc of 16±5 versus 38±6%. Relapse incidence at 2y was 31±4%, pTRM – 16±4%. After median follow-up of 1.9 years, 2-y pEFS was 53±4%, pOS - 54±5%. There was significant difference in survival according to the leukemia type: EFS at 2 years in AML 61±5% vs 44±5% in ALL, p = 0,05. No significant difference in survival was detected between donor types and GVHD prophylaxis regimens. Thymoglobulin/Rituximab/Bortezomib improves GVHD control in recipients of TCRalpha/beta depleted grafts in comparison to ATGAM/Tacro/Mtx.

High pre-transplant TREC levels indicate good prognosis after hematopoietic stem cell transplantation

BackgroundThymus-dependent T-cell reconstitution plays a role in immune recovery after stem cell transplantation (HSCT). High pre-HCST thymic function has been associated with higher survival, lower incidence of acute and chronic graft versus host disease (GVHD) and lower incidence of infections. The aim of this study was to analyze the relationship between pre-HSCT peripheral blood levels of T-cell receptor excision circles (TREC) and post-HSCT clinical events in recipients of HLA-identical hematopoietic stem cell transplants.MethodDelta deletion signal joint TRECs (sjTRECs) formed by the dREC-yJa rearrangement were quantified by real time PCR in peripheral blood lymphocytes of 62 HSCT recipients.ResultsUnivariate analysis revealed an association between low TREC levels and a higher incidence of grade II-IV acute GVHD (p=0.026), bacterial infection (p=0.005) and cytomegalovirus infection (p=0.033), whereas high TREC levels were associated with higher overall survival (p=0.028). In the multivariate analysis, low pre-HSCT TREC levels remained independently associated with lower survival (p=0.032; RR 2.6), occurrence of grade II-IV acute GVHD (p=0.031; RR: 2.5), bacterial infection (p=0.006, RR: 6.6) and cytomegalovirus infection (p=0.039; RR:2.8).ConclusionOur results corroborate the concept that pre-HSCT recipient´s thymic function is an important predictor of risk for acute grade II-IV GVHD and infection.

The Risk of Sinusoidal Obstruction Syndrome (SOS) in Allogeneic Hematopoietic Stem Cell Transplantation after Prior Gemtuzumab Ozogamicin Treatment: A Retrospective Study on Behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Background. Gemtuzumab ozogamicin (GO) is a humanized anti-CD33 monoclonal antibody conjugated with calicheamicin, used in acute myeloid leukemia (AML) either as monotherapy or in association with chemotherapeutic agents (Hamann et al. Bioconjug. Chem 2002). It is known to induce a significant liver toxicity that might increase the risk of sinusoidal obstruction syndrome (SOS), especially in patients undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT). Risk is especially high in patients transplanted within a short interval from last GO dose (≤ 3.5 months) (Wadleigh et al. Blood 2003). The current retrospective analysis aimed to assess the incidence of SOS and the outcome of AML patients receiving GO before allo-HSCT.Patients and methods. The primary endpoint of the study was the assessment of SOS incidence in a series of 146 adult patients (71 women and 75 men) with AML undergoing allo-HSCT after prior exposure to GO. Relevant data were captured by a specific designed questionnaire focusing on SOS (Med C) that was distributed to all EBMT centers. Secondary endpoints were engraftment, non-relapse mortality (NRM), graft-versus host disease (GVHD), leukemia-free survival (LFS) and overall survival (OS). Median age was 50 years (range 19-70). In most cases (n=127 out of 137 for which the information was available, 93%) GO was administered in parallel with other chemotherapeutic agents. Median GO dose was 3 mg/m2. Median number of cycles before allo-HSCT was 1 (range 1-6). The majority of the patients (n=79, 54%) received GO as induction treatment, while 51 (35%) and 16 (11%) received GO for relapsing or primary refractory disease, respectively. At time of allo-HSCT 97 (66%) patients were in complete remission. Of note, 11 patients underwent prior allo-HSCT and 8 patients prior auto-HSCT. Most patients received a reduced intensity conditioning (RIC) regimen pre allo-HSCT (n=84, 58%). SOS prophylaxis was given in a total of 69 patients (heparin n=57, ursodeoxycholic acid n=8, and defibrotide n=4). Cumulative incidence (CI) and Kaplan-Meier estimates were used when appropriate; Cox model was used for multivariate analysis.Results. Overall, cumulative incidence of SOS was 7.75% (95% CI 4.1-12.9) (n=11). Among patients receiving RIC, 4 (4,9%) developed SOS as compared to 7 (11,5%) among patients receiving MAC regimen (p=NS). SOS was the main cause of death in 3 out of 11 cases. Median interval between last GO dose and allo-HSCT was 130 days (range 13-1126). Neither OS nor SOS incidence differed significantly for patients receiving GO shortly before allo-HSCT (≤ 3.5 months) as compared to the others. None of the analyzed risk factors had an impact on the risk of SOS in our study. With a median of 15 days, CI of neutrophil and platelet engraftment was 93.8% (95% CI 88.1-96,8) and 89% (95% CI 82.3-93.3), respectively. CI of acute GVHD at day 100 was 30.6% (95% CI 23-38.2), occurring in 84 patients (out of them 45 had grade II-IV GVHD), while CI of chronic GVHD at 5 years was 25.5% (95% CI 18.6-33).With a median follow-up of 64 months the probability of OS and LFS at 5 years was 40% (95% CI: 31-48) and 37% (95% CI: 29-45), respectively. Cumulative RI and NRM at 5 years were 42% (95% CI: 34-50%) and 21% (95% CI: 14-28), respectively. In multivariate analysis patients transplanted with an active disease relapsed more often and had worse LFS and OS, while patients presenting with liver abnormalities before allo-HSCT had a worse OS (p<0.03).Conclusion. Our results in a large cohort of AML patients show that GO administration prior to allo-HSCT does not result in an excessive incidence of SOS as compared to historical controls reported in the literature (Carreras et al. Biol. Blood Marrow Transplant 2011). Notably incidence is low even when allo-HSCT is performed within a short interval from the last dose of GO. DisclosuresFanin:Novartis Farma: Speakers Bureau. Mohty:Janssen: Honoraria; Celgene: Honoraria. Nagler:Novaratis Pharmaceuticals Corporation: Consultancy, Honoraria, Research Funding.

Long-Term Clinical Outcomes of Allogeneic Stem Cell Transplantation in Multiple Myeloma

▪Allogeneic stem cell transplantation (allo-SCT), which provides a tumor-free graft, is an alternative approach to autologous transplantation for multiple myeloma (MM) that offers the possibility of cure through a graft vs myeloma effect (GVM). However, the inherent non relapse mortality (NRM) and the high post-transplant relapse rate are the major shortcomings of this strategy which continues to have a controversial role in MM treatment.To highlight the long-term clinical outcomes of allo-SCT, we performed a retrospective analysis on 102 patients (pts) with MM who received at our Institution either a myeloablative (MA) (74 pts) or a non-myeloablative (NMA) (28 pts) conditioning regimen between 1990 and 2014. The MA regimen consisted in low dose TBI and cyclophosphamide (cyclo) ± melphalan (mel) or busulfan-cyclo. The NMA regimen was mel-fludarabine. Graft versus host disease (GVHD) prophylaxis consisted in cyclosporine + methotrexate (83%) or mycophenolate (17%), with the addition of thymoglobulin for unrelated or related female vs male recipient donors. The median age was 42 yrs (IQR 38-47), 60% pts were male. The hematopoietic cell donors were sibling in 77 pts and unrelated in 25, while the source of stem cells was peripheral blood in 65 and bone marrow in 37 pts. Fifty-six pts received allo-SCT as first-line therapy, 31 as second-line and 13 as third or fourth-line. Median time from diagnosis to allo-SCT was 22 months. Response status at the time of transplant was at least PR in 63% of the pts, including ≥ VGPR in 36% and CR in 12%.Overall, the response rate after allo-SCT was as follows: CR 58%, VGPR 19%, PR 18%. Median CR duration was 10 years (44% at 15 years).The incidence of acute grade II-IV and III-IV GVHD was 25% and 15%, respectively. The incidence of all grades chronic cGVHD was 48%, grade ≥2: 24%, with a median onset time of 178 days. By competitive risks analysis, the cumulative incidence of cGVHD at 1 and 3 years was 20% and 32%, respectively. On univariate analysis, the gender combination of female donor-male patient resulted in significantly higher incidence of cGVHD (sub hazard ratio, SHR, 2.3, P= 0.03). The cumulative incidence of NRM was 6.6% at 100 days, 11% at 1 year and 14.4% at 3 years, with lack of statistically significant relationship with the conditioning regimen. By univariate analysis, < PR prior to allo-SCT (SHR 2.8) and all grades cGVHD (SHR 4.6) were significantly associated with an increased NRM.By competitive risks analysis, the cumulative incidence of relapse was 50% at 5 years, 58% at 10 years and 59% at 15 years. On univariate analysis, sibling donor (SHR 0.54, P=0.047), all grades cGVHD (SHR 0.5, P=0.011) and ≥VGPR after allo-SCT (SHR 0.38, P=0.001) were significantly associated with extended time to progression. All grades cGVHD (SHR 0.43, P=0.005) and ≥VGPR after allo-SCT (SHR 0.36, P= 0.001) were independent predictors for a lower risk of progression on multivariate analysis.With a median follow-up of 13 years, overall survival (OS) was 43% at 5 years and 34% at 10 years. In univariate analysis, low ISS stage at diagnosis, sibling donor, absence of female donor-male patient gender combination, ≥VGPR prior to allo-SCT and first-line allo-SCT were significantly related to OS. Multivariate analysis confirmed an OS benefit for having a sibling donor (HR 0.30, P<0.001), absence of female donor-male patient gender combination (HR 0.51, P=0.022) and being in ≥ VGPR prior to allo-SCT (HR 0.41, P=0.003).In conclusion, this retrospective analysis performed with an extended follow-up of 13 years shows that a fraction of MM pts can be long-term survivors after allo-SCT, one third of them being potentially cured. The best outcomes were obtained when allo-SCT was applied in pts in an early phase of their disease and with a small residual tumor size. The major challenge, both with MA and NMA allo-SCT, was the relatively high post-transplant relapse rate. The presence of cGVHD was protective for the risk of progression, supporting the role of GVM, but increased the risk of NRM. New approaches aimed at modulating cGVHD are warranted. In addition, incorporation of novel agents before and after allo-SCT to increase the rate and duration of high-quality responses, as well as identification of those patients mostly benefiting from this procedure, will likely contribute to improve long-term outcomes. DisclosuresZamagni:Celgene Corporation: Honoraria, Speakers Bureau; Janssen Pharmaceuticals: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Cavo:Sanofi: Consultancy, Honoraria; Onyx: Honoraria; Jansenn: Consultancy, Honoraria; Millenium Pharmaceuticals: Honoraria; Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; BMS: Honoraria.