Similar incidence of severe acute GVHD and less severe chronic GVHD in PBSCT from unmanipulated, haploidentical donors compared with that from matched sibling donors for patients with haematological malignancies

Ruxolitinib plus steroids for acute graft versus host disease: a multicenter, randomized, phase 3 trial

Newly diagnosed patients with high-risk acute graft-versus-host disease (aGVHD) often experience poor clinical outcomes and low complete remission rates. Ruxolitinib with corticosteroids showed promising efficacy in improving response and failure free survival in our phase I study. This study (ClinicalTrials.gov: NCT04061876) sought to evaluate the safety and effectiveness of combining ruxolitinib (RUX, 5 mg/day) with corticosteroids (1 mg/kg/day methylprednisolone, RUX/steroids combined group) versus using methylprednisolone alone (2 mg/kg/day, steroids-only group). Newly diagnosed patients with intermediate- or high-risk aGVHD were included, with risk levels classified by either the Minnesota aGVHD Risk Score or biomarker assessment. Patients were randomized in a ratio of 1:1 into 2 groups: 99 patients received RUX combined with methylprednisolone, while the other 99 received methylprednisolone alone as the initial treatment. The RUX/steroids group showed a significantly higher overall response rate (ORR) on day 28 (92.9%) compared to the steroids-only group (70.7%, Odds Ratio [OR] = 5.8; 95% Confidence Interval [CI], 2.4-14.0; P < 0.001). Similarly, the ORR on day 56 was higher in the RUX/steroids group (85.9% vs. 46.5%; OR = 7.07; 95% CI, 3.36-15.75; P < 0.001). Additionally, the 18-month failure-free survival was significantly better in the RUX/steroids group (57.2%) compared to the steroids-only group (33.3%; Hazard Ratio = 0.46; 95% CI, 0.31-0.68; P < 0.001). Adverse events (AEs) frequencies were comparable between both groups, with the exception of fewer grade 4 AEs in the RUX/steroids group (26.3% vs. 50.5% P = 0.005). To our knowledge, this study is the first prospective, randomized controlled trial to demonstrate that adding ruxolitinib to the standard methylprednisolone regimen provides an effective and safe first-line treatment for newly diagnosed high-risk acute GVHD.

Patients Beyond the Optimal Range of rATG-AUC Still Benefit from the Targeted Dosing Strategy in Unmanipulated Haplo-PBSCT

Rabbit antithymocyte globulin (rATG) is widely used in allogeneic hematopoietic stem cell transplantation to prevent graft failure and severe graft-versus-host disease (GVHD). We developed a rATG-targeted dosing strategy based on the optimal areas under the concentration-time curve (AUC) of active rATG. This study compared the outcomes of the optimal AUC arm with nonoptimal AUC arm to assess the effect of the rATG-targeted dosing strategy. Eighty patients (median age: 32 years) with hematological malignancies who received their first haplo-PBSCT were enrolled successively. With rATG-targeted dosing, the AUC values of 60 patients (75%, optimal AUC arm) fell within the optimal range (100-148.5 UE/mL/day) and 20 fell beyond this range (nonoptimal AUC arm). In the historical control group of 102 haplo-PBSCT patients who received a fixed dose of rATG (10 mg/kg), less patients fell within the optimal range (57.8%, P = .016). Looking at the nonoptimal AUC arms in both groups, lower cumulative incidence of CMV was noted in the targeted dosing group compared with the historical control group(50.0%, 95% CI, 30.8%-72.9% versus 81.4%, 95% CI, 68.6%-91.3%; P = .004). The cumulative incidences of EBV, relapse, overall survival and disease-free survival tended to be superior in the nonoptimal AUC arm in the targeted dosing group compared with the historical control. In the targeted dosing group, the cumulative incidence of cytomegalovirus (CMV) reactivation on day +180 tended to be lower in the optimal AUC arm (30.0%, 95% CI, 20.1%-43.3%) compared with the nonoptimal AUC arm (50.0%, 95% CI, 30.8%-72.9%, P = .199) without statistical difference. There were no significant differences of acute or chronic GVHD, relapse, nonrelapse mortality, overall survival, disease-free survival or lymphocyte reconstitution between the two arms. In conclusion, the rATG-targeted dosing strategy made the exposure of active rATG in more patients with the optimal AUC range. Even patients who fell beyond this range would still benefit from the strategy.

[Chinese expert consensus on the diagnosis and treatment of acute graft-versus-host disease after hematopoietic stem cell transplantation (2024)]

Despite the continuous improvement in the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT), acute graft-versus-host disease (GVHD) remains a major complication and cause of death. In recent years, with the emergence of new drugs for the prevention and treatment of acute GVHD and the update of a series of clinical studies, there have been varying degrees of changes in the routine prevention and treatment regimens for acute GVHD. Based on the main research achievements and the accumulation of clinical experience in this field in recent years, this consensus further updates the "The Consensus on Allogeneic Hematopoietic Stem Cell Transplantation for Hematological Diseases in China-Acute Graft-Versus-Host Disease (2020) .

Similar Survival But Less Chronic GVHD in Antithymocyte Globulin-Based Myeloablative Haploidentical Transplant Compared With Matched Sibling Transplant for Adult T-cell Acute Lymphoblastic Leukemia/Lymphoma

The annual number of human leukocyte antigen (HLA)-haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HCT) is increasing steadily. Comparative studies about haplo-HCT versus HCT with HLA-matched sibling donors (MSD-HCT) have been tried in acute myeloid leukemia and B-cell acute lymphoblastic leukemia/lymphoma (ALL). Few studies were reported in adult T-cell ALL (T-ALL). In this retrospective study, a total of 88 consecutive patients with T-ALL were enrolled who underwent MSD-HCT (n = 24) and haplo-HCT (n = 64) with antithymocyte globulin (ATG)-based graft versus host disease (GVHD) prophylaxis between 2010 and 2022. Median follow-up for survivors was similar (43.5 [range: 7-88] months for MSD-HCT versus 43.5 (range: 6-144) months in the Haplo-HCT group). The 100-day cumulative incidence of grade II to IV acute GVHD (aGVHD) was similar, 33% (95% confidence interval [CI], 16%-52%) after MSD-HCT versus 44% (95% CI, 31%-55%) after haplo-HCT, P = 0.52. The cumulative incidences of grade III-IV aGVHD were 8% (95% CI, 1%-23%) in the MSD-HCT group and 5% (95% CI, 1%-12%) in the haplo-HCT group (P = 0.50). The 2-year cumulative incidence of chronic GVHD (limited and extensive) in the haplo-HCT, 11% (95% CI, 5%-20%) was significantly lower than that in the MSD-HCT group (42% [95% CI, 21%-62%], P = 0.002). The cumulative incidence of 4-year relapse rates (44% versus 37%, P = 0.56) and non-relapse mortality (7% versus 21%, P = 0.08) did not differ between these two groups. There were also no differences in 4-year overall survival (46% versus 47%, P = 0.44) and progression-free survival (49% versus 42%, P = 0.45) between these two groups. On multivariate analysis, using busulfan/fludarabine (BU/Flu) conditioning regimen was found to be associated with worse clinical outcome. Our results suggested that ATG-based haplo-HCT platform could work as an alternative to MSD-HCT for adult patients with T-ALL. Compared with MSD-HCT, haplo-HCT might carry a low risk for cGVHD.

Hypomethylating agents (HMAs) show benefit in AML rather than in intermediate/high-risk MDS based on genetic mutations in epigenetic modification (EMMs): from a retrospective study

Since HMAs were recommended for treatments in AML and MDS, we wondered whether HMAs could provide similar benefit to AML and intermediate/high-risk MDS under the direction of next-generation sequencing. Here we retrospectively analyzed the prognosis of 176 AML and 128 intermediate/high-risk MDS patients treated with HMAs or non-HMA regimens. For AML, HMAs regimen was related to better CR rate compared with non-HMA regimen in elder cohort, while the situation was the opposite in younger cohort. In consolidation phase, EMM (+) patients could benefit from HMAs regimen. Relapsed AML patients receiving HMAs regimen rather than non-HMA regimen had better post-relapse survival. Multivariate analysis identified HMA regimen as an independent prognostic factor for OS in EMM (+) cohort. For intermediate/high-risk MDS patients not undergoing HSCT, however, HMA regimen showed no survival advantage in EMM (+) cohort and was conversely associated with shorter survival in EMM (-) cohort compared with non-HMA regimen. And among those undergoing HSCT, HMA prior to HSCT predicted poor prognosis compared with upfront HSCT regardless of the existence of EMMs. Therefore, HMAs had better therapeutic value in AML rather than in intermediate/high-risk MDS based on EMMs.

Targeted dosing of anti-thymocyte globulin in adult unmanipulated haploidentical peripheral blood stem cell transplantation: A single-arm, phase 2 trial

Anti-thymocyte globulin (ATG) is widely used in allogeneic hematopoietic stem cell transplantation to prevent severe graft-versus-host disease (GVHD) and graft failure. However, overexposure to ATG may increase cytomegalovirus (CMV), Epstein-Barr virus (EBV) reactivation, non-relapse mortality, and disease recurrence. To investigate the optimal dosing of ATG, we established a targeted dosing strategy based on ATG concentration monitoring for haploidentical peripheral blood stem cell transplantation (haplo-PBSCT). The aim of this phase 2 trial is to evaluate the safety and efficacy of the ATG-targeted dosing strategy in adult unmanipulated haplo-PBSCT. ATG was administered for 4 days (-5 days to -2 days) during conditioning. The ATG doses on -3 days and -2 days were adjusted by our dosing strategy to achieve the optimal ATG exposure. The primary endpoint was CMV reactivation on +180 days. Between December 2020 and January 2022, 66 haplo-PBSCT patients were enrolled and 63 of them were evaluable with a median follow-up of 632 days. The cumulative incidence of CMV reactivation was 36.7% and that of EBV was 58.7%. The 1-year disease-free survival was 82.5%, overall survival was 92.1%, and CD4+ T-cell reconstruction on +100 days was 76.8%. The most common severe regimen-associated toxicities (> grade 3) were infections (51.5%) and gastrointestinal toxicity (25.5%). A total of 102 haplo-PBSCT patients who received the conventional fixed ATG dose (cumulative 10 mg/kg) comprised historical control. The outcomes in historical control were inferior to those of phase 2 trial cohort (CMV reactivation: 70.8%, p < .001; EBV reactivation: 76.0%, p = .024; CD4 + T-cell reconstruction: 54.1%, p = .040). In conclusion, ATG-targeted dosing strategy reduced CMV/EBV reactivation and improved survival without increasing GVHD after haplo-PBSCT. These advantages may be associated with accelerated immune reconstitution.

Increased risk of nonrelapse mortality post T-cell-replete haploidentical stem cell transplantation in patients with recurrence of acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) causes significant morbidity and mortality. While most studies focus on classic or late aGVHD, some patients with previous aGVHD achieve complete remission and later develop another episode of aGVHD. Data on recurrence of aGVHD (RaGVHD) are lacking. This study aimed to identify the incidence, risk factors, and impacts of RaGVHD after T-cell-replete haploidentical hematopoietic cell transplantation (haplo-HCT) without posttransplantation cyclophosphamide. We evaluated patients with RaGVHD after haplo-HCT between 2017 and 2019 and compared their outcomes to those of patients with no aGVHD and those of patients with one episode of de novo aGVHD. Of 199 patients included in the analysis, 45 experienced 50 cases of RaGVHD with a 1-year cumulative incidence of 19.0% (95% CI: 14.5-24.6). Grade III-IV aGVHD was more common in RaGVHD than in previous aGVHD (22.2% vs 4.4%, p = 0.01). Female donor to male recipient was strongly associated with RaGVHD (HR: 2.5, p = 0.009). The most common death in patients with RaGVHD was GVHD-related, which was different from controls who mostly died from relapse (p =0.008). RaGVHD was an independent risk factor for chronic GVHD (HR: 2.6, p = 0.006) and nonrelapse mortality (HR: 2.4, p = 0.019) and a significant predictor of lower GVHD relapse-free survival (HR: 1.9, p = 0.020) and cGVHD relapse-free survival (HR: 2.1, p = 0.007). In conclusion, clinical manifestations and negative impacts of RaGVHD needs to be recognized independently. This article is protected by copyright. All rights reserved.

Optimal Active Anti-Thymocyte Globulin Exposure Associated with Minimum Risk of Virus Reactivation and Comparable Acute Graft-Versus-Host Disease Under Adult Myeloablative Haploidentical Peripheral Blood Stem Cell Transplantation

Anti-thymocyte globulin (ATG) is often included in the conditioning regimen to prevent graft-versus-host disease (GVHD) in allogeneic hematopoietic cell transplantation (allo-HCT). However, the risk of virus reactivation increases significantly. We conducted a single-center prospective study to identify the optimal ATG exposure that ensures engraftment, effectively prevents acute GVHD, and reduces the risk of virus reactivation without increasing relapse of malignant diseases in haploidentical peripheral blood stem cell transplantation (haplo-PBSCT). From September 2018 to June 2020, 106 patients (median age, 32 years) with malignant hematological diseases who received haplo-PBSCT for the first time were enrolled. All patients received 10 mg/kg rabbit ATG (thymoglobulin) divided for 4 days (days -5 to -2). Pre-transplant, post-transplant, and total areas under the concentration-time curve (AUCs) of active ATG were calculated. Total AUC of active ATG was shown to be the best predictor for virus reactivation and acute GVHD of grades II to IV or grades III and IV. The optimal total AUC range of active ATG was 100 to 148.5 UE/mL/day. The median time was 14 versus 13 days (P = .184) for myeloid engraftment and 13 versus 13 days (P = .263) for platelet engraftment in the optimal and non-optimal AUC groups, respectively. The optimal AUC group showed a lower cumulative incidence of cytomegalovirus (CMV) reactivation and persistent CMV viremia than the non-optimal AUC group: 60.6% (95% confidence interval [CI], 48.3%-73.1%) versus 77.1% (95% CI, 64.5%-87.7%; P = .016) and 31.5% (95% CI, 21.2%-45.3%) versus 56.3% (95% CI, 42.9%-70.4%; P = .007), respectively. The cumulative incidence of persistent Epstein-Barr virus (EBV) viremia in the optimal AUC group was significantly lower than the non-optimal total AUC group: 33.1% (95% CI, 22.5%-46.8%) versus 52.6% (95% CI, 39.3%-67.2%; P = .048). However, there was no difference in EBV reactivation (P = .752). Similar outcomes were observed for grade II to IV and grade III and IV acute GVHD between the two groups: 48.6% (95% CI, 36.8%-62.0%) versus 37.0% (95% CI, 24.8%-52.5%; P = .113) and 10.4% (95% CI, 4.8%-21.7%) versus 4.2% (95% CI, 1.0%-15.6%; P = .234, respectively. Relapse, non-relapse mortality, and disease-free survival demonstrated no significant differences between the two groups. But, overall survival at 2 years tended to increase in the optimal AUC group: 75.7% (95% CI, 62.4%-84.8%) versus 57.8% (95% CI, 42.4%-70.4%; P = .061). These data support an optimal active ATG exposure of 110 to 148.5 UE/mL/day in haplo-PBSCT. Individualized dosing of ATG in allo-HCT might reduce the risk of virus reactivation and effectively prevent acute GVHD simultaneously.

Elevated REG3α predicts refractory aGVHD in patients who received steroids-ruxolitinib as first-line therapy

We started a single-arm, phase II, open-label, prospective clinical trial using steroids-ruxolitinib as the first-line therapy for intermediate- to high-risk aGVHD (NCT04397367). Here, we report the association of a biomarker panel (sST2, REG3α, sTNFR1, IL-6 and IL-8) with responses to GVHD therapy. The novel first-line therapy for 39 patients with newly diagnosed aGVHD consisted of 1 mg/kg methylprednisolone and 5 mg/day ruxolitinib. The serum concentrations of the biomarkers were prospectively detected at planned time points. Of the 39 patients, the complete response rate at day 28 was 82.05%. In patients who achieved CR, the concentrations of REG3α (P₁₄ = 0.01; P₂₈ = 0.10) and sTNFR1 (P₁₄ = 0.42; P₂₈ = 0.04) declined at day 14 and day 28 compared with the pre-enrolment levels. In refractory patients, the levels of REG3α at day 14 were higher than those pre-enrolment (P = 0.04). REG3α (P = 0.02) was elevated in the refractory patients compared with the patients achieving CR at day 14 after enrolment, while there was no significant difference in the levels of sST2, sTNFR1 or IL-6. Elevated REG3α levels may predict refractory aGVHD after novel first-line therapy with steroids-ruxolitinib.

CMV Infection and CMV-Specific Immune Reconstitution Following Haploidentical Stem Cell Transplantation: An Update

Haploidentical stem cell transplantation (haploSCT) has advanced to a common procedure for treating patients with hematological malignancies and immunodeficiency diseases. However, cure is seriously hampered by cytomegalovirus (CMV) infections and delayed immune reconstitution for the majority of haploidentical transplant recipients compared to HLA-matched stem cell transplantation. Three major approaches, including in vivo T-cell depletion (TCD) using antithymocyte globulin for haploSCT (in vivo TCD-haploSCT), ex vivo TCD using CD34 + positive selection for haploSCT (ex vivo TCD-haploSCT), and T-cell replete haploSCT using posttransplant cyclophosphamide (PTCy-haploSCT), are currently used worldwide. We provide an update on CMV infection and CMV-specific immune recovery in this fast-evolving field. The progress made in cellular immunotherapy of CMV infection after haploSCT is also addressed. Groundwork has been prepared for the creation of personalized avenues to enhance immune reconstitution and decrease the incidence of CMV infection after haploSCT.

Haematologic malignancies with unfavourable gene mutations benefit from donor lymphocyte infusion with/without decitabine for prophylaxis of relapse after allogeneic HSCT: A pilot study

Relapse is the main cause of treatment failure for leukaemia patients with unfavourable gene mutations who receive allogeneic haematopoietic stem cell transplantation (allo‐HSCT). There is no consensus on the indication of donor lymphocyte infusion (DLI) for prophylaxis of relapse after allo‐HSCT. To evaluate the tolerance and efficacy of prophylactic DLI in patients with unfavourable gene mutations such as FLT3‐ITD, TP53, ASXL1, DNMT3A or TET2, we performed a prospective, single‐arm study. Prophylactic use of decitabine followed by DLI was planned in patients with TP53 or epigenetic modifier gene mutations. The prophylaxis was planned in 46 recipients: it was administered in 28 patients and it was not administered in 18 patients due to contraindications. No DLI‐associated pancytopenia was observed. The cumulative incidences of grade II–IV and III–IV acute graft‐versus‐host disease (GVHD) at 100 days post‐DLI were 25.8% and 11.0%, respectively. The rates of chronic GVHD, non‐relapse mortality and relapse at 3 years post‐DLI were 21.6%, 25.0% and 26.1%, respectively. The 3‐year relapse‐free survival and overall survival (OS) rates were 48.9% and 48.2%, respectively. Acute GVHD (HR: 2.30, p = 0.016) and relapse (HR: 2.46, p = 0.003) after DLI were independently associated with inferior OS. Data in the current study showed the feasibility of prophylactic DLI with/without decitabine in the early stage after allo‐HSCT in patients with unfavourable gene mutations.

Role of antithymocyte globulin in matched sibling donor peripheral blood stem cell transplantation for hematologic malignancies

BACKGROUND

High incidence of chronic graft-versus-host disease (GVHD) has been a major drawback of matched sibling donor peripheral blood stem cell transplantation (MSD -PBSCT). This study aimed to investigate the safety and efficacy of antithymocyte globulin (ATG) as a standardized part of GVHD prophylaxis in patients receiving MSD -PBSCT.

METHODS

A total of 72 patients with hematological malignancies receiving MSD -PBSCT who displayed similar baseline characteristics were either given rabbit ATG ( n = 42) or no ATG (n = 30), in addition to cyclosporine, methotrexate, and mycophenolate mofetil as a standard GVHD prophylaxis regimen. Either patients or donors aged ≥40 years were included in the study. Thymoglobulin was administered at a daily dose of 1.5 mg/kg on day -5 and 3.5 mg/kg on day -4 prior to transplant (the total dose was 5 mg/kg).

RESULTS

After a median follow-up of 874 days, the 3-year cumulative incidence of chronic GVHD (cGVHD) was 37.3% in the ATG group and 52.1% in the non -ATG group. The 3-year overall and disease-free survival probability were 71.0% and 62.0% (ATG versus non -ATG, P = .262) and 66.7% and 58.4% (ATG versus non -ATG, P = .334). No difference was found in the 2-year cumulative incidence of nonrelapse mortality and relapse between the ATG and non -ATG groups. This significant reduction in the incidence of cGVHD without increased relapse risk and nonrelapse mortality led to a 3-year GVHD-free, relapse-free survival probability of 66.7% and 40.0% in the ATG and non-ATG groups, respectively.

CONCLUSIONS

These data suggested that rabbit antithymocyte globulin in the current protocol for GVHD prophylaxis was well tolerable and efficacious.The clinical trial was registered on January 1, 2016 (ClinicalTrials.gov Identifier NCT02677181). https://clinicaltrials.gov/ct2/show/NCT02677181.

Ruxolitinib Combined with Corticosteroids as First-Line Therapy for Acute Graft-versus-Host Disease in Haploidentical Peripheral Blood Stem Cell Transplantation Recipients

Corticosteroids are commonly used as first-line treatment for acute graft-versus-host disease (aGVHD); however, they are effective in only approximately one-half of patients. This study prospectively evaluated the use of ruxolitinib combined with 1 mg/kg methylprednisolone in the initial treatment of aGVHD. A total of 32 patients were enrolled. aGVHD involved the skin (53.1%), gastrointestinal tract (68.8%), and liver (6.0%). The complete response rate at day +28 was 96.9%. The 1-year and 2-year cumulative incidence rates of chronic GVHD were 9.4% and 13.8%, respectively. The 1- year cumulative incidence of nonrelapse mortality was 8.7%, and the Kaplan-Meier curve estimated 1-year overall survival after transplantation at 73.4%. This prospective study suggests that patients with aGVHD show a high response rate to ruxolitinib (5 mg/day) combined with 1 mg/kg/day methylprednisolone. This novel regimen was seen to spare steroid exposure, alleviate toxicity, and improve long-term survival.

Reduced risk of chronic GVHD by low-dose rATG in adult matched sibling donor peripheral blood stem cell transplantation for hematologic malignancies

The optimal rabbit anti-thymocyte globulin (rATG) graft-versus-host disease (GVHD) prophylaxis regimen in matched sibling donor peripheral blood stem cell transplantation (MSD-PBSCT) remains to be elucidated. In this prospective study, we used low-dose rATG for GVHD prophylaxis in patients or donors aged ≥ 40 years with hematological malignancies receiving MSD-PBSCT. rATG was administered to 40 patients at an intravenous dose of 5 mg/kg divided over day 5 and day 4 before graft infusion. No graft failure occurred. Median times to leukocyte engraftment and platelet engraftment were 11.0 days and 13.9 days. The cumulative incidence of grades 2–4 and grades 3–4 acute GVHD at day +100 was 30.0% and 2.6%. The 2-year cumulative incidence of extensive chronic GVHD and severe chronic GVHD was 11.4% and 14.7%. 93.5% (29/31) of patients had discontinued immunosuppressive medication within 3 years after transplantation. The 2-year cumulative incidence of transplant-related mortality (TRM) and relapse was 14.0% and 22.6%. The cumulative incidence of cytomegalovirus reactivation, Epstein–Barr virus reactivation, and fungal infection was 22.3%, 12.9%, and 12.5%. Kaplan–Meier estimates for overall survival, disease-free survival, and GVHD-free and relapse-free survival 3 years after transplantation were 68.9%, 68.9%, and 54.0%. rATG for GVHD prophylaxis is tolerable and efficacious at a 5 mg/kg total dose administered over 2 days (days −5 to −4) in patients receiving allogeneic MSD-PBSCT.

Comparison of the safety and efficacy of prophylactic donor lymphocyte infusion after haploidentical versus matched-sibling PBSCT in very high-risk acute myeloid leukemia

Donor lymphocyte infusion (DLI) might be used prophylactically to reduce relapse after allogeneic hematopoietic stem cell transplantation for very high-risk leukemia/lymphoma without effective targeted therapy. To compare the safety and efficacy of prophylactic DLI for prevention of relapse after allogeneic peripheral blood stem cell transplantation from haploidentical donors (HID-SCT) and matched-sibling donors (MSD-SCT) in patients with very high-risk acute myeloid leukemia (AML), we performed a retrospective analysis in a cohort of 21 HID-SCT and 13 MSD-SCT recipients, displaying similar baseline characteristics except for donor's gender distribution. Grade 2-4 acute graft-versus-host disease (GVHD) at 100-day post-DLI was higher in HID-SCT group than that in MSD-SCT group (59.5% vs. 30.8%, p = 0.05). The grade 3-4 acute GVHD (17.5% vs. 7.7%), 1-year chronic GVHD (36.6% vs. 33.2%), and severe chronic GVHD (15.3% vs. 27.3%) were not statistically significant different between groups. One-year non-relapse mortality was higher in HID-SCT group than that in MSD-SCT group with marginal significance (27.9% vs. 0.0%, p = 0.061). One-year relapse rate was not statistically significant different between HID-SCT group and MSD-SCT group (21.6% vs. 36.5%, p = 0.543). For HID-SCT recipients, 1-year relapse rate was lower in patients receiving prophylactic DLI than that in a control cohort of eight patients with same very high-risk features but not receiving prophylactic DLI (62.5% vs. 28.3%, p = 0.037). No statistically significant difference was observed in 1-year overall survival (OS, 55.1% vs. 83.9%, p = 0.325) and relapse-free survival (RFS, 50.1% vs. 74.0%, p = 0.419) rates between HID-SCT group and MSD-SCT group. In multivariate analyses, non-remission status prior to transplant, poor-risk gene mutations, and donor's age ≥ 48 years predicted a higher risk of relapse after DLI. Non-remission status prior to transplant predicted inferior OS and RFS. Patient's age ≥ 40 years also predicted an inferior OS. In conclusion, prophylactic DLI was very safe and efficient for reducing relapse in patients with very high-risk AML receiving MSD-SCT. In the recipients of HID-SCT, the application of prophylactic DLI could reduce the risk of relapse, although with a higher incidence of DLI-associated acute GVHD than those of MSD-SCT.

Donor lymphocyte infusion for prevention of relapse after unmanipulated haploidentical PBSCT for very high-risk hematologic malignancies

Unmanipulated haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) has been an established treatment to cure high-risk leukemia/lymphoma. Relapse is the main cause of treatment failure for patients with relapsed/refractory disease or with very high-risk gene mutations such as TP53, TET2, and DNMT3a. In this study, we aimed to establish the tolerance and efficacy of prophylactic donor lymphocyte infusion (DLI) with G-CSF-primed peripheral blood progenitors for prevention of relapse in these very high-risk patients after haplo-PBSCT. The prophylactic DLI was given at a median of 77 days after transplantation in 31 of 45 consecutive patients with very high-risk leukemia/lymphoma. The median dose of CD3+ cells for infusion was 1.8 × 107/kg. The 100-day incidences of acute graft-versus-host disease (GVHD) grades 2-4 and 3-4 after DLI were 55.3% and 10.2%. The 2-year incidences of chronic GVHD and severe chronic GVHD were 52.0% and 18.2%. The 2-year incidences of non-relapse mortality and relapse were 33.1% and 32.5%. The 2-year probabilities of overall survival and relapse-free survival were 40.1% and 31.9%. Poor-risk gene mutations (p = 0.029), disease in non-remission status prior to transplantation (p = 0.005), and donors older than 40 years of age (p = 0.043) were associated with relapse after DLI. In multivariate analysis, disease in non-remission status prior to transplantation was an independent risk factor of relapse (hazard ratio = 4.079; p = 0.035). These data showed the feasibility of the prophylactic DLI in the haplo-PBSCT setting and the anti-leukemic efficacy in very high-risk leukemia/lymphoma.

Haploidentical versus matched donor stem cell transplantation for patients with hematological malignancies: a systemic review and meta-analysis

We compared the safety and efficacy of haploidentical stem cell transplantation (haplo-SCT) to matched donor SCT (matched-SCT) in treating hematological malignancies. The Medline, Cochrane, EMBASE, and Google Scholar databases were searched through 21 June 2017 using the search term "(hematological disease) AND matched AND (haploidentical OR haplo-identical OR haplo identical OR haplo transplantation OR haplo transplant OR haplo-SCT OR haplo-HSCT OR haplo-HCT)." Twenty-five studies enrolling 11,359 patients (haplo-SCT: 2677; matched-SCT: 8682) were included. The primary outcomes were acute and chronic graft-versus-host disease (GVHD), non-relapse mortality, and 1-year cumulative incidence of relapse. Haplo-SCT was associated with similar risks as matched-SCT for all primary endpoints. Subgroup analysis of patients who received a matched-SCT from a related donor revealed that patients who received haplo-SCT had a lower risk of acute GVHD. Among patients who received reduced-intensity conditioning (RIC), those who received haplo-SCT had a higher risk of acute grade II-IV GVHD and non-relapse mortality than did patients who received a matched-SCT from a related or unrelated donor. Haplo-SCT should continue to be considered as a safe and effective transplant option when a matched donor is unavailable, but it may not be suitable for patients who receive RIC.