A phase 2, open-label study of ibrutinib plus rituximab in Japanese patients with Waldenstrom's macroglobulinemia.

Ibrutinib is a first-in-class Bruton kinase inhibitor against B-cell neoplasms including Waldenström macroglobulinemia (WM). This study evaluated the efficacy and safety of ibrutinib-rituximab in Japanese patients with WM. Patients received ibrutinib 420 mg orally once daily plus weekly rituximab 375 mg/m2 IV (8 infusions total). The primary end point was major response rate (MRR; PR or better) by Independent Review Committee assessment. Secondary endpoints were progression-free survival (PFS), safety, pharmacokinetics, and biomarkers. Primary analysis was conducted in 16 patients [baseline, treatment naïve: 8 (50.0%); relapsed/refractory WM: 8 (50.0%)] who received ibrutinib-rituximab, after all patients completed Week 57 or end of treatment. At primary analysis, MRR was 87.5% [14/16 patients; 95% CI: 61.7, 98.4%; p < 0.0001 (null hypothesis: 32% response rate)]. At final analysis (median study intervention duration: 34.4 months, median follow-up: 35.0 months), MRR was unchanged at 87.5%, but VGPR [6/16 (37.5%)] and PR [8/16 (50.0%)] improved. Prior treatment status did not affect response. At final analysis, median PFS was not reached [36-month PFS rate: 86% (95% CI: 55, 96%)]. No critical safety signals were reported. This study demonstrated a positive benefit/risk profile of ibrutinib-rituximab in Japanese patients with WM, consistent with the iNNOVATE study.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical sibling donors for hematological malignancies in 6064 adults from 2003 to 2020: different impacts on survival according to time period.

BACKGROUND: Mobilized peripheral blood stem cells (PBSC) have been widely used instead of bone marrow (BM) as the graft source for allogeneic hematopoietic cell transplantation (HCT). Although early studies demonstrated no significant differences in survival between PBSC transplantation (PBSCT) and BM transplantation (BMT) from human leukocyte antigen (HLA)-identical sibling donors to adults with hematological malignancies, recent results have been unclear. OBJECTIVE: The objective of this retrospective study was to compare overall survival (OS), relapse, non-relapse mortality (NRM), hematopoietic recovery and graft-versus-host disease (GVHD) between PBSCT and BMT according to the time period of HCT (2003-2008, 2009-2014, or 2015-2020). STUDY DESIGN: We retrospectively compared the outcomes after PBSCT versus BMT in 6064 adults with hematological malignancies using a Japanese registry database between 2003 and 2020. RESULTS: The adjusted probability of OS was significantly higher in BMT recipients compared to PBSCT recipients during the early period of 2003-2008 (adjusted hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.70-0.91; P < 0.001) and the middle period of 2009-2014 (adjusted HR, 0.80; 95% CI, 0.70-0.91; P < 0.001). However, during the late period of 2015-2020, the adjusted probability of OS was comparable between BMT and PBSCT recipients (adjusted HR, 0.94; 95% CI, 0.79-1.13; P = 0.564), which were mainly due to the reduction of NRM. There was no significant difference in the relapse rate between the groups, irrespective of the time period. Compared to BMT, PBSCT led to faster neutrophil and platelet recovery and the cumulative incidences of grades II-IV and grades III-IV acute and overall and extensive chronic GVHD were significantly higher in PBSCT recipients, irrespective of the time period. CONCLUSIONS: PBSCT and BMT had similar survival outcomes and relapse rates in adult patients with hematological malignancies during the late time period of 2015-2020 despite the hematopoietic recovery and acute and chronic GVHD being higher in PBSCT recipients in all time periods.

Peripheral blood stem cell transplantation using HLA-haploidentical donor with post-transplant cyclophosphamide versus HLA-matched sibling donor for lymphoma.

Data comparing HLA-haploidentical donors and HLA-matched sibling donors (MSDs) in peripheral blood stem cell transplantation (PBSCT) for lymphoma are scarce. We retrospectively analyzed 465 patients with lymphoma aged 16 years or older who underwent PBSCT using haploidentical donors with post-transplant cyclophosphamide (PTCy-haplo) (n = 166) or MSDs with calcineurin inhibitor-based graft-versus-host disease (GVHD) prophylaxis (n = 299). Two-year overall survival (OS), progression-free survival (PFS), and GVHD-free, relapse-free survival (GRFS) in the PTCy-haplo and MSD groups were 49.2% versus 51.9% (P = 0.64), 38.0% versus 39.9% (P = 0.97), and 27.7% versus 18.5% (P = 0.006), respectively. In multivariable analyses, PTCy-haplo recipients had slower neutrophil recovery (hazard ratio [HR], 0.62; P < 0.001) and platelet recovery (HR, 0.54; P < 0.001), lower risk of chronic GVHD (HR, 0.64; P = 0.038) and extensive chronic GVHD (HR, 0.45; P = 0.008), and better GRFS (HR, 0.66; P = 0.003) than MSD transplant recipients. OS, PFS, relapse or progression, and non-relapse mortality were similar between the groups. The difference might be mainly due to PTCy use rather than donor type; however, the results suggested that PTCy-haplo could be a possible option as an alternative to conventional MSD transplantation for lymphoma in PBSCT.

Development of an umbilical cord blood transplantation-specific nonrelapse mortality risk assessment score.

ABSTRACT: Higher rate of nonrelapse mortality (NRM) remains yet to be resolved in umbilical cord blood transplantation (UCBT). Considering that UCBT has some unique features compared with allogeneic hematopoietic cell transplantation from other graft sources, a UCBT-specific NRM risk assessment system is required. Thus, in this study, we sought to develop a UCBT-specific NRM Risk Assessment (CoBRA) score. Using a nationwide registry database, we retrospectively analyzed 4437 recipients who had received their first single-unit UCBT. Using the backward elimination method, we constructed the CoBRA score in a training cohort (n = 2687), which consisted of recipients age ≥55 years (score 2), hematopoietic cell transplantation-specific comorbidity index ≥3 (score 2), male recipient, graft-versus-host disease prophylaxis other than tacrolimus in combination with methotrexate, performance status (PS) 2 to 4, HLA allele mismatch ≥ 2, refined Disease Risk Index high risk, myeloablative conditioning, and CD34+ cell doses < 0.82 × 105/kg (score 1 in each). The recipients were categorized into 3 groups: low (0-4 points), intermediate (5-7 points), and high (8-11 points) groups according to the CoBRA score. In the validation cohort (n = 1750), the cumulative incidence of NRM at 2 years was 14.9%, 25.5%, and 47.1% (P < .001), and 2-year overall survival (OS) was 74.2%, 52.7%, and 26.3% (P < .001) in the low, intermediate, and high groups, respectively. In summary, the CoBRA score could predict the NRM risk as well as OS after UCBT. Further external validation will be needed to confirm the significance of the CoBRA score.

Impaired humoral immunity following COVID-19 vaccination in HTLV-1 carriers.

BACKGROUND: Whether human T-lymphotropic virus type 1 (HTLV-1) carriers can develop sufficient humoral immunity after coronavirus disease 2019 (COVID-19) vaccination is unknown. METHODS: To investigate humoral immunity after COVID-19 vaccination in HTLV-1 carriers, a multicenter, prospective observational cohort study was conducted at five institutions in southwestern Japan, an endemic area for HTLV-1. HTLV-1 carriers and HTLV-1-negative controls were enrolled for this study from January to December 2022. During this period, the third dose of the COVID-19 vaccine was actively administered. HTLV-1 carriers were enrolled during outpatient visits, while HTLV-1-negative controls included health care workers and patients treated by participating institutions for diabetes, hypertension, or dyslipidemia. The main outcome was the effect of HTLV-1 infection on the plasma anti-COVID-19 spike IgG (IgG-S) titers after the third dose, assessed by multivariate linear regression with other clinical factors. RESULTS: We analyzed 181 cases (90 HTLV-1 carriers, 91 HTLV-1-negative controls) after receiving the third dose. HTLV-1 carriers were older (median age 67.0 vs. 45.0 years, p < 0.001) and more frequently had diabetes, hypertension, or dyslipidemia than did HTLV-1-negative controls (60.0% vs. 27.5%, p < 0.001). After the third dose, the IgG-S titers decreased over time in both carriers and controls. Multivariate linear regression in the entire cohort showed that time since the third dose, age, and HTLV-1 infection negatively influenced IgG-S titers. After adjusting for confounders such as age, or presence of diabetes, hypertension, or dyslipidemia between carriers and controls using the overlap weighting propensity score method, and performing weighted regression analysis in the entire cohort, both time since the third dose and HTLV-1 infection negatively influenced IgG-S titers. CONCLUSIONS: The humoral immunity after the third vaccination dose is impaired in HTLV-1 carriers; thus, customized vaccination schedules may be necessary for them.

Single-unit unrelated cord blood transplantation versus HLA-matched sibling transplantation in adults with advanced myelodysplastic syndrome: A registry-based study from the adult MDS working group of the Japanese society for transplantation and cellular therapy.

Allogeneic hematopoietic stem cell transplantation (HCT) remains the only potential curative therapeutic modality for advanced myelodysplastic syndrome (MDS). Within HCT, the advancement of cord blood transplantation (CBT) procedures has resulted in a drastic expansion of CBT as a donor source for MDS. However, data comparing matched sibling donors (MSDs) HCT with CBT for advanced MDS, which was defined as refractory anemia with an excess of blasts (RAEB)-1 and RAEB-2 according to the World Health Organization classification at the time of HCT, have not been explored. We retrospectively compared survival and other posttransplant outcomes in 999 adult patients with advanced MDS after receiving allogeneic HCT in Japan between 2011 and 2020, using either MSD (n = 331) or single-unit unrelated cord blood (UCB) (n = 668). In the multivariate analysis, there were no significant differences in overall survival (hazard ratio [HR], 1.10; 95% confidence interval [CI], 0.90-1.34; P = 0.347), disease-free survival (HR, 1.01; 95% CI, 0.84-1.23; P = 0.845), relapse (HR, 0.88; 95% CI, 0.68-1.15; P = 0.370), or non-relapse mortality (HR, 1.15; 95% CI, 0.87-1.50; P = 0.310) between MSD recipients and UCB recipients. UCB was significantly associated with lower neutrophil (HR, 0.28; 95% CI, 0.24-0.33; P < 0.001) and lower platelet (HR, 0.29; 95% CI, 0.23-0.36; P < 0.001) recovery compared to MSD. UCB was significantly associated with a lower incidence of chronic graft-versus-host disease (GVHD) (HR, 0.57; 95% CI, 0.44-0.75; P < 0.001) and extensive chronic GVHD (HR, 0.46; 95% CI, 0.32-0.67; P < 0.001) compared to MSD. Similar results were observed after adjusting for differences between MSD and UCB recipients by propensity score matching analysis. Our study demonstrated that single CBT and MSD HCT had similar survival outcomes for adult patients with advanced MDS despite the lower hematopoietic recovery in CBT recipients and higher chronic GVHD in MSD recipients.

Efficacy and safety of extended duration letermovir prophylaxis in recipients of haematopoietic stem-cell transplantation at risk of cytomegalovirus infection: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: In a pivotal phase 3 trial of cytomegalovirus prophylaxis with letermovir for up to 100 days after allogeneic haematopoietic stem-cell transplantation (HSCT), 12% of participants developed clinically significant cytomegalovirus infection after letermovir was discontinued. We aimed to evaluate the efficacy and safety of extending the duration of letermovir prophylaxis for clinically significant cytomegalovirus infection from 100 days to 200 days following HSCT. METHODS: We conducted a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 32 sites in six countries (France, Germany, Italy, Japan, the UK, and the USA). Cytomegalovirus­seropositive HSCT recipients (aged ≥18 years) who had received letermovir prophylaxis for up to 100 days following HSCT and who remained at high risk of late clinically significant cytomegalovirus infection (with no previous history of clinically significant cytomegalovirus infection, defined as initiation of pre-emptive therapy for documented cytomegalovirus viraemia, onset of cytomegalovirus end-organ disease, or both) were eligible. Participants were randomly assigned (2:1) to receive either an additional 100 days (ie, a total of 200 days; letermovir group) of oral or intravenous letermovir 480 mg once daily, adjusted to 240 mg once daily for participants on cyclosporin A, or 100 days of a placebo comparator for letermovir (ie, a total of 100 days of letermovir; placebo group), following HSCT. Randomisation was done using a central interactive response technology system, stratified by study centre and haploidentical donor (yes or no). Participants, investigators, and sponsor personnel were masked to the treatment allocation. The primary efficacy endpoint was the proportion of participants from randomisation to week 28 (200 days after HSCT) with clinically significant cytomegalovirus infection, analysed using the full analysis set population (ie, those who received at least one dose of study intervention). Safety was analysed in all participants as treated (ie, those who received at least one dose according to the study intervention they were assigned to). This study is registered with ClinicalTrials.gov, NCT03930615, and is complete. FINDINGS: Between June 21, 2019, and March 16, 2022, 255 patients were screened for eligibility and 220 (86%) were randomly assigned (145 [66%] in the letermovir group and 75 [34%] in the placebo group). Between randomisation and week 28, four (3%) of 144 participants in the letermovir group and 14 (19%) of 74 in the placebo group developed clinically significant cytomegalovirus infection (treatment difference -16·1% [95% CI -25·8 to -6·5]; p=0·0005). The most common adverse events among participants in the letermovir group versus the placebo group were graft-versus-host disease (43 [30%] vs 23 [31%]), diarrhoea (17 [12%] vs nine [12%]), nausea (16 [11%] vs 13 [18%]), pyrexia (13 [9%] vs nine [12%]), and decreased appetite (six [4%] vs nine [12%]). The most frequently reported serious adverse events were recurrent acute myeloid leukaemia (six [4%] vs none) and pneumonia (three [2%] vs two [3%]). No deaths were considered to be drug-related by the investigator. INTERPRETATION: Extending the duration of letermovir prophylaxis to 200 days following HSCT is efficacious and safe in reducing the incidence of late clinically significant cytomegalovirus infection in patients at risk. FUNDING: Merck Sharp & Dohme LLC.

Analysis of risk factors for fatal renal complications after allogeneic hematopoietic cell transplantation.

Various complications can influence hematopoietic cell transplantation (HCT) outcomes. Renal complications can occur during the early to late phases of HCT along with various factors. However, studies focusing on fatal renal complications (FRCs) are scarce. Herein, we analyzed 36,596 first allogeneic HCT recipients retrospectively. Overall, 782 patients died of FRCs at a median of 108 (range, 0-3,440) days after HCT. The cumulative incidence of FRCs was 1.7% and 2.2% at one and five years, respectively. FRCs were associated with older age, male sex, non-complete remission (non-CR), lower performance status (PS), and HCT comorbidity index (HCT-CI) associated with renal comorbidity in multivariate analysis. The risk factors within 100 days included older age, multiple myeloma, PS, and HCT-CI comorbidities (psychiatric disturbance, hepatic disease, obesity, and renal disease). Older age and male sex were risk factors between 100 days and one year. After one year, HCT-CI was associated with the presence of diabetes and prior solid tumor; total body irradiation was identified as a risk factor. Non-CR was a common risk factor in all three phases. Furthermore, acute and chronic graft-versus-host disease, reactivation of cytomegalovirus, and relapse of underlying disease also affected FRCs. Systematic follow-up may be necessary based on the patients' risk factors and post-HCT events.

Allogeneic hematopoietic cell transplantation for patients with acute myeloid leukemia not in remission.

Allogeneic hematopoietic cell transplantation (HCT) is the last option for long-term survival for patients with chemotherapy-refractory acute myeloid leukemia (AML). By using the Japanese nationwide registry data, we analyzed 6927 adults with AML having undergone first allogeneic HCT while not in complete remission (CR) between 2001 and 2020. The 5-year overall survival (OS), relapse, and non-relapse mortality (NRM) rates were 23%, 53%, and 27%, respectively. Multivariate analysis identified several factors predictive of OS mainly through their effects on relapse (cytogenetics, percentage of blasts in the peripheral blood, and transplantation year) and NRM (age, sex, and performance status). As regards disease status, relapsed disease was associated with a higher risk of overall mortality than primary induction failure (PIF). The shorter duration of the first CR increased the risks of relapse and overall mortality for the relapsed group, and the longer time from diagnosis to transplantation did so for the PIF group. Our experience compiled over the past two decades demonstrated that >20% of patients still enjoy long-term survival with allogeneic HCT performed during non-CR and identified those less likely to benefit from allogeneic HCT. Future efforts are needed to reduce the risk of posttransplant relapse in these patients.

Scoring system for optimal cord blood unit selection for single cord blood transplantation.

BACKGROUND: We conducted a retrospective study to categorize the cord blood unit (CBU)s to identify the optimal units. METHODS: A total of 8503 adults (female, n = 3592; male, n = 4911) receiving their first single cord blood transplantation (CBT) in 2000-2019 were analyzed. Factors associated with CBUs affecting overall survival (OS) and neutrophil engraftment were selected to create ranked categorization for each outcome, followed by comparison with transplantation using HLA-matched bone marrow (BMT)/peripheral blood stem cell (PBSCT) from unrelated (n = 6052) and related donors (n = 4546). RESULTS: Sex-mismatch, CD34+ cell and CFU-GM counts were selected in the OS analysis. Considering the strong interaction between sex mismatch and CD34+ cell counts, we analyzed females and males separately. For females, female CBU with CD34+ cell counts {greater than or equal to} 0.5 × 10e5/kg and CFU-GM counts {greater than or equal to} 15 × 10e3/kg offered the best OS (Group I), followed by other groups with any (Groups II-IV) or all (Group V) of the risk factors. Group I consistently showed favorable OS (Group IV: HR1.22, P = 0.027; Group V: HR1.31, P = 0.047), comparable to those of rBMT/PBSCT (OS: HR1.02, P = 0.654) and uBM/PBSCT in patients with higher rDRI (HR1.07, P = 0.353). Male patients lacked significant factors affecting OS. Categorization for neutrophil engraftment consisting of CD34+ cell and CFU-GM counts, sex-mismatch, presence of donor-specific antibodies, and the number of HLA-mismatches was effective but not predicted OS. CONCLUSION: Our ranked categorizations sufficiently predicted female OS and engraftment. The best-ranked CBUs offered preferable outcomes comparable to conventional BM/PB donors in female but not in male patients.

Low- versus standard-dose post-transplant cyclophosphamide as GVHD prophylaxis for haploidentical transplantation.

Haploidentical haematopoietic cell transplantation (haplo-HCT) using post-transplant cyclophosphamide (PTCY) as graft-versus-host disease (GVHD) prophylaxis is the standard of care for various haematological malignancies. The original PTCY dose after haplo-HCT was 100 mg/kg, but no dose-finding studies have been performed to identify the optimal dose. We performed a retrospective analysis to compare standard-dose PTCY (100 mg/kg) with reduced-dose PTCY (80 mg/kg): 969 in the standard-dose group and 538 in the reduced-dose group. As there was a significant difference between the two groups regarding patient and transplant characteristics, we performed propensity score (PS) matching. After PS matching, 425 patients in each group were included. The probabilities of 2-year OS were 55.9% in the standard-dose group and 47.0% in the reduced-dose group (p = 0.36). The cumulative incidences of 2-year non-relapse mortality were 21.3% in the standard-dose group and 20.5% in the reduced-dose group (p = 0.55). There was no significant difference in the incidence of acute (grade II-IV 29.2% [95% CI, 24.9-33.6] vs. 25.3% [95% CI, 21.3-29.6]; grade III-IV 7.3% [95% CI, 5.1-10.0] vs. 6.6% [95% CI, 4.5-9.3]) or chronic GVHD. In conclusion, reduced- and standard-dose PTCY were comparable in terms of major clinical outcomes.

Effect of Conditioning Regimens and Graft-versus-Host Disease Prophylaxis on the Outcomes of Umbilical Cord Blood Transplantation Performed with Cyclophosphamide/Total Body Irradiation-Based Regimens.

Umbilical cord blood (UCB) is a valuable alternative donor source for allogeneic hematopoietic stem cell transplantation. Various conditioning regimens and graft-versus-host disease (GVHD) prophylaxis regimens aimed at improving the outcomes of umbilical cord blood transplantation (UCBT) have been explored; however, the differences in their effects remain unclear. This study was conducted to elucidate the differences in the effects of conditioning and GVHD prophylaxis regimens on UCBT outcomes by disease type in a nationwide, retrospective study. We retrospectively analyzed the effects of conditioning and GVHD prophylaxis regimens on the outcomes of UCBT performed with cyclophosphamide (Cy)/total body irradiation (TBI)-based regimens in patients with acute myeloid leukemia (AML; n = 1126), acute lymphoblastic leukemia (ALL; n = 620), myelodysplastic syndrome (MDS; n = 170), and lymphoma (n = 128). Multivariate analysis for overall survival (OS) demonstrated the benefit of adding high-dose cytarabine to the Cy/TBI regimen for the AML group (relative risk [RR], .76; P = .003) and lymphoma group (RR, .54; P = .02), but not for the ALL and MDS groups. In the ALL group, adding etoposide to the Cy/TBI regimen was associated with a lower OS (RR, 1.45; P = .03). For GVHD prophylaxis, a tacrolimus/methotrexate regimen was associated with a lower OS compared with a cyclosporine/methotrexate regimen in the AML group (RR, 1.26; P = .01); this difference was not observed in the other groups. These differences in OS according to the conditioning and GVHD prophylaxis regimen were attributable mainly to differences in relapse risk. Our data show that the effects of conditioning regimens and GVHD prophylaxis on UCBT outcomes differed according to disease type. UCBT outcomes could be improved by selecting optimal conditioning regimens and GVHD prophylaxis for each disease type.

Long-term Use of Ibrutinib in Japanese Patients with Steroid Dependent/Refractory cGVHD: Final Analysis of Multicenter Study.

Background: Chronic graft-versus-host disease (cGVHD) is a serious complication after allogeneic stem cell transplantation. Poor prognosis has been shown in patients with cGVHD after the failure of primary steroid-based treatments. A previous report demonstrated the efficacy and safety of ibrutinib in these patients, leading to the approval of ibrutinib for cGVHD in Japan. Here, we report the extended follow-up of patients in this study. Objectives: To evaluate the safety and efficacy of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD. Study Design: An open-label, single-arm, multicenter study of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD (NCT No.: NCT03474679; Clinical Registry No.: CR108443). Results: At the time of the final data cutoff, 7/19 (36.8%) patients completed the study treatment, and 12/19 (63.2%) patients discontinued ibrutinib. After a median follow-up of 31.11 months (range:1.9 to 38.6 months), the best overall response rate was 84.2% (16/19 patients; 95% CI:60.4%, 96.6%) in all treated populations, with a median time to response of 2.81 (range:1.0 to 27.6) months. Of 15 responders with ≥2 organs involved at baseline, seven (46.7%) had responses in multiple organs. An improvement in the organ response rate was observed for the skin, eye, mouth, and esophagus compared with that in a previous report. The rate of sustained response for ≥20 weeks, ≥32 weeks, and ≥44 weeks were 68.8%, 62.5%, and 50.0%, respectively for 16 responders. The median daily corticosteroid dose requirement tended to decrease over time for all treated analysis sets. Twelve of 19 patients (63.2%) reached a corticosteroid dose of <0.15 mg/kg/day for at least one week, and four (21.1%) discontinued corticosteroid treatment for at least 28 days during the study. The failure-free and overall survival rates at 30 months were 62.7% and 62.0%, respectively. The safety findings of this updated analysis were consistent with the safety profile observed at the time of the primary analysis and the known ibrutinib safety profile. Common grade ≥3 treatment-emergent adverse events (TEAEs) were pneumonia (6/19 [31.6%] patients), platelet count decreased, and cellulitis (3/19 [15.8%] patients each). After the primary analysis, no new TEAEs leading to death, treatment discontinuation, or dose reduction were reported, and no new patients reported major hemorrhage. Cardiac arrhythmia (Grade 2 atrial flutter) was reported in 1/19 (5.3%) patients. No new safety signs were observed despite prolonged ibrutinib exposure. Conclusions: The final results support previous conclusions, demonstrating a clinically meaningful response and acceptable safety profile of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD.

Improved Long-Term Net Survival after Allogeneic Hematopoietic Cell Transplantation in Patients with Hematologic Malignancies over Two Decades.

Allogeneic (allo-) hematopoietic cell transplantation (HCT) has evolved as a curative therapy for hematologic malignancies and diseases, with practice changes over the past 2 decades. This study aimed to evaluate the change in 5-year net survival (NS) of allo-HCT recipients in a population-based cohort over the past 2 decades, which allows the estimation of a more HCT-specific long-term survival rate by considering background mortality changes. This study included 42,064 patients with hematologic malignancies who underwent their first allo-HCT in Japan between 2000 and 2018 and were reported to the Transplant Registry Unified Management Program. We compared the 5-year NS after allo-HCT in 4 consecutive HCT periods (2000 to 2004, 2005 to 2008, 2009 to 2012, and 2013 to 2018). The 5-year NS of the latest period was estimated using the period analysis method. Adjusted excess hazard ratios (EHRs) for 5-year NS over the HCT period were analyzed using an EHR model. In addition to the analysis of all hematologic malignancies, adjusted 5-year NS for each major hematologic malignancy, including acute myelogenous leukemia, acute lymphoblastic leukemia (ALL), myelodysplastic syndrome, adult T cell leukemia/lymphoma, chronic myeloid leukemia (CML), and malignant lymphoma, was analyzed. The probability of adjusted 5-year NS after HCT improved significantly over time: 35% in 2000 to 2004, 39% in 2005 to 2008, 45% in 2009 to 2012, and 49% in 2013 to 2018. The adjusted EHRs were .90 (95% confidence interval [CI], .86 to .93) in the 2005 to 2008 period, .77 (95% CI, .74 to .80) in the 2009 to 2012 period, and .65 (95% CI, .63 to .68) in the 2013 to 2018 period, with the 2000 to 2004 period as the reference. The 5-year NS improved among all hematologic malignancies, with a significant improvement in CML and ALL. The changes in 5-year NS from the 2000 to 2004 period to the 2013 to 2018 period ranged from 46% to 66% in CML and from 41% to 59% in ALL. In addition to the large improvement of 1-year NS, smaller but continued improvement in NS between 1 and 5 years after transplantation was observed. NS at 5 years conditional on being alive at 1 year increased from 64% in 2000 to 2004 to 73% in 2013 to 2018. Even after subtracting the background mortality in the general population, we found a significant improvement in long-term allo-HCT-specific survival rates for patients with hematologic malignancies over the past 2 decades in Japan.

Poor outcome of allogeneic transplantation for therapy-related acute myeloid leukemia induced by prior chemoradiotherapy.

Therapy-related acute myeloid leukemia (t-AML) is a therapeutic challenge as a late complication of chemotherapy (CHT) and/or radiotherapy (RT) for primary malignancy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) presents itself as a curative approach. To establish the optimal allo-HSCT strategy for t-AML, we evaluated the relationship between characteristics of primary malignancy and allo-HSCT outcomes. Patients with t-AML or de novo acute myeloid leukemia (AML) who underwent first allo-HSCT in Japan from 2011 to 2018 were identified using a nationwide database. The detailed background of t-AML was obtained by additional questionnaires. Multivariate analysis and propensity score matching (PSM) analysis were performed to detect the prognostic factors associated with t-AML and compare outcomes with de novo AML. We analyzed 285 t-AML and 6761 de novo AML patients. In patients with t-AML, receiving both CHT and RT for primary malignancy was an independent poor-risk factor for relapse and overall survival (OS) (hazard ratio (HR) 1.62; p = 0.029 and HR 1.65; p = 0.009, reference: CHT alone group), whereas other primary malignancy-related factors had no effect on the outcome. Compared to the CHT alone group, complex karyotypes were significantly increased in the CHT + RT group (86.1% vs. 57.5%, p = 0.007). In the PSM cohort, t-AML patients with prior CHT and RT had significantly worse 3-year OS than those with de novo AML (25.2% and 42.7%; p = 0.009). Our results suggest that prior CHT and RT for primary malignancy may be associated with increased relapse and worse OS of allo-HSCT in t-AML.

Unrelated female-to-male bone marrow transplantation would be preferred over cord blood transplantation in male patients.

BACKGROUND AIMS: Allogeneic hematopoietic stem cell transplantation from female donors to male recipients (female-to-male allo-HCT) is a well-established risk factor for a greater incidence of non-relapse mortality (NRM) and chronic graft-versus-host disease (GVHD). In contrast, unrelated cord blood transplantation (UCBT) is associated with a lower incidence of chronic GVHD. In this study, survival outcomes were compared between the UCBT and unrelated female-to-male bone marrow transplantation (UFMBMT) groups. METHODS: We evaluated male allo-HCT recipients who underwent UCBT or UFMBMT between 2012 and 2020 in Japan. There were 2517 cases in the UCBT group, 456 cases in the HLA-matched UFMBMT group and 457 cases in the HLA-mismatched UFMBMT group. RESULTS: HLA-mismatched UFMBMT was significantly associated with a decreased risk of relapse (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.57-0.98], P = 0.033) and HLA-matched UFMBMT had the tendency of a decreased risk of relapse (HR 0.78; 95% CI 0.61-1.01, P = 0.059). HLA-matched UFMBMT was also associated with favorable OS (HR 0.82; 95% CI 0.69-0.97, P = 0.021). The relationship between the donor sources and relapse was similarly observed in the lymphoid malignancy cohort. CONCLUSIONS: The difference of graft-versus leukemia effect by H-Y immunity according to donor sources might contribute to the difference in clinical impact. It might be desirable for patients who could sufficiently wait for donor coordination to select BMT rather than UCBT, even if only unrelated female donors are available for male recipients.

Risk factors and outcome of Stenotrophomonas maltophilia infection after allogeneic hematopoietic stem cell transplantation: JSTCT, Transplant Complications Working Group.

Stenotrophomonas maltophilia (S. maltophilia) is an aerobic nonfermenting Gram-negative bacillus widely distributed in the environment that has inherent multidrug resistance to beta-lactam and carbapenem antibiotics. S. maltophilia infection (SMI) is known as an important fatal complication following allogeneic hematopoietic stem cell transplantation (HSCT), but its clinical characteristics have not been well clarified. A retrospective study to identify the incidence, risk factors, and outcomes of SMI after allogeneic HSCT was performed using the database of the Japanese nationwide registry, including 29,052 patients who received allogeneic HSCT in Japan between January 2007 and December 2016. A total of 665 patients developed SMI (sepsis/septic shock, 432; pneumonia, 171; other, 62). The cumulative incidence of SMI at 100 days after HSCT was 2.2%. Among risk factors identified for SMI (age ≥ 50 years, male, performance status 2-4, cord blood transplantation [CBT], myeloablative conditioning, Hematopoietic Cell Transplant-Comorbidity Index [HCT-CI] score 1-2, HCT-CI score ≥ 3, and active infectious disease at HSCT), CBT was the strongest risk factor (hazard ratio, 2.89; 95%CI, 1.94-4.32; p < 0.001). The survival rate at day 30 after SMI was 45.7%, and SMI before neutrophil engraftment was significantly associated with poor survival (survival rate 30 days after SMI, 40.1% and 53.8% in patients with SMI before and after engraftment, respectively; p = 0.002). SMI is rare after allogeneic HSCT, but its prognosis is extremely poor. CBT was a strong risk factor for SMI, and its development prior to neutrophil engraftment was associated with poor survival.

Clinical characteristics of late-onset interstitial pneumonia after allogeneic hematopoietic stem cell transplantation.

Non-infectious pulmonary complications after allogeneic hematopoietic stem cell transplantation (HSCT) remain fatal. In particular, information regarding late-onset interstitial lung disease predominantly including organizing pneumonia and interstitial pneumonia (IP) is limited. A retrospective nationwide survey was conducted using data collected from the Japanese transplant outcome registry database from 2005 to 2010. This study focused on patients (n = 73) with IP diagnosed after day 90 post-HSCT. A total of 69 (94.5%) patients were treated with systemic steroids, and 34 (46.6%) experienced improvement. The presence of chronic graft-versus-host disease at the onset of IP was significantly associated with non-improvement of symptoms (odds ratio [OR] 0.35). At the time of last follow-up (median, 1471 days), 26 patients were alive. Of the 47 deaths, 32 (68%) were due to IP. The 3-year overall survival (OS) and non-relapse mortality (NRM) rates were 38.8% and 51.8%, respectively. In the multivariate analysis, the predictive factors for OS were comorbidities at IP onset (hazard ratio [HR]: 2.19) and performance status (PS) score of 2-4 (HR 2.77). Furthermore, cytomegalovirus reactivation requiring early intervention (HR 2.04), PS score of 2-4 (HR 2.63), and comorbidities at IP onset (HR 2.90) were also significantly associated with increased risk of NRM.