Effect of peptide-binding motif on survival of HLA-haploidentical transplantation with post-transplant cyclophosphamide.

Peptide-binding motif (PBM) model, a hierarchical clustering of HLA class I based on their binding specificity, was developed to predict immunopeptidome divergence. The effect of PBM mismatches on outcomes is unknown in HLA-haploidentical haematopoietic cell transplantation with post-transplant cyclophosphamide (PTCy-haplo). We therefore conducted a retrospective study using national registry data in PTCy-haplo. Overall, 1352 patients were included in the study. PBM-A bidirectional mismatch was associated with an increased risk of overall mortality in multivariable analysis (hazard ratio, 1.26; 95% confidence interval, 1.06 to 1.50; p = 0.010). None of relapse, non-relapse mortality (NRM) and graft-versus-host disease showed significant differences according to PBM-A bidirectional mismatch status in the entire cohort. The impact of PBM-A bidirectional mismatch on overall survival (OS) was preserved within the HLA-A genotype bidirectional mismatch population, and their lower OS stemmed from higher relapse rate in this population. The worse OS due to high NRM with PBM-A bidirectional mismatch was prominent in lymphoid malignancies receiving reduced-intensity conditioning. The PBM model may predict outcomes more accurately than HLA genotype mismatches. In conclusion, this study demonstrated that the presence of PBM-A bidirectional mismatch elevated the risk of mortality of PTCy-haplo. Avoiding PBM-A bidirectional mismatch might achieve better outcomes in PTCy-haplo.

Superiority of BM over PBSC for recipients with pre-transplant lung dysfunction in HLA-matched allogeneic HCT.

BACKGROUND AIMS: Pre-transplant lung dysfunction is known to be a risk factor for non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). It is unclear which cell source gives better outcomes for patients with pulmonary dysfunction. METHODS: We analyzed 3289 adult patients with standard-risk disease who had received HLA-matched allo-HCT, and compared outcomes between those who received peripheral blood stem cell (PBSC) vs. bone marrow (BM) in two cohorts based on the presence of a lung score by the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI): the Lung-scored (LS) and non-LS cohorts. RESULTS: In the LS cohort, the 2-year overall survival (OS) in the BM group tended to be higher than that in the PBSC group (72.4% vs. 61.4%; P = 0.044). In the non-LS cohort, there was no significant difference between the two groups (71.7% vs. 73.2%; P = 0.13). Multivariate analyses confirmed that PBSC was significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.66; 95% CI, 1.09-2.54; P = 0.019). On the other hand, the cell source did not affect OS in the non-LS cohort (HR, 0.92; 95% CI, 0.76-1.12; P = 0.41). We found that PBSC was associated with an increased risk of NRM in the LS cohort (HR, 2.17; 95% CI, 1.16-4.05; P = 0.016), while the cell source did not significantly affect NRM in the non-LS cohort. PBSC was not identified as a risk factor for relapse in either cohort. CONCLUSIONS: Our results suggest that BM might be beneficial for recipients with lung dysfunction in HLA-matched allo-HCT.

Real-World Outcomes of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation in Japan: Retrospective Analysis of the Transplant Registry Unified Management Program Registry.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important therapeutic option for patients with hematologic malignancies. However, the development of graft-versus-host disease (GVHD) after allo-HSCT remains a challenge. Although systemic steroid therapy is the established first-line therapy for acute GVHD (aGVHD) and chronic GVHD (cGVHD), many patients are unresponsive or resistant to corticosteroid therapy, and the response is insufficient. This study aimed to evaluate the clinical characteristics of patients who developed aGVHD and cGVHD after allo-HSCT. This noninterventional, retrospective study used large national registry data from the Transplant Registry Unified Management Program. The study included 29,690 patients with a hematologic disease who underwent their first allo-HSCT between January 2010 and December 2019. The primary study endpoints were the cumulative incidence of aGVHD and cGVHD. The secondary endpoints were overall survival (OS) and nonrelapse mortality (NRM) of patients with aGVHD and cGVHD and OS and NRM of patients who received second-line therapy for aGVHD. Of 29,690 patients who underwent allo-HSCT, the graft source was related bone marrow (RBM) in 2807, related peripheral blood (RPB) in 6167, unrelated bone marrow in 10,556, unrelated peripheral blood (UPB) in 774, and unrelated cord blood in 9339. The cumulative incidence of grade II-IV aGVHD at 100 days was high after the related and unrelated mismatched transplantation. The response rates for first- and second-line therapy for aGVHD were low in the RBM/RPB-mismatched (59.6%/61.6%) and UPB-mismatched subgroups (45.5%), respectively. The 3-year NRM in patients with aGVHD was high in the RPB and UPB mismatched subgroups (37.9% and 31.2%, respectively). Developing a novel treatment for steroid-refractory aGVHD is necessary to improve transplantation outcomes, particularly for patients undergoing HLA-mismatched allo-HSCT.

An open-label study of belumosudil, a selective ROCK2 inhibitor, as second or subsequent line of therapy for steroid-dependent/steroid-resistant chronic GVHD.

Belumosudil mesylate is a selective Rho-associated coiled-coil kinase 2 inhibitor with immunomodulatory and antifibrosis effects. This multicenter, open-label, single-arm study evaluated belumosudil 200 mg once daily as second or subsequent line of therapy (LOT) in 21 Japanese patients ≥12 years of age with steroid-dependent/steroid-resistant chronic graft-versus-host disease (cGVHD). The primary endpoint of best overall response rate (ORR) at 24 weeks after enrollment of the last patient was 85.7% (95% confidence interval [CI]: 63.7-97.0), and the lower limit of the 95% CI exceeded the pre-defined threshold of 25%. The Kaplan-Meier estimate of duration of response rate at 24 weeks was 75% (95% CI: 46-90); 13/18 responders (72.2%) had a sustained response for ≥20 weeks. The median time to response was 4.1 weeks (range 3.90-8.10); ORR was 47.6% at 4 weeks and 75.0% at 24 weeks; best ORR was 80% for joints/fascia, 66.7% for the mouth, and 54.5% for skin. Overall, 57.1% of patients had clinically meaningful symptom improvement at least once; the median duration of symptom improvement was 22.2 weeks (range 4.0-51.3). Corticosteroid dose reductions were recorded for 57.1% of patients. Median failure-free and overall survival were not reached. Treatment-emergent adverse events occurred in 85.7% of patients (most commonly diarrhea, 19.0%), of which 38.1% were drug-related. There were no drug-related discontinuations or deaths. In summary, belumosudil 200 mg once daily as second or subsequent LOT in Japanese patients with steroid-dependent/steroid-resistant cGVHD was effective, with no new safety concerns.

Individual HLAs affect survival after allogeneic stem cell transplantation in adult T-cell leukaemia/lymphoma.

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for adult T-cell leukaemia/lymphoma (ATL). Specific HLAs are associated with outcomes of immunotherapy and allo-HSCT. We hypothesised that individual HLAs would affect the clinical outcomes of ATL patients after allo-HSCT. Using data from a Japanese registry, we retrospectively analysed 829 patients with ATL who received transplants from HLA-identical sibling donors or HLA-A, -B, -C or -DRB1 allele-matched unrelated donors between 1996 and 2015. We evaluated the overall mortality risk of HLA-A, -B and -DR antigens with frequencies exceeding 3%. Outcomes were compared between transplants with or without specific HLA antigens. Of the 25 HLAs, two candidates were identified but showed no statistically significant differences by multiple comparison. HLA-B62 was associated with a lower risk of mortality (hazard ratio [HR], 0.68; 95% confidence interval [CI]: 0.51-0.90; p = 0.008), whereas HLA-B60 was associated with a higher risk of mortality (HR, 1.64; 95% CI: 1.19-2.27; p = 0.003). In addition, HLA-B62 was associated with a lower risk of transplant-related mortality (TRM) (HR, 0.52; 95% CI: 0.32-0.85, p = 0.009), whereas HLA-B60 was associated with a higher risk of grades III-IV acute graft-versus-host disease (HR, 2.63; 95% CI: 1.62-4.27; p < 0.001). Neither HLA influenced relapse. The higher risk of acute GVHD in HLA-B60-positive patients and the lower risk of TRM in HLA-B62-positive patients were consistent with previously obtained results from patients with other haematological malignancies. Consideration of HLA in ATL patients may help to predict risk and outcomes after allo-HSCT.

Prognostic impact of the conditioning intensity on outcomes after allogeneic transplantation for MDS with low blasts: a nationwide retrospective study by the adult MDS working group of the Japan Society for Transplantation and Cellular Therapy.

Poor prognostic factors, such as transfusion dependency and chromosomal risk, need to be considered in the indication of allogeneic hematopoietic cell transplantation (allo-HCT) for patients harboring myelodysplastic syndromes with less than 5% marrow blasts (MDS-Lo). We analyzed the post-transplant outcomes of 1229 MDS-Lo patients who received myeloablative (MAC)(n = 651), reduced-intensity (RIC)(n = 397), and non-myeloablative conditioning (NMAC) regimens (n = 181). The multivariate analysis revealed that the RIC group had better chronic graft-versus-host disease (GVHD)- and relapse-free survival (CRFS) (P = 0.021), and GVHD- and relapse-free survival (GRFS) than the MAC group (P = 0.001), while no significant differences were observed between the NMAC and MAC groups. In the subgroup analysis, the MAC group has better overall survival (P = 0.008) than the RIC group among patients with an HCT-comorbidity index (HCT-CI) score of 0, while the RIC group had better overall survival (P = 0.029) than the MAC group among those with an HCT-CI score ≥3. According to the type of conditioning regimen, total body irradiation 12 Gy-based MAC regimen showed better OS and CRFS than the other MAC regimen, and comparable outcomes to the RIC regimen. In conclusion, the RIC and NMAC regimens are promising options for MDS-Lo patients in addition to the MAC regimen.

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.

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.

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.

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.

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.

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.

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.

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.