Prevymis (letermovir) / Merck (MSD), AiCuris - LARVOL DELTA

Optimal infection prophylaxis strategy for relapsed/refractory multiple myeloma patients undergoing elranatamab therapy (OPTIMUS-EL) (ASH 2025) - P2 | "To close the gaps of current guidelines on infection risk mitigation and subsequently BsAb treatment optimization, we aim to investigate the efficacy and safety of letermovir for the prevention of clinically significant CMV infection in patients undergoing elranatamab therapy. Based on one-sample multiple testing procedure for phase II clinical trial (one-sided α error rate 5%, power 90%, p0 39.4 versus p1 17.5), the optimal sample size is 35. Considering the drop-off rate of 10%, 40 patients will be enrolled"

Clinical • Bone Marrow Transplantation • CNS Disorders • Cytomegalovirus Infection • Gastroenterology • Gastrointestinal Disorder • Genetic Disorders • Hematological Malignancies • Infectious Disease • Multiple Myeloma • Ocular Inflammation • Ophthalmology • Pneumonia • Respiratory Diseases • Retinal Disorders

Efficacy of early single low dose of rituximab in prophylaxis of EBV reactivation and EBV related post-transplant lymphoproliferative disorder after allogeneic hematopoietic cell transplantation (ASH 2025) - "All patients received ATG based conditioning, and letermovir for CMV prophylaxis. Our study shows that early single low dose of rituximab after allo-HCT can significantly reduce incidence of EBV viremia and the risk of EBV-related PTLD, without severe adverse effect despite delayed humoral immune reestablishment. It will provide an effective prophylactic strategy for patients at high risk of EBV and reduce transplant-related mortality after allo-HCT."

Clinical • Post-transplantation • Acute Graft versus Host Disease • Acute Lymphocytic Leukemia • Acute Myelogenous Leukemia • Aplastic Anemia • Epstein-Barr Virus Infections • Graft versus Host Disease • Hematological Disorders • Hematological Malignancies • Immunology • Infectious Disease • Leukemia • Lymphoblastic Lymphoma • Lymphoma • Transplantation

CMV reactivation under foscarnet prophylaxis in cord blood transplantation: Increased NRM without impact on relapse or survival (ASH 2025) - "Prophylactic administration of letermovir was not performed. Tacrolimus and mycophenolate mofetil were used for GVHD prophylaxis... In CBT with early post-transplant prophylactic administration of FOS, CMV reactivation was associated with increased NRM, although no significant impact on relapse or OS was observed. CMV disease had a substantial negative impact on NRM and OS, underscoring the importance of timely intervention."

Acute Graft versus Host Disease • Acute Lymphocytic Leukemia • Acute Myelogenous Leukemia • CNS Disorders • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Gastroenterology • Gastrointestinal Disorder • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Leukemia • Myelodysplastic Syndrome • Nephrology • Pneumonia • Respiratory Diseases • Transplantation

Epidemiology, risk factors, and outcomes of cytomegalovirus (CMV) reactivation in allogeneic hematopoietic stem cell transplantation: A retrospective observational single-centre study from western India (ASH 2025) - "While pre-emptive therapy has reduced CMV disease, reactivation remains common, particularly in alternate donor transplants and resource-limited settings where access to newer antivirals like letermovir is limited...Serotherapy type did not impact overall reactivation, but early reactivation was significantly higher with Grafalon vs. Thymoglobulin (90% vs. 33.6%, p<0.001)...Adverse effects included neutropenia (ganciclovir/valganciclovir) and nephrotoxicity (foscarnet/cidofovir)... This single-centre study demonstrates a high CMV reactivation rate (89.7%) in a high-seroprevalence Indian cohort, especially in alternate donor and PTCy-treated patients. While CMV disease was rare due to effective surveillance and pre-emptive therapy, recurrence and antiviral toxicity were common. The type of serotherapy influenced early reactivation risk."

Retrospective data • Acute Graft versus Host Disease • Bone Marrow Transplantation • Cytomegalovirus Infection • Gastrointestinal Disorder • Graft versus Host Disease • Hematological Disorders • Immunology • Neutropenia • Transplantation

Eravacycline in allogeneic stem cell transplant recipients: A real-world study of drug-drug interactions with cyclosporine/tacrolimus and anti-infective efficacy (ASH 2025) - "Eravacycline, a novel synthetic tetracycline, shares the Cytochrome P450 3A4 (CYP3A4) metabolic pathway with CNIs, yet comprehensive data on their potential pharmacokinetic interactions are scarce...Subgroup analysis revealed that when co-administered azoles and letermovir, no significant changes in C/D ratio were observed between pre-treatment and during treatment both in cyclosporine group (n=18) and tacrolimus group (n=7)... This study presented the first clinical evidence of drug-drug interaction between eravacycline with CNIs in allo-HSCT, characterized by increased CNI exposure during eravacycline administration and delayed post-cessation exposure elevation. Intensified CNI monitoring and stepwise dose adjustments are recommended throughout and after eravacycline therapy."

Clinical • Real-world • Real-world evidence • Acute Graft versus Host Disease • Bone Marrow Transplantation • Cardiovascular • Graft versus Host Disease • Hematological Disorders • Hypertension • Immunology • Infectious Disease • Transplantation • CYP3A4

Novel use of low-dose cidofovir (2.5 mg/kg Weekly) as CMV prophylaxis in the pre-engraftment Phase of stem cell transplantation: A viable alternative when ganciclovir is contraindicated and letermovir is not available (ASH 2025) - "These include CMV-seropositive recipients (R+) with seronegative donors (D-) who are deemed to be at highest risk of CMV infection due to latent virus reactivation, those with previous CMV infections and in haploidentical BMT cases where Post Transplant Cyclophosphamide (PTCy) was used as GVHD prophylaxis. Low-dose weekly cidofovir represents a novel, cost-effective, and practical approach for CMV prophylaxis and treatment in the pre-engraftment phase of HSCT, particularly in settings where letermovir is unavailable. This strategy may reduce CMV-related graft loss while avoiding the myelotoxicity of ganciclovir. Further prospective studies are warranted to validate its role in global transplant protocols."

Beta-Thalassemia • Bone Marrow Transplantation • Cytomegalovirus Infection • Gastroenterology • Gastrointestinal Disorder • Genetic Disorders • Graft versus Host Disease • Immunology • Infectious Disease • Transplantation

Letermovir primary prophylaxis is associated with reduced and delayed CMV reactivation in haploidentical allohct using ptcy. (ASH 2025) - "Such effect has been retrospectively observed also in the setting of haploidentical alloHCT (Haplo) using post-transplant cyclophosphamide (PTCy), a very-high risk landscape for CMVr and disease...We included adult patients (> 18y.o), with oncohematological diseases, receiving a first Haplo, using myeloablativemor reduced intensity conditioning (RIC) based on thiotepa/fludarabine/busulphan (TBF), peripheral blood stem cells as graft source, a GVHD prophylaxis based on PTCy... LTV is associated to a significant reduction in CMVr also in a high-risk population (Haplo with PTCy) without observing significant differences in terms of NRM. For those patients experiencing CMVr, the previous use of LTV was associated to a delayed reactivation and absence of CMV disease or death. Larger cohort of patients will be necessary to confirm these results"

Chronic Graft versus Host Disease • Cytomegalovirus Infection • Graft versus Host Disease • Hematological Disorders • Hematological Malignancies • Immunology • Leukemia • Lymphoma • Nephrology • Non-Hodgkin’s Lymphoma

Clinically significant cytomegalovirus infection (csCMVi) after matched related donor allogeneic HSCT using post-transplant cyclophosphamide: A systematic review and meta-analysis. (ASH 2025) - "Background :Post-transplant cyclophosphamide (PTCy) is increasingly used as graft-versus-host disease (GVHD)prophylaxis in matched related donor (MRD) allogeneic hematopoietic stem cell transplantation (allo-HSCT). Despite the use of PTCy in MRD allo-HSCT, clinically significant CMV infection remains a frequent andclinically relevant complication, with pooled incidence approaching 30%. The marked heterogeneityunderscores the need for consistent antiviral prophylaxis and stratified CMV risk assessment.Theconsistent absence of anti-CMV prophylaxis such as Letermovir underscores the need for standardizedprevention protocols. Notably, data on CMV incidence in patients receiving prophylaxis are lacking,warranting further studies."

Post-transplantation • Retrospective data • Review • Bone Marrow Transplantation • Cytomegalovirus Infection • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Transplantation

Letermovir prophylaxis for cytomegalovirus and immune reconstitution after allogeneic hematopoietic stem cell transplantation: A single-center real-world study (ASH 2025) - "Letermovir reduces the incidence of csCMVi after allo-HSCT, but it increases the risk ofEBV/PTLD, which may be related to the influence of lymphocyte reconstitution."

Clinical • Real-world • Real-world evidence • Bone Marrow Transplantation • Cytomegalovirus Infection • Hematological Disorders • Infectious Disease • Transplantation

Single-center retrospective analysis of maribavir in the treatment of refractory and drug-intolerant cytomegalovirus viremia and cytomegalovirus disease after allogeneic hematopoietic stem cell transplantation (ASH 2025) - P3 | "Maribavir, a novel anti-CMV agent, exhibits multimodal anti-CMV activity without cross-resistance to ganciclovir or foscarnet...Fifty patients received letermovir for CMV prophylaxis...The 1-year overall survival rate was 86.5% (95% CI: 74.7%–98.4%). Conclusion Maribavir demonstrated high efficacy and a favorable safety profile in treating refractory or drug-intolerant CMV viremia and CMV disease post- allo HSCT, characterized by rapid viral clearance (shortmedian time to response) and minimal adverse effects."

Retrospective data • Acute Graft versus Host Disease • Acute Lymphocytic Leukemia • Acute Myelogenous Leukemia • Anemia • Aplastic Anemia • Bone Marrow Transplantation • Chronic Myeloid Leukemia • Cutaneous T-cell Lymphoma • Cytomegalovirus Infection • Graft versus Host Disease • Hematological Disorders • Hematological Malignancies • Immunology • Infectious Disease • Leukemia • Lymphoblastic Lymphoma • Lymphoma • Multiple Myeloma • Myelodysplastic Syndrome • Nephrology • Pneumonia • Respiratory Diseases • Septic Shock • T Cell Non-Hodgkin Lymphoma • Transplantation

Letermovir cytomegalovirus prophylaxis in hematopoietic-cell transplantation; Real world evidence from high endemic regions. (ASH 2025) - "Patients were categorized intotwo groups:Study Group: Patients at ultra-high risk for CMV reactivation—defined as those who receivedhaploidentical or mismatched transplants, had R+/D− CMV serostatus, or received T-cell depletionwith anti-thymocyte globulin (ATG) or alemtuzumab (Campath)—who received letermovirprophylaxis and completed at least one year of post-transplant follow-up.Control Group: Patients with similar risk profiles who did not receive letermovir prophylaxis butcompleted at least one year of follow-up.The primary objective was to assess the proportion of patients with clinically significant CMV infection(csCMVi) through Week 24 post-transplant among those without detectable CMV DNA at baseline.Secondary objectives included:Proportion of patients with csCMVi through Week 14Time to csCMVi through Week 24Transplant-related mortality (TRM)Graft failureIncidence and severity of graft-versus-host disease (GVHD)Clinical and laboratory data were collected from..."

Clinical • HEOR • Real-world • Real-world evidence • Bone Marrow Transplantation • Cytomegalovirus Infection • Genetic Disorders • Graft versus Host Disease • Hematological Disorders • Hematological Malignancies • Immunology • Infectious Disease • Leukemia • Sickle Cell Disease • Transplantation

Low CMV and EBV infections in the era of letermovir with post-transplantation cyclophosphamide combined with tacrolimus and low-dose post engraftment ATG as gvhd prophylaxis. (ASH 2025) - "Overall, the NRM was significantly lower in the LTV group (4.3 % vs 14.2 %, p=0.01), yielding superior OS(94.5 % vs 79.9 %, p=0.004) and DFS (83.9 % vs 73.7 %, p=0.008), while the relapse incidence did not differ(p=0.64).ConclusionsIn the context of PTCy, tacrolimus and low-dose ATG as GVHD prophylaxis, LTV effectively prevents earlyCMV infection without increasing the risk of EBV reactivation or PTLD. These findings support LTV as aneffective antiviral prophylaxis in allo-HSCT and suggest its use contributes to improved transplantationoutcomes."

Post-transplantation • Acute Graft versus Host Disease • Bone Marrow Transplantation • Chronic Graft versus Host Disease • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Transplantation

A novel predictive model for posttransplant lymphoproliferative disorder in the letermovir prophylaxis era (ASH 2025) - "The score model showed acceptablediscrimination, with a C statistic of 0.65 and a relatively good moderate calibration curve (HL test, p =0.74).ConclusionsOur study demonstrates a novel comprehensive model for predicting PTLD in patients undergoingallogeneic hematopoietic stem cell transplantation, in the new context of the wide range of letermoviruse. This model may help clinicians quickly identify patients at high risk of PTLD and take correspondingprevention and treatment measures."

Post-transplantation • Predictive model • Acute Graft versus Host Disease • Anemia • Aplastic Anemia • Bone Marrow Transplantation • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Fibrosis • Genetic Disorders • Graft versus Host Disease • Hematological Disorders • Immunology • Infectious Disease • Metabolic Disorders • Ocular Inflammation • Ophthalmology • Pneumonia • Respiratory Diseases • Retinal Disorders • Transplantation

Maribavir for cytomegalovirus infections after hematopoietic stem cell transplantation: A real world comparative cohort study (ASH 2025) - "No treatment-relatedadverse events were observed during therapy.Nineteen patients received first-line maribavir for post-HSCT CMV infection, while 20 control patientsreceived other first-line regimens (12 predominantly foscarnet; 8 received combination therapy includingganciclovir or letermovir). In real-world, maribavir demonstrated rapid, effective, and safe clearance of CMV viremia inHSCT recipients. The comparative cohort study demonstrates comparable CMV clearance rates betweenfirst-line maribavir and conventional antiviral regimens in HSCT recipients. Notably, maribavir wasassociated with a clinically relevant 5-day reduction in median time to viral clearance (7 vs 12 days)."

Clinical • Real-world • Real-world evidence • Bone Marrow Transplantation • Cytomegalovirus Infection • Hematological Disorders • Infectious Disease • Transplantation

Peri-transplant ruxolitinib therapy significantly improves GVHD-free, relapse-free survival rates in transplantation for myelofibrosis (ASH 2025) - "Most patients (86%) received fludarabine/busulfan-based reduced intensity conditioning, with ATG-basedGVHD prophylaxis in all but 3 cases...Letermovir prophylaxis had no independent impact...Crucially, our results demonstrate thatperi-transplant ruxolitinib continuation appears to significantly improve composite outcomes such asGRFS without compromising engraftment. These findings support ongoing prospective evaluation of JAKinhibition as part of transplant preparation and emphasise the need for optimised donor selection andgraft composition in MF."

Acute Graft versus Host Disease • Bone Marrow Transplantation • Chronic Graft versus Host Disease • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Myelofibrosis • Transplantation • CD34

Signal-rich and signal-poor: Divergent detection of early bacterial sepsis and latent viral complications after hematopoietic stem cell transplantation in the FDA adverse event reporting system (ASH 2025) - "Allo-HSCT cases were identified using MedDRA indication terms, witha drug-based heuristic classifying records listing a graft-versus-host disease (GVHD) prophylactic agent (e.g., tacrolimus,cyclosporine, sirolimus, or post-transplant cyclophosphamide) as allogeneic...Contemporary meta-analyses report 10–20% clinically significant CMV incidence despite letermovir prophylaxis, underscoring under-ascertainment in FAERS...Regulators and investigators shouldprioritize FAERS for severe, early toxicities, while relying on transplant registries and EHR linkages to track prophylaxis-modulated or slow-onset infections. Future integration of FAERS with registry denominators may help calibratepharmacovigilance sensitivity across the post-HSCT infection spectrum."

Adverse events • Bone Marrow Transplantation • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Graft versus Host Disease • Immunology • Infectious Disease • Septic Shock • Transplantation • ROR1

Optimizing letermovir timing: Day +5 to +8 post haplo-HSCT minimizes EBV dnaemia without compromising CMV prophylaxis (ASH 2025) - "These findings suggest that day +5 to +8 may represent the optimal window forinitiating LTV prophylaxis to balance effective CMV prevention while minimizing the risk of EBVreactivation. Further prospective validation is needed."

Acute Lymphocytic Leukemia • Acute Myelogenous Leukemia • Anemia • Aplastic Anemia • Bone Marrow Transplantation • Cytomegalovirus Infection • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Leukemia

Efficacy and safety analysis of letermovir for the prevention of CMV infection after haploidentical hematopoietic stem cell transplantation in children with acute leukemia (ASH 2025) - "For children with acute leukemia who undergo haploidentical hematopoietic stem celltransplantation (Haplo-HSCT), the use of letermovir for the prevention of cytomegalovirus (CMV) infectionafter transplantation is effective. It does not increase the incidence of Epstein-Barr virus (EBV) infection orthe incidence of grade II-IV acute graft-versus-host disease (aGVHD), and it improves the 3-year survivalrate and reduces the 3-year recurrence rate."

Clinical • Acute Graft versus Host Disease • Acute Lymphocytic Leukemia • Acute Myelogenous Leukemia • Bone Marrow Transplantation • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Graft versus Host Disease • Hematological Malignancies • Immunology • Infectious Disease • Leukemia • Transplantation • CD34

Mini-ATG/TBI conditioning regimen facilitates cure of acquired aplastic anemia in children via unrelated umbilical cord blood transplantation (ASH 2025) - P4 | "The mini-ATG/TBI regimen comprised: rabbit ATG (rATG, 2.5 mg/kg)on day -7, total body irradiation (TBI, 3 Gy) on day -7, fludarabine (FLU, 40 mg/m²) on days -6 to -2, andcyclophosphamide (CTX, 40 mg/m²) on days -4 and -2...In the mini-ATG/TBI group,odd-numbered patients received avatrombopag starting on day +7 to promote platelet engraftment,while even-numbered patients received thrombopoietin (TPO)... These data support the mini-ATG/TBI regimen as an effective conditioning approach forUCBT in acquired aplastic anemia, demonstrating particular utility in pediatric patients or low bodyweight adults.Key words: Aplastic Anemia; Unrelated Umbilical Cord Blood Transplantation; mini ATG"

Clinical • Acute Graft versus Host Disease • Anemia • Aplastic Anemia • Epstein-Barr Virus Infections • Graft versus Host Disease • Hematological Disorders • Hemophagocytic lymphohistiocytosis • Immunology • Infectious Disease • Septic Shock • Transplantation

Utilization of FAERS Public Dashboard to Identify Letermovir-Associated Safety Signals. (PubMed, Ann Pharmacother) - No abstract available

Journal

Letermovir Prophylaxis and Risk of Bacterial or Fungal Infection after Allogeneic Hematopoietic Cell Transplantation. (PubMed, J Infect Chemother) - "LTV prophylaxis significantly reduced the risk of bacteremia. However, it was not associated with the risk of invasive fungal infections."

Journal • Acute Graft versus Host Disease • Cytomegalovirus Infection • Graft versus Host Disease • Immunology • Infectious Disease • Pulmonary Disease • Respiratory Diseases • Transplantation

Letermovir Prophylaxis for CMV DNAemia/Disease after HLA-Mismatched HSCT: A Retrospective Real-World Analysis with Overlap Propensity Score Weighting. (PubMed, Clin Pharmacol Ther) - "Overall survival and non-relapse mortality (NRM) were unaffected by letermovir, probably reflecting effective preemptive management and the study's overlap-weighted design. Based on our results, letermovir prophylaxis can effectively reduce CMV DNAemia/disease in HLA-mismatched and mGIAC haplo-HSCT, and may serve as a standard of care for these high-risk patients."

Journal • Real-world evidence • Retrospective data • Bone Marrow Transplantation • Transplantation

Clinical Outcomes of Low-Grade Cytomegalovirus DNAemia in Hematopoietic Stem Cell Transplantation Recipients Receiving Letermovir Prophylaxis. (PubMed, J Med Virol) - "No significant associations were observed with engraftment failure (p = 0.098), disease relapse (p = 0.165), or all-cause mortality (p = 0.537). Our findings suggest that close monitoring may be sufficient for low-grade DNAemia under letermovir prophylaxis."

Clinical data • Journal • Retrospective data • Bone Marrow Transplantation • Cytomegalovirus Infection • Hematological Disorders • Infectious Disease • Transplantation

OPTIMUS-EL: Phase II Trials of Letermovir Prophylaxis in Patients With RRMM Undergoing Elranatamab Therapy (clinicaltrials.gov) - P2 | N=40 | Recruiting | Sponsor: Seoul National University Hospital | Not yet recruiting ➔ Recruiting

Enrollment open • Hematological Malignancies • Infectious Disease • Multiple Myeloma • Oncology

Cytomegalovirus and Crohn's disease as competing causes of small bowel inflammation after double-lung transplantation. (PubMed, Eur Clin Respir J) - "CMV infection was identified in intestinal biopsies and initially managed with two courses of valganciclovir. Due to persistent symptoms, genotypic analysis was performed, revealing UL97 mutations conferring ganciclovir resistance. Sequential therapy with foscarnet, maribavir, and letermovir achieved virological clearance, but diarrhea persisted...The patient was commenced on standard biological therapy for Crohn's disease, resulting in marked clinical improvement and recovery. This case illustrates the diagnostic challenge of distinguishing CMV enteritis from de novo Crohn's disease and determining the primary driver of the clinical presentation."

Journal • Crohn's disease • Cytomegalovirus Infection • Gastroenterology • Gastrointestinal Disorder • Immunology • Infectious Disease • Inflammation • Inflammatory Bowel Disease • Mucositis • Respiratory Diseases • Solid Organ Transplantation • Transplantation