Ganciclovir prophylaxis of cytomegalovirus infection and disease in allogeneic bone marrow transplant recipients. Results of a placebo-controlled, double-blind trial

Impact of cytopenias and early versus late treatment with ruxolitinib in patients with steroid-refractory acute or chronic graft-versus-host disease

REACH2 and REACH3 were randomized, multicenter, open-label phase 3 studies comparing the selective Janus kinase (JAK)1/JAK2 inhibitor ruxolitinib versus investigators' choice of best available therapy (BAT) in steroid-refractory (SR) acute (REACH2) or chronic (REACH3) graft-versus-host disease (aGVHD/cGVHD). Moderate-severe aGVHD/cGVHD can progress rapidly; thus, key clinical considerations driving management of patients with SR-aGVHD/SR-cGVHD are prompt treatment initiation and concomitant cytopenias. These post hoc analyses of REACH2/REACH3 describe the impact of timing of treatment initiation after SR-aGVHD/SR-cGVHD diagnosis and development of concomitant cytopenias on treatment outcomes. Ruxolitinib initiation within 3 days from SR-aGVHD diagnosis yielded an extended duration of response and higher Day 28 complete response rates compared with initiation ≥7 days after SR-aGVHD diagnosis (median 178 vs 167 days and 36.6% vs 25.0%, respectively). For patients with SR-cGVHD, Week 24 overall response was not impacted by time to treatment (54.5% vs 42.6% for <14 vs >28 days). Clinically relevant cytopenias were manageable, allowing for maintenance of dose intensity (median 20 mg/d), and did not impact the favorable efficacy outcomes from ruxolitinib treatment. This analysis highlights the practical importance of considering earlier ruxolitinib initiation after SR diagnosis in GVHD and the benefits of ruxolitinib treatment compared with BAT even for patients with cytopenias.

CMV reactivation during pretransplantation evaluation: a novel risk factor for posttransplantation CMV reactivation

ABSTRACT

Cytomegalovirus (CMV) disease occurs occasionally before allogeneic hematopoietic cell transplantation (HCT) and is associated with poor post-HCT outcomes; however, the impact of pre-HCT CMV reactivation is unknown. Pre-HCT CMV reactivation was assessed in HCT candidates from the preemptive antiviral therapy (2007-2017) and letermovir prophylaxis (2018-2021) eras. CMV DNA polymerase chain reaction (PCR) surveillance was routinely performed during the pre-HCT workup period, and antiviral therapy was recommended according to risk of progression to CMV disease. Risk factors for pre-HCT CMV reactivation were characterized, and the associations of pre-HCT CMV reactivation with post-HCT outcomes were examined using logistic regression and Cox proportional hazard models, respectively. A total of 1694 patients were identified, and 11% had pre-HCT CMV reactivation 14 days (median; interquartile range [IQR], 6-23) before HCT. Lymphopenia (≤0.3 × 103/μL) was the strongest risk factor for pre-HCT CMV reactivation at multiple PCR levels. In the preemptive therapy era, patients with pre-HCT CMV reactivation had a significantly increased risk of CMV reactivation by day 100 as well as CMV disease and death by 1 year after HCT. Clearance of pre-HCT CMV reactivation was associated with a lower risk of post-HCT CMV reactivation. Similar associations with post-HCT CMV end points were observed in a cohort of patients receiving letermovir prophylaxis. Pre-HCT CMV reactivation can be routinely detected in high-risk HCT candidates and is a significant risk factor for post-HCT CMV reactivation and disease. Pre-HCT CMV DNA PCR surveillance is recommended in high-risk HCT candidates, and antiviral therapy may be indicated to prevent post-HCT CMV reactivation.

Real-World Safety and Effectiveness of Letermovir in Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation: Final Results of Post-Marketing Surveillance in Japan

BACKGROUND AND OBJECTIVE

Cytomegalovirus (CMV) is a common opportunistic infection after allogenic hematopoietic stem cell transplantation (allo-HSCT). Letermovir, an inhibitor of CMV DNA terminase, is approved for CMV prophylaxis in allo-HSCT patients. We report the final results of post-marketing surveillance of letermovir in Japan.

METHODS

The case report forms were drafted in part by the Japanese Data Center for Hematopoietic Cell Transplantation using data elements in the Transplant Registry Unified Management Program and sent to individual HSCT centers to decrease the burden of reporting. Hematopoietic stem cell transplantation patients who received letermovir between May 2018 and May 2022 were registered. Data collected included physician-assessed adverse events/adverse drug reactions and clinical effectiveness (development of CMV disease, CMV antigen status, and use of preemptive therapy).

RESULTS

A total of 821 HSCT patients were included in the safety analyses. Adverse drug reactions occurred in 11.33% of patients, with serious adverse drug reactions in 3.05%. The five most common adverse drug reactions were nausea (1.58%), renal impairment (1.46%), and acute graft versus host disease, CMV test positive, and hepatic function abnormal (0.61% each). A total of 670 patients were eligible for effectiveness analyses. Among these patients, 16.57% and 28.66% required preemptive therapy through week 14 and week 48, respectively. In addition, relatively few patients developed CMV disease throughout the follow-up period (1.34% at week 14 and 3.85% at week 48).

CONCLUSIONS

This final analysis of post-marketing surveillance with up to 48 weeks follow-up period in Japan provides further evidence supporting the safety profile and effectiveness of letermovir for CMV prophylaxis in patients undergoing allo-HSCT in real-world settings.

Efficacy, Safety, and Cost-effectiveness Analysis of Antiviral Agents for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Stem Cell Transplantation Recipients

BACKGROUND

Cytomegalovirus (CMV) infection is associated with higher non-relapse mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). But the preferred drug for preventing cytomegalovirus infection is still controversial. We evaluate the efficacy, safety, and cost-effectiveness of antiviral agents based on the most recent studies.

METHODS

A pairwise and network meta-analysis was conducted to obtain direct and indirect evidence of antivirals. The cost of allo-HSCT recipients in a teaching hospital was collected, and a cost-effectiveness analysis using a decision tree combined with Markov model was completed from the perspective of allo-HSCT recipients over a lifetime horizon.

RESULTS

A total of 19 RCTs involving 3565 patients (8 antivirals) were included. In the network meta-analysis, relative to placebo, letermovir, valacyclovir, and ganciclovir significantly reduced CMV infection incidence; ganciclovir significantly reduced CMV disease incidence; ganciclovir significantly increased the incidence of serious adverse event; none of antivirals significantly reduced all-cause mortality. Based on meta-analysis and Chinese medical data, the incremental cost-effectiveness ratios (ICER) per quality-adjusted life year (QALY) saved for maribavir, acyclovir, valacyclovir, ganciclovir, and letermovir relative to placebo corresponded to US$216 635.70, US$11 590.20, US$11 816.40, US$13 049.90, and US$12 189.40, respectively. One-way sensitivity analysis showed the most influential parameter was discount rate. The probabilistic sensitivity analysis indicated a 53.0% probability of letermovir producing an ICER below the willingness-to-pay threshold of US$38 824.23/QALY. The scenario analysis demonstrated prophylaxis with letermovir is considered cost-effective in the United States.

CONCLUSIONS

Currently, letermovir is an effective and well-tolerated treatment for preventing CMV infection, and it might be a cost-effective choice in allo-HSCT recipients in China.

Risk Factors Associated with Survival Following Ganciclovir Prophylaxis through Day +100 in Cytomegalovirus At-Risk Pediatric Allogeneic Stem Cell Transplantation Recipients: Development of Cytomegalovirus Viremia Associated with Significantly Decreased 1-Year Survival

Cytomegalovirus (CMV) reactivation is a major cause of morbidity and nonrelapse mortality (NRM) in pediatric allogeneic stem cell transplantation (alloSCT) recipients. Approximately 80% of CMV seropositive alloHCT recipients will experience CMV reactivation without prophylaxis. The impacts of ganciclovir prophylaxis and subsequent CMV viremia on 1-year survival and 1-year NRM are unknown. The primary objective of this study was to determine the effect of CMV viremia on the probability of 1-year survival and 1-year NRM in pediatric alloSCT recipients receiving 100 days of ganciclovir prophylaxis. The secondary objective was to determine the effect of other risk factors on 1-year survival and 1-year NRM. All patients age 0 to 26 years who underwent alloSCT between June 2011 and May 2020 and received ganciclovir prophylaxis for 100 days at Westchester Medical Center, an academic medical center, were analyzed. Ganciclovir was administered to at-risk alloSCT recipients (donor and or recipient CMV+ serostatus) as 5 mg/kg every 12 hours from the first day of conditioning through day -1 (recipient CMV+ only) followed by 6 mg/kg every 24 hours on Monday through Friday beginning on the day of an absolute neutrophil count >750/mm3 and continuing through day +100. National Cancer Institute Common Terminology Criteria for Adverse Events 5.0 criteria were used to grade toxicity. NRM was analyzed using competing survival analysis with relapse death as a competing event. The log-rank and Gray tests were performed to compare the 1-year survival probabilities and NRM cumulative incidence between patients who experienced CMV viremia post-alloSCT and those who did not. Univariate Cox regression analysis was performed for the following risk factors: CMV viremia, donor source, sex, malignant disease, disease risk index, conditioning intensity, receipt of rabbit antithymocyte globulin (rATG)/alemtuzumab, graft-versus-host disease (GVHD) prophylaxis, CMV donor/recipient serostatus, grade II-IV acute GVHD, and grade 3/4 neutropenia necessitating discontinuation of ganciclovir, treating the last 3 factors as time-dependent covariates. Those with P values < .2 were included in the multivariate Cox regression analysis. Eighty-four alloSCT recipients (41 males, 43 females; median age, 10.8 years [range, .4 to 24.4 years]) were analyzed. Multivariate analysis showed significantly lower 1-year survival and significantly higher 1-year NRM in patients who developed CMV viremia compared to those who did not (P = .0036). No other risk factors were significantly associated with 1-year survival or 1-year NRM. One-year survival was significantly decreased and 1-year NRM was significantly increased in pediatric alloSCT recipients who developed CMV viremia following ganciclovir prophylaxis. No other risk factors were found to be associated with 1-year survival or 1-year NRM. Alternative CMV prophylaxis regimens that reduce CMV viremia should be investigated in pediatric alloSCT recipients at risk for CMV infection.

Antimicrobials in patients with hematologic malignancies and recipients of hematopoietic cell transplantation and other cellular therapies

BACKGROUND

Appropriate use of antimicrobials for hematologic malignancy, hematopoietic stem cell transplant recipients, and other cellular therapies is vital, with infection causing significant morbidity and mortality in this unique population of immunocompromised hosts. However, often in this population the choice and management of antimicrobial therapy is complex. When selecting an antimicrobial agent, key considerations include the need for dose adjustments due to renal or hepatic impairment, managing drug interactions, the potential for additive drug toxicity among those receiving polypharmacy and therapeutic drug monitoring. Other factors include leveraging pharmacodynamic principles to enable optimization of directed therapy against challenging pathogens, as well as judicious use of antimicrobials to limit drug resistance and adverse drug reactions.

SUMMARY

This review summarizes the clinical considerations for commonly used antimicrobials in this setting, including antibacterial, antiviral, and antifungal agents.

Safety and efficacy of weight-based ganciclovir dosing strategies in overweight/obese patients

BACKGROUND

The management of cytomegalovirus (CMV) is particularly challenging as both CMV and its usual first-line treatment, ganciclovir, are associated with neutropenia. Ganciclovir dosing is weight-based, most commonly utilizing total body weight (TBW). The subsequent high doses of ganciclovir in overweight/obese patients may increase the risk of toxicity. Utilizing adjusted body weight (AdjBW) dosing may help mitigate this risk. Therefore, the objective of this study was to evaluate the difference in toxicity and efficacy between TBW and AdjBW ganciclovir dosing strategies in overweight/obese patients.

METHODS

This retrospective study conducted safety and efficacy analyses of ganciclovir courses (≥72 h) used as CMV treatment. The primary safety outcome was the incidence of neutropenia (absolute neutrophil count <1000 cells/μL), and the primary efficacy outcome was a 2-log decrease in CMV polymerase chain reaction within 4 weeks following ganciclovir initiation. In both analyses, courses were excluded in which ganciclovir was dosed outside of specified renal dosing parameters for >20% of the course.

RESULTS

Among the 253 courses in the safety cohort, there was no difference in the incidence of neutropenia (17.4% vs. 13.5%, p = .50) in AdjBW compared to TBW dosing. In the 62 courses evaluating efficacy, there was no statistical difference between AdjBW and TBW dosing (60.0% vs. 45.2%, p = .28). No subgroups were identified in which AdjBW dosing was advantageous.

CONCLUSION

Utilization of AdjBW ganciclovir dosing did not result in decreased neutropenia or treatment efficacy as compared to TBW dosing. Further studies with larger patient populations would be beneficial to confirm these findings.

Cost Effectiveness of Letermovir for Cytomegalovirus Prophylaxis Compared with Pre-Emptive Therapy in Allogeneic Hematopoietic Stem Cell Transplant Recipients in the United States

PURPOSE

The aim of this study was to assess the cost effectiveness of letermovir prophylaxis with the option for subsequent pre-emptive therapy (PET) for the prevention of cytomegalovirus (CMV) infection compared with a PET-only scenario in adult allogeneic hematopoietic stem cell transplant (allo-HCT) recipients in the United States over a 10-year time horizon.

MATERIALS AND METHODS

A publicly available decision tree model was constructed using a commercial third-party payer perspective to simulate an allo-HCT recipient's clinical trajectory in the first-year post-transplant, followed by entry to a Markov model to simulate years 2 through 10. Clinical inputs and utility estimates were derived from published literature. Costs were derived from published literature and US Department of Veterans Affairs Federal Supply Schedule drug pricing. Outcomes assessed included life expectancy, quality-adjusted life-years (QALYs), direct medical costs, and the incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses (PSA) were performed to test the robustness of the findings.

RESULTS

Compared with PET alone, letermovir prophylaxis was projected to increase life-years per person (4.99 vs. 4.70 life-years), and increase QALYs (3.29 vs. 3.08) and costs (US$83.411 vs. US$70,698), yielding an ICER of US$59,356 per QALY gained. One-way sensitivity analyses indicated our model was sensitive to mortality (ICER: $164,771/QALY) and utility (letermovir ICER: $117,447/QALY; PET ICER: $107,290/QALY) in the first-year post-transplant. In 57.1% of the PSA simulations, letermovir was a cost-effective option using a willingness-to-pay threshold of US$100,000 per QALY.

CONCLUSIONS

Letermovir prophylaxis is cost effective compared with PET alone with a willingness-to-pay threshold of US$100,000 per QALY gained. Sensitivity analysis results indicate future research is required to understand the impact of mortality and quality of life in the first-year post-transplant to arrive at a conclusive decision on letermovir adoption.

The Ten Most Common Questions on Cytomegalovirus Infection in Hematopoietic Stem Cell Transplant Patients

With the rising number of patients undergoing hematopoietic stem cell transplantation (HSCT), clinicians are more likely to encounter infectious complications in immunocompromised hosts, particularly cytomegalovirus (CMV) infection. Besides the high mortality of CMV end-organ disease, patients with detectable CMV viremia may have worse outcomes and decreased survival even in the absence of end-organ disease. In view of the implications on morbidity and mortality, clinicians should maintain a high index of suspicion and initiate antiviral drugs promptly when CMV infection is confirmed. High-risk patients should be identified in order to provide optimal management. Additionally, novel antiviral agents with a good safety profile and minor adverse events are now available for prophylaxis in high-risk patients and for treatment of resistant or refractory CMV infection. The following review provides concise, yet comprehensive, guidance on the burden and risk factors of CMV in this population, as well as an update on the latest evidence for the management of CMV infection.

Prophylactic Pretransplant Ganciclovir to Reduce Cytomegalovirus Infection After Hematopoietic Stem Cell Transplantation

OBJECTIVE/BACKGROUND

Cytomegalovirus (CMV) reactivation remains a serious complication after allogeneic hematopoietic cell transplantation (HCT) occurring in approximately 60-70% of CMV-seropositive HCT recipients. CMV reactivation leads to adverse outcomes including end-organ damage, graft-versus-host disease, and graft failure.

METHODS

Ganciclovir was administered pretransplant at 5 mg/kg twice daily intravenously from the start of conditioning to Day T-2 to CMV-seropositive patients receiving their first allogeneic HCT. CMV DNA was monitored weekly until at least Day 100 posttransplant.

RESULTS

A total of 109 consecutive patients were treated, median age 57 (range 20-73) years. Of these, 36 (33%) patients had a CMV reactivation within the first 105 days posttransplant with a median time of reactivation of 52.5 (range 36-104) days posttransplant. The cumulative incidence of CMV reactivation at Day 105 posttransplant was 33.1% (95% confidence interval: 24.4-42.0). One patient developed CMV disease.

CONCLUSION

The use of pretransplant ganciclovir was associated with low incidence of CMV reactivation and disease. These data suggest that pretransplant ganciclovir with preemptive therapy for viral reactivation may be a useful strategy to reduce CMV reactivation. Future prospective trials are needed to compare strategies for CMV prophylaxis.

Dominant epitopes presented by prevalent HLA alleles permit wide use of banked CMVpp65 T-cells in adoptive therapy

We established and characterized a bank of 138 CMVpp65 peptide-specific T-cell lines (CMVpp65CTLs) from healthy marrow transplant donors who consented to their use for treatment of individuals other than their transplant recipient. CMVpp65CTL lines included 131 containing predominantly CD8+ T-cells and 7 CD4+ T-cell. CD8+ CMVpp65CTLs were specific for 1-3 epitopes each presented by one of only 34 of the 148 class I alleles in the bank. Similarly, the 7 predominantly CD4+ CMVpp65CTL lines were each specific for epitopes presented by 14 of 40 HLA DR alleles in the bank. Although the number of HLA alleles presenting CMV epitopes is low, their prevalence is high, permitting selection of CMVpp65CTLs restricted by an HLA allele shared by transplant recipient and HCT donor for >90% of an ethnogeographically diverse population of HCT recipients. Within individuals, responses to CMVpp65 peptides presented by different HLA alleles are hierarchical. Furthermore, within groups, epitopes presented by HLA B*07:02 and HLA A*02:01 consistently elicit immunodominant CMVpp65 CTLs, irrespective of other HLA alleles inherited. All dominant CMVpp65CTLs exhibited HLA-restricted cytotoxicity against epitope loaded targets, and usually cleared CMV infections. However, immunodominant CMVpp65 CTL responding to epitopes presented by certain HLA B*35 alleles were ineffective in lysing CMV infected cells in vitro or controlling CMV infections post adoptive therapy. Analysis of the hierarchy of T-cell responses to CMVpp65, the HLA alleles presenting immunodominant CMVpp65 epitopes, and the responses they induce, may lead to detailed algorithms for optimal choice of 3rd party CMVpp65CTLs for effective adoptive therapy.

Detection of human herpes virus 6 DNA and chromosomal integration after allogeneic hematopoietic stem cell transplantation: a retrospective single center analysis

INTRODUCTION

Human herpes virus 6 (HHV-6) can reactivate after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and may be associated with significant morbidity and mortality.

METHODS

The epidemiology of HHV-6 infections and their impact on outcome after allo-HSCT were retrospectively analyzed in 689 adult allo-HSCT recipients (January 2015-December 2018). Chromosomal integration of HHV-6 (ciHHV-6) in the donor was retrospectively investigated to critically evaluate antiviral treatment strategies.

RESULTS

HHV-6 DNA in any specimen was found in 89 patients. HHV-6 infections (encephalitis (1), gastroenteritis (44), dermatitis (2), hepatitis (1) or pneumonitis (5)) were diagnosed in 53/689 patients (7.7%). Elevated levels of HHV-6 DNA were found in 38 patients (5.5%). CiHHV-6, analyzed in patients with HHV-6 viral loads ≥10⁴ copies/mL, was identified in 4 patients (10/38 patients; 10.5%). Two of those displayed copy numbers of HHV-6 ranging from ≥ 2 × 10⁵ to 2.5 × 10⁶ copies/mL (HHV-6A). Here, ciHHV-6 was integrated into donor and not into the patients' cells. In this series of allo-HSCT recipients, 10.5% of patients with blood viral loads of HHV-6 showed ciHHV-6.

CONCLUSION

Screening of the donor for chromosomal integration of HHV-6 (ciHHV-6) before initiation of antiviral therapy is recommended. This article is protected by copyright. All rights reserved.

Letermovir vs. high-dose valacyclovir for cytomegalovirus prophylaxis following haploidentical or mismatched unrelated donor allogeneic hematopoietic cell transplantation receiving post-transplant cyclophosphamide

Patients undergoing haploidentical or mismatched unrelated donor (haplo/MMUD) allogeneic hematopoietic cell transplantation (alloHCT) receiving post-transplant cyclophosphamide (PTCy) are at high risk of cytomegalovirus (CMV) infection. Experience with letermovir (LET) in this population is limited. This single center retrospective cohort study compared CMV and transplant outcomes between LET and a historical control with high-dose valacyclovir (HDV) prophylaxis in adults undergoing haplo/MMUD alloHCT. Thirty-eight CMV seropositive patients were included, 19 in each arm. LET reduced the incidence of CMV infection (5% vs. 53%, RR 0.01, 95% CI 0.014-0.71, p = .001) and need for CMV treatment by day +100 (5% vs. 37%, RR 0.14, 95% CI 0.18-0.99, p = .017) compared to HDV. Median CMV event-free-survival was improved with LET (not reached vs. 80 days, HR 0.114, 95% CI 0.07-0.61, p = .004). These data support the efficacy of LET in alternative donor transplants.

Human cytomegalovirus-specific T-cell reconstitution and late-onset cytomegalovirus infection in hematopoietic stem cell transplant recipients following letermovir prophylaxis

BACKGROUND

Letermovir (LTV), recently approved for the prophylaxis of human Citomegalovirus (HCMV) reactivation after hematopoietic stem cell transplantation (HSCT), has decreased the rate of infection in the first months post-transplant.

OBJECTIVE

The aim of this study was to evaluate the impact of LTV prophylaxis on immune reconstitution and late-onset infection.

STUDY DESIGN

We studied HCMV infection and HCMV-specific T-cell reconstitution in two matched groups of HSCT recipients receiving LTV prophylaxis (N=30, LTV group) vs pre-emptive therapy (N=31, PET group). Rate of GvHD, neutropenia, baseline disease recurrence and overall survival were analyzed.

RESULTS

Clinically significant infections requiring pre-emptive therapy showed a similar rate in the PET (21/31, 68%) vs the LTV group (17/30, 57%; P=0.434), but occurred significantly later (after prophylaxis discontinuation) in the LTV group. No difference was found in peak HCMV DNAemia levels (P=0.232). HCMV-specific T-cell recovery was delayed by about 100 days in the LTV group. HCMV-specific CD4 and CD8 T cells were significantly lower in the LTV group between days 120-360 and 90-120, respectively. A lower rate of chronic GvHD (P=0.024) was found in the LTV-group. Time to engraftment, rate of disease relapse and one-year survival were not different in the two groups, whereas a trend towards a lower occurrence of neutropenia (P=0.124) and higher occurrence of acute GvHD grade III-IV (P=0.103) was observed in the LTV group.

CONCLUSIONS

LTV prophylaxis delays HCMV infection and HCMV-specific immune reconstitution, therefore immunological and virological monitoring should be implemented post-prophylaxis discontinuation. The potential effect of LTV prophylaxis in reducing chronic GvHD should be evaluated by prospective studies.

Safety and Effectiveness of Letermovir in Allogenic Hematopoietic Stem Cell Transplantation Recipients: Interim Report of Post-marketing Surveillance in Japan

OBJECTIVE

Since May 2018, a 6-year post‑marketing surveillance (PMS) has been underway to evaluate the safety and effectiveness of letermovir for cytomegalovirus (CMV) prophylaxis in Japanese patients with allogenic hematopoietic stem-cell transplantation (allo-HSCT). The interim PMS data for 461 patients collected as of March 2021 are reported in this publication.

METHODS

The case report forms (CRFs) were drafted in part by the Japanese Data Center for Hematopoietic Cell Transplantation (JDCHCT) using data elements in the Transplant Registry Unified Management Program (TRUMP) and sent to individual HSCT centers to decrease burden of reporting. These CRFs were completed by physicians in the respective HSCT centers and sent to MSD K.K., Tokyo, Japan.

RESULTS

Allo-HSCT recipients prescribed with letermovir for CMV prophylaxis were included across 136 centers in Japan between May 2018 and March 2021. Safety and effectiveness were assessed for 460 and 373 patients, respectively. Of the patients in the safety analysis, 13.9 % experienced adverse drug reactions, the most frequent of which were renal impairment (2.2 %) and nausea (1.7 %). Among patients in the effectiveness analysis, the overall CMV antigen positivity rate was 21.2 % at Week 14 and 37.5 % at Week 24 after allo-HSCT.

CONCLUSIONS

Interim data from this largest of real-world studies confirm the safety and effectiveness of letermovir for CMV prophylaxis in Japanese allo-HSCT recipients. Given the limited data on Asian patients for letermovir use, this survey will provide valuable information for medical decision-making in routine clinical practice, serving as a vital supplement to the results obtained from clinical trials.

Letermovir Prophylaxis for Cytomegalovirus Infection in Allogeneic Stem Cell Transplantation: A Real-World Experience

Despite effective treatments, cytomegalovirus (CMV) continues to have a significant impact on morbidity and mortality in allogeneic stem cell transplant (allo-SCT) recipients. This multicenter, retrospective, cohort study aimed to evaluate the reproducibility of the safety and efficacy of commercially available letermovir for CMV prophylaxis in a real-world setting. Endpoints were rates of clinically significant CMV infection (CSCI), defined as CMV disease or CMV viremia reactivation within day +100-+168. 204 adult CMV-seropositive allo-SCT recipients from 17 Italian centres (median age 52 years) were treated with LET 240 mg/day between day 0 and day +28. Overall, 28.9% of patients underwent a haploidentical, 32.4% a matched related, and 27.5% a matched unrelated donor (MUD) transplant. 65.7% were considered at high risk of CSCI and 65.2% had a CMV seropositive donor. Low to mild severe adverse events were observed in 40.7% of patients during treatment [gastrointestinal toxicity (36.3%) and skin rash (10.3%)]. Cumulative incidence of CSCI at day +100 and day +168 was 5.4% and 18.1%, respectively, whereas the Kaplan-Meier event rate was 5.8% (95% CI: 2.4-9.1) and 23.3% (95% CI: 16.3-29.7), respectively. Overall mortality was 6.4% at day +100 and 7.3% at day +168. This real-world experience confirms the efficacy and safety of CMV.

CMV viral load kinetics as surrogate endpoints after allogeneic transplantation

BACKGROUNDViral load (VL) surrogate endpoints transformed development of HIV and hepatitis C therapeutics. Surrogate endpoints for CMV-related morbidity and mortality could advance development of antiviral treatments. Although observational data support using CMV VL as a trial endpoint, randomized controlled trials (RCTs) demonstrating direct associations between virological markers and clinical endpoints are lacking.METHODSWe performed CMV DNA PCR on frozen serum samples from the only placebo-controlled RCT of ganciclovir for early treatment of CMV after hematopoietic cell transplantation (HCT). We used established criteria to assess VL kinetics as surrogates for CMV disease or death by weeks 8, 24, and 48 after randomization and quantified antiviral effects captured by each marker. We used ensemble-based machine learning to assess the predictive ability of VL kinetics and performed this analysis on a ganciclovir prophylaxis RCT for validation.RESULTSVL suppression with ganciclovir reduced cumulative incidence of CMV disease and death for 20 years after HCT. Mean VL, peak VL, and change in VL during the first 5 weeks of treatment fulfilled the Prentice definition for surrogacy, capturing more than 95% of ganciclovir's effect, and yielded highly sensitive and specific predictions by week 48. In the prophylaxis trial, the viral shedding rate satisfied the Prentice definition for CMV disease by week 24.CONCLUSIONSOur results support using CMV VL kinetics as surrogates for CMV disease, provide a framework for developing CMV preventative and therapeutic agents, and support reductions in VL as the mechanism through which antivirals reduce CMV disease.FUNDINGMerck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

American Society for Transplantation and Cellular Therapy Series: #3-Prevention of Cytomegalovirus Infection and Disease After Hematopoietic Cell Transplantation

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious diseases guidelines for the care of hematopoietic cell transplant (HCT) recipients. A new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and answered FAQs. Topics were finalized with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. The third topic in the series focuses on the prevention of cytomegalovirus infection and disease in HCT recipients by reviewing prophylaxis and preemptive therapy approaches; key definitions, relevant risk factors, and diagnostic monitoring considerations are also reviewed.

Delayed-onset cytomegalovirus infection is frequent after discontinuing letermovir in cord blood transplant recipients

Cytomegalovirus (CMV)-seropositive umbilical cord blood transplantation (CBT) recipients have a high incidence of CMV-associated complications. There are limited data regarding the efficacy of letermovir for preventing clinically significant CMV infection (CS-CMVi), and the impact of letermovir prophylaxis on delayed-onset CMV reactivation after letermovir discontinuation, in CBT recipients. We compared the cumulative incidence of CS-CMVi and CMV detection in 21 CMV-seropositive CBT recipients receiving letermovir prophylaxis with a historical cohort of 40 CBT recipients receiving high-dose valacyclovir prophylaxis. Letermovir was administered on day +1 up to day +98. The cumulative incidence of CS-CMVi was significantly lower by day 98 in the letermovir cohort (19% vs 65%). This difference was lost by 1 year due to a higher incidence of delayed-onset CMV reactivation in the letermovir cohort. No patients developed CMV disease in the letermovir cohort within the first 98 days compared with 2 cases (2.4%) in the high-dose valacyclovir cohort; 2 patients developed CMV enteritis after discontinuing letermovir. Median viral loads were similar in both cohorts. Thus, letermovir is effective at preventing CS-CMVi after CBT, but frequent delayed-onset infections after letermovir discontinuation mandate close monitoring and consideration for extended prophylaxis.

Cost-effectiveness analysis of cytomegalovirus prophylaxis in allogeneic hematopoietic cell transplant recipients from a US payer perspective

To evaluate the cost-effectiveness of letermovir versus no prophylaxis for the prevention of cytomegalovirus infection and disease in adult cytomegalovirus-seropositive allogeneic hematopoietic cell transplantation (allo-HCT) recipients. A decision model for 100 patients was developed to estimate the probabilities of cytomegalovirus infection, cytomegalovirus disease, various other complications, and death in patients receiving letermovir versus no prophylaxis. The probabilities of clinical outcomes were based on the pivotal phase 3 trial of letermovir use for cytomegalovirus prophylaxis versus placebo in adult cytomegalovirus-seropositive recipients of an allo-HCT. Costs of prophylaxis with letermovir and of each clinical outcome were derived from published sources or the trial clinical study reports. Incremental cost-effectiveness ratios (ICERs) in terms of cost per quality-adjusted life year (QALY) gained were used in the model. One-way and probabilistic sensitivity analyses were conducted to explore uncertainty around the base-case analysis. In this model, the use of letermovir prophylaxis would lead to an increase of QALYs (619) and direct medical cost ($1  733  794) compared with no prophylaxis (578 QALYs; $710  300) in cytomegalovirus-seropositive recipients of an allo-HCT. Letermovir use for cytomegalovirus prophylaxis was a cost-effective option versus no prophylaxis with base-case analysis ICER $25 046/QALY gained. One-way sensitivity analysis showed the most influential parameter was mortality rate. The probabilistic sensitivity analysis showed a 92% probability of letermovir producing an ICER below the commonly accepted willingness-to-pay threshold of $100 000/QALY gained. Based on this model, letermovir use for cytomegalovirus prophylaxis was a cost-effective option in adult cytomegalovirus-seropositive recipients of an allo-HCT.

Heterogeneous impact of cytomegalovirus reactivation on nonrelapse mortality in hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection is a major complication in allogeneic stem cell transplantation. The utility of CMV prophylaxis with letermovir has been reported; however, the specific applications remain unclear. In this study, we retrospectively analyzed large-scale registry data (N = 10 480) to clarify the risk factors for nonrelapse mortality (NRM) in connection with CMV reactivation. First, we identified risk factors for CMV reactivation using multivariate analysis and developed a scoring model. Although the model effectively stratified reactivation risk into 3 groups (43.7% vs 60.9% vs 71.5%; P < .001), the 3-year NRM was significantly higher in patients with CMV reactivation, even in the low (20.9% vs 13.0%, P < .001), intermediate (21.4% vs 15.6%; P < .001), and high (29.3% vs 18.0%; P < .001) reactivation risk groups. Next, survival analysis considering competing risks, time-dependent covariates, and interaction terms for exploring the heterogeneous impact of CMV reactivation on NRM in the training cohort revealed that chronic myeloid leukemia (CML) (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.05-2.96; P = .033), good performance status (PS) (HR, 1.42; 95% CI, 1.04-1.94; P = .028), HLA-matched donor (HR, 1.34; 95% CI, 1.06-1.70; P = .013), and standard-risk disease (HR, 1.28; 95% CI, 1.04-1.58; P = .022) were associated with increased NRM. In the test cohort, CMV reactivation was significantly associated with increased 3-year NRM among patients with 2 to 4 factors (22.1% vs 13.1%; P < .001) but was comparable among patients with 0 or 1 factor (23.2% vs 20.4%; P = .62). We propose that CMV prophylaxis should be determined based on reactivation risk, as well as these other factors.

Cytomegalovirus prophylaxis using low-dose valganciclovir in patients with acute leukemia undergoing allogeneic hematopoietic stem-cell transplantation

Background

Letermovir prophylaxis is currently the standard of care for the prevention of cytomegalovirus (CMV) infections in allogeneic hematopoietic stem-cell transplantation (allo-HSCT). However, drug-drug interactions between letermovir and azoles or calcineurin inhibitors and the high financial burden of letermovir remain problematic, especially in resource-limited countries. It has not been clarified whether a lower dose of valganciclovir would constitute an effective strategy for CMV prevention in patients with acute leukemia undergoing allo-HSCT.

Methods

We retrospectively assessed 84 consecutive adult patients with acute leukemia who underwent allo-HSCT. These 84 patients were stratified into a valganciclovir prophylaxis group (n = 20) and a non-valganciclovir prophylaxis group (n = 64).

Results

Patients in the valganciclovir prophylaxis group had a lower possibility of CMV DNAemia at week 14 after allo-HSCT than those in the non-valganciclovir prophylaxis group (15.0% versus 50.0%; p = 0.012). The cumulative incidence of CMV DNAemia at week 14 was also lower in patients with valganciclovir CMV prophylaxis than in those without (15.0% versus 50.4%; p = 0.006). Multivariate analysis validated these data, showing that a low dose of valganciclovir significantly reduced the risk of CMV DNAemia at week 14 by 88% (hazard ratio: 0.12; 95% confidence interval: 0.04-0.42; p = 0.001). However, these two groups had similar overall survival rates at week 48 (75.0% versus 76.6%; p = 0.805). Four of 20 (20%) patients discontinued valganciclovir prophylaxis because of adverse events.

Conclusion

Low-dose valganciclovir prophylaxis could be an alternative to letermovir to prevent CMV infection in allo-HSCT, especially in resource-limited countries.

Human cytomegalovirus infection: A considerable issue following allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) is an opportunistic virus, whereby recipients are most susceptible following allogeneic hematopoietic stem cell transplantation (allo-HSCT). With the development of novel immunosuppressive agents and antiviral drugs, accompanied with the widespread application of prophylaxis and preemptive treatment, significant developments have been made in transplant recipients with human (H)CMV infection. However, HCMV remains an important cause of short- and long-term morbidity and mortality in transplant recipients. The present review summarizes the molecular mechanism and risk factors of HCMV reactivation following allo-HSCT, the diagnosis of CMV infection following allo-HSCT, prophylaxis and treatment of HCMV infection, and future perspectives. All relevant literature were retrieved from PubMed and have been reviewed.

Early T cell reconstitution and cytokine profile may help to guide a personalized management of human cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Human cytomegalovirus (HCMV) infection is one of the major causes of mortality and morbidity after allo-hematopoietic stem cell transplantation (HSCT). Antiviral therapies are associated with toxicity and high economic burden. The aim of this retrospective study was to identify allo-HSCT HCMV-seropositive recipients at low risk of clinically significant HCMV infection who could avoid antiviral therapies. Sixty adult patients who underwent allo-HSCT were clustered in two groups: i) 22 (37%) spontaneously controlling HCMV reactivation (Controllers); ii) 38 (63%) developing clinically significant HCMV infection and receiving pre-emptive therapy (Non-Controllers). We analyzed several patient baseline characteristics, total/HCMV-specific CD4⁺ and CD8⁺ T-cell counts and their cytokine production (IFNγ, TNFα, IL2). Controllers presented a higher number of total/HCMV-specific CD4⁺ and CD8⁺ T-cells (P=0.001 and P=0.017 for total CD4⁺ and CD8⁺ T-cells respectively; P<0.001 for HCMV-specific T-cells) and a lower percentage of mono-functional IFNγ-producing HCMV-specific CD8⁺ T-cells (P=0.002). In bi-variable models, the prognostic impact of the percentage of mono-functional HCMV-specific CD8⁺ T-cells on treatment-free survival, adjusted for total/HCMVspecific CD4⁺ and CD8⁺ T-cells, was confirmed. An HCMV-seronegative donor was the only baseline characteristic associated with a clinically significant infection. These data, when confirmed by a larger prospective study, may provide information for guiding the personalized management of HCMV infection in allo-HSCT recipients.

Cytomegalovirus management after allogeneic hematopoietic stem cell transplantation: A mini-review

Because of the high incidence of cytomegalovirus (CMV) seropositivity in the population, CMV infection is a common and severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Taiwan. Here we propose a CMV management strategy for patients undergoing allo-HSCT from the Taiwanese perspective, which focuses on the epidemiology, diagnosis, monitoring, prophylaxis, and treatment of CMV infection after allo-HSCT. In terms of CMV monitoring, weekly CMV monitoring with the COBAS® AmpliPrep system is the standard approach because the pp65 CMV antigenemia assay has a lower sensitivity than CMV monitoring with the COBAS® AmpliPrep system. However, pp65 CMV antigenemia assay has a better correlation with clinical symptoms in immunocompromised patients. A 14-week prophylactic course of letermovir is recommended for allo-HSCT recipients in Taiwan, especially for recipients of hematopoietic stem cells from mismatched unrelated and haploidentical donors. Preemptive ganciclovir therapy should be initiated when the CMV viral load exceeds 1000 copies/mL, and should not be discontinued until CMV DNA is no longer detected in the blood. For allo-HSCT recipients who have CMV-related diseases, ganciclovir with or without CMV-specific intravenous immunoglobulin is the standard of care. The limited availability of foscarnet, an alternative for patients who are not responsive to or cannot tolerate ganciclovir, is a crucial issue in Taiwan. For pediatric allo-HSCT recipients, more data are needed to propose a CMV management recommendation.

First-line Therapy With Donor-derived Human Cytomegalovirus (HCMV)-specific T Cells Reduces Persistent HCMV Infection by Promoting Antiviral Immunity After Allogenic Stem Cell Transplantation

BACKGROUND

Human cytomegalovirus (HCMV) infection, especially persistent HCMV infection, is an important cause of morbidity and mortality after allogenic stem cell transplantation (allo-SCT). Antiviral agents remain the first-line therapy but are limited by side effects and acquired resistance.

METHODS

We evaluated the safety and efficacy of donor-derived HCMV-specific cytotoxic T cells (CTLs) as a first-line therapy for HCMV infection after allo-SCT and investigated the underlying mechanisms.

RESULTS

In humanized HCMV-infected mice, first-line therapy with CTLs effectively combated systemic HCMV infection by promoting the restoration of graft-derived endogenous HCMV-specific immunity in vivo. In a clinical trial, compared with the pair-matched, high-risk control cohort, first-line therapy with CTLs significantly reduced the rate of persistent (2.9% vs 20.0%, P = .018) and late (5.7% vs 20.0%, P = .01) HCMV infection and cumulative incidence of persistent HCMV infection (hazard ratio [HR], 0.13; 95% confidence interval [CI], 0.10-0.82; P = .02), lowered 1-year treatment-related mortality (HR, 0.15. 95% CI, 0.11-0.90. P = .03), and improved 1-year overall survival (HR, 6.35; 95% CI, 1.05-9.00; P = .04). Moreover, first-line therapy with CTLs promoted the quantitative and functional recovery of CTLs in patients, which was associated with HCMV clearance.

CONCLUSIONS

We provide robust support for the benefits of CTLs combined with antiviral drugs as a first-line therapy for treating HCMV infection and suggest that adoptively infused CTLs may stimulate the recovery of endogenous HCMV-specific immunity.

CLINICAL TRIALS REGISTRATION

NCT02985775.

A Mortality Analysis of Letermovir Prophylaxis for Cytomegalovirus (CMV) in CMV-seropositive Recipients of Allogeneic Hematopoietic Cell Transplantation

BACKGROUND

In a phase 3 trial, letermovir reduced clinically significant cytomegalovirus infections (CS-CMVi) and all-cause mortality at week 24 versus placebo in CMV-seropositive allogeneic hematopoietic cell transplantation (HCT) recipients. This post hoc analysis of phase 3 data further investigated the effects of letermovir on all-cause mortality.

METHODS

Kaplan-Meier survival curves were generated by treatment group for all-cause mortality. Observations were censored at trial discontinuation for reasons other than death or at trial completion. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox modeling, adjusting for risk factors associated with mortality.

RESULTS

Of 495 patients with no detectable CMV DNA at randomization, 437 had vital-status data available through week 48 post-HCT at trial completion (101 deaths, 20.4%). Following letermovir prophylaxis, the HR for all-cause mortality was 0.58 (95% CI, 0.35-0.98; P = .04) at week 24 and 0.74 (95% CI, 0.49-1.11; P = .14) at week 48 post-HCT versus placebo. Incidence of all-cause mortality through week 48 post-HCT in the letermovir group was similar in patients with or without CS-CMVi (15.8 vs 19.4%; P = .71). However, in the placebo group, all-cause mortality at week 48 post-HCT was higher in patients with versus those without CS-CMVi (31.0% vs 18.2%; P = .02). The HR for all-cause mortality in patients with CS-CMVi was 0.45 (95% CI, 0.21-1.00; P = .05) at week 48 for letermovir versus placebo.

CONCLUSIONS

Letermovir may reduce mortality by preventing or delaying CS-CMVi in HCT recipients.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov, NCT02137772.

How I treat CMV reactivation after allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) reactivation remains one of the most common and life-threatening infectious complications following allogeneic hematopoietic stem cell transplantation, despite novel diagnostic technologies, several novel prophylactic agents, and further improvements in preemptive therapy and treatment of established CMV disease. Treatment decisions for CMV reactivation are becoming increasingly difficult and must take into account whether the patient has received antiviral prophylaxis, the patient's individual risk profile for CMV disease, CMV-specific T-cell reconstitution, CMV viral load, and the potential drug resistance detected at the time of initiation of antiviral therapy. Thus, we increasingly use personalized treatment strategies for the recipient of an allograft with CMV reactivation based on prior use of anti-CMV prophylaxis, viral load, the assessment of CMV-specific T-cell immunity, and the molecular assessment of resistance to antiviral drugs.

Reducing infectious complications after allogeneic stem cell transplant

INTRODUCTION

Infections remain a significant problem, in patients undergoing an allogeneic hematopoietic stem-cell transplant (HSCT) and efforts have been made over the years, to reduce the incidence, morbidity and mortality of infectious complications.

AREAS COVERED

This manuscript is focused on the epidemiology, risk factors and prevention of infections after allogeneic HSCT. A systematic literature review was performed using the PubMed database, between November 2019 and January 2020, with the following MeSH terms: stem-cell transplantation, infection, fungal, bacterial, viral, prophylaxis, vaccines, prevention. The authors reviewed all the publications, and following a common revision, a summary report was made and results were divided in three sections: bacterial, fungal and viral infections.

EXPERT OPINION

Different infections occur in the early, intermediate and late post-transplant period, due to distinct risk factors. Improved diagnostic techniques, pre-emtive therapy and better prophylaxis of immunologic complications, have reduced the morbidity and mortality of infections. The role of the gut microbiota is under careful scrutiny and may further help us to identify high-risk patients.

Optimal pre-emptive cytomegalovirus therapy threshold in a patient population with high prevalence of seropositive status

INTRODUCTION

Preemptive therapy (PET) for cytomegalovirus (CMV) reactivation post allogeneic hematopoietic stem cell transplantation (SCT) was shown to decrease the incidence of CMV disease. However, the optimal PET threshold is elusive.

PURPOSE OF THE STUDY

To examine the efficacy of PET initiation at a viral threshold of 1000 copies/mL (1560 IU/mL) in a patient population with high prevalence of CMV seropositive status.

PATIENTS AND METHODS

A single center retrospective review of patients that underwent allogeneic SCT was done.

RESULTS

A total of 195 allogeneic SCT recipients were included with median follow up of 18.1 (0.7-95.6) months. A total of 178 (91 %) of patients had a positive CMV PCR with median days to initial reactivation post SCT of 17 (1-1187); 129 patients had peak CMV titer < 1000 copies/mL (low titer) whereas the remaining 49 patients had a peak titer ≥ 1000 copies/mL (high titer). 120 (93 %) of patients with low titers cleared spontaneously with median time to clearance of 40 days (4-188). One patient in the high titer group developed CMV disease. At multivariable analysis; age at SCT HR 1.02 (1.004-1.04; 0.017), malignant vs. benign condition HR 9.4 (2.47-61; 0.0005) and cGVHD HR 0.37 (0.2-0.65; 0.0005) were significant for OS.

CONCLUSIONS

CMV reactivation post SCT was very common in patients with high prevalence of seropositive status. A PET threshold of 1000 copies/mL (1560 IU/mL) appears desirable as it was associated with spontaneous clearance in over 90 % of patients while minimizing treatment related toxicity. Validation of these observations is warranted.

Incidence of viral and fungal complications after utilization of alternative donor sources in hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) remains the only curable option for adult patients with hematologic malignancies. According to guidelines published by the American Society for Transplantation and Cellular Therapy, allogeneic HCT should be offered to all intermediate- and high-risk patients with acute leukemia. While matched-related donor (MRD) grafts continue to be the preferred stem cell source for allogeneic HCT, studies comparing MRD grafts to matched-unrelated donor (MUD) grafts showed comparable outcomes in patients with acute leukemia. Unfortunately, for those without a suitable matched-related graft, the probability of finding a suitable matched-unrelated donor varies significantly depending on racial and ethnic background. With allogeneic HCT procedures increasing year after year due to the increased availability of suitable donors, each of these alternative donor sources merits special clinical considerations, specifically with regard to infections. Infections remain a significant cause of morbidity and mortality after allogeneic transplant, especially in those receiving alternative donor grafts. Due to the high-risk nature associated with these donor grafts, it is important to understand the true risk of developing infectious complications. While there are a multitude of infections that have been described in patients post-allogeneic HCT, this review seeks to focus on the incidence of cytomegalovirus (CMV) and invasive fungal infections (IFI) in adult patients receiving alternative donor source transplantation for hematologic malignancies.

Impact of Preemptive Therapy for Cytomegalovirus on Toxicities after Allogeneic Hematopoietic Cell Transplantation in Clinical Practice: A Retrospective Single-Center Cohort Study

(Val)ganciclovir (vGCV) or foscarnet (FCN) as preemptive therapy (PET) for cytomegalovirus (CMV) after allogeneic hematopoietic cell transplantation (HCT) is associated with myelosuppression and nephrotoxicity, respectively. We analyzed a cohort of CMV-seropositive (R⁺) HCT recipients managed preemptively at a single center. The objectives of our study were to (1) quantify the frequencies of neutropenia and acute kidney injury (AKI) through day +100 (D100) post-HCT and at PET discontinuation and (2) assess the impact of PET on neutropenia and AKI in multivariate models. This was a retrospective cohort study of adult CMV R⁺ recipients who underwent allo-HCT at Memorial Sloan Kettering Cancer Center from March 18, 2013, through December 31, 2017, and were managed with PET. Patients were grouped by receipt of PET (PET and no PET). Neutropenia and AKI were defined by Common Terminology Criteria for Adverse Events version 4. Frequencies of toxicities by D100 were compared between relevant groups. The impact of PET on toxicities was examined in univariate and multivariate Poisson/negative binomial regression models. Of 368 CMV R⁺ HCT recipients, 208 (56.5%) received PET. Neutropenia by D100 occurred in 41.8% and 28.6% patients in PET and no PET, respectively (P = .0009). PET increased the risk of neutropenia (adjusted relative risk = 1.81; 95% confidence interval [CI], 1.48 to 2.21; P < .0001) in multivariate analyses. AKI by D100 occurred in 12.0% and 7.8% patients in PET and no PET, respectively (P = .19). PET increased the risk of AKI by 2.75-fold (95% CI, 1.71 to 4.42; P < .0001). When PET recipients were grouped by first antiviral, neutropenia by D100 occurred in 34.8% and 48.9% of vGCV and FCN recipients, respectively, (P = .08), and AKI occurred in 13.0% and 34.0% of vGCV and FCN recipients, respectively (P = .001). At discontinuation of vGCV or FCN, neutropenia was present in 11.2% versus 2.1% patients, respectively (P = .08), and AKI was present in 1.9% of versus 12.8% patients respectively (P = .005). Preemptive therapy for CMV increased the risk of neutropenia and AKI in the first 100 days post-HCT by 1.8-fold and 2.8-fold, respectively. Our results underscore the need for safer antivirals for CMV management in HCT recipients.

Anti-herpesvirus prophylaxis, pre-emptive treatment or no treatment in adults undergoing allogeneic transplant for haematological disease: systematic review and meta-analysis

BACKGROUND

Herpesviridae infections incur significant morbidity and indirect effects on mortality among allogeneic haematopoietic cell transplant (allo-HCT) recipients.

OBJECTIVES

To study the effects of antiviral prevention strategies among haemato-oncological individuals undergoing allo-HCT.

DATA SOURCES

Cochrane Central Register of Controlled Trials, MEDLINE, Embase and LILACS. We further searched for conference proceedings and trial registries.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs).

PARTICIPANTS

Adults with haematological malignancy undergoing allo-HCT.

INTERVENTIONS

Antiviral prophylaxis versus no treatment/placebo or pre-emptive treatment and pre-emptive treatment versus prophylaxis with the same agent.

METHODS

Random-effects meta-analysis was conducted computing pooled risk ratios (RR) with 95% CI and the inconsistency measure (I²). The certainty of the evidence was appraised by GRADE.

RESULTS

We included 22 RCTs. Antiviral prophylaxis reduced all-cause mortality (RR 0.83, 95% CI 0.7-0.99; 15 trials, I² = 0%), cytomegalovirus (CMV) disease (RR 0.54, 95% CI 0.34-0.85; n = 15, I² = 20%) and herpes simplex virus (HSV) disease (RR 0.29, 95% CI 0.2-0.43; n = 13, I² = 18%) compared with no treatment/placebo or pre-emptive treatment, all with high-certainty evidence. Furthermore, antivirals reduced HSV infection, CMV pneumonitis, CMV infection and varicella zoster virus disease. Anti-CMV prophylaxis (+/- pre-emptive treatment) compared with pre-emptive treatment alone reduced non-significantly all-cause mortality (RR 0.78, 95% CI 0.6-1.02; n = 8, I² = 0%), CMV disease (RR 0.47, 95% CI 0.23-0.97; n = 9, I² = 30%) and HSV disease (RR 0.41, 95% CI 0.24-0.67; n = 4, I² = 0%) with high-certainty evidence, as well as CMV and HSV infections. Antiviral prophylaxis did not result in increased adverse event rates overall or more discontinuation due to adverse events.

CONCLUSIONS

Antiviral prophylaxis directed against herpesviruses is highly effective and safe, reducing mortality, HSV and CMV disease, as well as herpesvirus reactivations among allo-HCT recipients. Anti-CMV prophylaxis is more effective than pre-emptive treatment alone with respect to HSV and CMV disease and infection.

An update on the treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Introduction: Human Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Standard treatment options have for long been limited to a small number of effective drugs with significant toxicities.Areas covered: In this manuscript, the authors update a previous review summarizing recent developments in the virology lab and their possible implications for treatment strategies at bedside. In particular, the authors focused on new antiviral drugs already available and under investigation in clinical trials and innovative immunotherapeutic approaches, including adoptive T-cell therapy and vaccines.Expert opinion: Broader knowledge of CMV biology and its relationship with the host immune system is greatly contributing to the development of novel therapeutic approaches. The availability of new drugs, the improved techniques for virological testing and the more accurate patient risk stratification allow to better individualize treatment, limiting toxicity while sparing antiviral effects. The role of immunotherapy is clearly emerging and will further expand our treatment armamentarium.

Guidelines for the management of cytomegalovirus infection in patients with haematological malignancies and after stem cell transplantation from the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Cytomegalovirus is one of the most important infections to occur after allogeneic haematopoietic stem cell transplantation (HSCT), and an increasing number of reports indicate that cytomegalovirus is also a potentially important pathogen in patients treated with recently introduced drugs for hematological malignancies. Expert recommendations have been produced by the 2017 European Conference on Infections in Leukaemia (ECIL 7) after a review of the literature on the diagnosis and management of cytomegalovirus in patients after HSCT and in patients receiving other types of therapy for haematological malignancies. These recommendations cover diagnosis, preventive strategies such as prophylaxis and pre-emptive therapy, and management of cytomegalovirus disease. Antiviral drugs including maribavir and letermovir are in development and prospective clinical trials have recently been completed. However, management of patients with resistant or refractory cytomegalovirus infection or cytomegalovirus disease is a challenge. In this Review we summarise the reviewed literature and the recommendations of the ECIL 7 for management of cytomegalovirus in patients with haematological malignancies.

From academic research to founding a company: the story of AiCuris

This contribution describes the experiences with three careers: leading and building an academic research institute, heading a research area in a multinational pharma company and founding and leading a biotech company, which saw its first drug successfully enter the market in its 11thyear of existence. The three positions had very different challenges, the common denominator for success was good and innovative science. However, research in a commercial environment, in addition to scientific excellence, also means to demonstrate the likely commercial success of the particular research. The most challenging, but at the same time the most interesting mission was the foundation of a new company, securing the financial means and developing the drugs, which had been discovered, in the clinics.

Antiviral prophylaxis for cytomegalovirus infection in allogeneic hematopoietic cell transplantation

Patients treated with allogeneic hematopoietic cell transplantation (HCT) are at risk of cytomegalovirus (CMV) reactivation and disease, which results in increased morbidity and mortality. Although universal antiviral prophylaxis against CMV improves outcomes in solid organ transplant recipients, data have been conflicting regarding such prophylaxis in patients undergoing allogeneic HCT. We conducted a systematic review of randomized trials of prophylactic antivirals against CMV after allogeneic HCT to summarize the evolution of the field over the last 35 years and evaluate the prophylactic potential of antiviral agents against CMV after allogeneic HCT. Electronic databases were queried from database inception through 31 December 2017. For included studies, incidence of CMV infection and all-cause mortality were collected as primary outcomes; CMV disease incidence, use of preemptive therapy, and drug toxicities were collected as secondary outcomes. Nineteen clinical trials conducted between 1981 and 2017 involving a total of 4173 patients were included for review. Prophylactic strategies included use of acyclovir, valacyclovir, ganciclovir, maribavir, brincidofovir, and letermovir compared with placebo or a comparator antiviral. Fourteen trials that compared antiviral prophylaxis with placebo demonstrated overall effectiveness in reducing incidence of CMV infection (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.42-0.58), CMV disease (OR, 0.56; 95% CI, 0.40-0.80), and use of preemptive therapy (OR, 0.51; 95% CI, 0.42-0.62; 6 trials); however, none demonstrated reduction in all-cause mortality (OR, 0.96; 95% CI, 0.78-1.18) except the phase 3 trial of letermovir (week-24 OR, 0.59; 95% CI, 0.38-0.98). Additional research is warranted to determine patient groups most likely to benefit from antiviral prophylaxis and its optimal deployment after allogeneic HCT.

Mixed vs full donor engraftment early after hematopoietic cell transplant: Impact on incidence and control of cytomegalovirus infection

Recovery of cytomegalovirus (CMV)-specific immunity after hematopoietic cell transplantation (HCT) is essential in controlling CMV infection. We hypothesize that mixed donor engraftment as measured by chimerism at day 30 in CMV D(+) HCTs and full chimerism in CMV D(-) HCTs will be predictive of CMV reactivation. Prospectively collected data for 407 CMV R+ HCT recipients transplanted from 2006 to 2014 at the University of Minnesota were retrospectively analyzed. Full and mixed donor engraftment were defined as ≥95% or <95% donor cells at day 30, respectively. Source of engraftment determination included preferentially peripheral blood CD3 fraction, then myeloid cell fraction (CD15+), then bone marrow. In 407 CMV R+ subjects, 77% (n = 313) were CMV D(-) cells from umbilical cord blood (n = 209), peripheral blood (n = 58) or marrow (n = 46). Fifty three per cent received reduced intensity conditioning (RIC). At day +30, full donor engraftment was seen in 82% of myeloablative and 55% of RIC transplants. The cumulative incidence of CMV infection 1-year after transplant was not different in patients with full (54%, n = 276) or mixed (53%, n = 131) donor engraftment. Control of CMV did not significantly differ among the two groups. In multiple regression analysis, there was no significant association between donor engraftment (mixed or full) and incidence or control of CMV.

Hematopoietic stem cell transplant with HLA-mismatched grafts: impact of donor, source, conditioning, and graft versus host disease prophylaxis

INTRODUCTION

Allogeneic hematopoietic cell transplantation is frequently used to treat malignant and non-malignant conditions, and many patients lack a human leukocyte antigen (HLA) matched related or unrelated donor. For those patients, available alternative graft sources include HLA mismatched unrelated donors, cord blood, or haplo-identical donors. These graft sources have unique characteristics and associated outcomes requiring graft-specific variations to conditioning regimens, graft-versus-host disease prophylaxis, and post-transplant care. Areas covered: This manuscript will cover approaches in selecting donors, conditioning regimens, graft versus host disease prophylaxis, post-transplant care, and ongoing clinical trials related to mismatched grafts. Expert commentary: In the setting, haplo-identical grafts are increasingly popular due to low graft versus host disease (GVHD) risk and control of cellular dose. We recommend young male donors, utilizing bone marrow with post-transplant cyclophosphamide for GVHD prophylaxis. Cord blood transplant is appropriate for young healthy patients, and we recommend 6/8 HLA matched grafts with at least 2.0 × 10⁷/kg total nucleated cell dose. For mismatched unrelated donors we recommend young male donors, utilizing bone marrow with in vivo T-cell conditioning with post-transplant cyclophosphamide, alemtuzumab, or ATG. With these transplants, significant post-transplant surveillance and infectious prophylaxis is key to reducing treatment-related mortality.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

A Randomized, Double-Blind, Placebo-Controlled Phase 3 Trial of Oral Brincidofovir for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) infection is a common complication of allogeneic hematopoietic cell transplantation (HCT). In this trial, we randomized adult CMV-seropositive HCT recipients without CMV viremia at screening 2:1 to receive brincidofovir or placebo until week 14 post-HCT. Randomization was stratified by center and risk of CMV infection. Patients were assessed weekly through week 15 and every third week thereafter through week 24 post-HCT. Patients who developed clinically significant CMV infection (CS-CMVi; CMV viremia requiring preemptive therapy or CMV disease) discontinued the study drug and began anti-CMV treatment. The primary endpoint was the proportion of patients with CS-CMVi through week 24 post-HCT; patients who discontinued the trial or with missing data were imputed as primary endpoint events. Between August 2013 and June 2015, 452 patients were randomized at a median of 15 days after HCT and received study drug. The proportion of patients who developed CS-CMVi or were imputed as having a primary endpoint event through week 24 was similar between brincidofovir-treated patients and placebo recipients (155 of 303 [51.2%] versus 78 of 149 [52.3%]; odds ratio, .95 [95% confidence interval, .64 to 1.41]; P = .805); fewer brincidofovir recipients developed CMV viremia through week 14 compared with placebo recipients (41.6%; P < .001). Serious adverse events were more frequent among brincidofovir recipients (57.1% versus 37.6%), driven by acute graft-versus-host disease (32.3% versus 6.0%) and diarrhea (6.9% versus 2.7%). Week 24 all-cause mortality was 15.5% among brincidofovir recipients and 10.1% among placebo recipients. Brincidofovir did not reduce CS-CMVi by week 24 post-HCT and was associated with gastrointestinal toxicity.

Letermovir for the prevention of cytomegalovirus infection in adult cytomegalovirus-seropositive hematopoietic stem cell transplant recipients

INTRODUCTION

Allogeneic hematopoietic cell transplants (allo-HCT) recipients are at the high-risk of reactivation of cytomegalovirus (CMV), and reactivation is associated with significant morbidity and mortality. Although available anti-CMV therapies may be effective for the prevention of CMV, they are plagued by unacceptable toxicities that prohibit their use in the post-transplant period. Recently studied CMV-active agents, such as maribavir and brincidofovir, failed to reduce the incidence of CMV infection in HCT recipients. Letermovir represents the first agent in the non-nucleoside 3,4 dihydro-quinazoline class of CMV viral terminase complex inhibitors, with activity solely against CMV. The positive results from the recently published Phase III study of letermovir for prevention of CMV infection in CMV-seropositive allo-HCT recipients led to its approval as a prophylactic agent for CMV in multiple countries. Areas covered: In this review, we will evaluate this novel agent with a focus on letermovir mechanism of action, pharmacokinetics and metabolism, clinical efficacy, and safety and toxicities. Expert commentary: With the introduction of letermovir, prevention of CMV infection in allo-HCT recipients may shift considerably, from a predominantly preemptive strategy to one that utilizes this novel therapy for prophylaxis.

A Modified Intensive Strategy to Prevent Cytomegalovirus Disease in Seropositive Umbilical Cord Blood Transplantation Recipients

We previously demonstrated a lower rate of cytomegalovirus (CMV) reactivation and disease among seropositive umbilical cord blood transplantation (CBT) recipients receiving an intensive prophylaxis strategy consisting of ganciclovir on days -8 to -2 pretransplantation, high-dose valacyclovir post-transplantation, and twice-weekly serum CMV polymerase chain reaction testing. We hypothesized that a modified intensive strategy excluding pretransplantation ganciclovir would be similarly effective. We compared the risk of CMV reactivation, occurrence of CMV disease, and duration of anti-CMV therapy by day 100 post-CBT in patients receiving the modified intensive and intensive strategies. Forty patients received the modified intensive strategy, and 43 received the intensive strategy. There was no difference in the hazard for CMV reactivation (hazard ratio, 1.1; P = .77). No patients in the modified intensive cohort, but 2 patients in the intensive cohort, developed CMV disease (P = .53). There was no difference in the hazard for early (≤30 days post-CBT; P = .76) or high-level (>1000 IU/mL; P = .37) CMV reactivation. Patients in the modified intensive cohort had marginally higher CMV viral loads and percentage of days of CMV detection and treatment, although the contribution of pretransplantation ganciclovir to these differences is unclear. The overall percentage of treatment days was 32% in both cohorts after accounting for pretransplantation ganciclovir. In conclusion, exclusion of prophylactic ganciclovir before CBT did not impact the risk of CMV reactivation or disease, although CMV kinetics appeared to differ by prevention strategy. Best practices for CMV prevention will need further study as new prophylactic strategies become available.

Comparative Efficacy and Safety of Different Antiviral Agents for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Cell Transplantation: A Systematic Review and Meta-Analysis

Over the past 25 years, several randomized controlled trials have investigated the efficacy of different antiviral agents for cytomegalovirus (CMV) prophylaxis in allogeneic hematopoietic cell transplantation. We performed a systematic literature review, conventional meta-analysis, and network meta-analysis using a random-effects model and risk ratios (RRs) with corresponding 95% confidence intervals (CIs) as effect estimates. Fifteen randomized controlled trials were identified, including 7 different antiviral agents: acyclovir, ganciclovir, maribavir, brincidofovir, letermovir, valacyclovir, and vaccine. Twelve trials used placebo as comparator while 3 trials compared different antiviral agents. We found evidence for CMV disease and infection being significantly reduced by antiviral prophylaxis, with an RR of .66 (95% CI, .48 to .90) and .63 (95% CI, .50 to .79). Across the network, ganciclovir showed the best relative efficacy for CMV disease while letermovir provided first rank of being the best option for CMV infection. The risk for death was not significantly influenced by antiviral prophylaxis in the meta-analysis, with an RR of .92 (95% CI, .78 to 1.08), as well as in the network meta-analysis. In terms of safety, letermovir was at least similar in comparison with placebo and most agents while both letermovir and acyclovir showed significantly reduced risk for serious adverse events compared with ganciclovir, with RRs of .55 (95% CI, .30 to 1.00) for letermovir and .63 (95% CI, .42 to .93) for acyclovir. With a probability of 81%, letermovir appears to be the best option in terms of safety. Future randomized head-to-head comparisons are needed to evaluate the definite efficacy and safety of different prophylactic strategies.

Cytotect®CP as salvage therapy in patients with CMV infection following allogeneic hematopoietic cell transplantation: a multicenter retrospective study

Cytomegalovirus is one of the main contributing factors to high mortality rates in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). The main factors of treatment failure are both drug resistance and intolerance. In some cases, Cytotect®CP CMV-hyperimmune globulin is used as salvage therapy. This study aims to investigate the safety and efficacy of Cytotect®CP as a salvage therapy in patients with CMV infection after allo-HCT. Twenty-three consecutive patients received Cytotect®CP for CMV infection after prior CMV therapy. At the time of Cytotect®CP introduction, 17 patients (74%) had developed acute GVHD and 15 patients (64%) were receiving steroid treatment; Cytotect®CP was used as monotherapy (n = 7) and in combination (n = 16). Overall, response was observed in 18 patients (78%) with a median time of 15 days (range: 3-51). Of the 18 responders, 4 experienced CMV reactivation, while 5 responders died within 100 days of beginning treatment. Of these 5 deaths, 4 were due to causes unrelated to CMV. Estimated 100-day OS from the introduction of Cytotect®CP was 69.6%. No statistically significant difference was observed in 100-day OS between responders and non-responders (73.7% vs 50.0%, p = 0.258). Cytotect®CP as salvage therapy is effective and well-tolerated. Given its safety profile, early treatment use should be considered.

Letermovir Prophylaxis for Cytomegalovirus in Hematopoietic-Cell Transplantation

BACKGROUND

Cytomegalovirus (CMV) infection remains a common complication after allogeneic hematopoietic-cell transplantation. Letermovir is an antiviral drug that inhibits the CMV-terminase complex.

METHODS

In this phase 3, double-blind trial, we randomly assigned CMV-seropositive transplant recipients, 18 years of age or older, in a 2:1 ratio to receive letermovir or placebo, administered orally or intravenously, through week 14 after transplantation; randomization was stratified according to trial site and CMV disease risk. Letermovir was administered at a dose of 480 mg per day (or 240 mg per day in patients taking cyclosporine). Patients in whom clinically significant CMV infection (CMV disease or CMV viremia leading to preemptive treatment) developed discontinued the trial regimen and received anti-CMV treatment. The primary end point was the proportion of patients, among patients without detectable CMV DNA at randomization, who had clinically significant CMV infection through week 24 after transplantation. Patients who discontinued the trial or had missing end-point data at week 24 were imputed as having a primary end-point event. Patients were followed through week 48 after transplantation.

RESULTS

From June 2014 to March 2016, a total of 565 patients underwent randomization and received letermovir or placebo beginning a median of 9 days after transplantation. Among 495 patients with undetectable CMV DNA at randomization, fewer patients in the letermovir group than in the placebo group had clinically significant CMV infection or were imputed as having a primary end-point event by week 24 after transplantation (122 of 325 patients [37.5%] vs. 103 of 170 [60.6%], P<0.001). The frequency and severity of adverse events were similar in the two groups overall. Vomiting was reported in 18.5% of the patients who received letermovir and in 13.5% of those who received placebo; edema in 14.5% and 9.4%, respectively; and atrial fibrillation or flutter in 4.6% and 1.0%, respectively. The rates of myelotoxic and nephrotoxic events were similar in the letermovir group and the placebo group. All-cause mortality at week 48 after transplantation was 20.9% among letermovir recipients and 25.5% among placebo recipients.

CONCLUSIONS

Letermovir prophylaxis resulted in a significantly lower risk of clinically significant CMV infection than placebo. Adverse events with letermovir were mainly of low grade. (Funded by Merck; ClinicalTrials.gov number, NCT02137772 ; EudraCT number, 2013-003831-31 .).