Efficacy and safety of low-dose ganciclovir preemptive therapy in allogeneic haematopoietic stem cell transplant recipients compared with conventional-dose ganciclovir: a prospective observational study

Epidemiology, treatment patterns, and disease burden of cytomegalovirus in hematopoietic cell transplant recipients in selected countries outside of Europe and North America: A systematic review

BACKGROUND

Cytomegalovirus (CMV) disease impacts morbidity and mortality in hematopoietic cell transplant (HCT) recipients. This systematic review summarized data on the epidemiology, management, and burden of CMV post-HCT outside of Europe and North America.

METHODS

The MEDLINE, Embase, and Cochrane databases were searched for observational studies and treatment guidelines in HCT recipients across 15 selected countries from Asia-Pacific, Latin America, and Middle East (search period: 1 January 2011-17 September 2021). Outcomes included incidence of CMV infection/disease, recurrence, risk factors, CMV-related mortality, treatments, refractory, resistant CMV, and burden.

RESULTS

Of 2708 references identified, 68 were eligible (67 studies and one guideline; 45/67 studies specific to adult allogeneic HCT recipients). The rates of CMV infection and disease within 1 year of allogeneic HCT were 24.9%-61.2% (23 studies) and 2.9%-15.7% (10 studies), respectively. Recurrence occurred in 19.8%-37.9% of cases (11 studies). Up to 10% of HCT recipients died of CMV-related causes. In all countries, first-line treatment for CMV infection/disease involved intravenous ganciclovir or valganciclovir. Conventional treatments were associated with serious adverse events such as myelosuppression (10.0%) or neutropenia only (30.0%, 39.8%) and nephrotoxicity (11.0%) (three studies), frequently leading to treatment discontinuation (up to 13.6%). Refractory CMV was reported in 2.9%, 13.0%, and 28.9% of treated patients (three studies) with resistant CMV diagnosed in 0%-10% of recipients (five studies). Patient-reported outcomes and economic data were scarce.

CONCLUSION

The incidence of CMV infection and disease post-HCT is high outside of North America and Europe. CMV resistance and toxicity highlight a major unmet need with current conventional treatments.

Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines-e.g., live-attenuated, chimeric, viral-based-and non-living ones-subunit, RNA-based, virus-like particles, plasmid-based DNA-have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV's capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

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.

A Systematic Review of the Clinical Pharmacokinetics, Pharmacodynamics and Toxicodynamics of Ganciclovir/Valganciclovir in Allogeneic Haematopoietic Stem Cell Transplant Patients

BACKGROUND

Ganciclovir (GCV) and valganciclovir (VGCV) are the first-line agents used to prevent and treat cytomegalovirus (CMV) infection in allogeneic haematopoietic stem cell transplant (alloHCT) patients.

OBJECTIVE

The aim of this work was to describe available data for the clinical pharmacokinetics, pharmacodynamics and toxicodynamics of GCV and VGCV and the potential of a therapeutic drug monitoring strategy to improve outcomes in the alloHCT population.

METHODS

We systematically reviewed the pharmacokinetics (dose-exposure), pharmacodynamics (exposure-efficacy) and toxicodynamics (exposure-toxicity) of GCV and VGCV in alloHCT patients with CMV infection. Studies including alloHCT patients treated for CMV infection reporting the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV or VGCV were searched for using the PUBMED and EMBASE databases from 1946 to 2019. Only studies involving participants > 12 years of age and available in the English language were included.

RESULTS

A total of 179 patients were included in the 14 studies that met the inclusion criteria, of which 6 examined GCV pharmacokinetics only, while 8 also examined GCV pharmacodynamics and toxicodynamics. Reported pharmacokinetic parameters showed considerable interpatient variability and were different from other populations, such as solid organ transplant and human immunodeficiency virus-infected patients. Only one study found a correlation between neutropenia and elevated peak and trough GCV concentrations, with no other significant pharmacodynamic and toxicodynamic relationships identified. While therapeutic drug monitoring of GCV is performed in some institutions, no association between GCV therapeutic drug monitoring and clinical outcomes was identified.

CONCLUSION

Further studies of the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV/VGCV in alloHCT patients are required to identify a more robust therapeutic range and to subsequently quantify the potential value of therapeutic drug monitoring of GCV/VGCV in the alloHCT population.

Exploring failure of antimicrobial prophylaxis and pre-emptive therapy for transplant recipients: a systematic review

OBJECTIVES

Infections remain a threat for solid organ and stem cell transplant recipients. Antimicrobial prophylaxis and pre-emptive therapy have improved survival of these patients; however, the failure rates of prophylaxis are not negligible. The aim of this systematic review is to explore the reasons behind failure of antimicrobial prophylaxis and pre-emptive therapy.

SETTING

This systematic review included prospective randomised controlled trials and prospective single-arm studies.

PARTICIPANTS

The studies included were on prophylaxis and pre-emptive therapy of opportunistic infections in transplant recipients. Studies were included from databases MEDLINE, CENTRAL and Embase published until October first 2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measures were breakthrough infections, adverse events leading to stopping of treatment, switching medication or dose reduction. Secondary outcome measures were acquired resistance to antimicrobials, antifungals or antivirals and death.

RESULTS

From 3317 identified records, 30 records from 24 studies with 2851 patients were included in the systematic review. Seventeen focused on prophylactic and pre-emptive treatment of cytomegalovirus and seven studies on invasive fungal infection. The main reasons for failure of prophylaxis and pre-emptive therapy were adverse events and breakthrough infections, which were described in 54% (13 studies) and 38% (9 studies) of the included studies, respectively. In 25%, six of the studies, a detailed description of patients who experienced failure of prophylaxis or pre-emptive therapy was unclear or lacking.

CONCLUSIONS

Our results show that although failure is reported in the studies, the level of detail prohibits a detailed analysis of failure of prophylaxis and pre-emptive therapy. Clearly reporting on patients with a negative outcome should be improved. We have provided guidance on how to detect failure early in a clinical setting in accordance to the results from this systematic review.

PROSPERO REGISTRATION NUMBER

CRD42017077606.

Clinical significance of post-treatment viral load of cytomegalovirus in patients with hematologic malignancies

OBJECTIVES

Patients with hematologic diseases were at high risk for cytomegalovirus (CMV) diseases. In the present study, we compare various prognostic factors during CMV viremia, with specific emphasis on the relationship between viremia eradication and the long-term prognosis of patients after each episode.

METHODS

Adult patients with hematologic diseases who had a detectable CMV viral load (VL) (equal to or above 150 copies/mL) were included in the study. Medical records were reviewed for demographic data including age, sex, hematologic and other underlying diseases, status of stem cell transplantation, antiviral medication, serum CMV viral load before and after antiviral treatment.

RESULTS

A total of 101 episodes of CMV viremia occurred in patients with hematologic diseases. Comparison of various prognostic factors revealed non-survivors more frequently suffered from pneumonia and concomitant bacterial or fungal infections, had less frequently undergone hematopoietic stem cell transplantation (HSCT), and had higher peak VLs during viremic episodes. After antiviral therapy, eradication of viremia was much less frequently achieved in non-survivors. The Kaplan-Meier curves revealed that patients with detectable end-treatment VL had lower survival rates even if the antivirals were administered for more than 21 days. In a multivariate Cox proportional-hazard model, a detectable VL at the end of antiviral therapy independently predicted mortality within 180 days.

CONCLUSIONS

In patients with hematologic diseases suffering CMV viremia, failure to eradicate viremia after antiviral therapy indicates a higher chance of mortality and can be regarded as a useful indicator in evaluating the patient's long-term prognosis.

Clinical applications of interferon-γ releasing assays for cytomegalovirus to differentiate cytomegalovirus disease from bystander activation: a pilot proof-of-concept study

BACKGROUND/AIMS

We evaluated the proposed clinical application of the combined interpretation of host factors and viral factors in two different cytomegalovirus (CMV) co-infection models.

METHODS

We prospectively enrolled all human immunodeficiency virus non-infected patients with confirmed Pneumocystitis jirovecii pneumonia (PCP) and those with suspected gastrointestinal CMV disease in a tertiary hospital. All patients underwent CMV interferon-γ releasing assay (IGRA) for CMV (T-track CMV, Lophius Biosciences). We created the 2-axis model with the CMV IGRA results as the x-axis and the results for CMV virus replication as the y-axis, and hypothesized that cases falling in the left upper quadrant (high viral load and low CMV-specific immunity) of the model would be true CMV infections. The CMV IGRA results were concealed from the attending physicians.

RESULTS

Of 39 patients with PCP, four (10%) were classified as combined CMV pneumonia, 13 (33%) as bystander activation, and the remaining 22 (56%) as no CMV infection. The data for all four patients with PCP and CMV pneumonia fell in the left upper quadrant of the 2-axis model. Of 24 patients with suspected gastrointestinal CMV disease, 12 (50%) were classified as gastrointestinal CMV disease and the remaining 12 (50%) as bystander activation with no gastrointestinal CMV disease. The data for 11 of the 12 patients (92%) with gastrointestinal CMV disease were located in the left upper quadrant of the 2-axis model.

CONCLUSIONS

Cases yielding low CMV IGRA results and high CMV viral replication appear to be true CMV infections. Further studies with large number of cases in different types of CMV disease should be proposed.

Cytomegalovirus in hematopoietic stem cell transplant recipients - management of infection

INTRODUCTION

Cytomegalovirus (CMV) still causes significant morbidity and mortality in patients given allogeneic hematopoietic stem cell transplantation (HSCT). Despite effective pharmacotherapy, potentially life-threatening CMV disease occurs nowadays in up to 10% of HSCT recipients; moreover, routinely used anti-CMV agents have been shown to be associated with morbidity. Areas covered: This review examines different issues related to diagnosis and management of CMV infection in HSCT recipients, paying particular attention to the monitoring of CMV-specific immune recovery, approaches of adoptive cell therapy and new antiviral drugs. Expert commentary: Despite advances in diagnostic tests and treatment, there is still room for refining management of CMV in HSCT recipients. Immunological monitoring should be associated in the future to virological monitoring. The safety profile and efficacy of new anti-CMV agents should be compared with that of standard-of-care drugs. Donor-derived, pathogen-specific T cells adoptively transferred after transplantation could contribute to reduce the impact of CMV infection on patient's outcome.

Differences of cytomegalovirus diseases between kidney and hematopoietic stem cell transplant recipients during preemptive therapy

BACKGROUND/AIMS

Cytomegalovirus (CMV) surveillance and preemptive therapy is a widely-used strategy for preventing CMV disease in transplant recipients. However, there are limited data on the incidence and patterns of CMV disease during the preemptive period. Thus, we investigated the incidence and pattern of tissue-invasive CMV disease in CMV seropositive kidney transplantation (KT) and hematopoietic stem cell transplantation (HCT) recipients during preemptive therapy.

METHODS

We prospectively identified patients with tissue-invasive CMV disease among 664 KT (90%) and 496 HCT (96%) recipients who were D+/R+ (both donor and recipient seropositive) during a 4-year period.

RESULTS

The incidence rates of CMV disease were 4.1/100 person-years (4%, 27/664) in KT recipients and 5.0/100 person-years (4%, 21/496) in HCT recipients. Twenty-six (96%) of the KT recipients with CMV disease had gastrointestinal CMV, whereas 17 (81%) of the HCT recipients had gastrointestinal CMV and 4 (19%) had CMV retinitis. Thus, CMV retinitis was more common among HCT recipients (p = 0.03). All 27 KT recipients with CMV disease suffered abrupt onset of CMV disease before or during preemptive therapy; 10 (48%) of the 21 HCT recipients with CMV disease were also classified in this way but the other 11 (52%) were classified as CMV disease following successful ganciclovir preemptive therapy (p < 0.001).

CONCLUSIONS

The incidence of CMV disease was about 4% in both KT and HCT recipients during preemptive therapy. However, CMV retinitis and CMV disease as a relapsed infection were more frequently found among HCT recipients.

Treatment of CMV infection after allogeneic hematopoietic stem cell transplantation

Despite a remarkable reduction in the past decades, cytomegalovirus (CMV) disease in allogeneic hematopoietic stem cell transplant (HSCT) recipients remains a feared complication, still associated with significant morbidity and mortality. Today, first line treatment of CMV infection/reactivation is still based on dated antiviral compounds Ganciclovir (GCV), Foscarnet (FOS) and Cidofovir (CDF) with their burdensome weight of side effects. Maribavir (MBV), Letermovir (LMV) and Brincidofovir (BDF) are three new promising anti-CMV drugs without myelosuppressive properties or renal toxic effects that are under investigation in randomized phase II and III trials. Adoptive T-cell therapy (ATCT) in CMV infection possesses a strong rationale, demonstrated by several proof of concept studies; its feasibility is currently under investigation by clinical trials. ATCT from third-party and naïve donors could meet the needs of HSCT recipients of seronegative donors and cord blood grafts. In selected patients such as recipients of T-cell depleted grafts, ATCT, based on CMV-specific host T-cells reconstitution kinetics, would be of value in the prophylactic and/or preemptive CMV treatment. Vaccine-immunotherapy has the difficult task to reduce the incidence of CMV reactivation/infection in highly immunocompromised HSCT patients. Newer notions on CMV biology may represent the base to flush out the Troll of transplantation.

Efficacy of oral ribavirin in hematologic disease patients with paramyxovirus infection: analytic strategy using propensity scores

Few antiviral agents are available for treating paramyxovirus infections, such as those involving respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (hMPV). We evaluated the effect of oral ribavirin on clinical outcomes of paramyxovirus infections in patients with hematological diseases. All adult patients with paramyxovirus were retrospectively reviewed over a 2-year period. Patients who received oral ribavirin were compared to those who received supportive care without ribavirin therapy. A propensity-matched case-control study and a logistic regression model with inverse probability of treatment weighting (IPTW) were performed to reduce the effect of selection bias in assignment for oral ribavirin therapy. A total of 145 patients, including 64 (44%) with PIV, 60 (41%) with RSV, and 21 (15%) with hMPV, were analyzed. Of these 145 patients, 114 (78%) received oral ribavirin and the remaining 31 (21%) constituted the nonribavirin group. Thirty-day mortality and underlying respiratory death rates were 31% (35/114) and 12% (14/114), respectively, for the oral ribavirin group versus 19% (6/31) and 16% (5/31), respectively, for the nonribavirin group (P = 0.21 and P = 0.56). In the case-control study, the 30-day mortality rate in the ribavirin group was 24% (5/21) versus 19% (4/21) in the nonribavirin group (P = 0.71). In addition, the logistic regression model with IPTW revealed no significant difference in 30-day mortality (adjusted hazard ratio of 1.3; 95% confidence interval [95% CI] of 0.3 to 5.8) between the two groups. Steroid use (adjusted odds ratio, 5.67; P = 0.01) and upper respiratory tract infection (adjusted odds ratio, 0.07; P = 0.001) was independently associated with mortality. Our data suggest that oral ribavirin therapy may not improve clinical outcomes in hematologic disease patients infected with paramyxovirus.

Impact of viral reactivations in the era of pre-emptive antiviral drug therapy following allogeneic haematopoietic SCT in paediatric recipients

While pre-emptive rituximab therapy for EBV has substantially reduced the incidence of post-transplant lymphoproliferative disorder, following allogeneic haematopoietic SCT (HSCT), cytomegalovirus (CMV) and adenovirus (ADV) still contribute to significant morbidity and mortality after HSCT. We therefore aimed to identify high-risk children who could benefit from recent advances in virus-specific immunotherapy, define the impact of viral reactivations on survival and estimate the economic burden of pre-emptive antiviral drug therapy. Between 2005 and 2010, prospective monitoring of 291 paediatric HSCT procedures revealed that reactivation of CMV (16%), ADV (15%) and EBV (11%) was frequent during period of CD4 T-cell lymphopenia (0.15 × 10(9) L(-1); P<0.05). We report significant risk factors for reactivation, most notably the use of serotherapy and development of GVHD (grade II) in the presence of pre-existing infection (ADV) or donor and/or recipient seropositivity (CMV, EBV). Most interestingly, CMV and ADV viraemia were the major independent predictors of mortality (P<0.05). CMV, ADV or EBV viral reactivation caused prolonged hospitalization (P<0.05), accounted for 15% of all mortality and substantially increased the cost of transplantation by ∼£22 500 ($34 000). This provides an economic rationale for targeting high-risk HSCT recipients with interventions such as virus-specific cell therapy.