A randomized trial of preemptive therapy for prevention of cytomegalovirus disease after allogeneic hematopoietic stem cell transplantation

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.

Cost-effectiveness of letermovir as cytomegalovirus prophylaxis in adult recipients of allogeneic hematopoietic stem cell transplantation in Hong Kong

BACKGROUND

The cost-effectiveness of letermovir as cytomegalovirus (CMV) prophylaxis in adult seropositive patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT), compared with the conventional strategy of preemptive treatment, has not been evaluated in Asia.

METHODS

A decision analytical model, simulating the clinical progression of CMV infection on a lifetime horizon, was developed to compare prophylactic strategy with letermovir with preemptive therapy alone as anti-CMV strategies. Prophylaxis comprised administering letermovir for 14 weeks, with clinical outcomes measured at 24 weeks, followed by preemptive therapy if CMV infection occurred. This approach was modeled on outcomes of the letermovir phase 3 clinical study. The model enumerated the cost of letermovir prophylaxis, quality-adjusted life years (QALYs), and incremental cost per QALYs gained with prophylaxis. The opposite arm involved regular monitoring and preemptive therapy for CMV reactivation. Real-world costs from the adult HSCT center at Queen Mary Hospital, Hong Kong, were adopted for analysis. Costs and clinical benefits, expressed as QALYs, were discounted at 3% per year.

RESULTS

Letermovir prophylaxis compared with preemptive therapy only would lead to an increase of life-year and QALYs at increased costs. Incremental cost-effectiveness analysis showed that letermovir prophylaxis had an associated cost of HKD 193,580 for each life-year gained, and HKD 234,675 for each QALY gained. Probabilistic sensitivity analysis showed that the majority of incremental cost-effectiveness ratio fell below the cost-effectiveness threshold of HKD 382,046 (one gross domestic product per capita) per QALY gained.

CONCLUSIONS

Letermovir prophylaxis would be cost-effective for preventing CMV infection in adult seropositive allogeneic HSCT recipients in Hong Kong.

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.

Cost-effectiveness analysis of the use of letermovir for the prophylaxis of cytomegalovirus in adult cytomegalovirus seropositive recipients undergoing allogenic hematopoietic stem cell transplantation in Italy

Background: The aim of the analysis is to assess the efficiency of the allocation of economic resources related to the use of letermovir cytomegalovirus (CMV) prophylaxis in adult seropositive recipients (R+) patients receiving an allogenic hematopoietic stem cell transplantation (HSCT), compared with a no-prophylaxis strategy, assuming preemptive antiviral administration in both groups from the perspective of the Italian National Health Service (NHS), through a cost-effectiveness analysis.

Methods: The model used is based on a decision tree which simulates on a lifetime horizon the progression of CMV infection, considering two alternatives: the use of letermovir CMV prophylaxis, followed by preemptive therapy in case of clinically significant CMV infection, or the avoided use of letermovir CMV prophylaxis, considering direct medical costs (referred to 2018) and quality-adjusted life years (QALYs), both discounted considering a 3% annual rate. Two scenarios were considered, representing the differences related to regional contexts and clinical practice of different typologies of hospitals (public or private accredited with Regional Health Services).

Results: The use of letermovir prophylaxis compared with no prophylaxis strategy would lead to an increase of QALYs and direct medical costs in the two scenarios considered, with a mean increase of 0.45 QALYs, and an increase of direct medical costs of 10,222.4 € and of 10,809.9 € in the two scenarios. The incremental cost-effectiveness ratios are equal to 22,564 €/QALY and 23,861 €/QALY. The probabilistic sensitivity analysis conducted showed a percentage of results below the threshold of 40,000 €/QALY of 67.4% and 71.3%; and below a threshold of 25,000 €/QALY equal to 50.4% and to 53.0%.

Conclusions: The use of letermovir CMV prophylaxis in adult R+ patients receiving allogenic HSCT, compared with a no-prophylaxis strategy, would be cost-effective for the Italian NHS considering the incremental cost-effectiveness thresholds of 40,000 €/QALY and of 25,000 €/QALY.

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.

[Comparisons of occurrence and curative effect of interstitial pneumonia after the related HLA-haploidentical and HLA-matched sibling peripheral blood hematopoietic stem cell transplantation]

OBJECTIVE

To compare occurrence and curative effect of interstitial pneumonia (IP) of patients with malignant hematologic disease after related HLA-haploidentical peripheral blood stem cell transplantation without T-cell depletion (RHNT-PBSCT) and non T cell-depleted HLA-matched sibling peripheral blood stem cell transplantation (MSNT-PBSCT).

METHODS

109 patients with malignant hematologic disease as the research cases received RHNT-PBSCT from January 2006 to December 2014, which were compared with 125 patients treated with MSNT-PBSCT during the same period to determine the occurrence of IP and curative effect produced by ganciclovir and joint adrenal glucocorticoids.

RESULTS

The incidences of IP in RHNT-PBSCT and MSNT-PBSCT groups were 15.60%(17/109) and 13.60%(17/125) (P=0.150), respectively; both the effective rates were 76.47%(13/17) (P=0.536), the difference was not statistically significant. Single factor analysis showed that acute graft versus host disease was a risk factor for the occurrence of IP after RHNT-PBSCT (P=0.001).

CONCLUSION

The incidence of IP in patients with malignant hematologic disease after RHNT-PBSCT didn' t increase when compared with patients after MSNT-PBSCT. The curative effects of the two groups were equivalent after priority to ganciclovir and joint adrenal glucocorticoids.

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

OBJECTIVES

We performed a prospective observational study comparing the efficacy and safety of low-dose ganciclovir (5 mg/kg/day) as initial preemptive therapy in allogeneic haematopoietic stem cell transplantation (HSCT) recipients with conventional-dose ganciclovir (10 mg/kg/day).

METHODS

All adult patients undergoing allogeneic HSCT were enrolled at a transplant centre over a 24 month period. The decision to use low-dose or conventional-dose ganciclovir was at the discretion of each attending haematologist. A logistic regression model with inverse probability of treatment weighting (IPTW) using propensity scores was performed to reduce the effect of the selection bias in assignment for ganciclovir preemptive therapy.

RESULTS

Of the 252 HSCT recipients, 97 (38%) received preemptive ganciclovir therapy. Of these, 53 (55%) and 44 (45%) received low-dose and conventional-dose ganciclovir, respectively. The viral clearance rate was higher in the low-dose ganciclovir group [98% (52/53)] than in the conventional-dose ganciclovir group [86% (38/44), P = 0.04], while the low-dose ganciclovir group exhibited a longer viral clearance time (median 21.0 days) than the conventional-dose ganciclovir group (median 14.0 days, P = 0.05). The rate of discontinuation of therapy due to neutropenia or nephrotoxicity was similar in the two groups, although conventional-dose ganciclovir was changed to another regimen more frequently than low-dose ganciclovir. There were three cases of cytomegalovirus (CMV) disease in each group after the initial preemptive therapy. The logistic regression models using propensity scores also revealed that there were no significant differences in viral clearance, secondary episodes of CMV infection, CMV disease and overall mortality between the two groups.

CONCLUSIONS

Low-dose ganciclovir appears to be safe, and to be at least as effective as conventional-dose ganciclovir for CMV viraemia in allogeneic HSCT recipients.