Cost-effectiveness of maribavir versus conventional antiviral therapies for post-transplant refractory cytomegalovirus infection with or without genotypic resistance: A US perspective.

This study evaluated the cost-effectiveness of maribavir versus investigator-assigned therapy (IAT; valganciclovir/ganciclovir, foscarnet, or cidofovir) for post-transplant refractory cytomegalovirus (CMV) infection with or without resistance. A two-stage Markov model was designed using data from the SOLSTICE trial (NCT02931539), real-world multinational observational studies, and published literature. Stage 1 (0-78 weeks) comprised clinically significant CMV (csCMV), non-clinically significant CMV (n-csCMV), and dead states; stage 2 (78 weeks-lifetime) comprised alive and dead states. Total costs (2022 USD) and quality-adjusted life years (QALYs) were estimated for the maribavir and IAT cohorts. An incremental cost-effectiveness ratio was calculated to determine cost-effectiveness against a willingness-to-pay threshold of $100 000/QALY. Compared with IAT, maribavir had lower costs ($139 751 vs $147 949) and greater QALYs (6.04 vs 5.83), making it cost-saving and more cost-effective. Maribavir had higher acquisition costs compared with IAT ($80 531 vs $65 285), but lower costs associated with administration/monitoring ($16 493 vs $27 563), adverse events (AEs) ($11 055 vs $16 114), hospitalization ($27 157 vs $33 905), and graft loss ($4516 vs $5081), thus making treatment with maribavir cost-saving. Maribavir-treated patients spent more time without CMV compared with IAT-treated patients (0.85 years vs 0.68 years), leading to lower retreatment costs for maribavir (cost savings: -$42 970.80). Compared with IAT, maribavir was more cost-effective for transplant recipients with refractory CMV, owing to better clinical efficacy and avoidance of high costs associated with administration, monitoring, AEs, and hospitalizations. These results can inform healthcare decision-makers on the most effective use of their resources for post-transplant refractory CMV treatment.

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.

Chemically sulfated polysaccharides from natural sources: Assessment of extraction-sulfation efficiencies, structural features and antiviral activities.

The provisioning of compound libraries with a high degree of diversity and attractive pharmacological properties is a limiting step in drug development. This study reports the production of highly bioactive sulfated polysaccharides, originally present in a nonsulfated, dormant state in natural sources, and demonstrates their antiviral activity (human cytomegalovirus EC50 values of 2.34-7.77 µg/mL) at a low degree of cytotoxicity. Furthermore, data strongly suggested the inhibition of virus entry as the main mode of antiviral action. Remarkably, the utilized oleum-DMF reagent was able to generate a range of sulfated polysaccharides from various natural sources, possessing varying saccharide compositions, degrees of sulfation (0.4-1.7) and molecular masses (38-94,000 g/mol). Typically, in a matter of minutes, this reagent not only solubilized polysaccharides but also chemically converted their hydroxyl functionality into sulfates. The most active sulfated polysaccharide (EC50 of 2.62 µg/mL) proved to be a 94,000 g/mol branched glucan with sulfates at C-6/C-3,6/C-2,3,6 positions. In conclusion, the important determinants of such compounds' antiviral activity are: (i) degree of sulfation, (ii) molecular mass and (iii) structural features. Thus, our approach offers a huge prospect for the improvement of natural source-derived libraries based on biologically active polysaccharides with diversified chemical profiles.

Prospective Assessment of Cytomegalovirus Immunity in High-Risk Donor-Seropositive/Recipient-Seronegative Liver Transplant Recipients Receiving Either Preemptive Therapy or Antiviral Prophylaxis.

The differential impact of preemptive therapy (PET) and antiviral prophylaxis (AP) on development of cytomegalovirus (CMV)-specific neutralizing antibody (nAb) and T-cell responses have not previously been directly compared in high-risk donor-seropositive/recipient-seronegative (D+R-) organ transplant recipients. We prospectively assessed T-cell and nAb responses 3 months after transplantation in cohorts of high-risk D+R- liver transplant recipients who received either PET (n = 15) or AP (n = 25) and a control group of CMV-seropositive transplant recipients (R+) (AP; n = 24). CMV phosphoprotein 65 (pp65)- and immediate early protein 1-specific multifunctional T-cell responses were determined by means of intracellular cytokine staining and nAbs against BADrUL131-Y4 CMV in adult retinal pigment epithelial cell line-19 human epithelial cells; nAbs were detected in 8 of 12 (67%) in the PET group, none of 17 in the AP group, and 20 of 22 (91%) in the R+ group. Multifunctional CD8 and CD4 T-cell responses to pp65 were generally similar between PET and R+ groups, and lower for the AP group; multifunctional CD4 responses were similar across all groups. Among D+R- liver transplant recipients, PET was associated with the development of greater nAb and multifunctional CD8 T-cell responses compared with AP, providing a potential mechanism to explain the relative protection against late-onset disease with PET. Future studies are needed to define specific immune parameters predictive of late-onset CMV disease with AP.

Assessment of the effector function of CMV-specific CTLs isolated using MHC-multimers from granulocyte-colony stimulating factor mobilized peripheral blood.

BACKGROUND: Adoptive transfer of CMV-specific T cells has shown promising results in preventing pathological effects caused by opportunistic CMV infection in immunocompromised patients following allogeneic hematopoietic stem cell transplantation. The majority of studies have used steady-state leukapheresis for CMV-reactive product manufacture, a collection obtained prior to or months after G-CSF mobilization, but the procurement of this additional sample is often not available in the unrelated donor setting. If the cellular product for adoptive immunotherapy could be generated from the same G-CSF mobilized collection, the problems associated with the additional harvest could be overcome. Despite the tolerogenic effects associated with G-CSF mobilization, recent studies described that CMV-primed T cells generated from mobilized donors remain functional. METHODS: MHC-multimers are potent tools that allow the rapid production of antigen-specific CTLs. Therefore, in the present study we have assessed the feasibility and efficacy of CMV-specific CTL manufacture from G-CSF mobilized apheresis using MHC-multimers. RESULTS: CMV-specific CTLs can be efficiently isolated from G-CSF mobilized samples with Streptamers and are able to express activation markers and produce cytokines in response to antigenic stimulation. However, this anti-viral functionality is moderately reduced when compared to non-mobilized products. CONCLUSIONS: The translation of Streptamer technology for the isolation of anti-viral CTLs from G-CSF mobilized PBMCs into clinical practice would widen the number of patients that could benefit from this therapeutic strategy, although our results need to be taken into consideration before the infusion of antigen-specific T cells obtained from G-CSF mobilized samples.

Valganciclovir versus valacyclovir prophylaxis for prevention of cytomegalovirus: an economic perspective.

INTRODUCTION: Valganciclovir (vGCV) and valacyclovir (vACV) are used in cytomegalovirus (CMV) prophylaxis in renal transplant recipients. The aim of this study was to compare the economic impact of both regimens during 1-year follow-up. METHODS: A total of 117 renal transplant recipients at risk for CMV were randomized to 3-month prophylaxis either with vGCV (900 mg/day, n = 60) or vACV (8 g/day, n = 57) and their data used in a pharmacoeconomic analysis. The pharmacoeconomic evaluation involved all direct CMV-related expenses in the first year after transplantation. Sensitivity analysis was employed to examine the effects of various prices of antiviral drugs and diagnostic procedures on overall CMV-related costs. Simulation of the more expensive US healthcare perspective was performed, and a scenario involving costs of acute rejection (AR) was examined. RESULTS: Overall CMV-related costs were significantly lower in the vACV arm; median United States dollars (USD) 3473 (3108-3745) vs. USD 5810 (4409-6757; P < 0.001) per patient, respectively. Our data showed that the critical determinant of the major disparity between the prophylactic regimens was the prophylaxis price. Median cost of prophylaxis in the vACV group was USD 1729 (1527-2173) compared to USD 3968 (2683-4857) in the vGCV group (P < 0.001). In sensitivity analysis of the overall CMV-related costs, the least and the most expensive pharmacotherapy and diagnostic scenarios were used; nevertheless, the vACV arm remained markedly less expensive. Simulation considering the higher physician/nurse and hospitalization fees of the US healthcare system and the scenario including expenditure associated with AR episodes also favored vACV. CONCLUSION: VACV prophylaxis for CMV is associated with a significant 44% lower cost than vGCV at the first year after renal transplantation.

Stringent adherence to a cytomegalovirus-prevention protocol is associated with reduced overall costs in the first 6 months after kidney transplantation.

BACKGROUND: We previously documented that a stringent implementation of a preemptive cytomegalovirus (CMV) prevention protocol reduced the number of CMV disease episodes after kidney transplantation, when compared with a routine preemptive protocol. The impact on overall costs was assessed. METHODS: Cost comparisons were made for inpatient and outpatient costs and overall costs, using costs provided by the financial department. Variables were analyzed using the Wilcoxon rank-sum test. A multivariable global linear model evaluated the effect of all co-variables on cost differences. In Cohort 1 (n = 84), 74% were followed with a standard CMV preemptive protocol, and 26% received prophylaxis. In Cohort 2 (n = 74), an intensified CMV surveillance protocol was applied in 74% of patients, and 26% were given prophylaxis. RESULTS: Overall, Cohort 1 had significantly higher treatment costs as compared with Cohort 2 (mean Swiss francs [CHF] 104,548 and CHF 76,983, respectively, P = 0.0005). Excluding patients who received prophylaxis reduced these costs to CHF 89,318 in Cohort 1 and CHF 73,652 in Cohort 2. Outcome between Cohort 1 and 2 was comparable. CONCLUSION: A stringent adherence to the CMV prevention protocol was associated with a significant reduction in overall costs. Whether this benefit is because of the demonstrated reduction in the rate of CMV disease needs to be assessed in a randomized trial.

Assessment of drug candidates for broad-spectrum antiviral therapy targeting cellular pyrimidine biosynthesis.

Currently available antiviral drugs frequently induce side-effects or selection of drug-resistant viruses. We describe a novel antiviral principle based on targeting the cellular enzyme dihydroorotate dehydrogenase (DHODH). In silico drug design and biochemical evaluation identified Compound 1 (Cmp1) as a selective inhibitor of human DHODH in vitro (IC50 1.5±0.2nM). Crystallization data specified the mode of drug-target interaction. Importantly, Cmp1 displayed a very potent antiviral activity that could be reversed by co-application of uridine or other pyrimidine precursors, underlining the postulated DHODH-directed mode of activity. Human and animal cytomegaloviruses as well as adenoviruses showed strong sensitivity towards Cmp1 in cell culture-based infection systems with IC50 values in the low micromolar to nanomolar range. Particularly, broad inhibitory activity was demonstrated for various types of laboratory and clinically relevant adenoviruses. For replication of human cytomegalovirus in primary fibroblasts, antiviral mode of activity was attributed to the early stage of gene expression. A mouse in vivo model proved reduced replication of murine cytomegalovirus in various organs upon Cmp1 treatment. These findings suggested Cmp1 as drug candidate and validated DHODH as a promising cellular target for antiviral therapy.

Sensitive and rapid detection of ganciclovir resistance by PCR based MALDI-TOF analysis.

BACKGROUND: Cytomegalovirus (CMV) infection is associated with significant morbidity and mortality in transplant recipients. Resistance against ganciclovir is increasingly observed. According to current guidelines, direct drug resistance testing is not always performed due to high costs and work effort, even when resistance is suspected. OBJECTIVES: To develop a more sensitive, easy applicable and cost-effective assay as proof of concept for direct drug resistance testing in CMV surveillance of post-transplant patients. STUDY DESIGN: Five consecutive plasma samples from a heart transplant patient with a primary CMV infection were analyzed by quantitative real-time polymerase chain reaction (rtPCR) as a surrogate marker for therapy failure, and by direct drug resistance detection assays such as Sanger sequencing and the novel primer extension (PEX) reaction matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) based method. RESULTS: This report demonstrates that PEX reaction followed by MALDI-TOF analysis detects the A594V mutation, encoding ganciclovir resistance, ten days earlier compared to Sanger sequencing and more than 30 days prior to an increase in viral load. CONCLUSION: The greatly increased sensitivity and rapid turnaround-time combined with easy handling and moderate costs indicate that this procedure could make a major contribution to improve transplantation outcomes.

Compassionate use: a story of ethics and science in the development of a new drug.

This history chronicles the unusual development of the antiviral drug ganciclovir. The first compound with activity against human cytomegalovirus (CMV), ganciclovir was so clearly efficacious that a placebo-controlled clinical trial could not ethically be done, and the FDA rejected the first application to market the drug. Used to treat a blinding eye infection in patients with AIDS, the story of ganciclovir paralleled the spread of the AIDS epidemic. Both ganciclovir and AIDS caught the federal government off guard. Caught in a Catch-22 situation, the pharmaceutical company developing ganciclovir gave the drug away free for five years under compassionate use guidelines. The problems encountered in the development of ganciclovir provide guidance on how future drugs to treat life-threatening diseases can be developed.

A new synthesis and an antiviral assessment of the 4'-fluoro derivative of 4'-deoxy-5'-noraristeromycin.

A synthetic route to (1S,2S,3R,5S)-3-(6-amino-9H-purin-9-yl)-5-fluorocyclopentane-1,2-diol (that is, the 4'-fluoro derivative of 4'-deoxy-5'-noraristeromycin, 3) is described via a fluorinated cyclopentanol, which is in contrast to existing schemes where fluorination occurred once the purine ring was present. Compound 3 was assayed versus a number of viruses. A favorable response was observed towards measles (IC(50) of 1.2 microg/mL in the neutral red assay and 14 microg/mL by the visual assay) but this was accompanied by cytotoxicity in the CV-1 host cells (21-36 microg/mL). Among the viruses unaffected by 3 were human cytomegalovirus and the poxviruses (vaccinia and cowpox), which are three viruses that were inhibited by the 4',4'-difluoro analog of 3 (that is, 2).

Cost of prophylaxis in the management of cytomegalovirus infection in solid organ transplant recipients.

BACKGROUND: Limited economic data exist on the use of valganciclovir for the prevention of cytomegalovirus (CMV) infection and disease in solid organ transplant (SOT) recipients. We compared the economics of sequential i.v. and oral ganciclovir prophylaxis vs. oral valganciclovir prophylaxis alone in high-risk (D+/R-) SOT patients. METHODS: A cost-minimization analysis was performed from the perspective of the Spanish National Health System comparing the cost of sequential ganciclovir prophylaxis (induction with i.v. ganciclovir 10 mg/kg daily for 14 d followed by oral ganciclovir 1 g t.i.d. for 3 months) vs. oral valganciclovir prophylaxis (900 mg once daily for 100 d). Resource utilization data for both regimens were obtained from the literature and from clinical records of 83 patients in nine Spanish hospitals. Results were expressed as average cost per patient treated. RESULTS: The average cost per patient treated with sequential ganciclovir or valganciclovir prophylaxis was euro3715.51 and euro3295.90, respectively. The higher cost of ganciclovir therapy was due to concomitant administration of anti-CMV immunoglobulin (euro313.73), drug administration costs (euro401.45), catheter culture tests (euro13.64) and adverse events associated with catheter use (euro3.30). Following a sensitivity analysis, taking into account dose and duration of drug, concomitant medications and adverse events, costs for valganciclovir and sequential therapy were similar. CONCLUSIONS: Valganciclovir prophylaxis is as economical as sequential ganciclovir prophylaxis in high-risk D+/R- SOT patients. In addition, the once-daily dosing regimen of valganciclovir is more convenient, and avoids the complications associated with catheter use.

A prospective assessment of valganciclovir for the treatment of cytomegalovirus infection and disease in transplant recipients.

We assessed valganciclovir for the treatment of cytomegalovirus (CMV) in organ-transplant recipients. Virologic and clinical outcomes were compared with those in matched historical control individuals. Thirty-two patients (23 with symptomatic disease) received valganciclovir, and 32 patients received intravenous (iv) ganciclovir. The rate of virologic clearance by day 21 of therapy was similar in the valganciclovir arm (50.0%) and the ganciclovir arm (46.9%) (P value not significant). The change from baseline viral load by day 7 and day 14 of therapy was similar in both arms. Two patients treated with valganciclovir required a switch to iv ganciclovir, because of a lack of response. Valganciclovir is useful for the treatment of CMV infection and disease in selected organ-transplant recipients.

Impact of targeted oral ganciclovir prophylaxis for transplant recipients of livers from cytomegalovirus-seropositive donors.

OBJECTIVES: Symptomatic cytomegalovirus (CMV) infection can cause significant morbidity and occasional mortality after liver transplantation. In a previous audit, we showed that donor CMV seropositivity (D+) was a risk factor for symptomatic infection, and we estimated the likely clinical and financial impact of 14 weeks of oral ganciclovir prophylaxis given to recipients of CMV-seropositive organs. In August 2001, we adopted this policy of targeted oral ganciclovir prophylaxis for recipients of CMV-seropositive livers. METHOD: The additional costs of adopting targeted prophylaxis policy for 1 year, patient and doctor compliance with the new strategy, and its clinical impact were analysed. RESULTS: Targeted prophylaxis reduced the incidence of symptomatic CMV infection from 9.5% (in the earlier cohort that did not receive prophylaxis) to 5.8% (P = NS). Symptomatic infection was not observed in CMV-seropositive recipients of CMV-seropositive donor livers (P = 0.06 for comparison of the 2 cohorts), but the incidence of symptomatic infection in the CMV-seronegative recipients of CMV-seropositive organs did not change. However, symptomatic infection appeared to be less severe and was delayed by ganciclovir prophylaxis (median time from transplantation to symptom onset 96 vs. 39 days without prophylaxis). Death attributable to CMV infection was not observed in the cohort that received prophylaxis. The additional cost associated with implementation of the prophylaxis strategy was 108,068 pounds sterlings. CONCLUSION: Targeted CMV prophylaxis with oral ganciclovir reduces the incidence and severity of symptomatic infection and appears to be a cost-effective means of improving outcome following liver transplantation.

The cost-effectiveness of prophylaxis with valaciclovir in the management of cytomegalovirus after renal transplantation.

Prophylaxis-based antiviral treatment and intensive monitoring followed by pre-emptive antiviral treatment are both commonly used management strategies to reduce risk of cytomegalovirus (CMV) infection following renal transplantation. This study employed a decision-model approach using published efficacy data and information from a recent survey of French clinical practice to consider the relative costs and outcomes associated with CMV prevention strategies for high-risk patient groups. The cost per case of treating tissue invasive and symptomatic CMV disease was estimated at euro 15,431 and euro 10,852, respectively. In the highest infection-risk patient group (positive donor with no previous CMV history) prophylactic oral valaciclovir was shown to avoid the greatest number of CMV disease cases (35 cases per 100 transplanted patients) and reduced the overall CMV-related costs per transplanted patient by around 14% over a'wait-and-treat' baseline strategy. In contrast, intensive monitoring and preemptive treatment resulted in a much higher cost per transplanted patient. This analysis suggests that prophylactic treatment remains the most cost-effective approach to the management of CMV in renal-transplanted patients. Further comparative studies between prophylactic and pre-emptive treatment would be a valuable addition to the current evidence based on CMV prevention.

Preevaluation of clinical trial data: the case of preemptive cytomegalovirus therapy in patients with human immunodeficiency virus.

We developed a mathematical simulation model to anticipate outcomes from an upcoming trial of targeted, preemptive cytomegalovirus (CMV) therapy in high-risk, human immunodeficiency virus (HIV)-infected patients identified by means of CMV polymerase chain reaction screening. We estimated the costs and consequences of CMV prophylaxis in patients with CD4(+) counts < or =100 cells/microL under various assumptions regarding disease progression, complication rates, drug effects, and costs. Without CMV preemptive therapy, lifetime costs average $44,600 with expected duration of survival of 19.16 quality-adjusted life-months and 213 CMV cases per 1000 patients. Targeted preemptive therapy with orally administered valganciclovir increases costs and duration of survival to $46,900 and 19.63 quality-adjusted life-months, respectively. CMV cases decrease to 174 per 1000 patients. The cost per quality-adjusted life-year gained is $59,000. This result compares favorably with other strategies in end-stage HIV disease but hinges on valganciclovir cost and efficacy assumptions and the absence of minimally effective salvage antiretroviral therapy for HIV. The upcoming trial should resolve the clinical uncertainty surrounding some of these assumptions.

Comparison of the efficacy and cost effectiveness of pre-emptive therapy as directed by CMV antigenemia and prophylaxis with ganciclovir in lung transplant recipients.

BACKGROUND: CMV disease remains a major complication of lung transplantation and attempts to prevent it have met with marginal success. In a previous study we documented that universal prophylaxis did not prevent CMV disease but merely delayed it, and was very costly. METHODS: We compared the efficacy and cost of pre-emptive therapy with ganciclovir, guided by CMV antigenemia, to that of historic controls that received universal prophylaxis with ganciclovir. CMV antigenemia assay was done routinely and pre-emptive therapy was initiated if greater than 25 CMV positive cells per 100,000 polymorphonuclear cells were found. RESULTS: Nineteen patients were enrolled; 6 of of whom received 12 courses of pre-emptive therapy. The incidence of CMV disease was 26% compared to 38% for the historical controls (p = 0.51). None of the patients that received pre-emptive therapy developed CMV disease following that therapy. Antigenemia failed to predict disease in 5 patients that developed it, and thus it is unknown if pre-emptive therapy could have prevented it. There was no mortality in either the study patients or historic controls directly related to CMV. The net savings with pre-emptive therapy was $2569 per patient. CONCLUSIONS: We conclude that pre-emptive therapy with ganciclovir is as safe and effective as universal prophylaxis in preventing CMV disease in lung transplant recipients, and is less expensive. The appropriate surveillance technique and timing remain to be determine to optimize the efficacy of pre-emptive therapy.