Cytomegalovirus related hospitalization costs among hematopoietic stem cell and solid organ transplant recipients treated with maribavir versus investigator-assigned therapy: A US-based study.

BACKGROUND: Cytomegalovirus (CMV) infections among hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients impose a significant health care resource utilization (HCRU)-related economic burden. Maribavir (MBV), a novel anti-viral therapy (AVT), approved by the United States Food and Drug Administration for post-transplant CMV infections refractory (with/without resistance) to conventional AVTs has demonstrated lower hospital length of stay (LOS) versus investigator-assigned therapy (IAT; valgancilovir, ganciclovir, foscarnet, or cidofovir) in a phase 3 trial (SOLSTICE). This study estimated the HCRU costs of MBV versus IAT. METHODS: An economic model was developed to estimate HCRU costs for patients treated with MBV or IAT. Mean per-patient-per-year (PPPY) HCRU costs were calculated using (i) annualized mean hospital LOS in SOLSTICE, and (ii) CMV-related direct costs from published literature. Probabilistic sensitivity analysis with Monte-Carlo simulations assessed model robustness. RESULTS: Of 352 randomized patients receiving MBV (n = 235) or IAT (n = 117) for 8 weeks in SOLSTICE, 40% had HSCT and 60% had SOT. Mean overall PPPY HCRU costs of overall hospital-LOS were $67,205 (95% confidence interval [CI]: $33,767, $231,275) versus $145,501 (95% CI: $62,064, $589,505) for MBV and IAT groups, respectively. Mean PPPY ICU and non-ICU stay costs were: $32,231 (95% CI: $5,248, $184,524) versus $45,307 (95% CI: $3,957, $481,740) for MBV and IAT groups, and $82,237 (95% CI: $40,397, $156,945) MBV versus $228,329 (95% CI: $94,442, $517,476) for MBV and IAT groups, respectively. MBV demonstrated cost savings in over 99.99% of simulations. CONCLUSIONS: This analysis suggests that Mean PPPY HCRU costs were 29%-64% lower with MBV versus other-AVTs.

Population pharmacokinetic modeling and simulation of maribavir to support dose selection and regulatory approval in adolescents with posttransplant refractory cytomegalovirus.

Maribavir was approved by the US Food and Drug Administration for the treatment of patients aged ≥12 years and weighing ≥35 kg with posttransplant cytomegalovirus infection/disease refractory (with/without resistance) to valganciclovir, ganciclovir, cidofovir, or foscarnet, with an oral dose of 400 mg twice daily. With no pediatric clinical data available and difficulty in trial recruitment, population pharmacokinetic modeling and simulations were conducted to predict the pharmacokinetics and inform maribavir dosing in adolescents.

Fanconi syndrome in an elderly patient with membranous nephropathy during treatment with the immunosuppressant mizoribine.

We report on an 80-year-old man diagnosed with Fanconi syndrome induced by mizoribine after 4 weeks of administration to treat membranous nephropathy. Mizoribine is an oral immunosuppressant that inhibits inosine monophosphate dehydrogenase and is widely used in Japan for the treatment of autoimmune diseases and nephrotic syndrome, as well as after renal transplantation. Acquired Fanconi syndrome is often caused by drugs (antibacterial, antiviral, anticancer, and anticonvulsant drugs) and is sometimes caused by autoimmune diseases, monoclonal light chain-associated diseases, or heavy metal poisoning. In our patient, hypokalemia, hypophosphatemia, glucosuria, hypouricemia, and severe proteinuria resolved gradually after discontinuation of mizoribine administration, despite oral administration of prednisolone followed by a single intravenous injection of rituximab. The patient was ultimately diagnosed with Fanconi syndrome induced by mizoribine based on his clinical course and his typical laboratory data with the absence of proximal tubular acidosis. To our knowledge, this is the first report of Fanconi syndrome possibly induced by mizoribine. Although the precise mechanism by which mizoribine induces proximal tubular dysfunction is unknown, we suggest that nephrologists should be aware of the onset of Fanconi syndrome, a rare complication during mizoribine treatment.

The efficacy and safety of mizoribine for maintenance therapy in patients with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis: the usefulness of serum mizoribine monitoring.

BACKGROUND: The life prognosis of elderly patients with myeloperoxidase-anti-neutrophil cytoplasmic antibodies-associated vasculitis (MPO-AAV) has been improved by reducing the corticosteroid or cyclophosphamide dose to avoid opportunistic infection. However, many elderly MPO-AAV patients experience recurrence and renal death. An effective and safer maintenance treatment method is necessary to improve the renal prognosis of MPO-AAV. METHODS: Patients with MPO-AAV who reached complete or incomplete remission after induction therapy were prospectively and randomly divided into mizoribine (MZR; n = 25) and control (n = 28) groups. The primary endpoint was relapse of MPO-AAV. The patients' serum MZR concentration was measured before (C0) and 3 h after taking the MZR. The maximum drug concentration (Cmax) and the serum MZR concentration curves were determined using population pharmacokinetics parameters. We also assessed the relationship between the MZR concentrations and adverse events. The observation period was 12 months. RESULTS: Fifty-eight MPO-AAV patients from 16 hospitals in Japan were enrolled. Ten patients relapsed (MZR group, n = 6; control group, n = 4; a nonsignificant between-group difference). Changes in the serum MZR concentration could be estimated for 22 of the 25 MZR-treated patients: 2 of the 11 patients who reached a Cmax of 3 µg/mL relapsed, whereas 4 of the 11 patients who did not reach this Cmax relapsed. The treatment of one patient with C0 > 1 µg/mL was discontinued due to adverse events. No serious adverse events occurred. CONCLUSION: There was no significant difference in the recurrence rate of MPO-AAV between treatment with versus without MZR.

Effect of mizoribine pulse therapy in adult membranous nephropathy.

Membraneous nephropathy (MN) is one of the complicated kidney diseases associated with proteinuria. Mizoribine (MZR) is an emerging treatment option for nephrotic syndrome; however, its dosage and administration are yet lack of consensus. This study aims to evaluate the efficacy and safety of high-dose MZR pulse therapy for adult membraneous nephropathy. Sixty patients with membraneous nephropathy were recruited, and assigned to two treatment groups. One group received conventional treatment of steroid combining with cyclophosphamide (CPM), the other group received steroid combining with high-dose MZR pulse administration. Both groups were followed up for 1 year. Treatment efficacy and side effects were measured regularly. Fifty-nine patients completed the treatment courses. There was no significant difference in demographic and disease conditions prior to treatment between two treatment groups. Both groups showed significant decrease of urine proteins and increase of serum albumin levels after treatments with no severe side effects. After 6 months of treatment, MZR group has 71% reduction (compared to 74.4% reduction in CPM group) in urine protein compared to baseline after adjusting for age and gender. 89.7% of patients in CPM and 93.3% in MZR groups had partial/ complete remission after 12 months. This study demonstrated satisfactory safety and efficacy of high-dose mizoribine pulse administration combining with steroid treatment for adult patients with membranous nephropathy.

Evaluation of the Effect of Maribavir on Cardiac Repolarization in Healthy Participants: Thorough QT/QTc Study.

Maribavir is an orally bioavailable benzimidazole riboside in clinical development for treatment of cytomegalovirus infection in patients who undergo transplantation. Maribavir was evaluated in a thorough QT (TQT) study to determine any effects on cardiac repolarization. The effect of maribavir 100 and 1,200 mg oral doses on the baseline-adjusted and placebo-adjusted corrected QT (QTc) interval (delta delta QTc (ddQTc)) and other electrocardiogram (ECG) parameters was assessed in a randomized, phase I, placebo-controlled, four-period crossover study in healthy participants (men and women ages 18-50 years). Additionally, maribavir pharmacokinetics, safety, and tolerability were investigated. Moxifloxacin (400 mg) was used as a positive control to demonstrate the study's ability to detect QT prolongation. Digital 12-lead Holter ECG monitoring was performed over 22 hours following study drug administration. Individual, Fridericia's, and Bazett's QTc intervals were calculated. Of 52 randomized participants (29 ± 8.1 years old; 31 men (60%)), 50 (96%) completed the study. For both 100-mg and 1200-mg doses of maribavir, analysis of ddQTc demonstrated that the upper bound of the two-sided 90% confidence interval was below the 10-ms threshold at all time points. The concentration-effect analysis demonstrated no relationship between ddQTc and plasma concentrations of maribavir (and its metabolite). There were no clinically meaningful changes in heart rate and systolic blood pressure. The most common adverse event was dysgeusia; no serious adverse events were reported. This TQT study demonstrated that maribavir did not have impact on cardiac repolarization.

Immunosuppressive agents for treating IgA nephropathy.

BACKGROUND: IgA nephropathy is the most common glomerulonephritis world-wide. IgA nephropathy causes end-stage kidney disease (ESKD) in 15% to 20% of affected patients within 10 years and in 30% to 40% of patients within 20 years from the onset of disease. This is an update of a Cochrane review first published in 2003 and updated in 2015. OBJECTIVES: To determine the benefits and harms of immunosuppression strategies for the treatment of IgA nephropathy. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 9 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs of treatment for IgA nephropathy in adults and children and that compared immunosuppressive agents with placebo, no treatment, or other immunosuppressive or non-immunosuppressive agents. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study risk of bias and extracted data. Estimates of treatment effect were summarised using random effects meta-analysis. Treatment effects were expressed as relative risk (RR) and 95% confidence intervals (95% CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Risks of bias were assessed using the Cochrane tool. Evidence certainty was evaluated using GRADE methodology. MAIN RESULTS: Fifty-eight studies involving 3933 randomised participants were included. Six studies involving children were eligible. Disease characteristics (kidney function and level of proteinuria) were heterogeneous across studies. Studies evaluating steroid therapy generally included patients with protein excretion of 1 g/day or more. Risk of bias within the included studies was generally high or unclear for many of the assessed methodological domains. In patients with IgA nephropathy and proteinuria > 1 g/day, steroid therapy given for generally two to four months with a tapering course probably prevents the progression to ESKD compared to placebo or standard care (8 studies; 741 participants: RR 0.39, 95% CI 0.23 to 0.65; moderate certainty evidence). Steroid therapy may induce complete remission (4 studies, 305 participants: RR 1.76, 95% CI 1.03 to 3.01; low certainty evidence), prevent doubling of serum creatinine (SCr) (7 studies, 404 participants: RR 0.43, 95% CI 0.29 to 0.65; low certainty evidence), and may lower urinary protein excretion (10 studies, 705 participants: MD -0.58 g/24 h, 95% CI -0.84 to -0.33;low certainty evidence). Steroid therapy had uncertain effects on glomerular filtration rate (GFR), death, infection and malignancy. The risk of adverse events with steroid therapy was uncertain due to heterogeneity in the type of steroid treatment used and the rarity of events. Cytotoxic agents (azathioprine (AZA) or cyclophosphamide (CPA) alone or with concomitant steroid therapy had uncertain effects on ESKD (7 studies, 463 participants: RR 0.63, 95% CI 0.33 to 1.20; low certainty evidence), complete remission (5 studies; 381 participants: RR 1.47, 95% CI 0.94 to 2.30; very low certainty evidence), GFR (any measure), and protein excretion. Doubling of serum creatinine was not reported. Mycophenolate mofetil (MMF) had uncertain effects on the progression to ESKD, complete remission, doubling of SCr, GFR, protein excretion, infection, and malignancy. Death was not reported. Calcineurin inhibitors compared with placebo or standard care had uncertain effects on complete remission, SCr, GFR, protein excretion, infection, and malignancy. ESKD and death were not reported. Mizoribine administered with renin-angiotensin system inhibitor treatment had uncertain effects on progression to ESKD, complete remission, GFR, protein excretion, infection, and malignancy. Death and SCr were not reported. Leflunomide followed by a tapering course with oral prednisone compared to prednisone had uncertain effects on the progression to ESKD, complete remission, doubling of SCr, GFR, protein excretion, and infection. Death and malignancy were not reported. Effects of other immunosuppressive regimens (including steroid plus non-immunosuppressive agents or mTOR inhibitors) were inconclusive primarily due to insufficient data from the individual studies in low or very low certainty evidence. The effects of treatments on death, malignancy, reduction in GFR at least of 25% and adverse events were very uncertain. Subgroup analyses to determine the impact of specific patient characteristics such as ethnicity or disease severity on treatment effectiveness were not possible. AUTHORS' CONCLUSIONS: In moderate certainty evidence, corticosteroid therapy probably prevents decline in GFR or doubling of SCr in adults and children with IgA nephropathy and proteinuria. Evidence for treatment effects of immunosuppressive agents on death, infection, and malignancy is generally sparse or low-quality. Steroid therapy has uncertain adverse effects due to a paucity of studies. Available studies are few, small, have high risk of bias and generally do not systematically identify treatment-related harms. Subgroup analyses to identify specific patient characteristics that might predict better response to therapy were not possible due to a lack of studies. There is no evidence that other immunosuppressive agents including CPA, AZA, or MMF improve clinical outcomes in IgA nephropathy.

Efficacy and Safety of a Quadruple Regimen Compared with Triple Regimens in Patients with Mycophenolic Acid-Related Gastrointestinal Complications After Renal Transplantation: A Short-Term Single-Center Study.

BACKGROUND At present, there is no ideal conventional triple regimen that can effectively treat gastrointestinal (GI) complications in patients after kidney transplantation. We aimed to investigate the efficacy and safety of a quadruple regimen including standard-dose tacrolimus, low-dose enteric-coated mycophenolate sodium (EC-MPS), low-dose mizoribine (MZR), and corticosteroids, compared with regimens containing standard-dose tacrolimus, corticosteroids, plus either low-dose EC-MPS or standard-dose MZR in patients with mycophenolic acid (MPA)-related GI complications after renal transplantation. MATERIAL AND METHODS Between August 2016 and October 2018 in Qilu Hospital of Shandong University, 115 living donor kidney transplant recipients with MPA-related GI complications were enlisted in a single-center, prospective, randomized, control study. Thirty-six recipients were assigned to the low-dose EC-MPS plus low-dose MZR group, 37 recipients were assigned to the low-dose EC-MPS group, and 39 recipients were assigned to the standard-dose MZR group. We analyzed the Gastrointestinal Symptom Rating Scale (GSRS), estimated glomerular filtration rate (eGFR), graft rejection, serum creatinine, human leukocyte antigen (HLA) antibody, and the occurrence of adverse events among the 3 groups. RESULTS Compared with baseline, gastrointestinal symptoms improved significantly in all 3 groups. The reduction in mean subscale scores from baseline to month 3 was more significant in the standard-dose MZR group compared with the other 2 groups. The low-dose EC-MPS plus low-dose MZR group had better renal function. The incidence of graft rejection and cytomegalovirus (CMV) and polyomavirus BK (BKV) infection, as well as the incidence of hyperuricemia, in the low-dose EC-MPS plus low-dose MZR group were all significantly reduced. CONCLUSIONS This quadruple regimen may be equivalent to regimens containing standard-dose tacrolimus, corticosteroids plus either low-dose EC-MPS or standard-dose MZR in improving GI symptoms after kidney transplant, and is also advantageous for kidney function, graft rejection, and the rates of adverse events.

A case of anti-neutrophil cytoplasmic antibody-associated vasculitis with anti-glomerular basement membrane antibodies that was successfully treated with mizoribine as a safe and effective remission maintenance therapy with prednisolone and plasma exchange.

We herein report the case of myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis with anti-glomerular basement membrane (anti-GBM) antibody positivity that successfully treated with mizoribine (MZR) as an immunosuppressive drug for remission maintenance therapy after the initiation of dialysis in addition to plasma exchange (PE) and glucocorticoid treatment to control the disease condition. A 79-year-old woman developed serious renal dysfunction and pulmonary alveolar hemorrhaging due to MPO-ANCA and anti-GBM antibody double-positive vasculitis. She was started on hemodialysis and was treated with methylprednisolone (m-PSL) pulse therapy with PE, followed by oral prednisolone (PSL). The pulmonary alveolar hemorrhaging disappeared, and both antibody titers immediately decreased but then rose again. Thus, m-PSL pulse therapy performed again in combination with combined with MZR treatment. Her poor renal function was irreversible; however, this therapy decreased both antibody titers, and they did not increase again. The patient developed pancytopenia and hyperuricemia. It was considered likely that these conditions developed in association with MZR treatment. We, therefore, measured the patient's blood concentration of MZR, and the maintenance dose was finally set at 50 mg after each dialysis session. The patient's pancytopenia and hyperuricemia improved and PSL could be smoothly tapered. This is the first case report of the use of MZR for remission maintenance therapy in a patient on hemodialysis who was positive for both ANCA and anti-GBM antibodies. The findings suggest that MZR can be used safely and effectively in such cases.

Maribavir for Preemptive Treatment of Cytomegalovirus Reactivation.

BACKGROUND: Maribavir is a benzimidazole riboside with activity against cytomegalovirus (CMV). The safety and efficacy of maribavir for preemptive treatment of CMV infection in transplant recipients is not known. METHODS: In a phase 2, open-label, maribavir dose-blinded trial, recipients of hematopoietic-cell or solid-organ transplants (≥18 years of age, with CMV reactivation [1000 to 100,000 DNA copies per milliliter]) were randomly assigned to receive maribavir at a dose of 400, 800, or 1200 mg twice daily or the standard dose of valganciclovir for no more than 12 weeks. The primary efficacy end point was the percentage of patients with a response to treatment, defined as confirmed undetectable CMV DNA in plasma, within 3 weeks and 6 weeks after the start of treatment. The primary safety end point was the incidence of adverse events that occurred or worsened during treatment. RESULTS: Of the 161 patients who underwent randomization, 159 received treatment, and 156 had postbaseline data available - 117 in the maribavir group and 39 in the valganciclovir group. The percentage of patients with postbaseline data available who had a response to treatment within 3 weeks was 62% among those who received maribavir and 56% among those who received valganciclovir. Within 6 weeks, 79% and 67% of patients, respectively, had a response (risk ratio, 1.20; 95% confidence interval, 0.95 to 1.51). The percentages of patients with a response to treatment were similar among the maribavir dose groups. Two patients who had a response to treatment had a recurrence of CMV infection within 6 weeks after starting maribavir at a dose of 800 mg twice daily; T409M resistance mutations in CMV UL97 protein kinase developed in both patients. The incidence of serious adverse events that occurred or worsened during treatment was higher in the maribavir group than in the valganciclovir group (52 of 119 patients [44%] vs. 13 of 40 [32%]). A greater percentage of patients in the maribavir group discontinued the trial medication because of an adverse event (27 of 119 [23%] vs. 5 of 40 [12%]). A higher incidence of gastrointestinal adverse events was reported with maribavir, and a higher incidence of neutropenia was reported with valganciclovir. CONCLUSIONS: Maribavir at a dose of at least 400 mg twice daily had efficacy similar to that of valganciclovir for clearing CMV viremia among recipients of hematopoietic-cell or solid-organ transplants. A higher incidence of gastrointestinal adverse events - notably dysgeusia - and a lower incidence of neutropenia were found in the maribavir group. (Funded by ViroPharma/Shire Development; EudraCT number, 2010-024247-32.).

Assessment of factors associated with mizoribine responsiveness in children with steroid-dependent nephrotic syndrome.

BACKGROUND: Several immunosuppressants have been used to treat children with steroid-dependent nephrotic syndrome (SDNS). Mizoribine (MZR) is an immunosuppressant used to maintain remission in children with SDNS, although its effectiveness for treating SDNS remains controversial. Therefore, in this study, we assessed the clinical factors associated with children having SDNS who were successfully treated with MZR. METHODS: A total of 47 children with SDNS who underwent MZR treatment were retrospectively evaluated. Clinical features including pharmacokinetics after MZR administration were compared between MZR responders and non-responders. RESULTS: The comparison of the two groups revealed no significant differences in age, body weight (BW), daily dose of MZR per BW, serum concentration 2 h after administration (C2), peak serum concentration (Cmax), and area under the concentration curve 0-4 h after administration (AUC0-4). C2/(single dose/BW), Cmax/(single dose/BW), and AUC0-4/(single dose/BW) were significantly higher in the MZR responders than in the non-responders (all p < 0.01). Receiver operating characteristic analysis revealed that the cutoff values of C2 (single dose/kg), Cmax/(single dose/BW), and AUC0-4/(single dose/BW) were 0.55, 0.58, and 1.37, respectively. CONCLUSIONS: MZR is a useful immunosuppressant for treating frequent-relapse NS in children who are susceptible to the drug. The efficacy of MZR may be associated with not only serum concentrations defined by the dosage or absorption efficiency through MZR transporters, but also the susceptibility defined by the expression level and performance of MZR transporters on the target cells.

Hyperuricemia in Living Donor Kidney Transplantation Patients During Mizoribine Administration Caused Mainly by Changes in Kidney Function.

BACKGROUND: Although mizoribine (MZR) is used as an immunosuppressant after renal transplantation, the occurrence of hyperuricemia has been reported. The onset of hyperuricemia is often observed within the first several months after surgery. Since MZR is a renal excretion-type drug excreted as an unchanged drug from the kidneys, MZR blood concentrations may rise due to the influence of renal function. We investigated whether the onset of hyperuricemia after MZR administration was associated with the direct effect of a change in renal function. METHODS: Serum uric acid (serum UA), serum creatinine (sCr), serum ß2-microglobulin (serum ß2-MG), and serum cystatin C (serum Cys-C) were measured for about 3 months in 22 subjects. Correlation coefficients were calculated using the change rates of serum UA and sCr (Δ serum UA, Δ sCr), serum UA and serum ß2-MG (Δ serum UA, Δ serum ß2-MG), and serum UA and serum Cys-C (Δ serum UA, Δ serum Cys-C) at the onset of hyperuricemia. RESULTS: The correlation coefficients between Δ serum UA and Δ sCr, Δ serum UA and Δ serum ß2-MG, and Δ serum UA and Δ serum Cys-C were 0.723 (P < .001), 0.863 (P < .001) and 0.548 (P < .001), respectively. Further, serum UA and sCr level reached their highest peak on the same day after MZR administration, and the behavior was mostly consistent. CONCLUSION: It was suggested that hyperuricemia occurred about 3 months after MZR administration due mainly to temporary changes in kidney function.

Positive effects of single-daily high-dose mizoribine therapy after cyclophosphamide in young children with steroid-dependent nephrotic syndrome.

BACKGROUND: Mizoribine (MZR) therapy after cyclophosphamide (CPM) therapy may be an attractive option in patients with steroid-dependent nephrotic syndrome (SDNS) for the purpose of maintaining remission. This is because CPM is administered only once due to its severe side effects such as gonadal toxicity. However, the long-term prognosis after the treatment regimen remains unknown. METHODS: We retrospectively analyzed the clinical course (median follow-up, 5.9 years) of 54 young children with SDNS (43 boys; age < 10 years) who had undergone 12-week CPM therapy. The patients were classified into two groups: group A, undergoing MZR therapy for > 12 months for maintaining remission after CPM therapy (N = 36), and group B, undergoing CPM monotherapy (N = 18). RESULTS: For 2 years after CPM therapy, 21 of the 36 group A patients were in sustained remission, whereas only 4 of the 18 group B patients had maintained remission (58% vs. 22%, p < 0.05). Furthermore, the rate of regression to SDNS after CPM was significantly lower in group A than in group B (6% vs. 39%, p < 0.05). At the last follow-up (mean age, 10.9 years), 27 of the 36 group A patients (75%) had not received any steroid-sparing agent after the treatment regimen. CONCLUSIONS: Single daily high-dose MZR therapy after CPM therapy may have positive outcomes in young children with SDNS in the long term.

Combination therapy with or without warfarin and dipyridamole for severe childhood IgA nephropathy: an RCT.

BACKGROUND: Two previous randomized controlled trials showed that treatment of severe childhood immunoglobulin A (IgA) nephropathy using prednisolone with azathioprine, heparin-warfarin, or dipyridamole prevented the increase of sclerosed glomeruli. Prednisolone alone, however, did not prevent further increase. These studies indicated the importance of immunosuppressants in the treatment. An additional pilot study using mizoribine instead of azathioprine enabled us to complete 2 years of combined regimen. It showed non-numerical inferior effectiveness compared with the azathioprine regimen. Further examination of the additional efficacy of warfarin and dipyridamole was required. METHODS: A randomized control trial of prednisolone and mizoribine with (group 1) or without (group 2) warfarin and dipyridamole was administered for treatment of 71 children with severe IgA nephropathy to evaluate the efficacy of additional warfarin and dipyridamole. RESULTS: Thirty of 34 patients (88.2%) in group 1, and 27 of 36 patients (75.0%) showed the disappearance of proteinuria as defined by early morning urinary protein to creatinine ratio of < 0.2 during the 2-year treatment period. The cumulative disappearance rate of proteinuria determined by the Kaplan-Meier method showed that the disappearance rate of proteinuria was significantly higher in group 1 than in group 2 (log-rank P = 0.04). There was no significant difference in pathological findings, but there was a tendency of increase of global sclerosis in group1 which might be related to warfarin. Most of the adverse effects were related to prednisolone, but fortunately transient. CONCLUSIONS: The balance between minimal benefits of warfarin/dipyridamole and potential adverse effects may be in favor of avoiding them in children with IgA nephropathy.

The first year results of mizoribine/tacrolimus-based multitarget treatment for consecutive patients with lupus nephritis.

BACKGROUND: Despite the high efficacy of mycophenolate mofetil (MMF)/tacrolimus-based multitarget treatment, risks of infections are a matter of concern. In the present study, we clarified the potential of multitarget therapy using mizoribine opposed to MMF. METHODS: A total of 36 patients with biopsy-proven lupus nephritis were treated with mizoribine, tacrolimus, and glucocorticoids and then retrospectively evaluated. To determine the efficacy, proteinuria remission (≤ 0.2 g/day), complete remission (Liu et al. in Ann Intern Med 162:18-26, 2015) and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) remission rates, and the prednisolone dose at months 6 and 12 were evaluated. The associations between serum mizoribine/tacrolimus levels and clinical parameters were investigated. To assess safety, adverse events were inspected. RESULTS: All patients could continue the original treatment regimen without withdrawal or exacerbations through month 12. At month 6, the proteinuria remission, complete remission, SLEDAI remission rates, and prednisolone dose were 69, 53, 36%, and 12.1 mg/day, respectively, whereas the values at 12 months were 92, 67, 50%, and 8.8 mg/day, respectively. The treatment was efficacious for every histologic type of nephritis and non-renal manifestations of SLE. Excluding one patient who was hospitalized due to upper respiratory tract infection, serious infections, including pneumonia and cytomegalovirus disease, were not observed. Higher trough tacrolimus levels were associated with normalization of complement, whereas higher peak mizoribine levels with prevention of cytomegalovirus viremia. CONCLUSIONS: Our results suggest that multitarget therapy using mizoribine opposed to MMF is highly safe and effective through 12 months. The therapy may enable faster dose reduction of concomitant glucocorticoids.

A computational approach for predicting off-target toxicity of antiviral ribonucleoside analogues to mitochondrial RNA polymerase.

In the development of antiviral drugs that target viral RNA-dependent RNA polymerases, off-target toxicity caused by the inhibition of the human mitochondrial RNA polymerase (POLRMT) is a major liability. Therefore, it is essential that all new ribonucleoside analogue drugs be accurately screened for POLRMT inhibition. A computational tool that can accurately predict NTP binding to POLRMT could assist in evaluating any potential toxicity and in designing possible salvaging strategies. Using the available crystal structure of POLRMT bound to an RNA transcript, here we created a model of POLRMT with an NTP molecule bound in the active site. Furthermore, we implemented a computational screening procedure that determines the relative binding free energy of an NTP analogue to POLRMT by free energy perturbation (FEP), i.e. a simulation in which the natural NTP molecule is slowly transformed into the analogue and back. In each direction, the transformation was performed over 40 ns of simulation on our IBM Blue Gene Q supercomputer. This procedure was validated across a panel of drugs for which experimental dissociation constants were available, showing that NTP relative binding free energies could be predicted to within 0.97 kcal/mol of the experimental values on average. These results demonstrate for the first time that free-energy simulation can be a useful tool for predicting binding affinities of NTP analogues to a polymerase. We expect that our model, together with similar models of viral polymerases, will be very useful in the screening and future design of NTP inhibitors of viral polymerases that have no mitochondrial toxicity.

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.

Acute Inflammatory Syndrome Paradoxically Induced by De Novo Purine Inhibitors Synthesis Before Renal Transplantation: A Case Report and Review of the Literature.

BACKGROUND: Mycophenolate mofetil (MMF) and mizoribine (MZR) are increasingly used as immunosuppressive agents for organ transplantation and chronic inflammation. We report a patient with rheumatoid arthritis who had an acute inflammatory syndrome triggered by preoperative immunosuppression therapy with both MMF and MZR. CASE REPORT: A 41-year-old woman with IgA nephropathy was referred to our department for living donor renal transplantation. She had rheumatoid arthritis that was adequately treated with prednisolone 5 mg once a day and salazosulfapyridine 2000 mg once a day. MMF 1000 mg twice a day was started for desensitization therapy. Three days later, the patient developed arthritis in the joints of her left hand and elevated inflammatory markers. On day 7, MMF was switched to MZR 150 mg 3 times a day. However, the symptoms extended to both shoulders and the joints of the right foot; MZR was discontinued. The arthritis and inflammatory markers improved. Two months later, the patient was rechallenged with MMF followed by MZR, resulting in a similar clinical course as previously. Tacrolimus (TAC) 3 mg twice a day and everolimus (EVL) 0.5 mg twice a day were introduced as alternative immunosuppressant therapies. No arthritis occurred. ABO-compatible living donor renal transplantation was successfully performed. The patient received TAC, EVL, prednisolone, rituximab, and basiliximab, and her postoperative course was uneventful without arthritis or rejection. At 9 months postoperatively, the serum creatinine was 0.79 mg/dL. CONCLUSIONS: Acute inflammatory syndrome is an extremely rare complication triggered by preoperative immunosuppression therapy. If antimetabolites cannot be used in immunologically high-risk patients, transplantation becomes very difficult. Clinicians should keep in mind this paradoxical reaction.

Post-marketing surveillance study of the long-term use of mizoribine for the treatment of lupus nephritis: 2-Year results.

OBJECTIVES: To understand the status of mizoribine use in patients with lupus nephritis (LN) and to collect safety- and efficacy-related data on 2-year treatment with mizoribine. METHODS: A continuous survey was conducted between March 2010 and July 2015. RESULTS: The analysis set included 559 patients (mean age 39.5 years, females 82.6%, mean duration of systemic lupus erythematosus (SLE) 8.4 years, mean duration of LN 5.9 years). Renal function was satisfactory for 6 months, but worsened from 12 months, with significant worsening at 24 months. By the ACR 2006 remission criteria (eGFR >60), at 24 months, 26.5% of patients achieved complete remission, and 63.3% achieved complete or partial remission. The urine protein to creatinine ratio decreased significantly. The SLE Disease Activity Index 2000 score decreased significantly at 12 and 24 months. Overall, 98 (17.5%) patients experienced 124 adverse drug reactions (ADRs); 3.6% experienced serious ADRs. Mizoribine was used with a steroid in 99.3% and an immunosuppressant in 51.2%; tacrolimus was used in 43.8%. The oral steroid dosage decreased from baseline to 24 months. The incidence of ADRs was not significantly different with concomitant tacrolimus use. CONCLUSIONS: The results suggest that long-term mizoribine is safe and effective, even when used with tacrolimus.

High-dose mizoribine combined with calcineurin inhibitor (cyclosporine or tacrolimus), basiliximab and corticosteroids for renal transplantation: A Japanese multicenter study.

OBJECTIVE: To evaluate the utility and safety of high-dose mizoribine combination therapy using cyclosporine and tacrolimus as calcineurin inhibitors in patients undergoing kidney transplant. METHODS: The present study enrolled 156 patients who received kidney transplants in 18 institutions between 2009 and 2013. ABO-incompatible and/or pre-sensitized recipients were excluded. Immunosuppression used cyclosporine (88) or tacrolimus (68) as a calcineurin inhibitor, and the dosage was adjusted based on blood concentrations. Mizoribine was started at 6 mg/kg/day, and the target trough level was 1-2 ng/mL. Primary efficacy end-points of this study were 2-year patient survival, 2-year graft survival and the acute rejection rate within 2 years after transplantation. RESULTS: The 2-year patient and graft survival rates in the cyclosporine group were 98.9% and 94.3%, respectively, whereas those in the tacrolimus group were 100% and 98.5%, respectively, with no significant difference between groups. Rates of onset of rejection during the observation period were also equivalent, at 22.7% in the cyclosporine group and 17.6% in the tacrolimus group. Furthermore, groups showed no significant differences in transplanted renal function. No notable differences in adverse events were observed between groups. CONCLUSIONS: A regimen of high-dose mizoribine in combination with calcineurin inhibitors basiliximab, and corticosteroids can provide effective immunosuppression while lowering the rate of cytomegalovirus infection in kidney transplant patients.