Benefits of cyclosporine absorption profiling in nephrotic syndrome: preprandial once-daily administration of cyclosporine microemulsion improves slow absorption and can standardize the absorption profile

Cyclosporine A C1.5 monitoring reflects the area under the curve in children with nephrotic syndrome: a single-center experience

BACKGROUND

The currently used single-monitoring method for drug-blood-level evaluation in cyclosporine A (CsA) treatment for nephrotic syndrome (NS) was established through hourly measurements based on adult organ transplantation. However, the pharmacokinetics may differ due to different concomitant medications, age, and conditions. This study was conducted to determine the measurement timing that best reflects the CsA area under the curve (AUC) in pediatric NS.

METHODS

This retrospective study included children aged 2-14 years who were started on CsA treatment for idiopathic NS during 2013-2020. AUC_0-4 was calculated from 7 points, before and 0.5, 1, 1.5, 2, 3, and 4 h after administration. Mean values at each timing were compared with age-dependent different drug forms. Correlation between AUC_0-4 and measurement timing was analyzed.

RESULTS

There were 13 patients (11 boys) whose median age during testing was 7.3 years, and the total number of measurements was 94. The highest timing of CsA concentrations was found in C₁ 59.6%. The content liquid used at younger ages had a faster absorption time to peak value and lower blood concentration than those of capsules. Among the significant correlations observed, AUC_0-4 and C_1.5 showed the strongest significant correlation coefficient (r = 0.93, P < 0.001).

CONCLUSION

In pediatric NS, CsA metabolism may be faster than that in previous organ transplantation. Compared with C₂, C_1.5 monitoring may result in better disease control as it can best reflect the AUC_0-4 and peak values associated with side effects, which are indicators of therapeutic efficacy.

Population Pharmacokinetic Approach to the Use of Low Dose Cyclosporine in Patients with Connective Tissue Diseases

This study describes the population pharmacokinetics and dose personalization of cyclosporine in 36 patients with connective tissue diseases. A one-compartment open model with absorption was adopted as a pharmacokinetic model, and a nonlinear mixed effects model was used to analyze the population pharmacokinetic models. In the final model, age (AGE) and total body weight (TBW) were influential covariates on clearance (CL/F), which was expressed as CL/F (L/h)=17.8×(AGE/60)(-0.269)×(TBW/46.9)(0.408), in addition to the volume of distribution (Vd/F), (L)=98.0 and absorption rate constant (Ka) (h(-1))=0.67 (fixed). The results of the present study provide novel insights into factors involved in determining the most suitable dose and dosing strategy for individual patients with connective tissue disease.

Pharmacokinetics of cyclosporine a conversion from twice-daily infusion to oral administration in allogeneic hematopoietic stem cell transplantation

Twice-daily administration of cyclosporine A (CyA) has often been used for prophylaxis of acute graft versus host disease in allogeneic hematopoietic stem cell transplantation (allo-HSCT). But there have not been any reports that calculated the conversion ratio of the switch from twice-daily intravenous infusion to oral administration of CyA in adult patients. To establish the conversion ratio and the best strategy of twice-daily administration of CyA, the authors investigated the serial changes in the blood CyA concentration during the switch from twice-daily intravenous infusion to oral administration while maintaining high-peak concentration (over 1000 ng/mL) and calculated the bioavailability of Neoral, a micro emulsion cyclosporine, in 11 patients. All the patients underwent allo-HSCT with graft versus host disease prophylaxis consisting of CyA at a high-peak concentration of twice-daily infusion with short-term methotrexate and oral administration. Neoral was started at an oral dose, 2 times daily, at twice the latest dose of intravenous dose according to the bioavailability of healthy volunteers. Micafungin, a mild inhibitor of CYP3A4, was administered for prophylaxis against fungal infection. The total area under the concentration-time curve during oral administration (AUCpo) was nearly the same as AUC during intravenous infusion (AUCiv) (mean ± SD, 7206 ± 1557 ng·h·mL and 7783 ± 897.7 ng·h·mL, respectively). The bioavailability of Neoral, defined as F = AUCpo × DOSEiv/AUCiv × DOSEpo was 0.58 ± 0.15 (mean ± SD, range: 0.41-0.94). When patients were switched from twice-daily infusion to oral administration, the dose conversion ratio of 1:2 seemed to be appropriate. At that time, the target trough level of Neoral was nearly the same as that of the infusion.

Use of Cyclosporine Therapy in Steroid Resistant Nephrotic Syndrome (SRNS): A Review

A chronic, progressive disorder Steroid Resistant Nephrotic Syndrome (SRNS) accounts for 10-20% of all children with Nephrotic Syndrome. It is a heterogeneous disorder comprised of persistent edema, proteinuria, hypoalbuminemia and hyperlipidemia. Treatment for steroid-resistant nephrotic syndrome (SRNS) is challenging and children who suffer from SRNS require aggressive treatment to achieve remission. Calcineurin inhibitors have been used more in an empirical manner than on the basis of clear rationale. It was in 1984 when cyclosporine was first considered for the treatment of steroid resistant nephrotic syndrome. Cyclosporin is a calcineurin inhibitor that suppresses immune response by downregulating the transcription of various cytokine genes. Till now many studies have been conducted to determine dosages, duration of therapy, side effects and advantages of cyclosporine. Treatment of SRNS remains a difficult challenge in pediatric nephrology.  Treatment should be individualized according to the underlying histopathology, and clinical and environmental conditions of the children. There is an urgent need to distinguish as soon as possible those patients who may benefit from prolonged immunosuppressive treatment from those who will not benefit from such treatment and who will just suffer from its major side effects. The emerging evidence that the majority of genetic forms of SRNS should receive symptomatic treatment only, should also be clinically tested and studies baring its significance should be evaluated in the future.

Significance of combined cyclosporine-prednisolone therapy and cyclosporine blood concentration monitoring for idiopathic membranous nephropathy with steroid-resistant nephrotic syndrome: a randomized controlled multicenter trial

Background

Combined treatment with cyclosporine microemulsion preconcentrate (CyA MEPC) and steroids has been widely used for idiopathic membranous nephropathy (IMN) associated with steroid-resistant nephrotic syndrome (SRNS). Recent studies have shown that once-a-day and preprandial administration of CyA MEPC is more advantageous than the conventional twice-a-day administration in achieving the target blood CyA concentration at 2 h post dose (C2). We designed a randomized trial to compare these administrations.

Methods

IMN patients with SRNS (age 16–75 years) were divided prospectively and randomly into 2 groups. In group 1 (n = 23), 2–3 mg/kg body weight (BW) CyA MEPC was given orally once a day before breakfast. In group 2 (n = 25), 1.5 mg/kg BW CyA MEPC was given twice a day before meals. CyA + prednisolone was continued for 48 weeks.

Results

Group 1 showed a significantly higher cumulative complete remission (CR) rate (p = 0.0282), but not when incomplete remission 1 (ICR1; urine protein 0.3–1.0 g/day) was added (p = 0.314). Because a C2 of 600 ng/mL was determined as the best cut-off point, groups 1 and 2 were further divided into subgroups A (C2 ≥600 ng/mL) and B (C2 <600 ng/mL). Groups 1A and 2A revealed significantly higher cumulative remission (CR + ICR1) (p = 0.0069) and CR-alone (p = 0.0028) rates. On the other hand, 3 patients with high CyA levels (C2 >900 ng/mL) in Group 1A were withdrawn from the study because of complications.

Conclusion

CyA + prednisolone treatment is effective for IMN with associated SRNS at a C2 of ≥600 ng/mL. To achieve remission, preprandial once-a-day administration of CyA at 2–3 mg/kg BW may be the most appropriate option. However, we should adjust the dosage of CyA by therapeutic drug monitoring to avoid complications.

[Successful cyclosporine treatment in 2 patients with refractory CIDP, involving monitoring of both AUC(0-4h) and trough levels]

Cyclosporine A (CYA) treatment has been reported to be probably useful for patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) that is resistant to conventional treatment. Although several studies have shown that appropriate area under the concentration-time curve (AUC) monitoring of CYA levels results in improved outcomes for refractory nephrotic syndrome patients, the importance of using AUC analysis for CIDP remains unclear. In this study, we measured both trough and AUC from 0 to 4 h (AUC(0-4 h)) levels of CYA in 2 patients with CIDP and compared the findings for the clinical parameters. On the basis of the CYA dosing recommendations for patients with nephrotic syndrome, we used a CYA concentration of 150 ng/ml for the trough level and an AUC(0-4 h) value of 2,500 ng/(ml·h). Patient 1 showed a significant increase in grip strength and a prolonged remission period. Patient 2 showed improvement in the modified Rankin scale and manual muscle test (MMT) scores. Monitoring both AUC(0-4 h) and trough levels of CYA seems to be a better option than monitoring the trough level alone because it leads to improved estimation of the efficacy and safety of CYA treatment in the case of CIDP patients.

Age effect on whole blood cyclosporine concentrations following oral administration in children with nephrotic syndrome

The aim of this study was to investigate age-related pharmacokinetic differences of cyclosporine (CyA) in children with nephrotic syndrome. Whole blood concentrations of CyA were monitored for a total of 96 times in 36 cases. The 25 male and 11 female patients ranged in age from 1.9 to 19.7 years with a mean age of 9.1 years. Renal biopsy showed minimal change in 33 patients and focal segmental glomerulosclerosis in three patients. CyA was orally administered in two divided doses just before meals. The doses of CyA administered were adjusted such that the target value for blood concentration at 2 h post-dose (C2) was 400-450 ng/ml. The 96 subjects were divided into three groups according to age: group I, 1-5 years (n = 30); group II, 6-10 years (n = 34); and group III, ≥ 11 years (n = 32). In all subjects, peak levels (Cmax) of CyA were reached at C1 or C2. There was no significant difference between the groups for C2, area under the whole blood concentration-time curve up to 4 h post-dose (AUC0-4), and Cmax. The mean CyA doses of groups I, II, and III were 4.8 ± 1.0 mg/kg/day, 3.8 ± 0.9 mg/kg/day, and 3.0 ± 0.6 mg/kg/day, respectively, and there were significant differences between every two groups. In addition, the dose-normalized Cmax (Cmax/dose) and AUC0-4 (AUC0-4/dose) values were significantly lower in the younger group than in the older group. These findings suggested that in children, when the same concentration is targeted, the required CyA dose would vary according to age but would be significantly higher for the younger children.

Novel multidrug therapy for children with cyclosporine-resistant or -intolerant nephrotic syndrome

An effective treatment for children with refractory nephrotic syndrome (NS), especially in those with cyclosporine (CsA)-resistant or CsA-intolerant NS, has yet to be established. Recently, the efficacy of multidrug therapy consisting of tacrolimus (Tac), mycophenolate mofetil (MMF) in combination with prednisolone (PDN) in adult patients with refractory NS has been reported. We successfully treated 14 consecutive children with refractory CsA-resistant or CsA-intolerant NS using combination therapy consisting of relatively low-dose Tac, mizoribine (MZR), which has a mechanism of action very similar to that of MMF, and PDN. There were no serious clinical toxicities. Of the 14 children, 9 with a mean age of 13.0 years had steroid-dependent NS (SDNS) and 5 with a mean age of 9.6 years had steroid-resistant NS (SRNS). All SDNS patients had minimal change disease (MCD), 4 with SRNS had focal segmental glomerulosclerosis (FSGS), and the remaining child had MCD on renal biopsy. All patients were in a prospective cohort, but were evaluated retrospectively. The mean follow-up from the initiation of multidrug therapy was 18.4 months in SDNS and 18.6 months in SRNS patients. At the last observation point, the calculated relapse rate and minimum dose of PDN required for maintenance of clinical remission after the start of multidrug therapy were significantly decreased compared with those prior to this therapy, while on CsA, in SDNS patients (0.4 ± 0.5 times/year vs 2.9 ± 1.5 times/year, P = 0.0077, and 0.3 ± 0.2 mg/kg on alternate days vs 0.5 ± 0.2 mg/kg on alternate days, P = 0.0184 respectively). All SDNS and two SRNS patients (40%) achieved complete remission, allowing further decreases in the minimal doses of PDN required for maintenance of clinical remission in most our patients. However, one patient with FSGS remained refractory to multidrug therapy and subsequently developed end-stage renal disease. These clinical observations, although preliminary and involving a small number of patients, suggest that multidrug therapy consisting of relatively low-dose Tac, MZR, and PDN might be effective and safe for treating children with refractory CsA-resistant or CsA-intolerant NS. However, further studies involving larger numbers of patients are needed.

A case of membranous nephropathy with primary biliary cirrhosis and cyclosporine-induced remission

We report a case of membranous nephropathy with primary biliary cirrhosis (PBC). A 76-year-old Japanese man had been treated for PBC and was referred to our department because of acute severe proteinuria (10 g/day). Renal biopsy was performed and was compatible with a diagnosis of membranous nephropathy. The patient was treated with cyclosporine A (CsA; Neoral®), which was followed by normalization of liver function and partial remission of proteinuria (0.68 g/day) within six months without any significant side effects. This case suggests that CsA monotherapy is effective for the treatment of both liver dysfunction and membranous nephropathy associated with PBC.

Benefits of once-daily administration of cyclosporine a for children with steroid-dependent, relapsing nephrotic syndrome

Cyclosporine A (CsA) is an effective steroid-sparing agent for patients with steroid-dependent, relapsing nephrotic syndrome (SDRNS). The efficacy and safety of single-daily dose administration (SDD protocol) of CsA in selected patients with SDRNS has been reported. However, the efficacy of initial CsA treatment for children with SDRNS using the SDD protocol remains to be elucidated. The SDD protocol might be associated with lower clinical toxicity, compared to the conventional twice-daily dose administration (TDD protocol). Here we evaluated the efficacy and safety of the SDD protocol versus the TDD protocol in patients with SDRNS. The data from 19 patients (9.9 +/- 4.2 years old) were retrospectively collected and analyzed. Ten patients treated according to the SDD protocol for a mean of 27 months (SDD group), while 9 patients treated with the TDD protocol for a mean of 35 months (TDD group) as an initial CsA treatment. Although the mean daily CsA dose was significantly lower in the SDD group (1.5 +/- 0.4 mg/kg/day vs. 3.7 +/- 0.7 mg/kg/day, P < 0.01), there were no differences between the two groups in the mean minimum dose of prednisolone required for maintenance of clinical remission nor in the calculated relapse rate. One patient in the TDD group developed biopsy-proven mild CsA nephrotoxicity, whereas no patient in the SDD group showed nephrotoxicity. Despite a small number of patients, this study may support that the SDD protocol is at least as effective as the conventional TDD protocol, and is more cost-effective for selected children with SDRNS.

Effect of cyclosporine and sirolimus on fatty acid desaturase activities in cultured HEPG2 cells

The aim of the present work was to evaluate the influence of cyclosporine (CsA) and sirolimus (SRL) on fatty acid (FA) desaturase activities. These enzymes (named Delta9, Delta6, and Delta5 desaturases) catalyze reactions leading to the biosynthesis of n-9, n-6, and n-3 FA families. n-3 FA family, derived from alpha-linolenic acid, is involved in the prevention of vascular events, which appear after successful kidney transplantation. Five groups of HepG(2) cells in culture were treated with either CsA (1 microg/microL and 2 microg/microL) or SRL (10 ng/mL and 20 ng/mL) for 3 days, including a control group without immunosuppressive treatment. We studied the incorporation and metabolic conversion of radioactive [1-(14)C]palmitic, linoleic, and eicosatrienoic acids. We also analyzed fatty acid composition. The distribution of radioactive metabolic products after incubation of these cells with [1-(14)C]palmitic acid revealed a decrease in Delta9 desaturase activity in the presence of each immunosuppressive drug: CsA = 0.61 +/- 0.01; SRL = 0.59 +/- 0.04 versus control = 0.79 +/- 0.05 (P < .01). We observed a significant increase in Delta6 and Delta5 desaturase activities under the influence of the immunosuppressive drugs: radiolabeled linoleic acid (CsA: 0.93 +/- 0.04; SRL: 1.02 +/- 0.03 vs control 0.60 +/- 0.03; P < .01) and eicosatrienoic acid (CsA: 1.12 +/- 0.02; SRL: 1.07 +/- 0.01 vs control 0.75 +/- 0.01; P < .01). In conclusion, CsA and SRL modulated the biosynthesis of polyunsaturated FAs, decreasing Delta9 desaturase and increasing Delta6 and Delta5 desaturase activities.

Population pharmacokinetic study of cyclosporine in patients with nephrotic syndrome

Cyclosporine (CsA) is widely used in the treatment of nephrotic syndrome (NS). A population pharmacokinetic (PopPK) model was developed using trough blood CsA concentration data from 106 patients with NS. The pharmacokinetic analysis was performed using NONMEM with 1-compartment linear model and first-order elimination. Proportional and additive error models were used to describe the interindividual and intraindividual variabilities, respectively. Body weight (WT), serum albumin level (ALB), and combination therapy with rifampicin were found to be the most significant covariates explaining the variability of the apparent clearance (CL/F) of CsA among patients. The final model was as follows: TVCL/F=34.1x(WT/67.6)(1.08)x(1+RFAx0.67)x(1-ALBx0.0088); TVV/F=3.5xWT; Ka=1.28 fixed; where RFA=1 with concurrent rifampicin use and 0 otherwise. The interindividual variabilities of CL/F and V/F were 18% and 27%, respectively. The residual error was 0.064 mg/L. The mean+/-SD of CL/F and V/F of the 106 patients were 23.5+/-7.2 L/h and 232.3+/-71.5 L, respectively. The reliability and stability of the PopPK model were confirmed by nonparametric bootstrap procedure.

Monitoring of blood cyclosporine concentration in steroid-resistant nephrotic syndrome

OBJECTIVE

Cyclosporine has been used for patients with nephrotic syndrome. Because of substantial inter- and intra-patient variability and a narrow therapeutic window, drug monitoring of cyclosporine is mandatory. To confirm the therapeutic effects of a cyclosporine microemulsion (CSAME), the absorption profile of the agent after preprandial administration was determined in steroid-resistant patients with refractory nephrotic syndrome.

METHODS

Fourteen patients were enrolled into the study (mean age, 31.2+/-12; 6 men, 8 women). The patients received 1.5 mg/kg of cyclosporine 30 minutes before breakfast for 6 months. Blood cyclosporine concentration was measured 5 times serially: before administration (C0) and at 1-hour intervals until 4 hours after administration of cyclosporine (C1-C4). In addition, area under the concentration-time curve from 0-4 hours (AUC0-4) was calculated.

RESULTS

After 6 months, CSAME showed marked improvement in proteinuria levels (8.3+/-4.8 g/day vs 0.8+/-0.4 g/day, p<0.001). No changes in serum creatinine and urea nitrogen levels were observed. In 83% of the patients, the CSAME peak concentration appeared within 1 hour after administration (C1). A strong positive correlation was noted between AUC0-4 and C1 (R2=0.90312) and C2 (R2=0.78431). The mean steroid (prednisolone) dose was 40 mg/day when CSAME treatment was started, but a lowering of the dose to 17.5 mg/day (p<0.001) was achieved at 6 months after CSAME therapy.

CONCLUSION

Preprandial administration of CSAME is effective in steroid-resistant patients with refractory nephrotic syndrome. C1 or C2, but not C0, was a good clinical marker for CSAME exposure.