Cyclosporin: an updated review of the pharmacokinetic properties, clinical efficacy and tolerability of a microemulsion-based formulation (neoral)1 in organ transplantation

Systemic Treatment With Cyclosporine A in Children With Severe Vernal Keratoconjunctivitis

PURPOSE

To report our experience with systemic cyclosporine as a treatment for severe vernal keratoconjunctivitis (VKC) in pediatric patients who did not respond to previous treatments.

METHODS

We analyzed the medical records of 6 patients, aged 4 to 15 years, with severe VKC treated with systemic cyclosporine for VKC at Shamir Medical Center in Zerifin, Israel, between the years 2000 and 2023. The average treatment duration was 18 months. In all patients, previous treatments with antihistamines, mast cells stabilizers, topical steroids and topical cyclosporine, and systemic steroids did not result in sufficient improvement. The severity of inflammation was evaluated during clinical examinations and the patients' subjective assessment of their quality of life.

RESULTS

In all 6 patients, signs and symptoms showed significant improvement within 2 to 4 weeks of initiating systemic cyclosporine treatment. All patients were able to discontinue regular steroids use and reported a significant improvement in their quality of life. No significant side effects were observed in any of the patients.

CONCLUSIONS

Systemic cyclosporine is a safe and effective treatment for severe VKC. It is a steroid-sparing treatment that allows good quality of life, while keeping the disease latent.

Therapeutic drug monitoring in childhood idiopathic nephrotic syndrome: a state of the art review

Immunosuppressants are commonly used as steroid-sparing agents in childhood idiopathic nephrotic syndrome (NS) to induce and sustain remissions. These drugs have narrow therapeutic indices with high inter- and intra-patient variability. Therapeutic drug monitoring (TDM) would therefore be essential to guide the prescription. Multiple factors in NS contribute to additional variability in drug concentrations, especially during relapses. In this article, we review the currently available evidence of TDM in NS and suggest a practical approach for clinicians' reference.

Analysis of death avoidance by concomitant use of prednisone in patients with renal transplant using the Food and Drug Administration Adverse Event Reporting System

BACKGROUND

Patients with renal transplant are frequently administered immunosuppressants to prevent transplant-related adverse events. There are mainly nine immunosuppressants on the market, and multiple immunosuppressants are frequently administered for patients with renal transplant. Identifying which immunosuppressant was responsible when efficacy or safety was observed in patients taking multiple immunosuppressants is difficult. This study aimed to identify the immunosuppressant that was effective in reducing death in patients with renal transplant. A very large sample size was required to conduct prospective clinical trials of immunosuppressant combinations, which is impractical. We investigated cases wherein death occurred despite immunosuppressant administration in patients with renal transplant using Food and Drug Administration Adverse Event Reporting System (FAERS) data.

MATERIAL AND METHOD

We used FAERS data reported between January 2004 and December 2022 in patients with renal transplant who received one or more immunosuppressants. Groups were defined for each combination of immunosuppressants. Comparison between two identical groups except for the presence or absence of prednisone was performed using the reporting odds ratio (ROR) and the adjusted ROR (aROR) controlling for differences in patient background.

RESULTS

When the group without prednisone was set as the reference, the aROR for death was significantly <1.000 in several cases in the group to which prednisone was added.

CONCLUSIONS

The inclusion of prednisone in the immunosuppressant combinations was suggested to be effective in reducing death. We provided the sample code of software R that can reproduce the results.

Perfusion-Dependent Focal Neurologic Deficits in a Critically Ill Heart Transplant Recipient: A Case of Tacrolimus-Associated Reversible Cerebral Vasospasm Syndrome?

TACROLIMUS, a mainstay of immunosuppression after orthotopic heart transplantation (OHT), is associated with a broad range of side effects. Vasoconstriction caused by tacrolimus has been proposed as a mechanism underlying common side effects such as hypertension and renal injury. Neurologic side effects attributed to tacrolimus include headaches, posterior reversible encephalopathy syndrome (PRES), or reversible cerebral vasospasm syndrome (RCVS). Six case reports have been published describing RCVS in the setting of tacrolimus administration after OHT. The authors report a case of perfusion-dependent focal neurologic deficits attributed to tacrolimus-induced RCVS in an OHT recipient.

Optimizing the oral dose of cyclosporine with concomitant posaconazole post stem cell allograft

Cyclosporine is an immunosuppressive agent to prevent acute graft versus host disease (GVHD) in patients undergoing a stem cell allograft. It has a narrow therapeutic range, and its metabolism can be affected by posaconazole, commonly used as antifungal prophylaxis post allograft. There is limited evidence on the optimal oral cyclosporine starting dose in this setting. A delicate balance is required in dose adjustments to avoid toxic levels while maintaining sufficient drug concentrations to prevent GVHD. We undertook a retrospective audit of 28 patients undergoing their first allograft who received posaconazole and commenced on a starting oral cyclosporine dose of 2 mg/kg twice daily. Our key findings were that this starting dose was too high, with all patients experiencing at least one toxicity and an overall low incidence of GVHD.

Tacrolimus 4-hour monitoring in liver transplant patients is non-inferior to trough monitoring: The randomized controlled FK04 trial

BACKGROUND

After liver transplantation (LT), tacrolimus and ciclosporin treatment can lead to, partially concentration-dependent, chronic kidney disease. Monitoring ciclosporin with two-hour levels reduced overexposure and led to better renal function than trough-monitoring (C0). For tacrolimus, a 4-hour level (C4) can give a reasonable approximation of total drug exposure. We evaluated whether monitoring tacrolimus in stable patients after LT by C4 was superior to C0 regarding renal function, rejection and metabolic parameters.

METHODS

This open label randomized controlled trial compared C4 monitoring of tacrolimus BID (Prograft) to trough (C0) monitoring in stable LT recipients. The target range for C4 of 7.8-16 ng/ml was calculated to be comparable with target C0 of 4-8 ng/ml. Primary endpoint was the effect on renal function and secondary endpoints were the occurrence of treated biopsy-proven acute rejection, blood pressure and metabolic parameters, during 3 months of follow-up.

RESULTS

Fifty patients were randomized to C0 (n = 25) or C4 (n = 25) monitoring. There was no difference in renal function between the C0 and the C4 group (p = .98 and p = .13 for CG and MDRD at 3 months). Also, the amount of proteinuria was similar (p = .59). None of the patients suffered from graft loss or was treated for rejection. Metabolic parameters did not differ between the two groups.

CONCLUSION

Tacrolimus 4-hour monitoring in stable LT patients is not superior to trough monitoring, regarding the effect on renal function, but is safe for use to facilitate tacrolimus monitoring in an afternoon outpatient clinic.

Population Pharmacokinetics of Cyclosporine in Chinese Pediatric Patients With Acquired Aplastic Anemia

Cyclosporine (CsA) is a component of the first-line treatment for acquired aplastic anemia (acquired AA) in pediatric patients. This study aimed to develop a population pharmacokinetic (PK) model of CsA in Chinese pediatric patients with acquired AA to inform individual dosage regimens. A total of 681 CsA whole blood concentrations and laboratory data of 157 pediatric patients with acquired AA were retrospectively collected from two hospitals in Shanghai. A nonlinear mixed-effect model approach was used to build the population PK model. Potential covariate effects of age, body weight, and biochemical measurements (renal and liver functions) on CsA PK disposition were evaluated. Model fit was assessed using the basic goodness of fit and a visual predictive check. The CsA concentration data were accurately described using a two-compartment disposition model with first-order absorption and elimination. Body weight value was implemented as a fixed allometric function on all clearance and volume of distribution parameters. Total bilirubin level was identified as a significant covariate on apparent clearance (CL/F), with a 1.07% reduction per 1 nmol/L rise in total bilirubin level. The final estimates for CL/F and central volume (Vc/F) were 29.1 L/h and 325 L, respectively, for a typical 28 kg child. Other covariates (e.g., gender, age, albumin, hemoglobin, hematocrit, serum creatinine, and concomitant medication) did not significantly affect the PK properties of CsA. This population PK model, along with a maximum a posteriori Bayesian approach, could estimate individual PK parameters in pediatric patients with acquired AA to conduct individual CsA therapy.

Analysis of the variable factors affecting changes in the blood concentration of cyclosporine before and after transfusion of red blood cell concentrate

Background

The blood concentration of cyclosporine (CyA) is frequently elevated following the transfusion of red blood cell concentrate (RCC) to patients after allogeneic hematopoietic stem cell transplantation (HSCT). The aim of this retrospective study was to identify the variable factors affecting changes in the blood concentration of CyA before and after transfusion of RCC.

Methods

We enrolled 105 patients (age, 5–66 years) who received both CyA and transfusion after HSCT. The ratio of the measurement after transfusion to the measurement before transfusion was calculated for the hematocrit and blood concentration/dose ratio of CyA (termed the HCT ratio and the CyA ratio, respectively).

Results

The blood concentration/dose ratio of CyA was increased after transfusion compared with before transfusion (P < 0.001). The HCT ratio was significantly correlated with the CyA ratio (P = 0.23, P < 0.001). The HCT ratio, concomitant medication that could elevate CyA concentration after RCC transfusion, and difference in the alkaline phosphatase level between before and after transfusion (ΔALP) were explanatory variables associated with the variation in the CyA ratio. There was no correlation between the CyA concentration after transfusion and the change in the estimated glomerular filtration rate.

Conclusions

A change in the blood concentration/dose ratio of CyA was found to be associated with a change in the HCT, concomitant medication that could elevate CyA concentration after RCC transfusion, and ALP levels. If the HCT level rises significantly after RCC transfusion, clinicians and pharmacists should pay attention to changes in the blood CyA concentration.

Cyclosporin A: A Repurposable Drug in the Treatment of COVID-19?

Coronavirus disease 2019 (COVID-19) is now at the forefront of major health challenge faced globally, creating an urgent need for safe and efficient therapeutic strategies. Given the high attrition rates, high costs, and quite slow development of drug discovery, repurposing of known FDA-approved molecules is increasingly becoming an attractive issue in order to quickly find molecules capable of preventing and/or curing COVID-19 patients. Cyclosporin A (CsA), a common anti-rejection drug widely used in transplantation, has recently been shown to exhibit substantial anti-SARS-CoV-2 antiviral activity and anti-COVID-19 effect. Here, we review the molecular mechanisms of action of CsA in order to highlight why this molecule seems to be an interesting candidate for the therapeutic management of COVID-19 patients. We conclude that CsA could have at least three major targets in COVID-19 patients: (i) an anti-inflammatory effect reducing the production of proinflammatory cytokines, (ii) an antiviral effect preventing the formation of the viral RNA synthesis complex, and (iii) an effect on tissue damage and thrombosis by acting against the deleterious action of angiotensin II. Several preliminary CsA clinical trials performed on COVID-19 patients report lower incidence of death and suggest that this strategy should be investigated further in order to assess in which context the benefit/risk ratio of repurposing CsA as first-line therapy in COVID-19 is the most favorable.

Impact of a Bayesian Individualization of Cyclosporine Dosage Regimen for Children Undergoing Allogeneic Hematopoietic Cell Transplantation: A Cost-Effectiveness Analysis

BACKGROUND

Cyclosporine A (CsA) is the main drug used to prevent graft-versus-host disease in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). CsA therapeutic drug monitoring (TDM) has been performed for ages, with studies revealing clinical benefits, but failing to examine its economic impact. In this article, the main objective was to evaluate the economic impact of the CsA TDM strategy, based on a Bayesian approach, by assessing costs related to its clinical impact. Furthermore, TDM effectiveness was analyzed for pharmacokinetics and clinical outcomes.

METHODS

A cost-effective, nonrandomized, retrospective, single-center study compared 2 CsA monitoring and dose adaptation strategies in pediatric patients undergoing HSCT. From 2014 to 2016, CsA TDM was performed using a population pharmacokinetics model-coupled Bayesian approach by a pharmacist ["pharmacist-assisted individualization" (PAI)]. From 2017 to 2018, CsA TDM was performed by the clinician without a Bayesian approach (non-PAI group). HSCT costs were evaluated from the French National Insurance perspective. Economic and clinical outcomes were assessed by measuring incremental cost-effectiveness ratios.

RESULTS

The study included 144 patients: 90 and 54 patients in PAI and non-PAI groups, respectively. Both groups were comparable for sociodemographic and clinical characteristics. The mean total cost per patient was significantly lower (P < 0.01) in the PAI group (€85,947) than in the non-PAI group (€100,435). Multivariate analysis revealed that TDM based on the Bayesian approach was a protective factor (odds ratio = 0.86) for severe acute graft-versus-host disease. We noted that pharmacist-based TDM was the dominant strategy. Bayesian method-based TDM allowed an increase in the percentage of target attainment at any period post-HSCT.

CONCLUSIONS

CsA TDM with a Bayesian approach is a cost-effective procedure, and highlighted clinical benefits encourage the development of new TDM strategies for HSCT.

Trends in liposomal nanocarrier strategies for the oral delivery of biologics

The number of approved macromolecular drugs such as peptides, proteins and antibodies steadily increases. Since drugs with high molecular weight are commonly not suitable for oral delivery, research on carrier strategies enabling oral administration is of vital interest. In past decades, nanocarriers, in particular liposomes, have been exhaustively investigated as oral drug-delivery platform. Despite their successful application as parenteral delivery vehicles, liposomes have up to date not succeeded for oral administration. However, a plenitude of approaches aiming to increase the oral bioavailability of macromolecular drugs administered by liposomal formulations has been published. Here, we summarize the strategies published in the last 10 years (vaccine strategies excluded) with a main focus on strategies proven efficient in animal models.

Immunological discrepancy in aged mice facilitates skin allograft survival

More and more aged people are undergoing organ transplantation. Understanding aging effects on immunity will be helpful for post-transplantation care and adjustment of immunosuppressants for aged recipients. A mouse model, using C3H mice as donors and aged/young C57BL/10J mice as recipients, was employed to study aging effects on immunity. The results showed that frequency of myeloid-derived suppressor cells (MDSC) and level of TGF-β was higher in aged mice than in young mice (4.4 ± 1.4% versus 1.6 ± 1.1%, p = 0.026 for MDSC; 21.04 ± 3.91 ng/ml versus 15.26 ± 5.01 ng/ml, p = 0.026 for TGF-β). In vivo, skin allograft survived longer on the aged than on young mice (19.7 ± 5.2 days versus 11.9 ± 4.1 days, p = 0.005). When entinostat was applied to block MDSC, the survival of skin allografts on aged mice was shorten to 13.5 ± 4.7 days which was not different from the survival on young mice (p = 0.359). In conclusion, allogeneic immunity was different in aged from young mice in high frequency of MDSC and high serum level of TGF-β. Blocking the function of MDSC reversed the low immunity in aged mice and caused skin allograft rejection similar to young recipients.

PAF remodels the DREAM complex to bypass cell quiescence and promote lung tumorigenesis

The DREAM complex orchestrates cell quiescence and the cell cycle. However, how the DREAM complex is deregulated in cancer remains elusive. Here, we report that PAF (PCLAF/KIAA0101) drives cell quiescence exit to promote lung tumorigenesis by remodeling the DREAM complex. PAF is highly expressed in lung adenocarcinoma (LUAD) and is associated with poor prognosis. Importantly, Paf knockout markedly suppressed LUAD development in mouse models. PAF depletion induced LUAD cell quiescence and growth arrest. PAF is required for the global expression of cell-cycle genes controlled by the repressive DREAM complex. Mechanistically, PAF inhibits DREAM complex formation by binding to RBBP4, a core DREAM subunit, leading to transactivation of DREAM target genes. Furthermore, pharmacological mimicking of PAF-depleted transcriptomes inhibited LUAD tumor growth. Our results unveil how the PAF-remodeled DREAM complex bypasses cell quiescence to promote lung tumorigenesis and suggest that the PAF-DREAM axis may be a therapeutic vulnerability in lung cancer.

Skin immune cell characterization in juvenile and adult Göttingen Minipigs

The skin hosts a sophisticated immune system involving responses from both innate and adaptive immune cell populations. Swine skin is close to human skin by its structure, composition and function. In addition, the minipig is considered the model of choice in toxicology studies for drugs applied by the dermal route and developed for both the adult and paediatric indications. However, knowledge on the skin immune system in minipigs, particularly in Göttingen Minipigs, is still limited. The objective of our work was first to characterize the main skin immune populations (Langerhans cells, dermal dendritic cells, macrophages and T lymphocytes) in Göttingen Minipigs. In parallel, we compared the skin immune populations from healthy and immunocompromised piglets following oral treatment with cyclosporin A (CsA) at 10 mg/kg/day. We also explored other pathological conditions using a contact dermatitis model in minipigs challenged with a sensitizer, 2,4-dinitrochlorobenzene (DNCB). Langerhans cells and dermal MHCII^lowCD163⁺ cells were increased one month after oral treatment with CsA at 10 mg/kg/day. The contact dermatitis model in Göttingen Minipigs challenged by DNCB suggested migration of Langerhans cells and dermal dendritic cells as well as T cell recruitment into the skin. These data bring new information in skin immunotoxicology in Göttingen Minipigs and could contribute to a better understanding of the effects of new therapeutic drugs on the developing immune system.

Cyclosporine CsA—The Physicochemical Characterization of Liposomal and Colloidal Systems

This paper presents an overview of the possibilities of testing various cyclosporine (CsA) formulations with an emphasis on parameters that may be key to improving the stability and biocompatibility. The feasibility of CsA colloidal systems for oral (injection) administration were investigated using different techniques and compared with similar investigations of other researchers. The chosen CsA systems were developed using dipalmitoylphosphocholine (DPPC) and/or cholesterol as a lipid matrix, stabilized with ethanol, with soybean oil or n-tetradecane as oil phase in emulsions, under natural pH, room and physiological temperature. Their integrity was found to be strictly dependent on the stabilizers. The highest CsA penetrability with the system containing phospholipid in the context of its interactions with lipid membranes was shown. Also, the bioavailability of CsA can be enhanced with the biopolymer antibacterial chitosan. This mini-review suggests the suitability of liposome/microemulsion as promising vehicles for CsA delivery. The most hopeful proved to be formulation with the smaller particle size facilitating absorption, but when safety is assessed, relying on just the particle size cannot be the only criteria. Reassumed, the CsA formulation stability known on the basis of the size and zeta potential measurements guarantees a decrease of the individual variations in the drug bioavailability, toxicity and minimizes rejection.

Reappraisal of Oral Steroid Therapy for Myasthenia Gravis

Treatment with oral corticosteroids at high doses with an escalation and de-escalation schedule is effective against myasthena gravis (MG). In fact, the use of corticosteroids has led to a reduction in mortality to below 10% after the 1960s. However, long-term use of oral steroids above a certain dosage level is known to cause a number of problems. In 2014, the Japanese clinical guidelines for MG proposed that the first goal in MG treatment (treatment target) should be set at minimal manifestations (MM) with oral prednisolone (PSL) 5 mg/day or below, and that treatment strategies should strive to attain this level as rapidly as possible. In 2015, a multicenter, cross-sectional study revealed that higher PSL dose and longer PSL treatment do not ensure better outcome. In the absence of good response, the PSL dose should be decreased by combining with modalities such as plasma exchange/plasmapheresis and intravenous immunoglobulin (fast-acting treatments). In 2018, we conducted a multicenter, cross-sectional study in a large population of Japanese patients with generalized MG, aiming to elucidate the correlation between oral PSL regimens and achievement of treatment goals. The ORs for low vs. high dose to achieve treatment goals at 1, 2, and 3 years were 10.4, 2.75, and 1.86, respectively, whereas the corresponding ORs for low vs. medium dose were 13.4, 3.99, and 4.92. Early combination with fast-acting therapy (OR 2.19 at 2 years, 2.11 at 3 years) or combination with calcineurin inhibitors (OR 2.09 at 2 years, 2.36 at 3 years) were also positively associated with achieving treatment goals. These results indicate that early combination of low-dose PSL regimens with other therapies is the key for early achievement of treatment goals in generalized MG. However, even with this regimen, ~35% of patients did not achieve the treatment target after 3 years. These results suggest the limitation of the current oral corticosteroid therapy. We need to develop new treatment options to increase the rate of satisfactory outcome.

In vitro and in vivo amelioration of colitis using targeted delivery system of cyclosporine a in New Zealand rabbits

Necessity to develop the efficient targeted delivery of highly potent immunosuppressant for IBD in order to avoid surgical procedure, led to fabrication and evaluation of its anti-inflammatory potential. Previously formulated cyclosporine A (Cyp A) into enteric coated capsules was further evaluated for its site-specificity in the treatment of TNBS induced colitis. Contact angle measurement studies showed excellent spreadability of the developed formulation over the hydrophilic biological tissue substrate. HET-CAM study demonstrates that the formulation prepared is nonirritant to the highly vascular tissues and hence can be used for the immunological sensitive tissues like inflamed intestine in IBD. Further the developed formulation has been characterized for site specificity to distal parts of intestine by pharmacokinetic studies. The appearance of drug in systemic circulation at approximately 5 hours in New Zealand strain of rabbits confirms drug delivery at distal parts of intestine. Significant reduced levels of TNF-α, IL-6 and IL-10 in drug treated animals signifies inhibition of inflammatory reactions at the TNBS treated site. Simultaneously, the change in body weight of same group of animals was observed for 15 days. Results showed a marginal recovery of body weight in Cyp A treated TNBS induced colitis animals. In conclusion, all in vitro and in vivo results confirm the successful site specific delivery and anti-inflammatory efficacy of developed formulation of Cyp A in TNBS induced colitis in New Zealand rabbits.

Food and lipid intake alters the pharmacokinetics of cyclosporine in kidney transplants

Prevention of kidney graft rejection with cyclosporine leads to a large interindividual pharmacokinetic variability. However, food intake is likely to alter cyclosporine pharmacokinetics, and therefore its efficacy. The aim of our study was to evaluate the influence of food and lipid intake on cyclosporine pharmacokinetics. Twenty-four kidney grafted patients treated with Neoral® were included in this prospective monocentric study. In all patients, the pharmacokinetics of cyclosporine was evaluated in two occasions, after meal ('feed') and without meal ('fasting'). At each occasion, blood samples were collected at trough, and 0.5, 1, 2, 3, and 4 h after administration. Cyclosporine pharmacokinetics was described using a Bayesian pharmacokinetic model including two-compartments with first-order transfer and elimination rate constants, and a gamma absorption model. Influence of meal or olive oil, very common in Morocco, was tested as covariates on interoccasion variability parameters. Cyclosporine concentration-time data were satisfactorily described using the Bayesian pharmacokinetic model. Food intake significantly increased volume of distribution and decreased elimination of cyclosporine. The influence of oil intake explained a large part of this effect, suggesting that lipid intake was the main factor of pharmacokinetic variability due to food. This intake resulted in a decrease in area under the concentration curve between two administrations of 14.6%. Food, and especially lipid intake is likely to decrease the exposure to cyclosporine and may therefore lead to a decrease in treatment efficacy. Therefore, to ensure optimal immunosuppression in time, meal composition should remain as steady as possible.

Optimal oral cyclosporin dosing with concomitant posaconazole post allogeneic stem cell transplantation

Cyclosporin is an immunosuppressive agent in allogeneic hematopoietic stem cell transplantation and its metabolism is strongly affected by concomitant drugs, including posaconazole which is now extensively used as anti-fungal prophylaxis post-allograft. We undertook a retrospective audit of 29 patients undergoing their first allograft who were receiving posaconazole at the time of transition from intravenous to oral cyclosporin. This group had a median initial oral cyclosporin dose of 2.58 mg/kg bd (range 1.75-3.95) and high incidence of cyclosporin-related toxicity was noted, requiring significant dose reductions such that by day 60 the media dose was 1.60 mg/kg bd (range 0.86-3.33). We subsequently amended our dosing protocol and analyzed a further 20 patients specifying an initial oral cyclosporin dose of 2.25 mg/kg bd and found this had little impact on toxicity or requirement for dose reductions. Starting doses of no greater than 2 mg/kg bd appear optimal to prevent toxicity in allograft recipients receiving concomitant posaconazole.

Simultaneous Determination of Tacrolimus and Cyclosporine A in Whole Blood by Ultrafast LC-MS/MS

Numerous methods for the measurement of tacrolimus and cyclosporine A involving traditional liquid chromatography tandem mass spectrometry (LC-MS/MS) have previously been described. The majority of these methods use solid-phase extraction, liquid-liquid extraction, or protein precipitation extraction with instrument run times greater than 15 s per sample. Continued demands in clinical labs for greater efficiency and throughput have put increased stress on traditional technologies such as high-performance liquid chromatography-ultraviolet detection (HPLC-UV) and traditional LC-MS/MS. As an improvement to the existing methods, we describe a sensitive ultrafast LC-MS/MS with run times of less than 15 s per sample.

Enhanced Dissolution and Oral Bioavailability of Cyclosporine A: Microspheres Based on αβ-Cyclodextrins Polymers

Cyclosporine (CsA) has a selective property of suppressing various T-lymphocyte functions. This is of utmost importance in preventing allograft rejection by several organ transplantations, as well as in the treatment of systemic and local autoimmune disorders. However, the poor water solubility of CsA can be a major hurdle for its absorption into the blood stream, which leads to low bioavailability and thus less efficacy. The aim of this study was to prepare, characterize, and evaluate in vitro as well as in vivo, the potential of the innovative CsA drug delivery system. The latter contains CsA in spherical amorphous solid dispersion (SASD) which is embedded in an original α-cyclodextrin and β-cyclodextrin polymer mixture (Poly-αβ-CD) as a multifunctional amorphous carrier. The new developed SASD formulation showed that CsA was molecularly dispersed in αβ-cyclodextrins in an amorphous form, as was confirmed by physicochemical characterization studies. Interestingly, the peptide secondary structure, and thus, the drug activity was not impacted by the preparation of SASD as was shown by circular dichroism. Furthermore, the in vitro CsA release profile kinetics was almost identical to the commercially available product Neoral^®. This study presents the first in vivo proof-of-concept for a novel drug delivery system based on Poly-αβ-CD containing CsA, with SASD allowing for increased bioavailibility. The pharmacokinetic parameters of cyclosporine A from the spherical spray-dried dispersion formulation was demonstrated in a “rat” animal model. For comparison, the commercially available Neoral® was studied. Importantly, the pharmacokinetic parameters were improved by extending T_max from 2 to 3 h after the oral administration in rats, and eventually preventing the enterohepatic circulation. All these results clearly demonstrate the improved pharmacokinetic parameters and enhanced bioavailability of CsA in the new developed drug delivery system. These data demonstrated the superiority of the newly developed Poly-αβ-CD formulation for oral administration of the poorly soluble CsA in vivo without altering its secondary structure. Poly-αβ-CD can be a very useful tool for the oral administration of poorly water-soluble drugs.

Immunosuppressive drugs and the gastrointestinal tract in renal transplant patients

Gastrointestinal (GI) discomfort is common after renal transplantation and can be caused by the use of various immunosuppressive drugs. GI symptoms affect the quality of life, lead to an impaired graft survival and an increased mortality. Moreover, diseases and disturbances of the GI tract also affect the pharmacokinetics of immunosuppressive drugs. This review addresses the interaction between immunosuppressive agents and GI disorders. The GI tract is involved in the metabolism of several immunosuppressive drugs. Calcineurin inhibitors, mTor inhibitors, and corticosteroids are subjected to metabolism by the intestinal cytochrome P450 (CYP3A) and by the drug efflux pump ABCB1. Mycophenolate is partly metabolized in the stomach and intestine and undergoes enterohepatic recirculation. Gastrointestinal disturbances can lead to a modified exposure to immunosuppressive drugs. In the first and second part of this review, we focus on the role of the GI tract in the pharmacokinetics of the immunosuppressive drugs and how to adjust immunosuppressive therapy in patients with vomiting, need for tube feeding, delayed gastric emptying, intestinal resection, and diarrhea. In the third part, we review the GI adverse effects of the various immunosuppressive drugs, with special attention for diarrhea and dyspepsia. Finally, we discuss the effects of drugs used for relief of GI complaints on the exposure to immunosuppressive agents.

Bayesian Networks: A New Approach to Predict Therapeutic Range Achievement of Initial Cyclosporine Blood Concentration After Pediatric Hematopoietic Stem Cell Transplantation

BACKGROUND

Pediatric hematopoietic stem cell transplantation (HSCT) allows the treatment of numerous diseases, both malignant and non-malignant. Cyclosporine, a narrow therapeutic index drug, is the major immunosuppressant used to prevent graft-versus-host disease (GVHD), but may also cause severe adverse effects in case of overdosing.

OBJECTIVE

The objective of this study is to predict the initial cyclosporine residual blood concentration value after pediatric HSCT, and consequently the dose necessary to reach the therapeutic range, using a mathematical individual predictive model.

METHODS

Clinical and biological data collected from the graft infusion for 2 months after transplantation in 155 pediatric patients undergoing HSCT between 2008 and 2016 were used to generate synthetic data for 1000 subjects which were used to build a Bayesian network model. We compared the characteristics and sensitivity to clinical or biological missing data of this model with four other methods.

RESULTS

The tree-augmented Naïve Bayesian network showed the best characteristics, with no missing data (area under the curve of the receiving operator characteristics curve [AUC-ROC] of 0.89 ± 0.02), 18.9 ± 2.6% of patients misclassified, and positive and negative predictive values of 85.9 ± 3.4% and 74.2 ± 5.1%, respectively, and this trend is found in the synthetic dataset from no to 10% missing data. The most relevant variables that could influence whether the initial residual cyclosporine concentration is in the therapeutic range are the last dose before measurement and the mean dose before measurement.

CONCLUSIONS

We developed and cross-validated an online Bayesian network to predict the first cyclosporine concentration after pediatric HSCT. This model allows simulation of different dosing regimens, and enables the best dosing regimen to reach the therapeutic range immediately after transplantation to be found, minimizing the risk of adverse effects and GVHD occurrence.

Renal Function Improvement by Telbivudine in Liver Transplant Recipients with Chronic Kidney Disease

Chronic renal failure is a frequent complication in liver transplantation. Telbivudine, anti-hepatitis B virus (HBV) nucleoside, can improve renal function. It is interesting if using telbivudine for prophylaxis of HBV recurrence has additional value on renal function improvement. 120 liver transplant recipients with lamivudine prophylaxis for HBV recurrence were 1 : 1 randomized into lamivudine-continuous (n = 60) and telbivudine-replacement (n = 60) groups. Fifty-eight patients in lamivudine-continuous group and 54 in telbivudine-replacement group completed the study. In telbivudine-replacement group, the estimated glomerular filtration rate (eGRF) was improved from 63.0 ± 16.3 ml/min to 72.8 ± 21.1 ml/min at 12 months after telbivudine administration (p = 0.003). Stratifying the patients according to renal function staging, the eGRF was improved from 74.7 ± 6.9 ml/min to 84.2 ± 16.6 ml/min (p = 0.002) in 32 stage II patients and from 48.2 ± 7.3 ml/min to 59.7 ± 11.8 ml/min in 20 stage III patients after 12 months of telbivudine administration (p < 0.001). Eleven (18.3%) patients with telbivudine developed polyneuritis during the trial and post hoc following-up. In conclusion, renal function was improved by telbivudine in liver transplant recipients with long-term chronic kidney disease. However, the high incidence of polyneuritis induced by telbivudine has to be closely monitored. This trial is registered with ClinicalTrials NCT02447705.

Diltiazem co treatment with cyclosporine for induction of disease remission in sight-threatening non-infectious intraocular inflammation

PURPOSE

To investigate the effects of diltiazem co-treatment with microemulsified cyclosporine-A (CsA) on dosage, blood concentrations of CsA, as well as therapeutic and side effects in patients with sight-threatening non-infectious intraocular inflammation.

METHODS

A prospective, randomized, placebo-controlled, open-label trial of 39 patients with sight-threatening non-infectious intraocular inflammation. The change in visual acuity (LogMAR), the grade of inflammatory activity, therapeutic concentration of CsA in the blood and systemic and renal toxicity were determined after comparing two groups, one treated with CsA and diltiazem (treatment group), and the other without diltiazem (control group).

RESULTS

Compared with the control group, the concentration of CsA in the blood of the treatment group significantly increased (P < 0.05) requiring a reduction in dosage of CsA (P < 0.05).

CONCLUSION

In patients with severe intraocular inflammation treated with CsA and diltiazem, blood concentrations of CsA increased as the dosage decreased. This efficient combination therapy reduced patient's economic burden, at the same time decreasing systemic and renal toxicity which in turn may promote the use of CsA for longer periods.

Current status of selected oral peptide technologies in advanced preclinical development and in clinical trials

The development of oral dosage forms that allows absorption of therapeutic peptides to the systemic circulation is one of the greatest challenges for the pharmaceutical industry. Currently, a number of technologies including either mixtures of penetration enhancers or protease inhibitors and/or nanotechnology-based products are under clinical development. Typically, these formulations are presented in the form of enteric-coated tablets or capsules. Systems undergoing preclinical investigation include further advances in nanotechnology, including intestinal microneedle patches, as well as their combination with regional delivery to the colon. This review critically examines four selected promising oral peptide technologies at preclinical stage and the twelve that have progressed to clinical trials, as indicated in www.clinicaltrials.gov. We examined these technologies under the criteria of peptide selection, formulation design, system components and excipients, intestinal mechanism of action, efficacy in man, and safety issues. The conclusion is that most of the technologies in clinical trials are incremental rather than paradigm-shifting and that even the more clinically advanced oral peptide drugs examples of oral bioavailability appear to yield oral bioavailability values of only 1-2% and are, therefore, only currently suitable for a limited range of peptides.

Immunosuppression for in vivo research: state-of-the-art protocols and experimental approaches

Almost every experimental treatment strategy using non-autologous cell, tissue or organ transplantation is tested in small and large animal models before clinical translation. Because these strategies require immunosuppression in most cases, immunosuppressive protocols are a key element in transplantation experiments. However, standard immunosuppressive protocols are often applied without detailed knowledge regarding their efficacy within the particular experimental setting and in the chosen model species. Optimization of such protocols is pertinent to the translation of experimental results to human patients and thus warrants further investigation. This review summarizes current knowledge regarding immunosuppressive drug classes as well as their dosages and application regimens with consideration of species-specific drug metabolization and side effects. It also summarizes contemporary knowledge of novel immunomodulatory strategies, such as the use of mesenchymal stem cells or antibodies. Thus, this review is intended to serve as a state-of-the-art compendium for researchers to refine applied experimental immunosuppression and immunomodulation strategies to enhance the predictive value of preclinical transplantation studies.

Delayed Cytotoxic T Lymphocyte-Associated Protein 4-Immunoglobulin Treatment Reverses Ongoing Alloantibody Responses and Rescues Allografts From Acute Rejection

Antibody-mediated rejection has emerged as the leading cause of late graft loss in kidney transplant recipients, and inhibition of donor-specific antibody production should lead to improved transplant outcomes. The fusion protein cytotoxic T lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) blocks T cell activation and consequently inhibits T-dependent B cell antibody production, and the current paradigm is that CTLA4-Ig is effective with naïve T cells and less so with activated or memory T cells. In this study, we used a mouse model of allosensitization to investigate the efficacy of continuous CTLA4-Ig treatment, initiated 7 or 14 days after sensitization, for inhibiting ongoing allospecific B cell responses. Delayed treatment with CTLA4-Ig collapsed the allospecific germinal center B cell response and inhibited alloantibody production. Using adoptively transferred T cell receptor transgenic T cells and a novel approach to track endogenous graft-specific T cells, we demonstrate that delayed CTLA4-Ig minimally inhibited graft-specific CD4(+) and T follicular helper responses. Remarkably, delaying CTLA4-Ig until day 6 after transplantation in a fully mismatched heart transplant model inhibited alloantibody production and prevented acute rejection, whereas transferred hyperimmune sera reversed the effects of delayed CTLA4-Ig. Collectively, our studies revealed the unexpected efficacy of CTLA4-Ig for inhibiting ongoing B cell responses even when the graft-specific T cell response was robustly established.

Elderly patients and inflammatory bowel disease

The incidence and prevalence of inflammatory bowel disease (IBD) is increasing globally. Coupled with an ageing population, the number of older patients with IBD is set to increase. The clinical features and therapeutic options in young and elderly patients are comparable but there are some significant differences. The wide differential diagnosis of IBD in elderly patients may result in a delay in diagnosis. The relative dearth of data specific to elderly IBD patients often resulting from their exclusion from pivotal clinical trials and the lack of consensus guidelines have made clinical decisions somewhat challenging. In addition, age specific concerns such as co-morbidity; loco-motor and cognitive function, poly-pharmacy and its consequences need to be taken into account. In applying modern treatment paradigms to the elderly, the clinician must consider the potential for more pronounced adverse effects in this vulnerable group and set appropriate boundaries maximising benefit and minimising harm. Meanwhile, clinicians need to make personalised decisions but as evidence based as possible in the holistic, considered and optimal management of IBD in elderly patients. In this review we will cover the clinical features and therapeutic options of IBD in the elderly; as well as addressing common questions and challenges posed by its management.

Oral cyclosporine A treatment is feasible after myeloablative conditioning in allogeneic hematopoietic stem cell transplantation

WHAT IS KNOWN AND OBJECTIVE

The target level and route of administration of cyclosporine A (CsA) differ between transplantation centres. It is unclear whether oral CsA is sufficient to maintain target level of CsA.

CASE SUMMARY

We retrospectively analysed data from 48 adult patients, who underwent myeloablative hematopoietic stem cell transplantation. Twenty-one patients (44%) tolerated CsA orally throughout the transplantation period without increased incidence of acute graft versus host disease(aGVHD). Low concentration of CsA in week 2 was associated with increased incidence of aGVHD.

WHAT IS NEW AND CONCLUSION

Oral administration of CsA is safe, less time-consuming and economically advantageous. Close monitoring of CsA concentration is important.

Genetic variance in ABCB1 and CYP3A5 does not contribute toward the development of chronic kidney disease after liver transplantation

INTRODUCTION

Chronic kidney disease (CKD) after liver transplantation (LT) is a major clinical problem that appears to be associated with nongenetic as well as genetic determinants. Calcineurin inhibitor (CNI) use is considered to play a major role in the development of CKD after LT. We studied the influence of single-nucleotide polymorphisms (SNPs) in the genes of the donor and recipient CNI-metabolizing enzyme CYP3A5 and the CNI-transporting ABCB1 on the development of CKD after LT.

MATERIALS AND METHODS

Tacrolimus (Tac) predose concentrations at different time-points after transplantation and the CYP3A5 6986A>G and ABCB1 3435C>T SNPs were determined in 125 LT recipients and their respective donors to study the influence of Tac predose levels and genetics on the development of CKD.

RESULTS

After a median follow-up of 5.7±2.9 years, CKD developed in 47 patients (36%). The Tac predose levels were not correlated with the development of CKD. Neither did we find a correlation between the investigated SNPs in either donor or recipient ABCB1 and CYP3A5 genes (or combinations thereof) and the development of CKD. These genetic variations did not relate to Tac predose blood concentrations in our study.

CONCLUSION

An individual's risk of developing CKD after LT is not associated with genetic variation in either recipient or donor CYP3A5 or ABCB1 genotype status.

Therapeutic drug monitoring in pediatric renal transplantation

Finding the balance between clinical efficacy and toxicity of immunosuppressive drugs is a challenge in renal transplantation (RTx), but especially in pediatric RTx patients. Due to the expected longer life-span of pediatric transplant patients and the long-term consequences of drug-induced infectious, malignant and cardiovascular adverse effects, protocols which minimize immunosuppressive therapy make conceptual sense. In this context, therapeutic drug monitoring is a tool which provides support for the individualization of therapy. It has, however, limitations, and specific data in the pediatric cohort are comparatively sparse. There is large heterogeneity among the studies conducted to date in terms of methods, follow-up, endpoints, immunosuppressive regimens and patients. In addition, data from adult studies are not readily transferrable to the pediatric situation. This educational review gives a concise overview on aspects of therapeutic drug monitoring in pediatric RTx.

The Effect of ABCB1 C3435T Polymorphism on Cyclosporine Dose Requirements in Kidney Transplant Recipients: A Meta-Analysis

Cyclosporine A (CsA) is a substrate of the multi-drug efflux pump P-glycoprotein (P-gp) encoded by ABCB1. Among the various single nucleotide polymorphisms (SNPs) of ABCB1, C3435T has been extensively investigated to determine the relationship with the pharmacokinetics of CsA. However, the results are controversial. This meta-analysis was designed to evaluate the influence of C3435T SNP on the dose-adjusted trough (C0 /D) and peak (Cmax /D) concentrations of CsA. Based on a literature search of four authoritative databases, 13 studies since 2001 concerning 1293 kidney transplant recipients were included. The results indicated a significant difference of C0 /D and Cmax /D between 3435CC and 3435TT genotype carriers (weighted mean difference (WMD) of C0 /D: 4.18 (ng ml(-1))/(mg kg(-1)), 95% CIs: 1.00-7.37, p = 0.01; WMD of Cmax /D: 20.85 (ng ml(-1))/(mg kg(-1)), 95% CIs: 2.25-39.46, p = 0.03). Subgroup analysis by ethnicity demonstrated that C0 /D was lower in Asian CC versus TT genotype carriers (WMD = 10.32 (ng ml(-1))/(mg kg(-1)), 95% CIs: 4.78-15.85, p = 0.0003) but did not vary by genotype for Caucasian recipients. Moreover, significant variation of C0 /D was found at 1 week and 1-3 months after transplantation between CC and TT genotype carriers. Therefore, this meta-analysis showed a correlation between ABCB1 C3435T polymorphism and the dose-adjusted concentration of CsA. Patients with 3435CC genotype will require a higher dose of CsA to achieve target therapeutic concentrations when compared with 3435TT carriers after kidney transplantation, especially in the Asian population and especially during the early and middle time periods after transplantation.

Clinical implementation of pharmacogenetics in kidney transplantation: calcineurin inhibitors in the starting blocks

Pharmacogenetics has generated many expectations for its potential to individualize therapy proactively and improve medical care. However, despite the huge amount of reported genetic associations with either pharmacokinetics or pharmacodynamics of drugs, the translation into patient care is still slow. In fact, strong evidence for a substantial clinical benefit of pharmacogenetic testing is still limited, with a few exceptions. In kidney transplantation, established pharmacogenetic discoveries are being investigated for application in the clinic to improve efficacy and to limit toxicity associated with the use of immunosuppressive drugs, especially the frequently used calcineurin inhibitors (CNIs) tacrolimus and ciclosporin. The purpose of the present review is to picture the current status of CNI pharmacogenetics and to discuss the most promising leads that have been followed so far.

Sylysia 350/Eudragit S100 solid nanomatrix as a promising system for oral delivery of cyclosporine A

Cyclosporine A (CyA) is a poorly soluble peptide and the available preparation is the surfactant based Sandimmum Neoral(®). In this study, we developed a novel pH-sensitive nanomatrix system of CyA with medical-grade nanoporous silica and Eudragit(®) to enhance the oral absorption of CyA as well as to improve the potential nephrotoxicity caused by the pronounced initial plasma peak of Neoral(®). The nanomatrixs were prepared by an absolutely simple conventional process. The scanning electron microscopy (SEM), X-ray powder diffraction analysis (XRD), differential thermal analysis (DSC) and specific surface area and pore size analysis were used to analyze the physicochemical characterization of the nanomatrix. The nanomatrix, consisted of CyA, Eudragit(®) S100 and Sylysia 350 (1/5/5, w/w/w %), not only increased the dissolution of CyA in vitro but also exhibited excellent enteric behavior. The characterization of CyA nanomatrix showed the CyA was highly dispersed in the nanomatrix in a molecular or amorphous state and partly filled into the nanopores of Sylysia 350. The results of comparative pharmacokinetic study showed that the optimized nanomatrix had a relative bioavailability of 90.8% with Neoral(®) but a lower Cmax than that of Neoral(®). In conclusion, the novel nanomatrix of CyA, composed of pharmaceutical excipients of biological safety and easily prepared, is expected to become a promising marketed product for the oral delivery of CyA.

Early non-steady-state population pharmacokinetics of oral cyclosporine in renal transplant recipients

This study aimed to evaluate the change in the pharmacokinetics (PK) of cyclosporine in the non-steady-state period in the first week after renal transplantation; the factors influencing this change, including genetic variability; and the time point concentration that correlated best with drug exposure. Data were obtained from 69 patients, and PK studies were conducted on postoperative days (PODs) 2, 3, and 7. Samples were taken pre-dose and at 1, 2, 3, 4, 6, 8, and 12 hours after drug administration. MDR1, CYP3A4, and CYP3A5 were genotyped. A population PK analysis and correlational analysis between the concentration at each time point and the area under the time-concentration curve were performed. A two-compartment model with first-order absorption was chosen. The rate and extent of drug absorption showed a significant increase on POD3, followed by a slight decrease on POD7. Until POD3, 8 hours post-dose was the single time point concentration that correlated best with drug exposure and 3 hours was the best time point on POD7. In both analyses, the MDR1 genotype showed potential as a factor influencing PK change. We conclude that oral administration of cyclosporine and dose adjustment based on a single concentration measurement might result in unexpected drug exposure during this early posttransplantation period.