The evaluation of the safety and tolerability of two formulations of cyclosporine: neoral and sandimmune. A meta-analysis

Oral Drug Delivery Systems Applied to Launched Products: Value for the Patients and Industrial Considerations

Drug delivery systems (DDS) control the amount, rate, and site of administration of drug substances in the body as well as their release and ADME (absorption, distribution, metabolism, excretion). Among the various types of DDS, amount-controlled DDS for solubilization and absorption increase the bioavailability. Time- and amount-controlled DDS are controlled release formulations classified as (1) membrane-type, (2) matrix-type, (3) osmotic-type, and (4) ion-exchange type. Timed-release formulations also control the time and amount of release and the absorption of drugs. Site- and amount-controlled DDS are characterized by colonic delivery and intestinal lymph-targeting to improve release and ADME of drug substances. Finally, site-, time-, and amount-controlled DDS are gastroretentive formulations and local delivery in the oral cavity to improve site retention, release, and ADME of drugs. DDS can enhance efficacy, reduce adverse effects, and optimize the dosing frequency of various drug products to increase patient value. This review focuses on patient value and industrial considerations of launched oral DDS. We provide a technological overview of candidate and marketed DDS, as well as the pros/cons of the technologies for industrialization with consideration to excipients, manufacturing, and storage stability. Moreover, to demonstrate the usefulness of the technology and support the selection and development of the best technologies for patients, we also describe patient value from clinical studies and analyses, particularly with regard to increased new medical options, higher efficacy, reduced adverse effects, reduced number of doses and clinic visits, easier administration, higher quality of life, greater adherence, and satisfaction.

New Insights into the Nephroprotective Potential of Lercanidipine

Kidneys are responsible for many crucial biological processes in the human body, including maintaining the water-electrolyte balance, pH, and blood pressure (BP), along with the elimination of toxins. Despite this, chronic kidney disease (CKD), which affects more and more people, is a disease that develops insidiously without causing any symptoms at first. The main purpose of this article is to summarize the existing literature on lercanidipine, with a particular focus on its nephroprotective properties. Lercanidipine is a third-generation dihydropyridine (DHP) blocker of calcium channels, and as such it possesses unique qualities such as high lipophilicity and high vascular selectivity. Furthermore, it acts by reversibly inhibiting L-type and T-type calcium channels responsible for exerting positive renal effects. It has been shown to reduce tissue inflammation and tubulointerstitial fibrosis, contributing to a decrease in proteinuria. Moreover, it exhibited antioxidative effects and increased expression of molecules responsible for repairing damaged tissues. It also decreased cell proliferation, preventing thickening of the vascular lumen. This article summarizes studies simultaneously comparing the effect of lercanidipine with other antihypertensive drugs. There is still a lack of studies on the medications used in patients with CKD, and an even greater lack of studies on those used in patients with concomitant hypertension. Therefore, further studies on lercanidipine and its potential in hypertensive patients with coexisting CKD are required.

Overview of Immunosuppressive Therapy in Solid Organ Transplantation

Mechanisms of rejection, new pharmacologic approaches, and genomic medicine are major foci for current research in transplantation. It is hoped that these new agents and personalized immunosuppression will provide for less toxic regimens that are effective in preventing both acute and chronic allograft rejection. Until new agents are available, practitioners must use various combinations of currently approved agents to find the best regimens for improved long-term outcomes.

Flow cytometry assessment of graft-infiltrating lymphocytes can accurately identify acute rejection in kidney transplants

BACKGROUND

Previously, we have reported that flow cytometry analysis of fine-needle aspirates can accurately predict rejection in kidney transplants treated with cyclosporine-azathioprine-prednisolone. In this study, we examined this technique's accuracy using current immunosuppression.

METHODS

Kidney transplant recipients were treated with calcineurin inhibitors, mycophenolate mofetil, and prednisolone: 92 remained rejection-free - Group I - and 37 developed acute rejection - Group II. An allograft aspiration specimen and peripheral blood were collected from Group I on post-transplant day 7 and from Group II on the day of clinical rejection.

RESULTS

Significant changes were seen in both aspiration and peripheral blood samples in several T cell subsets when comparing Groups I and II. A sensitivity of 94.6%, specificity of 85%, and AUC = 0.966 were observed through combining CD8DR with CD3CD69 values from aspiration specimen; the corresponding AUC in peripheral blood was 0.847. Irreversible rejections displayed a significantly higher activation score (p = 0.024).

CONCLUSIONS

Flow cytometry analysis of aspiration specimen achieved high diagnostic performance in renal transplants through studying CD8DR and CD3CD69 under current immunosuppressive therapy. Peripheral blood analysis, although not significant, showed the same trend. The activation score anticipated the irreversibility of rejection. The data suggest this test, through an easily tolerated technique, merits further diagnostic use.

The Clinical Benefits of Cyclosporine C2-Level Monitoring: A Systematic Review

BACKGROUND

Monitoring of cyclosporine microemulsion (Neoral) using 2-hour postdose (C2) levels is alleged to improve clinical outcomes, but the efficacy of this strategy is uncertain.

METHODS

A systematic literature search was performed for trials directly comparing patients monitored with C2 levels with those monitored by trough (C0) levels. Primary outcomes assessed were renal function and acute rejection.

RESULTS

A total of 29 studies met the inclusion criteria. Only 10 of these were randomized controlled trials. Overall quality was poor and this precluded meta-analysis. The most consistent finding in de novo renal, hepatic, and cardiac transplant recipients is a higher mean cyclosporine dose in the early postoperative period in C2 monitored patients. There is no clear evidence that this leads to impaired renal function. In the majority of studies, the monitoring strategy had no significant effect on the rate of acute rejection. In stable transplant recipients, the majority of studies show a reduction in mean cyclosporine dose with adoption of C2 monitoring. No obvious clinical benefit was derived from this reduction in dose.

CONCLUSION

In de novo transplant patients, there is little evidence from prospective studies to support the theoretical benefits of C2 monitoring. Potential dose reductions in stable patients may reduce costs, but no short-term clinical benefit is seen. Quality of studies in this area is poor, and the practical limitations of C2 monitoring mean that further evidence is required before a strategy for the administration of cyclosporine based on C2 levels can be recommended.

Mycophenolate mofetil versus azathioprine for prevention of chronic allograft dysfunction in renal transplantation: the MYSS follow-up randomized, controlled clinical trial

The Mycophenolate Steroids Sparing (MYSS) study found that in renal transplant recipients who were on immunosuppressive therapy with the cyclosporine microemulsion Neoral, mycophenolate mofetil (MMF) was not better than azathioprine in preventing acute rejection at 21 mo after transplantation and was 15 times more expensive. The MYSS Follow-up Study, an extension of MYSS, was aimed at comparing long-term outcome of 248 MYSS patients according to their original randomization to MMF (1 g twice daily) or azathioprine (75 to 100 mg/d). Primary outcome was estimated GFR at 5 yr after transplantation. Mean 5-yr GFR difference between azathioprine and mycophenolate was 4.67 ml/min per 1.73 m(2) (95% confidence interval [CI] -0.43 to 9.77 ml/min per 1.73 m(2); P = 0.07). GFR from month 6 (mean +/- SEM: 54.3 +/- 1.6 versus 53.9 +/- 1.5 ml/min per 1.73 m(2); P = 0.83) to month 72 after transplantation (49.5 +/- 2.2 versus 47.3 +/- 2.4 ml/min per 1.73 m(2); P = 0.50); GFR slopes (mean +/- SEM: -1.10 +/- 0.56 versus -1.23 +/- 0.31 ml/min per 1.73 m(2) per year; P = 0.83); and 72-mo patient mortality (4.0 versus 4.0% [P = 0.95]; HR 0.96; 95% CI 0.28 to 3.31; P = 0.95), graft loss (6.8 versus 6.1% [P = 0.82]; HR 0.89; 95% CI 0.32 to 2.46; P = 0.83), incidence of persistent proteinuria (25.0 versus 27.4%; P = 0.72), late (>6 mo after transplantation) rejections (25.3 versus 21.2%; P = 0.53), and adverse events were similar on azathioprine (n = 124) and MMF (n = 124), respectively. Outcomes in the two groups were comparable also among patients with or without steroid therapy, considered separately. In kidney transplantation, the long-term risk/benefit profile of MMF and azathioprine therapy in combination with cyclosporine Neoral is similar. In view of the cost, standard immunosuppression regimens for kidney transplantation should perhaps include azathioprine rather than MMF.

Lost in publication: Half of all renal practice evidence is published in non-renal journals

Physicians often scan a select number of journals to keep up to date with practice evidence for patients with kidney conditions. This raises the question of where relevant studies are published. We performed a bibliometric analysis using 195 renal systematic reviews. Each review used a comprehensive method to identify all primary studies for a focused clinical question relevant to patient care. We compiled all the primary studies included in these reviews, and considered where each study was published. Of the 2779 studies, 1351 (49%) were published in the top 20 journals. Predictably, this list included Transplantation Proceedings (5.9% of studies), Kidney International (5.3%), American Journal of Kidney Diseases (4.7%), Nephrology Dialysis Transplantation (4.3%), Transplantation (4.2%), and Journal of the American Society of Nephrology (2.4%). Ten non-renal journals were also on this list, including New England Journal of Medicine (2.4%), Lancet (2.3%), and Diabetes Care (2.2%). The remaining 1428 (51%) studies were published across other 446 journals. When the disciplines of all journals were considered, 59 were classified as renal or transplant journals (42% of articles). Other specialties included general and internal medicine (16%), endocrinology (diabetes) and metabolism (6.5%), surgery (6.2%), cardiovascular diseases (6.1%), pediatrics (4.3%), and radiology (3.3%). About half of all renal practice evidence is published in non-renal journals. Browsing the top journals is important. However, relevant studies are also scattered across a large range of journals that may not be routinely scanned by busy physicians, and keeping up with this literature requires other continuing education strategies.

Assessment of the bioequivalence of a generic cyclosporine A by a randomized controlled trial in stable renal recipients

BACKGROUND

The aim of this study was to determine the bioequivalence of Cysporin, a generic cyclosporine A, compared with Neoral in stable renal transplant recipients.

METHODS

Study design consisted of an open label, two-way crossover, randomized controlled trial of Cysporin versus Neoral in stable renal transplant recipients. In all, 33 patients were enrolled; 31 were randomized and 28 were evaluable. AUCs(0-12) were done on day 14 and 28; C(0) and C(2) were done on days 0, 7, 21 and 35. Dose conversion was 1:1. Outcome measures for serum cyclosporin A concentrations expressed as the mean+/-SD were AUC(0-12) (microg x hr/L), C(max) (microg/L), C(2) (microg/L), T(max) (hr) and T(1/2) (hr). Mean and 90% CI of the ratio Cysporin/Neoral of log-transformed data were calculated using a general linear model.

RESULTS

The main pharmacokinetic features were: AUC(0-12): Cysporin 3495+/-1319, Neoral 3853+/-1378 (P<0.05); C(max): Cysporin 755+/-301, Neoral 881+/-368 (P<0.05); C(2): Cysporin 613+/-235, Neoral 672+/-255 (P>0.05); T(max): Cysporin 1.9+/-0.8, Neoral 1.4+/-0.6 (P<0.005); and T1/2: Cysporin 8.8+/-4.3, Neoral 8.7+/-6.2 (P>0.05). Estimated ratios of Cysporin/Neoral were: AUC 0.93 (90% CI 0.88-0.98; P<0.05); C(max) 0.88 (90% CI 0.80-0.97; P<0.05); and T(max) 1.32 (90% CI 1.14-1.53; P<0.005).

CONCLUSIONS

Both the extent and rate of absorption of Cysporin are significantly less than those of Neoral. The 90% CI for the ratios of Cysporin/Neoral for AUC and C(max) lie within 0.80-1.25. Hence in this clinical context Cysporin is pharmacologically bioequivalent with Neoral. This study illustrates the importance of testing bioequivalence of generic cyclosporine A products in transplant recipients not healthy volunteers.

Therapeutic drug monitoring of cyclosporine

The introduction of cyclosporine into clinical practice improved transplant outcome. However, the use of cyclosporine is not without problems. A narrow therapeutic index (the drug causes irreversible kidney damage when given in too high a dose) coupled with variable absorption and unpredictable pharmacokinetics has resulted in the need to measure cyclosporine blood concentrations to enable the dose of the drug to be individualised to the patient. When this is done correctly therapeutic efficacy can be maximised while toxicity is kept to a minimum. The evolution of cyclosporine dose optimisation started with the adjustment of empirical fixed doses by clinical "judgement;" progressed to therapeutic drug monitoring of trough, predose, C0 concentration with non specific assays that measured parent drug and metabolite; then on to "specific" cyclosporine C0 measurements; through area under curve monitoring using full profile measurements and limited sampling scheme procedures; and finally ending up with absorption profiling that targets AUC in the first 4 hours or the 2 hour blood cyclosporine concentration, C2. At the same time the formulation of cyclosporine has changed from Sandimmune to Neoral and now generic forms of the latter are available. The evidence base supporting C2 monitoring continues to grow and the technique will need to be customised as new combination therapies emerge. Therapeutic drug monitoring of cyclosporine may also need to be tailored to avoid the potential negative impact of switching patients to generic forms of the drug.

Update on liver transplantation using cyclosporine

After the introduction of cyclosporine into liver transplantation in 1983, 1-year patient survival more than doubled. Later, with the improved microemulsified formulation of cyclosporine (Neoral) more stable pharmacokinetics were achieved. Today, C(2) monitoring of cyclosporine blood levels allows a more accurate estimation of the area under the concentration-versus-time curve as the single best indicator of cyclosporine exposure. As a consequence, with better control of side effects as well as desired effects the results of cyclosporine in liver transplantation have been further improved. The introduction of mycophenolate mofetil and basiliximab/daclizumab combination therapy has provided new options for the prevention of allograft rejection. The safety profile of individual immunosuppressive regimens comes more into focus since acute allograft rejection may be controlled successfully with competing strategies. As the focus in liver transplantation is shifting toward greatly improved long-term results, late posttransplant mortality with a functioning graft is a major concern. Prevention of long-term complications associated with highly effective immunosuppressants--posttransplant lymphoproliferative disease, cytomegalovirus infection, diabetes, hypertension, and hyperlipidemia-gains importance. Technical advances in living-related and cadaveric split-liver transplantation have lead to increasing use of segmental liver transplantation with the need to consider the effects of immunosuppression on liver regeneration and metabolism. The individualized orchestration of immunosuppression taking into account the underlying liver disease as well as other individual predispositions remains a future challenge.

Cyclosporine levels at 2 hours after dose and body mass index in relation to graft function in renal transplant patients treated with azathioprine or mycophenolate mofetil

The aim of this study was to evaluate the effect of C(2) levels on renal graft function in relation to body mass index (BMI). This retrospective study of 95 renal transplant patients included 53 on AZA and 42 on MMF at 3.1 years after transplantation. The cohort was divided into groups according to their C(2) levels, namely <600 ng/mL, 600 to 900 ng/mL, or >900 ng/mL, and according to BMI (>26 kg/m(2)). In every group, we evaluated the percentage of patients with an increase in creatinine by 1 mg/dL or >/=50% from the first year posttransplant. There was no difference in age, gender, graft source, and dose of corticosteroids or CsA between the groups. Patients on AZA with C(2) 600 to 900 ng/mL showed a lower prevalence of renal dysfunction (3.4%) than those with C(2) levels <600 ng/mL (14.3%) or >900 ng/mL (20%). Seventeen percent of the patients on AZA and 11.9% on MMF had BMI >26 kg/m(2) (P = NS). An increased serum creatinine was present in 22.2% of patients with BMI >26 kg/m(2) in the AZA group vs 20% in the cohort MMF (P = NS). These findings suggest that long-standing renal recipients on AZA with C(2) levels of between 600 and 900 ng/mL show better preservation of renal function. We did not identify differences on the basis of C(2) levels in MMF-treated recipients. The influence of BMI on long-term graft function seemed to be independent of AZA or MMF therapy.

Experience with conversion from sandimmun to neoral cyclosporine and the correlation of c2 levels with renal function

Pharmacologic monitoring of the cyclosporine microemulsion Neoral is an important tool to improve the efficacy and to avoid toxicity of the drug. Recent trials have shown that the absorption profiling tools represented by the area under the time-concentration curve from 0 to 4 hours postdose and concentration 2 hours postdose (C2) levels are the best predictors of acute rejection in the early posttransplant period. Since similar data regarding maintenance immunosuppression are scarce, we report our experience on Neoral C2 monitoring in renal transplant recipients during the late posttransplant period. However, available data on optimal Neoral C2 levels in the late posttransplantation period are scant and have not been correlated with well-defined endpoints such as chronic allograft nephropathy.

Editorials: Ethical Conflicts for Physicians Treating ESRD Patients

Managing an end-stage renal disease (ESRD) patient is complex and presents many ethical challenges for the physician. Ownership of dialysis facilities has shifted over the past decade from largely nonprofit organizations to large companies whose shareholders are primarily interested in the profitability of their investments rather than the well-being of the patients being treated. Furthermore, market forces rather than scientific questions that need to be answered now drive much of the research regarding patients with ESRD. These developments have created ethical dilemmas for treating physicians. This editorial describes some of these ethical challenges and expresses the point of view that the doctor-patient relationship and its ethical imperatives are more important than company profit and loss statements.

A pharmacokinetic and clinical review of the potential clinical impact of using different formulations of cyclosporin A. Berlin, Germany, November 19, 2001

A meeting of 14 transplant and pharmacokinetic specialists from Europe and North America was convened in November 2001 to evaluate scientific and clinical data regarding the use of different formulations of cyclosporin A (CsA). The following consensus was achieved. (1) CsA is a critical-dose drug with a narrow therapeutic window. Clinical outcomes after transplantation are affected by the pharmacokinetic properties of CsA, particularly by its bioavailability, and by intrapatient variability in CsA exposure. (2) Standard bioequivalence criteria do not address differences in CsA pharmacokinetics between transplant recipients and healthy volunteers, or between subpopulations of transplant recipients. (3) In some circumstances, currently available formulations of CsA that meet standard bioequivalence criteria are likely to be nonequivalent with respect to pharmacokinetic characteristics. (4) The choice of CsA formulation can affect the short- and long-term clinical outcome. Currently, there is a lack of clinical comparisons between generic CsA formulations and the Neoral formulation (Novartis Pharmaceuticals Corporation, East Hanover, New Jersey). Initial retrospective data from the Collaborative Transplant Study suggest that use of generic CsA formulations may result in reduced graft survival at 1 year. (5) Management of transplant recipients by monitoring Neoral concentrations 2 hours after dosing (C(2)) reduces the incidence and severity of acute rejection compared with monitoring of trough concentrations with no increase in toxicity. C(2) monitoring has been developed based on the pharmacokinetics of Neoral only and has not been evaluated or validated for generic formulations of CsA. (6) The major costs of care after transplantation relate to the management of poor clinical outcomes and toxicity. CsA formulations with different pharmacokinetic properties may be associated with varying clinical outcomes, which would be expected to affect total health care costs. (7) The transplant physician is responsible for selecting immunosuppressive agents and formulations for his or her patients. Any switch between CsA formulations in a particular patient should take place only in a controlled setting with adequate pharmacokinetic monitoring.

Prevention and treatment of severe hemodynamic compromise in pediatric heart transplant patients

Allograft rejection is a leading cause of severe hemodynamic compromise in pediatric heart transplant patients. A triple-drug immunosuppression regimen, which includes a calcineurin inhibitor, antiproliferative agent, and corticosteroid, suppresses the immune system at multiple different levels for optimal graft protection while minimizing the adverse effects of any one particular agent. Some pediatric centers also use induction therapy with anti-T cell antibodies immediately following transplantation as additional rejection prophylaxis. These antibodies augment immunosuppression by either depleting the T cell pool or blocking interleukin-2 receptors on activated T cells. Despite the aggressive preventive measures outlined above, some pediatric heart transplant patients will develop severe hemodynamic compromise, most commonly due to fulminant rejection. Such patients require attention to, and optimization of, the four determinants of cardiac output (heart rate, preload, contractility and afterload) to stabilize the circulation until the rejection can be reversed. Careful administration of volume, diuretics, inotropes, and afterload-reducing agents will meet this goal. Patients with allograft rejection require augmentation of immune suppression to facilitate myocardial recovery. Corticosteroids form the cornerstone of treatment for both cellular and vascular rejection. In patients with refractory cellular rejection, conversion to mycophenolate mofetil or tacrolimus may be appropriate if these agents are not already being used for maintenance immunosuppression. Critically ill patients may additionally benefit from muromonab-CD3 (OKT3) to augment lympholysis. Treatment employed specifically for humoral rejection is prescribed with the intention of suppressing new antibody formation, removing circulating antibody, and improving coronary blood flow. In addition to corticosteroids, cyclophosphamide and antithymocyte globulin or muromonab-CD3, along with plasmapheresis, may improve survival. Systemic heparinization should be considered to minimize coronary thrombosis in patients with humoral rejection. In the future, novel immunosuppressive agents may further assist in the prevention as well as treatment of severe hemodynamic compromise due to rejection in pediatric heart transplant recipients.

Conversion of stable renal allograft recipients to a bioequivalent cyclosporine formulation

BACKGROUND

Gengraf capsule, an AB-rated generic cyclosporine for Neoral, has been shown to be bioequivalent in previous studies. The purpose of this pharmacokinetic study performed in stable renal transplant recipients was to evaluate interchangeability of Gengraf and Neoral.

METHODS

Using an open-label, three-period design, 50 renal transplant recipients taking stable doses of Neoral completed a multicenter study. Subjects continued their Neoral regimen during period I (days 1-14). Subjects then switched from Neoral on a milligram-for-milligram basis to Gengraf during period II (days 15-28), followed by conversion to the same milligram-for-milligram dosing regimen of Neoral during period III (days 29-35). Twelve-hour pharmacokinetic evaluations (maximum observed blood concentration [C(max) ], concentration before dosing [C(trough) ], time to maximum observed concentration [T(max) ], and area under the blood concentration-vs.-time curve [AUC]) occurred on days 1, 14, 15, 28, and 29. Additional predose samples (C (trough)) were evaluated on days 7, 21, and 35. Laboratory and safety parameters were also evaluated.

RESULTS

The pharmacokinetics of Gengraf (C(max), T(max), C(trough), and AUC) were indistinguishable from the Neoral values in stable renal allograft recipients. The bioequivalent capsules were interchangeable with respect to C(max), C(trough), and AUC at steady state and also on conversion from one capsule formulation to the other. The 90% confidence intervals (CI) for the Gengraf versus Neoral comparison at steady state (day 28 vs. day 14) were 0.95 to 1.03 for AUC and 0.92 to 1.04 for C(max). Trough concentrations remained consistent throughout the study, with no need for dosage adjustment in any of the subjects. Gengraf is well tolerated, with an excellent safety profile, comparable to the safety profile of Neoral. CONCLUSIONS The pharmacokinetics of Gengraf are equivalent and indistinguishable from those of Neoral. Gengraf is well tolerated and interchangeable with Neoral in stable renal transplant recipients.

Improving safety reporting from randomised trials

Randomised clinical trials offer a unique opportunity for capturing safety information under a controlled setting that minimises biases in the comparison of different therapeutic options. Nevertheless, empirical evidence across diverse medical fields suggests that the reporting of safety information in clinical trials is largely neglected and receives less attention compared with efficacy outcomes. An analysis of 192 randomised trials has shown that reasons for withdrawals due to toxicity were specified per study arm in only 46% of the trial reports. Adequate reporting of clinical adverse effects and laboratory-determined toxicity occurred in only 39 and 29% of the trials, respectively, even with lenient definitions of what constitutes adequate reporting. The use of standardised scales for adverse effects is a prerequisite for improved reporting on safety in randomised trials. Safety data need to be collected and analysed in a systematic fashion and active surveillance for toxicity during the conduct of a randomised trial is preferable to passive surveillance. Standardised reporting of safety data does not necessarily require extensive space to accomplish. It is essential to provide numerical data per study arm on each type of adverse effect along with a categorisation of the severity of the adverse effects with an emphasis on severe and life-threatening reactions. The severity grading must be referred to well-known standardised scales and new scales need to be carefully defined. Information on withdrawals due to toxicity is also important to report, along with the specific reasons leading to discontinuation. Tabulation of information may be helpful and rare or not previously reported adverse effects should be described in detail. The availability of newer options such as electronic publication, publication of raw databases, large database research, meta-analytic approaches, and prospective registration of clinical trials and of their databases may further improve the safety insights we can gain from randomised clinical trials.

Standardized retrieval of side effects data for meta-analysis of safety outcomes. A feasibility study in acute sinusitis

Accurate and complete safety data are indispensable for the proper evaluation of the benefit-to-harm ratio of medical interventions. We evaluated whether a systematic review and meta-analysis of standardized safety data is feasible by requesting information on side effects directly from the investigators of all 38 antibiotic trials on acute sinusitis published in the last decade. We requested standardized information on gastrointestinal toxicity outcomes, including hospitalizations, discontinuations, and days with nausea/vomiting, diarrhea, or both. Responses were received only for 16 trials (42%), and safety data were contributed only for 9 trials (24%). In some trials, safety data had not been collected, had been lost, or had been transferred to other companies. The odds of data retrieval was higher in general medical journals (P =.024) and independently improved with an increase in sample size (P =.064). The available information suggested side effects may equal or exceed in severity the marginal treatment benefits. Interpretation of safety data was further complicated by heterogeneity or lack of information of use of concomitant drugs, mode of collection of safety information, use of blinding, and other study design parameters. Availability of standardized information for performing meta-analysis of safety data may be limited. Standardized reporting, prospective collection, and long-term availability of safety information should be improved.

A long-term comparison of tacrolimus (FK506) and cyclosporine in kidney transplantation: evidence for improved allograft survival at five years

BACKGROUND

The 1-year results of the Phase III U.S. Multicenter Trial comparing tacrolimus (FK506)- and cyclosporine (CsA)-based immunosuppressive therapy in kidney transplantation revealed a significant reduction in the incidence and severity of acute rejection episodes among patients maintained on tacrolimus. The present report at 5 years of follow-up focuses on the long-term impact of tacrolimus treatment on kidney allograft outcome.

METHODS

The study protocol permitted crossover of patients to the alternate treatment arm under stringent conditions. The effect of crossover on graft survival was analyzed. Cardiovascular risk factors and serious adverse events were also monitored over 5 years.

RESULTS

Intent-to-treat analysis revealed equivalent patient and graft survival between treatment arms at 5 years of follow-up (79.1% vs. 81.4%; P=0.472 and 64.3% vs. 61.6%; P=0.558 among tacrolimus and CsA-treated patients, respectively). However, the rate of crossover was significantly higher among patients randomized to receive CsA-based therapy (27.5% vs. 9.3%; P<0.001). The incidence of treatment failure (43.8% vs. 56.3%; P=0.008) was significantly lower among tacrolimus-treated patients. Graft survival was significantly improved in the tacrolimus treatment arm when crossover due to rejection was counted as graft failure (63.8% vs. 53.8%; P=0.014). Tacrolimus therapy was also associated with a significantly reduced requirement for medications to control hypertension and hyperlipidemia. There was a substantial rate of reversal of tacrolimus-associated insulin dependence.

CONCLUSION

Tacrolimus-based therapy resulted in significantly reduced risk of graft failure, without an increase in the incidence of adverse events associated with long-term immunosuppression.

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

Cyclosporin is a lipophilic cyclic polypeptide immunosuppressant that interferes with the activity of T cells chiefly via calcineurin inhibition. The original oil-based oral formulation of this drug (Sandimmun)l was characterised by high intra- and interpatient pharmacokinetic variability, with poor bioavailability in many patients; a novel microemulsion formulation (Neoral)1 was therefore developed to circumvent these problems. Studies show increases, attributable chiefly to improved absorption in patients who absorb the drug only poorly from the original formulation, in mean systemic exposure to cyclosporin with the microemulsion, with no clinically significant differences in tolerability or drug interaction profiles. Cyclosporin microemulsion is at least as effective as the oil-based formulation in renal, liver and heart transplant recipients, with trends towards decreased incidence of acute rejection with the microemulsion formulation in some (statistically significant in a few) trials. Cyclosporin microemulsion and tacrolimus appear to have similar efficacy in preventing acute rejection episodes in most renal, pancreas-kidney, liver and heart transplant recipients. However, there are indications of superior efficacy for tacrolimus in some trials, particularly in the prevention of severe acute rejection and in Black transplant recipients. Current 12-month data also indicate equivalent efficacy of sirolimus in renal transplantation. Conversion from the oil-based to microemulsion formulation in stable renal, liver and heart transplant recipients is achievable with no change in acute rejection rates. The addition of an anti-interleukin-2 receptor monoclonal antibody and/or mycophenolate mofetil to cyclosporin microemulsion plus corticosteroids decreases rates of acute rejection; corticosteroid withdrawal without increased acute rejection rates was also achieved on the addition of these agents in some trials. Pharmacoeconomic analyses have shown savings in direct healthcare costs in kidney or liver transplantation when cyclosporin microemulsion is used in preference to the oil-based formulation, although studies incorporating indirect costs or expressing costs in terms of therapeutic outcomes are currently unavailable.

CONCLUSIONS

The introduction of cyclosporin microemulsion has consolidated the place of the drug as a mainstay of therapy in all types of solid organ transplantation; research into optimisation of outcomes through more effective therapeutic monitoring in patients receiving this formulation is ongoing. Several novel immunosuppressants have been introduced in recent years: further clinical and pharmacoeconomic research will be needed to clarify the relative positioning of these agents, particularly with respect to specific patient groups. Other new drugs (basiliximab/daclizumab and mycophenolate mofetil) offer particular advantages when used in combination with cyclosporin.

Effects of changing immunosuppressive regimen on the incidence, duration, and viral load of cytomegalovirus infection in renal transplantation: a single center report

Background. In this retrospective single center study we have evaluated the relation between the immunosuppressive regimen and the incidence and characteristics of cytomegalovirus (CMV) infection in the setting without CMV prophylaxis from 1989 through 1998. Methods. All (470) first cadaveric renal transplantations in nonsensitized (PRA < 60%) patients were analyzed. Immunosuppression consisted of cyclosporine A (Sandimmune) and prednisolone from 1989 through 2-1993 (S; 189 patients), of cyclosporine microemulsion (Neoral) and prednisolone from 3-1993 through 5-1997 (N; 200 patients) and of mycophenolate mofetil, Neoral and prednisolone from 5-1997 until 1998 (M; 81 patients). The CMV pp65-antigenemia was measured routinely at least once weekly from day 10 till 12 weeks after transplantation or until pp65-antigenemia became negative. No CMV-prophylaxis was given. Results. By changing from Sandimmune to Neoral and by adding mycophenolate mofetil, respectively, we observed a higher frequency of especially secondary CMV infections (S vs. N vs. M, respectively, 28 vs. 50 vs. 63%, P = 0.026; S vs. N, P = 0.027; S vs. M, P = 0.015; and N vs. M, n.s). The CMV infections lasted longer (median duration antigenemia S vs. N vs. M, respectively, 3 vs. 5 vs. 7 weeks, P = 0.0003; S vs. N, P < 0.002; S vs. M, P < 0.001; and N vs. M, P < 0.05). Viral load was higher in M (median maximal pp65-antigenemia S vs. N vs. M, respectively, 19 vs. 14.5 vs. 73, P < 0.01; S vs. N, n.s.; S vs. M, P < 0.001 and N vs. M, P < 0.01). Conclusions. The use of Neoral and the addition of mycophenolate mofetil caused significant changes in the incidence, duration and viral load of CMV infections.

Cyclosporine microemulsion and tacrolimus are associated with decreased chronic allograft failure and improved long-term graft survival as compared with sandimmune

Tacrolimus and cyclosporine in the microemulsion formulation Neoral have demonstrated improvements in acute rejection rates after renal transplantation compared with conventional cyclosporine formulation, Sandimmune. To evaluate whether these drugs are also associated with improvements in chronic allograft failure (CAF) rates, we retrospectively analyzed 32,040 primary renal allograft recipients reported to the United States Renal Data System (USRDS) between 1994 and 1997. Graft loss secondary to CAF was defined as graft loss beyond 6 months post-transplant, censored for death, acute rejection, thrombosis, infections and noncompliance. A Cox proportional hazard model was used to investigate the relationship between graft loss secondary to CAF and the use of conventional cyclosporine formulation, as opposed to cyclosporine microemulsion and tacrolimus (Prograf). The analysis was corrected for confounding variables, such as acute rejection, sex, race, human leukocyte antigen (HLA) mismatch, % panel reactive antibodies (PRA), delayed graft function (DGF), cold ischemia time, induction therapy, dialysis time, etiology of end-stage renal disease, cytomegalovirus (CMV) risk group, donor source, era effect, and mycophenolate mofetil (MMF) use. Cyclosporine microemulsion use was associated with a significantly lower relative risk (RR = 0.6, Cl = 0.5-0.7) for CAF as opposed to conventional cyclosporine formulation. Likewise tacrolimus as compared with conventional cyclosporine formulation was associated with a significantly lower relative risk (RR = 0.7, CI = 0.6-0.8) for CAF. Conventional cyclosporine formulation treatment was associated with a 87.6% adjusted CAF-free survival rate at 4 years. Both tacrolimus and cyclosporine microemulsion were associated with a significantly better adjusted CAF-free survival at 4years (91.4 and 92.4%, respectively). Both cyclosporine microemulsion and tacrolimus are associated with improved graft survival and a decreased relative risk for CAF when compared with the older conventional cyclosporine formulation. This association is independent of the use of MMF or changes in era.

[Neoral (Cyclosporin microemulsion preconcentrate): pharmacokinetics, pharmacodynamics and its improved clinical outcome]

Sandimmun displays considerable inter- and intra-patient variability because its absorption is bile-dependent and affected by concomitant intake of food. Neoral is a microemulsion preconcentrate; a microemulsion is a mixture of the lipophilic active substance with accurately balanced amounts of lipophilic solvent, hydrophilic solvent and surfactant. As the result of advanced microemulsion technique, Neoral has more consistent and improved absorption characteristics. Cyclosporin (cyclosporin A) has been used as an immunosuppressive agent. The major pharmacodynamic action of cyclosporin within T cells is calcineurin inhibition. The complex cyclophilin-cyclosporin competitively binds to the Ca(2+)- and calmodulin-dependent phosphatase calcineurin which then inhibits downstream dephosphorylation and activation of NFAT(transcription factor). The greatest calcineurin inhibition is seen 1-2 h after administration of Neoral in parallel to the highest blood concentration. Variability in cyclosporin exposure was also identified as a risk factor for acute rejection in organ transplant recipients. "Absorption profiling" provides a more accurate prediction of drug exposure and leads to less acute rejection and toxicity. The evolution of Neoral monitoring strategies from trough level to absorption profile will raise the standard of performance of Neoral, resulting in clinical benefits for transplant patients.

Microemulsion cyclosporin formulation, in contrast to the old formulation, widens the T lymphocyte subsets differences between stable and acute rejection of kidney transplants

BACKGROUND

The new cyclosporin (CsA) formulation, Neoral, has different pharmacokinetics compared with Sandimmune (SIM). Larger area under the curve (AUC) values with equivalent trough blood values are reached when Neoral is administered at equivalent doses to SIM. Previously, we showed a great diagnostic reliability when using cytofluorometric analysis from fine-needle aspiration biopsy (FNAB) samples. We investigated possible changes brought about by Neoral on lymphocyte subsets and the repercussions on the activation score cut-off for acute rejection, defined under SIM treatment.

METHODS

Of 63 patients that received SIM, 40 remained rejection-free and 23 suffered one episode of rejection. Of 52 patients that received Neoral, 38 remained rejection-free. Peripheral blood lymphocytes (PBL) and lymphocytes from FNAB taken on days 7 and 14 post-transplantation and on the first day of acute rejection were analysed by flow cytometry.

RESULTS

Trough blood CsA levels were not different between SIM and Neoral treatments. Among rejection-free patients, a significant down-regulation of CD3DR and of CD8DR expression on both graft-infiltrating lymphocytes (GIL) and PBL, and significant up-regulation of naïve T cells on GIL were observed with Neoral. These changes were followed by a significant down-regulation of the activation score with Neoral. Conversely, within the acute rejection group, the activation score was significantly higher with Neoral than with SIM. The activation score performed equally well in Neoral transplants compared with what we had reported with SIM.

CONCLUSIONS

Our study indicates that Neoral elicits stronger immunosuppressive effects in stable patients, which eventually should translate into better clinical efficiency. However, when acute rejection supervenes, the treatment breakthrough seems stronger with Neoral. Cytofluorometric studies from FNAB samples showed that diagnostic reliability was maintained at a high level under Neoral therapy.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Maintenance immunosuppression: new agents and persistent dilemmas

Since the approval of cyclosporine in 1983, only 3 drugs, mycophenolate mofetil, tacrolimus, and sirolimus, have been approved for maintenance immunosuppression in renal transplant recipients. All 3 agents decrease the incidence of early acute allograft rejection. An increase in intermediate and long-term graft survival has not been shown. However, survival data from these clinical trials should be interpreted with caution because the studies were not designed for this purpose. All 3 drugs have significant, albeit different, safety profiles. It remains to be seen whether, the lower incidence of hypertension and hyperlipidemia seen in tacrolimus-treated patients will reduce the incidence and severity of the cardiovascular disease experienced by renal transplant recipients. Sirolimus causes severe hyperlipidemia, and the long-term consequences both on the pathogenesis of cardiovascular disease and on lipid-associated renal injury have yet to be determined. Tacrolimus and mycophenolate mofetil appear to increase graft survival in pancreas-kidney recipients but their efficacy in another high-risk group, African-American recipients, has not yet been clearly shown. However, the trend toward improved graft survival in African-American recipients treated with tacrolimus is encouraging. Steroid-withdrawal remains a goal in the posttransplant period. The available data from steroid-withdrawal and steroid-avoidance clinical trials are mixed. Steroid withdrawal can be achieved in about 50% of patients on a cyclosporine-based immunosuppression regimen. Steroid-withdrawal under coverage of tacrolimus, mycophenolate mofetil or Neoral (Novartis Pharmaceuticals, East Hanover, NJ) may be more successful than that achieved in patients receiving Sandimmune (Novartis Pharmaceuticals). Further studies are needed in this area.

Randomized trial of tacrolimus (Prograf) in combination with azathioprine or mycophenolate mofetil versus cyclosporine (Neoral) with mycophenolate mofetil after cadaveric kidney transplantation

BACKGROUND

Our clinical trial was designed to investigate the optimal combination of immunosuppressants for renal transplantation.

METHODS

A randomized three-arm, parallel group, open label, prospective study was performed at 15 North American centers to compare three immunosuppressive regimens: tacrolimus + azathioprine (AZA) versus cyclosporine (Neoral) + mycophenolate mofetil (MMF) versus tacrolimus + MMF. All patients were first cadaveric kidney transplants receiving the same maintenance corticosteroid regimen. Only patients with delayed graft function (32%) received antilymphocyte induction. A total of 223 patients were randomized, transplanted, and followed for 1 year.

RESULTS

There were no significant differences in baseline demography between the three treatment groups. At 1 year the results are as follows: acute rejection 17% (95% confidence interval 9%, 26%) in tacrolimus + AZA; 20% (confidence interval 11%, 29%) in cyclosporine + MMF; and 15% (confidence interval 7%, 24%) in tacrolimus + MMF. The incidence of steroid resistant rejection requiring antilymphocyte therapy was 12% in the tacrolimus + AZA group, 11% in the cyclosporine + MMF group, and 4% in the tacrolimus + MMF group. There were no significant differences in overall patient or graft survival. Tacrolimus-treated patients had a lower incidence of hyperlipidemia through 6 months posttransplant. The incidence of posttransplant diabetes mellitus requiring insulin was 14% in the tacrolimus + AZA group, 7% in the cyclosporine + MMF and 7% in the tacrolimus + MMF groups.

CONCLUSIONS

All regimens yielded similar acute rejection rates and graft survival, but the tacrolimus + MMF regimen was associated with the lowest rate of steroid resistant rejection requiring antilymphocyte therapy.

Tacrolimus: a further update of its pharmacology and therapeutic use in the management of organ transplantation

Tacrolimus (FK-506) is an immunosuppressant agent that acts by a variety of different mechanisms which include inhibition of calcineurin. It is used as a therapeutic alternative to cyclosporin, and therefore represents a cornerstone of immunosuppressive therapy in organ transplant recipients. Tacrolimus is now well established for primary immunosuppression in liver and kidney transplantation, and experience with its use in other types of solid organ transplantation, including heart, lung, pancreas and intestinal, as well as its use for the prevention of graft-versus-host disease in allogeneic bone marrow transplantation (BMT), is rapidly accumulating. Large randomised nonblind multicentre studies conducted in the US and Europe in both liver and kidney transplantation showed similar patient and graft survival rates between treatment groups (although rates were numerically higher with tacrolimus- versus cyclosporin-based immunosuppression in adults with liver transplants), and a consistent statistically significant advantage for tacrolimus with respect to acute rejection rate. Chronic rejection rates were also significantly lower with tacrolimus in a large randomised liver transplantation trial, and a trend towards a lower rate of chronic rejection was noted with tacrolimus in a large multicentre renal transplantation study. In general, a similar trend in overall efficacy has been demonstrated in a number of additional clinical trials comparing tacrolimus- with cyclosporin-based immunosuppression in various types of transplantation. One notable exception is in BMT, where a large randomised trial showed significantly better 2-year patient survival with cyclosporin over tacrolimus, which was primarily attributed to patients with advanced haematological malignancies at the time of (matched sibling donor) BMT. These survival results in BMT require further elucidation. Tacrolimus has also demonstrated efficacy in various types of transplantation as rescue therapy in patients who experience persistent acute rejection (or significant adverse effect's) with cyclosporin-based therapy, whereas cyclosporin has not demonstrated a similar capacity to reverse refractory acute rejection. A corticosteroid-sparing effect has been demonstrated in several studies with tacrolimus, which may be a particularly useful consideration in children receiving transplants. The differences in the tolerability profiles of tacrolimus and cyclosporin may well be an influential factor in selecting the optimal treatment for patients undergoing organ transplantation. Although both drugs have a similar degree of nephrotoxicity, cyclosporin has a higher incidence of significant hypertension, hypercholesterolaemia, hirsutism and gingival hyperplasia, while tacrolimus has a higher incidence of diabetes mellitus, some types of neurotoxicity (e.g. tremor, paraesthesia), diarrhoea and alopecia.

CONCLUSION

Tacrolimus is an important therapeutic option for the optimal individualisation of immunosuppressive therapy in transplant recipients.