Experience with new cyclosporine formulations: Consupren and Neoral in renal transplant patients

Prograf five milligrams versus Tacrolimus medis in healthy volunteers: a bioequivalence study

For FDA approval, bioequivalence of a generic version of Tacrolimus must be demonstrated in a randomized, two-treatments, two-periods, two-sequences, single-dose crossover study in healthy adult volunteers. Currently there are at least 3 differents generic equivalent for Tacrolimus, that are approved by the EMA and the FDA, with a USA market share of nearly 50%. However, the market share of generic immunosuppressive drugs in the Middle East region is still very low due to the reluctance of the physician to accept Tacrolimus generics, considered to be a narrow therapeutic window drug, that are approved using the standard bioequivalence criteria of 80% to 125%. Herein we present a bioequivalence study of a new Tacrolimus generic, Tacrolimus Medis 5 mg developed by Medis Tunisia batch number 12G3003 compared with Prograf® 5 mg batch number 7202 manufactured by Astellas Toyama Co., Ltd. Japan and HIKMA Pharmaceuticals, Amman-Jordan in healthy adult volunteers using the 90%-111% criteria recommended for drugs with narrow therapeutic window. The study was, balanced, randomized, two-treatments, two-periods, two-sequences, single dose, crossover, comparative oral bioavailability study in healthy adult human volunteers. The study was carried out in accordance with the Basic Principles defined in the U.S. 21 CFR Part 312.20, the principles enunciated in the Declaration of Helsinki (World Medical Association Declaration of Helsinki). Thirty six non-smoking healthy, as determined by medical history, volunteers, 18 years and older, were included. Following randomization using a computer software (pharma solution) the volunteers were given a single oral dose of 5 milligrams following a 12 hour fast with a wash out period of 7 days. Pharmacokinetics profile with blood levels at: 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, and 24 hours were performed following each dose. Tacrolimus plasma level was determined using an HPLC validated method (Transmedical For Life S.A.R.L. Beirut Lebanon), for accuracy, suitability, reproducibility, precision , long-term stability and robustness. Physical examinations, hematology, urine analysis and serum chemistry tests were performed at screening and before dosing in each period and at end of the study. Volunteers were monitored for safety and adverse events throughout the study. Both products were bioequivalent at the entire pharmacokinetic parameters tested. The LSM were 95.31%-101.21% for AUC, 94.65%-101.11% for AUC0-inf, 97.15%-100.02% for Cmax and 91.54%-103.75% for Half-life. Respectively all of which are within the EU and FDA approval limits (90-111%) indicating that the 2 products are equivalent and switchable.

Bioavailability of a New Generic Formulation of Mycophenolate Mofetil MMF 500 Versus CellCept in Healthy Adult Volunteers

Several studies have revealed a decreased incidence of early graft rejection with the use of mycophenate mofetil (MMF). The cost of the drug is, however, prohibitive especially in developing countries with limited resources. We compared the pharmacokinetic profile of a new MMF generic formulation (MMF 500 batch number: 06T3001; Medis Tunis) with those of Cellcept, (batch number: M1427; Hoffmann La Roche, Switzerland) in healthy volunteers. The study was double-blinded to investigator and volunteers. It had a balanced randomized, two-treatment, two-period, two-sequence, single-dose, crossover, comparative oral bioavailability design in adult healthy human volunteers. The study was designed, performed, and monitored by CRO Transmedical s.a.l International (Beirut, Lebanon) in accordance with the Basic Principals defined in the US 21 CFR Part 312.20, and the principals enunciated in the World Medical Association Declaration of Helsinki. We included nonsmoking healthy volunteers between the ages of 22 and 45 years. The subjects were admitted to the hospital one night prior to blood sampling. After volunteers received the same dinner, they were fasted overnight and for 2 hours postdosing. At 8 am each person received a single oral dose of 500 mg of either formulation. Blood samples were collected to construct the pharmacokinetic profiles as follows: 0, 0.15, 0.30, 0.45 minutes and 1, 1.15, 1.30, 2, 4, 6, 10, 12, and 24 hours. Water and food intake were the same for all volunteers during the whole study period. Following an 8-day washout period, the subjects were crossed over. Plasma mycophenolic acid concentrations were determined using a high-performance liquid chromatography validated enzyme-linked immunosorbent assay-based method (TransMedical, Beirut Lebanon). Physical examinations, hematology, urinanalysis, serum chemistry tests, and liver enzymes were performed at screening and at the end of each period. Subjects were monitored for safety and adverse events throughout the study by two physicians (one from the hospital and one from TransMedical). The Cmax, Tmax, and AUC for MMF 500 were 10.14 ng/mL, 51.82 minutes, and 18.33 ng/mL/h vs 10.94 ng/mL, 49.09 minutes, and 17.46 ng/mL/h for CellCept, respectively. The 90% confidence intervals (LSM) of Cmax, Tmax, and AUC for MMF 500 were 92.7%, 105.6%, and 105%, respectively, which is within the Food and Drug Administration (FDA)-assigned range for immunosuppressive drugs (90% to 111%). These results indicated that the products are equivalent and switchable according to FDA rulings.

Switchability of neoral and equoral according to Food and Drug Administration rules and regulations

According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.

The pharmacokinetics of equoral versus neoral in stable renal transplant patients: a multinational multicenter study

We studied the pharmacokinetics (PKs) of the new generic cyclosporine formulation, Equoral capsules, after the switch from original formulation Neoral capsules in stable renal transplant patients. The study was carried out in accordance with the basic principles defined in the US 21 CFR Part 312.20 and the principles of the Declaration of Helsinki. The study included clinically stable first renal transplant patients maintained on cyclosporine with no rejection episode during the past 6 months. Hematology, biochemistry, and urine chemistry were determined on day 7, and day 21. The patients were all switched to Neoral (lot number 416MFD0601) on day 0 when the first sparse sampling PK was performed. On day 14 a 12-hour PK profile included predose, 30 minutes; 1 hour; 1 hour 30 minutes; 2 hours; 3 hours; 4 hours; 5 hours; 6 hours; 8 hours; 10-hours and 12-hour samples. Cyclosporine levels were determined using a CYA kit (Abbott TDx). On day 15 the patients were switched from Neoral capsules to Equoral capsules (lot 5T111014) at an equivalent dosage (mg/mg). The second sparse sampling PK was performed on day 21 and a 12-hour PK was performed on day 28. On the morning of day 29 patients were switched from Equoral capsules to Neoral capsules at an equivalent dosage (mg/mg). Additional concentrations were measured on days -7, 18, and 35. Safety parameters were monitored at each visit. The pharmacokinetics of both formulations were equivalent. The mean AUC for Neoral and Equoral was 2856 and 2892, respectively. The ratios of LSM and the 90% confidence intervals for the in-transformed parameters (AUC o-t, AUC inf, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, suggesting that Equoral and Neoral SGC are bioequivalent.

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.