Overview of the clinical experience with Neoral in transplantation

Comparison of clinical effects, trough and peak levels between branded and generic formulation of Cyclosporine in stable psoriatic patients

BACKGROUND

Cyclosporine A (CyA) is a drug for moderate-to-severe psoriasis. Recently, a generic formulation has been approved as bioequivalent to the branded one. The guidelines for the bioequivalence for critical-dose drugs with a narrow therapeutic range, such as CyA, are questionable. Therefore, it is important to assess the clinical outcome and the pharmacokinetics of different formulations in various patient groups. The current literature lacks of this information in dermatology. The primary objective of this prospective study is to investigate the clinical equivalence (in terms of maintenance of clinical effect) between the generic formulation of CyA and its branded one in patients with psoriasis. A secondary objective is to analyze their trough (C<inf>0</inf>) and peak levels (C<inf>2</inf>).

METHODS

Twenty patients with stable psoriasis under treatment with the branded CyA were monitored in terms of clinical efficacy (psoriasis area severity index, PASI), safety (laboratory values), and their pharmacokinetics utilizing trough (C<inf>0</inf>) and peak plasma concentration (C<inf>2</inf>). The same patients were subsequently shifted to the generic formulation for comparison.

RESULTS

In our sample the efficacy of the two formulations was equal in most cases (P=0.863). A non-significant difference between the C<inf>0</inf> and C<inf>2</inf> of the branded CyA compared to the generic one emerged (respectively P=0.738 and P=0.695).

CONCLUSIONS

The branded and the generic formulations of CyA seem to be not only bioequivalent, but also comparable in terms of clinical efficacy in patients with psoriasis. However, larger samples are required to confirm these findings.

Comparison of the efficacy of tacrolimus and cyclosporine A in a murine model of dinitrofluorobenzene-induced atopic dermatitis

Tacrolimus (FK506) and cyclosporine A (Cys A) are immunosuppressive drugs used in the treatment of inflammatory diseases and for preventing rejection of allogeneic transplants. Tacrolimus forms a complex with FK506 binding protein (FKBP), and Cys A forms a complex with cyclophilin. These tacrolimus-FKBP and Cys A-cyclophilin complexes interact with calcineurin (CaN), thereby suppressing activation of T cells. In contrast, steroidal anti-inflammatory drugs suppress the immune system mainly via inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) and the activating protein-1 (AP-1) pathway. Previously, we reported that tacrolimus, but not dexamethasone, reduced scratching behavior in a murine model of atopic dermatitis. To elucidate the mechanism involved in the inhibition of scratching behavior, we used a mouse model of allergic dermatitis to compare the characteristics of tacrolimus and Cys A treatment. We found that Cys A suppressed scratching behavior induced by application of 2,4-dinitrofluorobenzene, as did tacrolimus. In addition, both drugs attenuated increases in vascular permeability and scratching behavior induced by passive cutaneous anaphylaxis. These results indicate that inhibition of the CaN pathway plays an important role in tacrolimus- and Cys A-induced inhibition of scratching behavior in mice. Furthermore, we observed that CaN inhibitors suppressed mast cell-dependent allergic reaction.

Healthcare costs in renal transplant recipients using branded versus generic ciclosporin

BACKGROUND

Generic ciclosporin A modified (CsA) does not have an equivalent pharmacokinetic profile to branded CsA in some transplant populations, potentially leading to negative clinical consequences and increased long-term costs.

OBJECTIVE

To assess direct healthcare costs for de novo renal transplant recipients in the US receiving branded versus generic CsA in the first month after transplantation.

METHODS

Administrative claims data from eight private US health plans were linked to the Organ Procurement and Transplantation Network data. A total of 227 renal transplant cases between 1996 and 2004 were included: 183 were dispensed branded CsA and 44 received generic CsA. Log transformed multiple linear regression was used to model total first-year healthcare costs after the initial CsA claim, controlling for both patient demographics and clinical characteristics and clustering at the transplant centre level.

RESULTS

After controlling for patient factors and pre-CsA costs, total healthcare costs were significantly higher (p = 0.04) for patients receiving generic CsA versus branded CsA. The main driver for the difference was the cost associated with immunosuppressants other than CsA (p = 0.01).

CONCLUSION

Despite initial perceived cost savings associated with generic CsA, de novo renal transplant recipients incurred greater total healthcare costs than those treated with branded CsA. Patients receiving generic CsA may need higher doses or other immunosuppressants to maintain the transplanted kidney than patients receiving branded CsA. Providers and payers need to be aware of potential differences in total healthcare costs between formulations of bioequivalent critical-dose drugs to make the best choice for patient care.

The Utility of the Population Approach Applied to Bioequivalence in Patients

Mixed-effect modeling was used to compare the population pharmacokinetics of 2 formulations of cyclosporine in patients. An open-label, multicenter, conversion study in stable, 6-month post-renal allograft recipients was conducted to compare the safety and pharmacokinetics of oral Pliva Cyclosporine Soft Gelatin Capsules (USP Modified) with Neoral (cyclosporine soft gelatin capsules, USP Modified) in stable post-renal transplant patients. Blood samples were collected predose and for 12 hours postdose on days 1, 14, 15, 28, and 29. Whole-blood samples were analyzed for cyclosporine using high-performance liquid chromatography and mass spectroscopy. Estimates of pharmacokinetic parameters were generated using noncompartmental and population compartmental pharmacokinetic analysis. Moreover, the effects of demographic factors on the pharmacokinetics of cyclosporine were evaluated using the nonlinear mixed-effects modeling program NONMEM. The rate and extent of bioavailability of cyclosporine did not differ between Pliva Cyclosporine Soft Gelatin Capsules and Neoral. In the final model, gender and actual body weight significantly affected the central and peripheral volumes of distribution. In addition, the pharmacokinetics of cyclosporine was defined robustly in this patient population using population pharmacokinetic approaches. Results indicate that the Pliva Cyclosporine Soft Gelatin Capsules and Neoral are bioequivalent when administered to renal transplant patients. Pliva Cyclosporine Soft Gelatin Capsules can then be substituted for Neoral in stabilized patients without anticipating dose adjustments.

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.

Impact of C2 measurement on cyclosporine Neoral dosing in a Latin-American transplant program: the Guatemalan experience

Optimal dosing of cyclosporine is difficult in transplant recipients. The introduction of the microemulsion Neoral in 1997 into our program and the measurement of C2 levels since 2000 in our center has allowed for more accurate individual dose finding. In our series, 141 transplant recipients (92 de novo, 49 maintenance) were followed for a 3-year period with C2 monitoring and serum creatinine levels as well as creatinine clearance studies. Biopsy proven acute rejection episodes appeared in three patients. The target levels of C2 during the first week were of vital importance to prevent acute rejection. Targets for the later periods of our study were somewhat lower than those recommended in North American or European studies. Even so, the incidence of acute rejection was low (3.2% for the de novo group). We feel that special populations like ours (mostly Mayan) deserve more attention regarding the finding of the optimal dose for immunosuppressive therapy after kidney transplantation.

The impact of cyclosporine on the development of immunosuppressive therapy

The first immunosuppressive regimens based on glucocorticoids and azathioprine were introduced in the early 1960s. However, many patients developed acute rejection, which required treatment with high doses of prednisolone. Leading to a high mortality due to opportunistic infection. Prior to 1985, our center used a regimen of prednisolone and azathioprine for 352 renal transplantations with 1-year graft and patient survival rates of 63.9% and 82.4%, respectively. Cyclosporine was introduced into clinical practice in 1978, enabling more effective control of acute rejection. In 1985, our center adopted a protocol consisting of prednisolone, azathioprine, and cyclosporine producing significantly increased 1-, 3-, and 5-year patient and graft survival rates for living-related and cadaveric renal transplants. Newer drug combinations, which are less toxic and more potent than cyclosporine based protocols, have further decreased acute rejection rates from 60% to approximately 10%. Still, graft loss continues to be a problem. We believe that the most recent strategy of combining monoclonal antibodies with less toxic agents, such as sirolimus and mycophenolate mofetil, may eventually replace calcineurin inhibitors. Such protocols would eliminate the side effects of calcineurin inhibitors, and possibly permit steroid-free maintenance therapy. The immunosuppressive therapy that is currently available is not ideal; the ability to convert patients to a state of permanent immunologic tolerance would minimize the need for these drugs. The new generation of agents that includes FTY 20, anti-sense oligonucleotides, and agents capable of blocking the costimulatory pathway of allorecognition may improve host tolerance.

An evaluation of combined immunosuppression with MNA 715 and microemulsified cyclosporine on renal allograft rejection in mismatched mongrel dogs

OBJECTIVE

To evaluate a combination of MNA 715 and microemulsifed cyclosporine for the prevention of renal allograft rejection in mismatched mongrel dogs.

STUDY DESIGN

Randomized, experimental study.

ANIMALS

Fourteen female mismatched mongrel dogs.

METHODS

Heterotopic renal transplantation and bilateral nephrectomy were performed in each dog. Dogs were randomly assigned to receive either MNA 715 and cyclosporine (n = 8) or cyclosporine alone (n = 6). Dogs were killed at 100 days after transplantation or when plasma creatinine exceeded 7 mg/dL.

RESULTS

In the cyclosporine and MNA 715 group: 4 dogs survived to 100 days with normal plasma creatinine concentrations; 2 dogs with intestinal intussusceptions were killed at 5 and 8 days, 1 dog with a wound infection and sepsis was killed at 14 days, and 1 dog with a serum creatinine concentration >7 mg/dL was killed at 51 days postoperatively. In the cyclosporine-alone group: 3 dogs with acute rejection were killed at 6 to 9 days and 3 dogs survived to 100 days. In dogs treated with cyclosporine and MNA 715, survival to histologically confirmed acute rejection was significantly longer (P =.044) and the degree of mononuclear cell infiltration was significantly reduced (P =.040), compared with dogs treated with cyclosporine alone.

CONCLUSIONS

MNA 715 combined with cyclosporine prolonged allograft survival and reduced the severity of histologic rejection in a clinically relevant renal transplant model.

CLINICAL RELEVANCE

An immunosuppressive regimen consisting of MNA715 and microemulsified cyclosporine may be effective in preventing allograft rejection in canine renal transplant patients.

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.

Cyclosporin ameliorates traumatic brain-injury-induced alterations of hippocampal synaptic plasticity

Although traumatic brain injury (TBI) often results in impaired learning and memory functions, the underlying mechanisms are unknown and there are currently no treatments that can preserve such functions. We studied plasticity at CA3-CA1 synapses in hippocampal slices from rats subjected to controlled cortical impact TBI. Long-term potentiation (LTP) of synaptic transmission was markedly impaired, whereas long-term depression (LTD) was enhanced, 48 h following TBI when compared to unoperated and sham control rats. Post-TBI administration of cyclosporin A, a compound that stabilizes mitochondrial function, resulted in a highly significant amelioration of the impairment of LTP and completely prevented the enhancement of LTD. Our data suggest that alterations in hippocampal synaptic plasticity may be responsible for learning and memory deficits resulting from TBI and that agents such as cyclosporin A that stabilize mitochondrial function may be effective treatments for TBI.