The macrolide SDZ RAD is efficacious in a nonhuman primate model of allotransplantation

Novel everolimus-loaded nanocarriers for topical treatment of murine experimental autoimmune uveoretinitis (EAU)

In the present study, therapeutic effect of topically applied everolimus (EV)-loaded methoxy-poly(ethylene-glycol)-hexyl substituted poly (lactic acid) (mPEGhexPLA) nanocarriers on experimental autoimmune uveoretinitis (EAU) were investigated. EAU was induced in B10.RIII mice via immunization with human interphotoreceptor retinoid-binding protein peptide 161-180 (hIRBPp161-180) in complete Freund's adjuvant. Everolimus-loaded mPEGhexPLA (EV/mPEGhexPLA) nanocarriers were prepared by using a solvent evaporation method. On days 12-21 postimmunization (p.i.), the right eyes were treated five times daily either with 10 μl of 0.5% everolimus formulation or PBS (control). The EAU score of the eyes was determined histologically. On day 21 p.i., the peripheral immune responses were measured in serum, cervical lymph nodes (LN), and spleens via hIRBPp161-180-specific serum antibodies, cytokine secretion (ELISA), lymphocyte proliferation, and FoxP3+ regulatory T cells (Treg; flow cytometry). Compared to the PBS-treated mice, unilateral topical everolimus treatment significantly reduced EAU severity in both eyes (p < .05). The treatment reduced the antigen (Ag)-specific hIRBPp161-180-induced proliferation (p < .05), IL-2, IL-17, and IFN-γ secretion from cells isolated from the left and right cervical LN (p < .05). Under everolimus treatment, IL-10 secretion and CD4⁺CD25⁺FoxP3⁺ Treg frequency from cervical LN were enhanced. The proliferative response and cytokine secretion as well as the frequency of splenic Treg were almost unchanged. Topical administration of an everolimus formulation improved EAU in both eyes. The effect might also be related to systemic immunosuppressive effects, as several systemic cellular immune responses were influenced.

Cardiac allograft vasculopathy by intravascular ultrasound in heart transplant patients: substudy from the Everolimus versus mycophenolate mofetil randomized, multicenter trial

OBJECTIVES

A pre-planned substudy of a larger multicenter randomized trial was undertaken to compare the efficacy of everolimus with reduced-dose cyclosporine in the prevention of cardiac allograft vasculopathy (CAV) after heart transplantation to that of mycophenolate mofetil (MMF) with standard-dose cyclosporine.

BACKGROUND

CAV is a major cause of long-term mortality following heart transplantation. Everolimus has been shown to reduce the severity and incidence of CAV as measured by first year intravascular ultrasound (IVUS). MMF, in combination with cyclosporine, has also been shown to have a beneficial effect in slowing the progression of CAV.

METHODS

Study patients were a pre-specified subgroup of the 553-patient Everolimus versus mycophenolate mofetil in heart transplantation: a randomized, multicenter trial who underwent heart transplantation and were randomized to everolimus 1.5 mg or MMF 3 g/day. IVUS was performed at baseline and at 12 months. Evaluable IVUS data were available in 189 patients (34.6%).

RESULTS

Increase in average maximal intimal thickness (MIT) from baseline to month 12 was significantly smaller in the everolimus 1.5 mg group compared with the MMF group (0.03 mm vs. 0.07 mm, p < 0.001). The incidence of CAV, defined as an increase in MIT from baseline to month 12 of greater than 0.5 mm, was 12.5% with everolimus versus 26.7% with MMF (p = 0.018). These findings remained irrespective of sex, age, diabetic status, donor disease, and across lipid categories.

CONCLUSIONS

Everolimus was significantly more efficacious than MMF in preventing CAV as measured by IVUS among heart-transplant recipients after 1 year, a finding, which was maintained in a range of patient subpopulations. CV surgery: transplantation, ventricular assistance, cardiomyopathy.

Everolimus for the treatment of uveitis refractory to cyclosporine A: a pilot study

BACKGROUND

This study investigated the efficacy of everolimus, a potent inhibitor of T lymphocyte proliferation, for treating noninfectious uveitis. The study design was an open-label prospective trial.

METHODS

Twelve patients with severe chronic uveitis (anterior and intermediate n = 9, panuveitis n = 3) refractive to cyclosporine A (CsA) received additional everolimus.

MAIN OUTCOME MEASURE

the primary outcome measure was uveitis inactivity at 3 months. Secondary outcome measures were uveitis recurrence, visual acuity (BCVA), laser flare photometry values, cystoid macular edema, and tapering of concomitant corticosteroids and/or immunosuppressive drugs in 12 months with the addition of everolimus and after withdrawing everolimus. Percentages of peripheral blood CD3(+)CD4(+)CD25(+)Foxp3(+) cells were studied.

RESULTS

At month 3 with everolimus, uveitis was inactive in all patients. By 12 months, uveitis had recurred in four patients after tapering (n = 2) or withdrawing (n = 2) CsA. BCVA remained stable in all patients, mean foveal thickness (OCT) was slightly reduced from 308 μm at baseline to 255 μm (p = 0.1), and mean flare values were slightly reduced from 27.8 to 19.3 photons/msec (p = 0.1). It was possible to achieve a 50 % dose reduction of systemic prednisone (n = 8) or CsA (n = 8). After withdrawing everolimus, uveitis recurred in 50 % within 1 month; by 6 months, BCVA dropped ≥2 lines in five patients, and prednisone use increased ≥50 % in four patients. The percentage of peripheral blood CD3(+)CD4(+)CD25(+)FoxP3(+) T cells increased during the everolimus treatment, and dropped after withdrawal.

CONCLUSIONS

Uveitis inactivity was achieved with the addition of everolimus in patients with chronic, CsA-refractive anterior and intermediate uveitis, or panuveitis.

Everolimus as primary immunosuppression in kidney transplantation: experience in conversion from calcineurin inhibitors

BACKGROUND

We analyzed our clinical experience with everolimus (EVL) and identified prognostic factors for a successful conversion.

METHODS

Retrospective study of 220 kidney recipients consecutively converted to EVL with calcineurin inhibitor elimination. We studied risk factors for proteinuria at 1 year after conversion, decline in renal function, and graft survival.

RESULTS

Baseline creatinine clearance was 52.4±17.8 mL/min vs. 53.4±20.1 mL/min 1 year after conversion (P=0.150). Median proteinuria increased from 304 mg/day (interquartile range 160-507) to 458 mg/day (interquartile range 238-892; P<0.001). Risk factors for development of proteinuria ≥900 mg/day (P75) at 1-year postconversion were creatinine clearance less than 60 mL/min (odds ratio [OR] 3.37; 95% confidence interval [CI]: 1.15-9.89), serum triglycerides ≥150 mg/day (OR 4.35; 95% CI: 1.70-11.17), no treatment with prednisone (OR 3.04; 95% CI: 1.22-7.59), baseline proteinuria ≥550 mg/day (OR 10.37; 95% CI: 3.99-26.99), and conversion ≥3 years after transplant (OR 5.77; 95% CI: 1.89-17.59). An interaction was observed between baseline proteinuria and time to conversion: in patients with baseline proteinuria ≥550 mg/day, the risk of developing proteinuria ≥900 mg/day was 77.1% if they were converted after ≥3 years posttransplant. However, this risk was 29.8% in the subgroup converted before (P=0.02). Actuarial graft survival at 1 and 4 years postconversion was 98.2% and 86.5%, respectively. Baseline proteinuria ≥550 mg/day was a risk factor for graft loss in patients converted after the third year but not in patients converted before this time. EVL discontinuation rate was 24% in the first year postconversion.

CONCLUSIONS

Conversion to EVL and elimination of calcineurin inhibitors is safe. Success depends on not making late conversions and not converting patients with high baseline proteinuria.

Everolimus: an update on the mechanism of action, pharmacokinetics and recent clinical trials

BACKGROUND

A growing body of evidence suggests that everolimus might offer effective immunosuppressive activity together with antiproliferative effects that may address some of the unmet needs in the long-term therapeutic management of the post-transplant patient.

OBJECTIVE

To summarize the emerging evidence for employing everolimus-based immunosuppression.

METHODS

A systematic review was conducted of the Medline, Embase and Renal Health Library (Cochrane Collaboration) databases, and of the summary publications from international transplant meetings and congresses during 2000-2008.

RESULTS

This article summarizes this analysis, with special focus on the pharmacokinetic characteristics of everolimus and on the results of its use in renal transplantation. Some data has also been included about the efficacy of the drug in other solid organ transplantation and in tumours.

CONCLUSIONS

Everolimus is an immunosuppressant drug with proven efficacy in transplantation. When used in combination with cyclosporin, better results are obtained in renal function with low cyclosporin doses. Adverse events related to this drug are frequent and lead to moderate dropout rates.

RAD inhibition of sarcoma growth: implications for laryngeal transplantation

PURPOSE

Laryngeal transplantation has not been widely accepted because of concerns regarding accelerated tumor recurrences in the setting of nonspecific immunosuppression. Allotransplantation could potentially be offered to patients if immunosuppressive therapy could be demonstrated to exert tumor suppressive properties. Preliminary reports have demonstrated an antiproliferative effect of everolimus (RAD), a derivative of the immunosuppressant rapamycin.

MATERIALS AND METHODS

Forty-five 10-week-old inbred C57BL/6N (B6) mice were injected subcutaneously with 1 x 10(6) MCA205 sarcoma cells. On the third postinoculation day, the mice were divided into 4 treatment groups, undergoing daily gavage with RAD at 0, 0.2, 1.0, and 5.0 mg/kg per day for 10 consecutive days. Thereafter, treatment with RAD was discontinued and tumor size was measured every 2 days during treatment and biweekly until sacrifice on the 31st postinoculation day. Whole-blood trough levels (C(min)) were measured for each group.

RESULTS

Mean tumor diameter among the control animals and the mice treated with RAD 0.2 mg/kg per day demonstrated no significant difference (P > .07). Groups treated with RAD 1 and 5 mg/kg per day demonstrated significant growth inhibition between the 7th and the 23rd postinoculation days (P < .0001), with no significant differences being noted between these two groups (P > .09). Mean tumor suppressive whole-blood C(min)'s for the 1 and 5 mg/kg per day groups were 75.6 and 368.9 pg/microL, respectively.

CONCLUSIONS

RAD delivered at immunosuppressive doses of 1 and 5 mg/kg per day resulted in significant growth restriction of a fibrosarcoma in a murine model.

[Systemic immunosuppressives after penetrating keratoplasty]

Immunologic rejection is the main cause of corneal graft failure. If corneal transplantation is performed in a high-risk situation without the use of systemic immunosuppression, corneal graft failure has to be expected in over 50% of patients within the first postoperative year. The clonal expansion of graft-specific lymphocytes occurs in lymphoid tissues. As topical steroids do not reach the secondary lymphoid organs, and even systemic steroids do not interfere sufficiently with the clonal expansion of activated T cells, it is essential to administer systemic immunosuppressives in order to achieve clear graft survival. As corneal transplantation is not a life-saving procedure, the profile of side-effects is a central issue when choosing an immunosuppressive medication.

Everolimus (RAD) inhibits in vivo growth of murine squamous cell carcinoma (SCC VII)

OBJECTIVE

Everolimus (RAD) is an mTOR inhibitor closely related to rapamycin. A potent immunosuppressive agent, it has also shown evidence of antineoplastic properties. SCC VII is a spontaneously arising murine squamous cell carcinoma line. This study examines the effect of everolimus on SCC VII proliferation. The data may provide support for the use of everolimus in transplant recipients with a history of malignancy.

METHODS

A dose efficacy study was conducted that used a murine model of intradermal tumor growth and pulmonary metastases. The development of intradermal tumors and pulmonary metastases were studied. Of 80 total mice, 40 received intradermal injection of 1 x 10 SCC VII cells and 40 received intravenous injection of 1 x 10 cells to establish pulmonary metastases. Within each group, animals were subdivided into four subgroups that received 1) 1 mg/kg everolimus twice a day, 2) 0.5 mg/kg everolimus twice a day, 3) 7.5 mg/kg cyclosporine per day, and 4) no treatment. Intradermal tumors were measured three times per week. Animals receiving an intravenous tumor injection were killed after 17 days and pulmonary metastases were quantified. Medication trough levels were measured in all treated animals.

RESULTS

Everolimus showed statistically significant tumor inhibition at 1.0 mg/kg twice a day and 0.5 mg/kg twice a day when compared with animals treated with cyclosporine and with untreated animals (P < .0001). Tumor inhibition was evident in both models studied (intradermal tumors and pulmonary metastasis generation).

CONCLUSIONS

Everolimus provides potent tumor inhibition in animals inoculated with SCC VII cells. Inhibition of both local and distant spread of disease is evident. Although most immunosuppressives are known to potentiate neoplastic disease, this study supports the use of everolimus immunosuppression in the face of prior malignancy. This data has significant implication for laryngeal transplantation after laryngectomy.

Economic evaluation of everolimus vs. azathioprine at one year after de novo heart transplantation

BACKGROUND

Everolimus decreases acute rejection and cardiac allograft vasculopathy after heart transplantation. We compared within-trial costs and resource use over 1 yr of follow-up in de novo heart transplant patients randomized to everolimus 1.5 mg/d (n = 209), everolimus 3.0 mg/d (n = 211), or azathioprine (n = 214).

PATIENTS AND METHODS

Resource use data were collected prospectively for 634 patients from 14 countries. We used the nonparametric bootstrap method to test for differences in mean costs and to estimate confidence intervals for cost-effectiveness ratios.

RESULTS

Everolimus patients had lower incidence of efficacy failure compared with azathioprine patients (41.6%, everolimus 1.5 mg; 32.2%, everolimus 3.0 mg; 52.8%, azathioprine). Compared with patients receiving azathioprine, everolimus patients spent more days in the hospital [36.3 d for everolimus 1.5 mg/d (p = 0.21); 38.4 d for everolimus 3.0 mg/d (p = 0.01); 32.2 d for azathioprine]. Mean total costs, excluding the study medications, were not significantly different among treatment groups ($72 065 for everolimus 1.5 mg; $72 631 for everolimus 3.0 mg; $70 815 for azathioprine).

CONCLUSIONS

Over 1 yr of follow-up after heart transplantation, everolimus did not significantly increase treatment costs, excluding the costs of the study medications, while reducing efficacy failure. Longer follow-up and the cost of everolimus are required to fully evaluate the cost-effectiveness of everolimus vs. azathioprine in post-transplant maintenance.

Everolimus in pediatric de nova renal transplant patients

BACKGROUND

The steady-state pharmacokinetics of everolimus were longitudinally assessed in pediatric de novo kidney allograft recipients during a 6-month period.

METHODS

Nineteen patients received everolimus 0.8 mg/m2 (maximum 1.5 mg) twice daily as a dispersible tablet in water in addition to cyclosporine and corticosteroids. Everolimus and cyclosporine trough concentrations were obtained on days 3, 5, 6, and 7 and at months 1, 2, 3, and 6; an everolimus pharmacokinetic profile was obtained on day 7 and month 3.

RESULTS

There were 9 boys and 10 girls with a median age of 9.9 (range, 1-16) years. Steady-state pharmacokinetic parameters were as follows (median, range): C(min) (trough level), 4.7 (2.3- 9.5) ng/mL; peak concentration, 13.5 (5.9-22.2) ng/mL; area under the concentration-time curve (AUC), 77 (53-147) ng x hr/mL; and apparent oral clearance, 10.2 (5.5-15.6) L/hr/m2. Clearance (unadjusted for demographic factors) was positively correlated with age (r=0.66), body surface area (r=0.68), and weight (r=0.67). There were no trends in C(min) or AUC versus patient age when everolimus was dosed on a mg/m2 basis. Everolimus C(min) were stable over time with median values of 3.9, 3.4, and 3.1 ng/mL at months 1, 3, and 6, respectively. Intra- and interpatient variability in AUC was 29% and 35%, similar to that in adults. During the observation period, eight patients maintained stable AUCs and nine patients had increases or decreases, generally between 30% and 50% compared with the AUC at week 1. The concurrent median cyclosporine C(min) were generally at the lower end of conventional target ranges: 156, 83, and 69 ng/mL at months 1, 3, and 6, respectively. There were no graft losses and only three mild or moderate, reversible rejection episodes occurred. Everolimus was generally safe and well tolerated.

CONCLUSIONS

These data support the use of body surface area-adjusted dosing for everolimus in pediatric patients. Although exposure is generally stable over time with moderate variability in AUC, therapeutic monitoring would be a helpful adjunct for individualizing everolimus exposure, assessing regimen adherence, and adjusting doses as the child matures.

Evaluation for synergistic suppression of T cell responses to minor histocompatibility antigens by chloroquine in combination with tacrolimus and a rapamycin derivative, SDZ-RAD

The 4-aminoquinolines, chloroquine and hydroxychloroquine, can suppress chronic graft-versus-host disease (GVHD) following blood and marrow transplantation (BMT) in mice and humans, respectively. We hypothesized that chloroquine in combination with tacrolimus and the rapamycin derivative SDZ-RAD can synergistically suppress T cell responses and antigen-presenting cell (APC) function in vitro. We used the APC-dependent C57BL/6 anti-BALB.B T cell response and APC-independent anti-CD3epsilon antibody-induced response to evaluate the role of synergism between chloroquine and tacrolimus or SDZ-RAD on each component of a T cell response to minor histocompatibility antigens. We found that chloroquine with tacrolimus had a greater synergistic suppression of APC-dependent compared to the APC-independent T cell responses, with a combination index (CIx) for 50% inhibition by mean effect analysis of 0.16 and 0.50, respectively (a lower number indicates greater suppression). By contrast, chloroquine with SDZ-RAD had a similar CIx between the two responsed 0.50 vs0.45) suggesting only T cell suppression. Synergy between chloroquine and SDZ-RAD involved a direct effect on T cell cytokine production, whereas synergism between chloroquine and tacrolimus was due to an effect on both T cells and APCs. We conclude that the renal-sparing 4-aminoquinolines may be used syneristically with immunosuppressive drugs currently used for BMT.

Review of the proliferation inhibitor everolimus

Everolimus (Certican) is being developed for prevention of acute and chronic rejection of solid organ transplants. A novel proliferation inhibitor, everolimus synergies with cyclosporine to prevent and reverse acute rejection in preclinical models of kidney, heart or lung transplantation. The manifestations of chronic rejection that may contribute to graft loss are also inhibited by everolimus in preclinical models. Although everolimus is metabolised by the cytochrome P450 CYP3A isoenzyme, coadministration with cyclosporine does not alter the pharmacokinetics of cyclosporine, but cyclosporine coadministration increases exposure to everolimus. Everolimus interacts with inhibitors and inducers of this system; its clearance is reduced in patients with hepatic impairment. In an immunosuppressive regimen with cyclosporine microemulsion formulation and corticosteroids, transplant recipients treated with everolimus show low rates of acute rejection and, in one heart and one renal trial, lower rates of cytomegalovirus infection. Acute rejection rates are lower than those seen with azathioprine in cardiac transplant recipients and similar to those seen with mycophenolate mofetil in renal transplant recipients. Low rates of acute rejection are maintained when everolimus is given as part of a quadruple immunosuppressive regimen with low-dose cyclosporine in renal transplant recipients, with the added benefit of better renal function compared with full-dose cyclosporine. Use of C(2) monitoring to optimise cyclosporine exposure and enhance efficacy and safety of everolimus is planned in future studies. Hypertriglyceridaemia and hypercholesterolaemia have been associated with everolimus, but these effects are not dose-limiting. There is no clear upper therapeutic limit of everolimus. However, thrombocytopenia occurs at a rate of 17% at everolimus trough serum concentrations above 7.8 ng/ml in renal transplant recipients. There are limited safety data available in patients with trough concentrations > 12 ng/ml. Studies suggest everolimus targets primary causes of chronic rejection by reducing acute rejection, allowing for cyclosporine dose reduction (which may lead to improved renal function relative to full-dose cyclosporine) and by reducing cytomegalovirus infection and inhibiting vascular remodelling.

Single-dose pharmacokinetics and tolerability of everolimus in stable pediatric renal transplant patients

Everolimus (Certican; RAD), a novel macrolide with potent immunosuppressive and anti-proliferative activities, prevents acute rejection in adult recipients of renal transplantation. This phase I trial conducted in stable pediatric renal transplant patients examined the single-dose pharmacokinetics, safety, and tolerability of everolimus in combination with cyclosporin A (CsA; Neoral) and corticosteroids, with or without azathioprine. Nineteen pediatric patients were enrolled and received a single 1.2 mg/m2 dose of everolimus. Everolimus was safe and well tolerated, with a low incidence of adverse events reported and none judged to be related to the study medication. Everolimus administration did not increase infection rates or produce clinically significant changes in vital signs or changes in electrocardiograms. Apparent clearance and volume of distribution of everolimus increased with age, weight, and body surface area in a generally linear manner across the pediatric demographic ranges. Compared with adults from a previous study, apparent clearance (L/h) and distribution volume (L) were lower in pediatric patients, whereas the elimination half-life was similar. Single-dose everolimus co-administration did not affect the steady-state pharmacokinetics of CsA. Based on this information, pediatric patients will need a dose scaled down for body size, but can probably maintain the same twice-daily dosing schedule used in adults.

Early clinical experience with a novel rapamycin derivative

SDZ RAD (everolimus, Certican is a novel macrolide immunosuppressant that blocks growth factor-driven transduction signals in the T-cell response to alloantigen. After stimulation of the IL-2 receptor on the activated T-cell, SDZ RAD inhibits p70S6 kinase, acting at a later stage in the T-cell mediated response than do cyclosporine and other calcineurin inhibitors (CNIs). Unlike the CNIs, SDZ RAD is a proliferation signal inhibitor, blocking growth factor-driven proliferation of both hematopoietic and nonhematopoietic cells. These activities are complementary to those of cyclosporine and provide a rationale for the addition of SDZ RAD to cyclosporine-based immunosuppression, with the potential for minimizing CNI nephrotoxicity, reducing the incidence of acute rejection, and favoring long-term graft survival. Potential also exists for beneficial effects on other factors that may influence the development of chronic rejection. These factors include comorbid diseases such as hypertension, which may affect transplant vasculopathy, and opportunistic infection with cytomegalovirus (CMV) and other viruses, which may increase the risk of chronic rejection. The synergistic effect of SDZ RAD and cyclosporine has been confirmed in preclinical models, with graft survival being significantly prolonged in rat models of kidney and heart allotransplantation. Clinical experience with SDZ RAD in cyclosporine-based immunosuppression, including low-dose cyclosporine regimens, has also resulted in predictable and favorable clinical outcomes. Low rates of acute rejection, excellent rates of patient and graft survival, lower incidence of CMV infections, better cholesterol, triglyceride and creatinine profiles, and better renal function have been demonstrated with SDZ RAD and lower doses of cyclosporine (Neoral; Novartis) in recipients of renal transplants. These findings, combined with good tolerability rates and an acceptable side-effect profile, indicate that the synergistic profile of SDZ RAD in combination with nontoxic dosages of CNI's and IL2 inhibitors will further improve longterm results in renal transplantation.

Synergism of RAD and cyclosporin A in prevention of acute rat corneal allograft rejection

PURPOSE

The novel immunosuppressant RAD, 40-0-(2-hydroxy-ethyl)-rapamycin, has synergistic effects with cyclosporin A. The aim of this study was to evaluate the combined effect of RAD and cyclosporin A in the prevention of acute allograft rejection after murine corneal transplantation.

METHODS

Fisher donor corneas were implanted into Lewis recipients. Postoperative evaluation included slit-lamp biomicroscopy and immunohistology. Treatment groups were comprised of rats treated orally with RAD 2.5 mg/kg/day, cyclosporin A 10 mg/kg/day, RAD 1.5 mg/kg/day plus cyclosporin A 5 mg/kg/day.

RESULTS

Therapy with RAD 2.5 mg/kg and cyclosporin A 10 mg/kg led to a statistically significant and comparable prolongation of transplant survival. However. combination therapy was significantly superior. There was a significant reduction in the number of infiltrating cells in the animals treated with RAD and cyclosporin A.

CONCLUSIONS

This is the first study on the efficacy of a double drug regimen with RAD and cyclosporin A for the control of acute corneal allograft rejection. Combination therapy resulted in superior graft survival.

RAD in stable lung and heart/lung transplant recipients: safety, tolerability, pharmacokinetics, and impact of cystic fibrosis

BACKGROUND

RAD is a novel macrolide with potent immunosuppressive and antiproliferative activities. This study characterizes the safety, tolerability, and pharmacokinetics of two different single oral doses of RAD in stable lung and heart/lung transplant recipients with and without cystic fibrosis (CF).

METHODS

This was a Phase I, multicenter, randomized, double-blind, two-period, two-sequence, crossover study. Single doses of RAD capsules at doses of 0.035 mg/kg (2.5 mg maximum) or 0.10 mg/kg (7.5 mg maximum) were administered with cyclosporine (Neoral [cyclosporine, USP] modified), steroids, and azathioprine on Day 1. The alternate dose was administered on Day 16. Laboratory assessments, vital signs, and adverse events were recorded throughout the study. RAD pharmacokinetic profiles were assessed over a 7-day period following each dose. Steady-state cyclosporine (CsA) profiles were assessed at baseline and with each RAD dose; RAD and CsA trough concentrations were obtained throughout the study period.

RESULTS

Of the 20 patients randomized, 8 had CF and 12 did not. Single doses of RAD were safe and well tolerated. Headache was the most common side effect. RAD produced a mild, dose-dependent, reversible decrease in platelet and leukocyte counts. Cholesterol and triglycerides were minimally affected. At both doses, CF patients had significantly lower peak concentrations of RAD than did non-CF patients (p = 0.03); however, overall exposure (area under the curve/dose) was not different between the groups (p = 0.63). At the higher dose, there was a clinically minor under-proportionality in AUC, averaging -11%. Steady-state pharmacokinetics of CsA were not affected by RAD co-administration.RAD was safe and well tolerated by stable lung and heart/lung transplant recipients with and without CF. The presence of CF did not influence the extent of RAD exposure. Single doses of RAD did not affect the pharmacokinetics of CsA. Ongoing studies are assessing the long-term safety and efficacy of RAD in lung and heart/lung transplantation.

Pharmacokinetics and tolerability of 40-0-[2-hydroxyethyl]rapamycin in de novo liver transplant recipients

BACKGROUND

40-0-[2-Hydroxyethyl]rapamycin (RAD), a novel macrolide with potent immunosuppressive and antiproliferative activities, prevents rejection in animal allotransplantation models. This phase I trial assessed the effects of bile diversion, administration route, and time after transplant on RAD pharmacokinetics after single-dose administration in de novo liver allograft recipients. The influence of RAD on cyclosporine (CsA) pharmacokinetics and the safety of RAD were also evaluated.

METHODS

Twenty-six de novo liver allograft recipients were assigned to one of four treatment groups based on the presence or absence of a T tube, administration route (nasogastric or nasoduodenal), and timing of RAD administration. Patients received a single 7.5-mg RAD dose on one to three occasions in addition to CsA (Neoral) and corticosteroids. Steady-state cyclosporine profiles with and without RAD coadministration were evaluated. Results. Recipients with bile diversion demonstrated lower peak concentration (Cmax) than those without, but overall drug exposure (AUC) was not altered. Cmax and AUC were not influenced by administration route. A trend towards higher Cmax on postoperative day 3 than on postoperative day 1 was noted, although AUC was not altered. Single-dose RAD coadministration did not affect steady-state CsA pharmacokinetics. RAD was well tolerated and caused few drug-related adverse effects. RAD administration did not increase infection rates or produce clinically significant changes in laboratory parameters. Conclusions. In de novo liver transplant recipients, the overall extent of RAD absorption was not influenced by bile diversion, administration route, or time of administration. CsA pharmacokinetics were not affected by single-dose RAD coadministration. RAD capsules administered in single doses of 7.5 mg were well tolerated and safe.

Coadministration of the new macrolide immunosuppressant RAD and mycophenolate mofetil in experimental corneal transplantation

INTRODUCTION

The effect of RAD, a new macrolide immunosuppressant, was examined as mono- and combination therapy with mycophenolate mofetil (MMF) in prevention of acute allograft rejection in murine corneal transplantation.

METHODS

Both drugs were administered orally for 18 days beginning at the day of transplantation. The inbred strains Fisher and Lewis were used as donors and recipients, respectively. Five groups were involved: syngeneic control, allogeneic control, 2.5 mg/kg RAD, 40 mg/kg MMF, and double drug therapy with 1.5 mg/kg RAD and 20 mg/kg MMF.

RESULTS

The median transplant survival time in the allogeneic combination was 12 (+/-0.3) days. Monotherapy with 2.5 mg/kg RAD and 40 mg/kg MMF led to a statistically significant prolongation of transplant survival to 25.5 (+/-12.5, P=0.0001) days and 19.5 (+/-13.9, P=0.0053) days, respectively. Combination therapy was superior to both monotherapies (100+/-15.8 days, P=0.03). There was a significant reduction in the number of CD4+, CD8+, as well as CD45RA+ cells in the RAD- and double drug-treated animals when compared with the allogeneic control. This significant reduction in graft-infiltrating lymphocytes has not been found in the MMF monotherapy.

CONCLUSIONS

The unique finding of this first study on the combination of RAD and MMF in murine corneal transplantation is that double drug therapy produces a highly synergistic effect in prevention of acute allograft rejection without a higher incidence of complications related to drug toxicity or overimmunosuppression.

The novel immunosuppressant FTY720 induces peripheral lymphodepletion of both T- and B-cells in cynomolgus monkeys when given alone, with Cyclosporine Neoral or with RAD

OBJECTIVE

FTY720 is a new immunosuppressant active in transplantation models, which modulates lymphocyte recirculation, leading to transient peripheral lymphopenia and increased lymphocytes in lymph nodes and Peyer's patches. Here, we investigated the susceptibility of cynomolgus monkeys to FTY720 given orally either alone or in combination with two other immunosuppressants, Cyclosporin Neoral or RAD, as an introductory study to transplantation protocols.

METHODS

Each of the three phases of the study comprised a 3-week treatment period with FTY720 administered daily orally at 0.3, 0.1 or 0.03 mg/kg/day, respectively, followed by a 3-week recovery. FTY720 was given as single compound during the first week and in combination with Neoral at 20 mg/kg/day p.o. or RAD at 0.5 mg/kg/day p.o. during the subsequent 2 weeks.

MAIN FINDINGS

These treatment regimen were well tolerated, except for some body weight loss at high FTY720 dose (0.3 mg/kg/day). FTY720 treatment resulted in a rapid decrease of white blood cell counts which reached a plateau after 3 days. A decrease in both T- and B-lymphocyte counts by up to 80-90% was seen with FTY720 doses of 0.1 and 0.3 mg/kg/day. FTY720 blood levels, both trough levels and AUC(0-24 h), showed a linear relationship with FTY720 dose. The reduction in lymphocyte counts was not directly proportional to FTY720 blood levels. The exposure to FTY720 significantly increased upon coadministration of Neoral. This pharmacokinetic interaction was not observed for coadministration of RAD. However, the peripheral lymphodepletion was slightly increased after coadministration of RAD but not of Neoral. This may be related to the intrinsic effects of RAD on hematopoietic cells.

CONCLUSIONS

FTY720 given orally was effective in terms of peripheral T- and B-lymphodepletion and was well tolerated in cynomolgus monkeys even in combination with Cyclosporine Neoral or RAD, indicating that such combination protocols could be used in allo- and xenotransplantation in this species. However, the data indicate a potentiation of FTY720 exposure by CsA coadministration and additional lymphodepletion by coadministration of FTY720 and RAD which should be carefully monitored.

The peripheral lymphocyte count predicts graft survival in DA to Lewis heterotopic heart transplantation treated with FTY720 and SDZ RAD

OBJECTIVE

The new immunomodulator 2-amino-2-(2-[4-octylphenyl]ethyl)-1,3-propanediol hydrochloride (FTY720) lowers the peripheral lymphocyte count (PLC) by inducing migration of circulating lymphocytes to secondary lymphoid organs. This effect is dose-dependent at low (up to 0.1 mg/kg per day) doses in rats. We investigated the correlation between PLC and the later rejection, when FTY720 was combined with RAD.

METHODS

Heterotopic cardiac grafting was performed using the DA-Lewis strain combination. FTY720 and RAD were administered as single daily doses by gavage alone and in combination starting 3 days before to 28 days after transplantation. Graft survival was monitored daily by palpation. PLC was determined at 1 and 4 weeks, body weight (BW) weekly. Histologic evaluation of grafted hearts was performed after rejection.

MAIN FINDINGS

FTY720 at doses of 0.03, 0.1 and 0.3 mg/kg per day prolonged graft survival dose-dependently from 6 (placebo) to 7, 9.5 and 15 days median survival time (MST). RAD at doses of 0.3, 1 and 3 mg/kg per day delayed rejection to 8.5, 18 and 37.5 days MST. Very small FTY720 doses added to the lower RAD doses were effective in maintaining grafts throughout the treatment period and with normal weight gain, as opposed to regimens with 1 mg/kg or more per day RAD, which resulted in delayed weight gain. FTY720 lowered the PLC significantly and dose-dependently. The PLC correlated well with graft survival [Spearman rank correlation (n = 30, rs = -0.75)].

CONCLUSIONS

Fully effective FTY720 + RAD combination regimens caused no side effects with respect to the rats' general well-being or weight gain and were better tolerated than equiactive RAD monotherapy, suggesting a broader therapeutic window for the combinations. Under the experimental conditions, the PLC decrease showed an interesting correlation with the anti-rejection effects in these two-drug regimens. Thus, in rats the PLC is helpful for monitoring the biological activity of FTY720 at low doses (< 0.1 mg/kg per day), i.e. in the range of the steep part of its dose-response relationship.

The immunosuppressive macrolide RAD inhibits growth of human Epstein-Barr virus-transformed B lymphocytes in vitro and in vivo: A potential approach to prevention and treatment of posttransplant lymphoproliferative disorders

Whereas the standard immunosuppressive agents foster development of posttransplant lymphoproliferative disorders (PTLDs), the impact of RAD, a macrolide with potent immunosuppressive properties, and other immunosuppressive macrolides on these disorders remains undetermined. We found that RAD had a profound inhibitory effect on in vitro growth of six different PTLD-like Epstein-Barr virus+ lymphoblastoid B cell lines. Similar to normal T cells, RAD blocked cell-cycle progression in PTLD-like B cells in the early (G(0)/G(1)) phase. Furthermore, RAD increased the apoptotic rate in such cells. The drug also had a profound inhibitory effect on the growth of PTLD-like Epstein-Barr virus+ B cells xenotransplanted s.c. into SCID mice. The degree of the RAD effect varied among the three B cell lines tested and was proportional to its effects on the cell lines in vitro. In this in vivo xenotransplant model, RAD markedly delayed growth or induced regression of the established tumors. In one line, it was able to eradicate the tumor in four of eight mice. When RAD treatment was initiated before tumor cell injection, a marked inhibition of tumor growth was seen in all three lines. In two of them, the drug prevented tumor establishment in approximately 50% of mice (5/11 and 5/8). In summary, RAD is a potent inhibitor of PTLD-like cells in vitro and in vivo. These findings indicate that, in contrast to the standard immunosuppressive agents, macrolides such as RAD may be effective in prevention and treatment of PTLDs.

The novel immunosuppressant SDZ-RAD protects rat brain slices from cyclosporine-induced reduction of high-energy phosphates

1. SDZ-RAD, 40-O-(2-hydroxyethyl)-rapamycin, is a novel macrolide immunosuppressant. Because of its synergistic interaction, SDZ-RAD is under clinical investigation as immunosuppressant in combination with cyclosporine after organ transplantation. Neurotoxicity is a critical side-effect of cyclosporine. 2. We studied the effect of SDZ-RAD and its combination with cyclosporine on high-energy phosphates, phosphocreatine (PCr) and nucleoside triphosphates (NTP), in brain slices using 31P-magnetic resonance spectroscopy (MRS). 3. Cyclosporine significantly reduced high-energy phosphates after 2 h in a dose-dependent manner (100 micrograms l-1: 93 +/- 3% of control (NTP), 91 +/- 3% (PCr); 500 micrograms l-1: 84 +/- 2% (NTP), 73 +/- 2 (PCr); 5000 micrograms l-1: 68 +/- 3% (NTP), 55 +/- 5% (PCr); n = 6; P < 0.02). 4. In contrast, after perfusion for 2 h, SDZ-RAD (500 micrograms l-1 and 5000 micrograms l-1) significantly increased high-energy phosphate concentrations in the brain slices (P < 0.02). Even at the lowest concentration, SDZ-RAD protected brain energy metabolism against cyclosporine toxicity: 100 micrograms l-1 SDZ-RAD + 5000 micrograms l-1 cyclosporine: 86 +/- 3% (NTP), 83 +/- 7% (PCr), n = 3, P < 0.03 compared to cyclosporine alone. 5. As evaluated using an algorithm based on Loewe isobolograms, the effects of SDZ-RAD/cyclosporine combinations on brain energy reduction were antagonistic. Both drugs were found in mitochondria using h.p.l.c-MS analysis. 6. We conclude that cyclosporine inhibits mitochondrial high-energy phosphate metabolism, which can be antagonized by SDZ-RAD.

Combined immunosuppression with cyclosporine (neoral) and SDZ RAD in non-human primate lung transplantation: systematic pharmacokinetic-based trials to improve efficacy and tolerability

BACKGROUND

We studied the efficacy and tolerability of combined immunosuppressive therapy with cyclosporine A microemulsion (Neoral) plus the macrolide SDZ RAD 40-0 (2-hydroxyethyl) rapamycin (RAD) in a stringent cynomolgus monkey lung graft model in comparison with cyclosporine or SDZ RAD monotherapy.

METHODS

Thirty-nine cynomolgus monkeys received mixed lymphocyte reaction (MLR) mismatched unilateral lung transplants. Immunosuppressants were administered orally as single daily doses. The observation period was 28 days and follow-up included serial trough blood drug concentrations measured by high performance liquid chromatography/mass spectrometry, blood analyses, chest radiographs, open lung biopsies, as well as tissue drug concentrations and graft histology at necropsy.

RESULTS

Graft biopsies in monkeys treated with vehicle (n=4), Neoral (day 1-7: 150 mg/kg/day; day 8-28: 100 mg/kg/day; n=6; mean +/- SE trough level (MTL): 292+/-17 ng/ml) or SDZ RAD monotherapy (1.5 mg/kg/day; n=6; MTL: 15+/-1 ng/ml) showed severe rejection. Coadministration in two transplant monkeys of Neoral (150/100 mg/kg/day) and SDZ RAD (1.5 mg/kg/day) caused their early death. In both animals, SDZ RAD blood levels were more than 5-fold higher than under monotherapy (MTL: 82+/-18 ng/ml). Simultaneous administration (n=6) of Neoral (150/100 mg/kg/day; MTL: 217+/-16 ng/ml) and SDZ RAD (0.3 mg/kg/day; MTL: 24+/-2 ng/ml) improved graft outcome (mild rejection). Side effects included renal failure (n=2) and seizures (n=1). Three monkeys survived to day 28. In this group the MTL for cyclosporin was 143+/-13 and for RAD 38+/-3. Staggered treatment completely prevented rejection in four of six grafts. However, five of six monkeys had moderate to severe diarrhea. In a concentration-controlled trial of simultaneously administered Neoral and SDZ RAD in transplant monkeys (target SDZ RAD MTL: 20-40 ng/ml; cyclosporine MTL: 100-200 ng/ml) all six monkeys survived with improved drug tolerability and an average biopsy score of mild rejection.

CONCLUSION

Combination of orally administered SDZ RAD and Neoral showed excellent immunosuppressive efficacy in a stringent lung transplant model. The drug interaction and the narrow therapeutic index of this drug combination required careful dose adjustments to optimize tolerability and efficacy.

A phase I study of a 4-week course of SDZ-RAD (RAD) quiescent cyclosporine-prednisone-treated renal transplant recipients

BACKGROUND AND METHODS

This phase I, randomized, blinded, placebo-controlled study assessed the safety profile and pharmacokinetics of a 4-week course of once-daily, sequential ascending doses (0.75, 2.5, or 7.5 mg/day) of SDZ-RAD (RAD) capsules in renal transplant recipients on a stable regimen of cyclosporine (CsA; Neoral) and prednisone.

RESULTS

RAD displayed a similar spectrum of side effects as observed with rapamycin, namely, an increased incidence of infection associated with the augmented immunosuppression and a dose-related occurrence of thrombocytopenia, hypercholesterolemia, and hypertriglyceridemia, particularly at the 7.5-mg dose. The pharmacokinetic parameters of RAD showed dose proportionality, a good correlation between trough and area under the curve (AUC) concentrations, and a moderate accumulation of 2.5-fold. The drug was absorbed within 2 hr and displayed a 16-19-hr half-life, which is shorter than that of rapamycin. RAD reached steady state at 4 days. Preliminary kinetic-dynamic correlations indicate a correlation between thrombocytopenia (but not hyperlipidemia) and AUC, as well as maximum drug concentrations, and weight-adjusted dose. At the end of a 4-week course of simultaneous dosing, there was no evidence of a pharmacokinetic interaction between CsA and RAD.

CONCLUSION

This study suggests that the shorter half-life of RAD compared to rapamycin may confer the benefits of rapid attainment of steady state and dissipation of effects upon drug cessation. Controlled, multicenter trials are being planned to assess the impact of these features on clinical outcomes.