Long-term safety, tolerability and efficacy of daclizumab (Zenapax) in a two-dose regimen in liver transplant recipients

miR-151-5p alleviates corneal allograft rejection by activating PI3K/AKT signaling pathway and balancing Th17/Treg after corneal transplantation via targeting IL-2Rɑ

Background

Worldwide, corneal transplantation (CT) is the most common type of tissue replacement and the increased rate of corneal graft rejection (CGR) after CT is a critical problem. Corneal endothelium cells (CECs) are often targets of the immune response mediated by graft-attacking effector T cells. However, the molecular mechanism underlying CGR remains poorly understood.

Methods

The differentially expressed microRNAs (miRNAs) and mRNA of graft-fail corneas were measured by transcriptome sequencing (RNA-Seq). real-time quantitative polymerase chain reaction was used to measure gene expression levels. Western blot and immunofluorescence staining were used to measure protein expression levels. Kaplan-Meier survival curves were constructed to assess corneal graft survival. Hematoxylin and eosin staining was used for histopathological examination. CCK-8 and ELISA staining were used to detect cell viability and inflammatory cytokines levels, respectively. Flow cytometry was used to detect cell apoptosis and the population of Treg and Th17. Transwell migration and wound-healing assays were used to measure cell migration.

Results

We identified 453 miRNAs and 4,279 mRNAs aberrant expression in the corneas showing CGR. The differentially expressed miR-151-5p and its potential target gene [interleukin 2 receptor subunit alpha (IL-2Rɑ)] were selected from the RNA-Seq microarrays. The levels of miR-151-5p and IL-2Rɑ were respectively downregulated and upregulated in the CGR. The luciferase activity assay suggested that IL-2Rɑ is a target of miR-151-5p in 293 T cells. In addition, the miR-151-5p inhibitor, si-IL-2Rɑ, and oe-IL-2Rɑ transfection tests in CECs further confirmed that miR-151-5p downregulation and IL-2Rɑ overexpression promoted apoptosis of CECs and inhibited CEC migration, tight junction-related protein ZO-1 and Claudin-5 expression, and PI3K/AKT signaling pathway activity; however, downregulation of IL-2Rɑ abolished the inhibitor effect of miR-151-5p. Similarly, upregulation of miR-151-5p alleviated CGR via activation of the PI3K/AKT signaling pathway and balancing of Th17/Treg, and upregulation of IL-2Rɑ abolished the alleviating effect of miR-151-5p.

Conclusions

Upregulation of miR-151-5p alleviated CGR by activating the PI3K/AKT signaling pathway and balancing Th17/Treg via targeting of IL-2Rɑ, which contributes to improving the results of CT.

Selection and use of immunosuppressive therapies after liver transplantation: current German practice

In recent years, immunosuppression (IS) after liver transplantation (LT) has become increasingly diversified as the choice of agents has expanded and clinicians seek to optimize the balance of immunosuppressive potency with the risk of adverse events in individual patients. Calcineurin inhibitors (CNIs) are the primary agents used for patients undergoing liver transplantation. Other therapeutic agents like interleukin-2 receptor antagonists are not universally administered, but can be considered for the delay or reduction in CNI exposure. An early addition of mycophenolate mofetil (MMF) or the mTOR inhibitor everolimus also allows for the reduction in the CNI dose. To reduce the risk of malignancy, in particular of skin tumors, as well as to prevent the deterioration of renal function, everolimus-based therapy may be advantageous. Apart from patients with autoimmune hepatitis, steroids are withdrawn within 3-6 months after transplantation. Overall, immunosuppression can only be standardized in a limited proportion of patients due to specific clinical requirements and risk factors. Future studies should attempt to refine accurate individualization of the immunosuppressive regimen in specific difficult-to-treat patient subpopulations.

A randomized controlled trial of daclizumab versus anti-thymocyte globulin induction for heart transplantation

Background

The purpose of this study was to test the efficacy and safety of daclizumab (DZM) versus anti-thymocyte globulin (ATG) as a component of induction therapy in heart transplant recipients.

Methods

Thirty heart transplant patients were randomized to receive either ATG or DZM during induction therapy. Patients in the DZM group received an initial dose of 2 mg/kg intravenous (IV) at the time of transplant and 1 mg/kg IV on postoperative day 4.

Discussion

Recipient, donor, and intraoperative variables did not differ significantly between groups. The cost of induction therapy, total drug cost, and hospital ward costs were significantly less for the DZM group. Average absolute lymphocyte and platelet counts were significantly higher in the DZM group. There were no significant differences in the incidence of rejection, infection, malignancy, or steroid-induced diabetes. One year survival was excellent in both groups (87%, P = 0.1). Daclizumab is a safe component of induction therapy in heart transplantation.

Antibody induction versus corticosteroid induction for liver transplant recipients

BACKGROUND

Liver transplantation is an established treatment option for end-stage liver failure. To date, no consensus has been reached on the use of immunosuppressive T-cell specific antibody induction compared with corticosteroid induction of immunosuppression after liver transplantation.

OBJECTIVES

To assess the benefits and harms of T-cell specific antibody induction versus corticosteroid induction for prevention of acute rejection in liver transplant recipients.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 30 September 2013 together with reference checking, citation searching, contact with trial authors and pharmaceutical companies to identify additional trials.

SELECTION CRITERIA

We included all randomised clinical trials assessing immunosuppression with T-cell specific antibody induction versus corticosteroid induction in liver transplant recipients. Our inclusion criteria stated that participants within each included trial should have received the same maintenance immunosuppressive therapy.

DATA COLLECTION AND ANALYSIS

We used RevMan for statistical analysis of dichotomous data with risk ratio (RR) and of continuous data with mean difference (MD), both with 95% confidence intervals (CIs). We assessed risk of systematic errors (bias) using bias risk domains with definitions. We used trial sequential analysis to control for random errors (play of chance).

MAIN RESULTS

We included 10 randomised trials with a total of 1589 liver transplant recipients, which studied the use of T-cell specific antibody induction versus corticosteroid induction. All trials were with high risk of bias. We compared any kind of T-cell specific antibody induction versus corticosteroid induction in 10 trials with 1589 participants, including interleukin-2 receptor antagonist induction versus corticosteroid induction in nine trials with 1470 participants, and polyclonal T-cell specific antibody induction versus corticosteroid induction in one trial with 119 participants.Our analyses showed no significant differences regarding mortality (RR 1.01, 95% CI 0.72 to 1.43), graft loss (RR 1.12, 95% CI 0.82 to 1.53) and acute rejection (RR 0.84, 95% CI 0.70 to 1.00), infection (RR 0.96, 95% CI 0.85 to 1.09), hepatitis C virus recurrence (RR 0.89, 95% CI 0.79 to 1.00), malignancy (RR 0.59, 95% CI 0.13 to 2.73), and post-transplantation lymphoproliferative disorder (RR 1.00, 95% CI 0.07 to 15.38) when any kind of T-cell specific antibody induction was compared with corticosteroid induction (all low-quality evidence). Cytomegalovirus infection was less frequent in patients receiving any kind of T-cell specific antibody induction compared with corticosteroid induction (RR 0.50, 95% CI 0.33 to 0.75; low-quality evidence). This was also observed when interleukin-2 receptor antagonist induction was compared with corticosteroid induction (RR 0.55, 95% CI 0.37 to 0.83; low-quality evidence), and when polyclonal T-cell specific antibody induction was compared with corticosteroid induction (RR 0.21, 95% CI 0.06 to 0.70; low-quality evidence). However, when trial sequential analysis regarding cytomegalovirus infection was applied, the required information size was not reached. Furthermore, diabetes mellitus occurred less frequently when T-cell specific antibody induction was compared with corticosteroid induction (RR 0.45, 95% CI 0.34 to 0.60; low-quality evidence), when interleukin-2 receptor antagonist induction was compared with corticosteroid induction (RR 0.45, 95% CI 0.35 to 0.61; low-quality evidence), and when polyclonal T-cell specific antibody induction was compared with corticosteroid induction (RR 0.12, 95% CI 0.02 to 0.95; low-quality evidence). When trial sequential analysis was applied, the trial sequential monitoring boundary for benefit was crossed. We found no subgroup differences for type of interleukin-2 receptor antagonist (basiliximab versus daclizumab). Four trials reported on adverse events. However, no differences between trial groups were noted. Limited data were available for meta-analysis on drug-specific adverse events such as haematological adverse events for antithymocyte globulin. No data were available on quality of life.

AUTHORS' CONCLUSIONS

Because of the low quality of the evidence, the effects of T-cell antibody induction remain uncertain. T-cell specific antibody induction seems to reduce diabetes mellitus and may reduce cytomegalovirus infection when compared with corticosteroid induction. No other clear benefits or harms were associated with the use of T-cell specific antibody induction compared with corticosteroid induction. For some analyses, the number of trials investigating the use of T-cell specific antibody induction after liver transplantation is small, and the numbers of participants and outcomes in these randomised trials are limited. Furthermore, the included trials are heterogeneous in nature and have applied different types of T-cell specific antibody induction therapy. All trials were at high risk of bias. Hence, additional randomised clinical trials are needed to assess the benefits and harms of T-cell specific antibody induction compared with corticosteroid induction for liver transplant recipients. Such trials ought to be conducted with low risks of systematic error and of random error.

Interleukin-2 receptor blockade with humanized monoclonal antibody for solid organ transplantation

IMPORTANCE OF THE FIELD

Induction therapy has reduced the incidence of acute rejection compared with historical standards. The potency of currently available induction immunosuppression is not without risk and should be carefully considered. Induction with daclizumab, an IL-2 receptor antagonist, has been used safely and effectively for over 10 years across different transplant types. As a result of daclizumab use, transplant centers are able to implement steroid-sparing or calcineurin minimization protocols. Unfortunately, the manufacturing costs have resulted in withdrawal of this agent from the market reducing the options for patients undergoing transplantation.

AREAS COVERED IN THIS REVIEW

This review will update the reader on recently published daclizumab studies in adult solid organ transplant recipients, focusing on comparative studies with other induction agents.

WHAT THE READER WILL GAIN

This paper will provide a summary of comparative studies between daclizumab and other induction therapies focusing on their efficacy and safety.

TAKE HOME MESSAGE

Novel applications, such as long-term use in combination with calcineurin-inhibitor dose reduction and its value in the treatment of acute or chronic rejection have yet to be explored. Since daclizumab has been withdrawn from the market, future IL-2 receptor blockade will have to be achieved with basiliximab, which is a chimeric, monoclonal antibody directed against the same epitope.

Two-dose daclizumab induction in pediatric renal transplantation

DCZ, an IL-2 receptor antagonist, has been widely used for induction therapy in pediatric and adult solid organ transplantation. Originally, it was recommended as a five-dose regimen; however, fewer doses may be efficacious and less costly for prevention of rejection. There is limited experience with the use of fewer doses in pediatric renal transplantation. We retrospectively reviewed the outcomes of 26 primary pediatric renal transplants performed at a single center between June 2004 and May 2007 receiving induction therapy with two-dose DCZ (1.5 mg/kg preoperatively and day seven post-transplant). Maintenance immunosuppression included tacrolimus, MMF, and prednisone in all patients. Forty-six percent were African American and 92% were deceased-donor transplants. After a mean follow-up of 17.8 +/- 7.5 months, acute rejection was noted in 11.5% and graft survival was 92.3%. CMV infection occurred in 11.5%, but no case of BK nephropathy or post-transplant lymphoproliferative disorder was observed. Our preliminary results suggest that induction therapy with two-dose DCZ was convenient, economical, and effective in preventing rejection episodes without an increase in adverse events or hospital stay. Larger randomized clinical trials with longer duration of follow-up are needed to more fully validate the use of this regimen in pediatric renal transplantation.

Interleukin-2 in CD8+ T cells correlates with Banff score during organ rejection in liver transplant recipients

The aim of this study is to compare the histological grading of acute organ rejection according to the Banff score with intracellular interleukin-2 (IL-2) concentrations in cytotoxic CD8+ T cells from peripheral blood samples. 66 recipients after liver transplantation and 20 healthy controls were included into this study. Blood samples of liver transplant recipients were collected beside routine visits or, in case of suspected organ rejection, with additional liver biopsy. For cytometry, the blood cells were stained with CD3, CD8 and intracellular-IL-2. The percentage of cells with detectable intracellular IL-2 was significantly increased in patients with acute rejection (n = 7, P < 0.001, t Test) compared to recipients without rejection. The percentage of cells with detectable intracellular IL-2 (mean +/- SEM) was 7.6 +/- 0.9% in rejection patients, 2.3 +/- 0.22% in stable liver transplant recipients, and 14 +/- 2.99% in healthy controls. Intracellular IL-2 correlates to the Banff score in rejection patients (Spearmans-rho = 0.81, P < 0.05). This cytometric method shows a good sensitivity (71%) with a cut-off based on a high specificity of 95% for histological proven organ rejection in our study cohort. Measurement of intracellular IL-2 in cytotoxic CD8+ T-lymphocytes by flow cytometry correlates very well to the histological grading according to the Banff score and shows a good sensitivity and excellent specificity in acute organ rejection.

Daclizumab

Daclizumab is a humanized monoclonal antibody which binds to the IL-2 receptor on activated lymphocytes and blocks the production of IL-2. Its use is well established in solid organ transplantation as induction therapy, especially in high-risk patients where reduction or delayed dose of standard immunosuppression would be beneficial. It has been used effectively in both 2-dose and 5-dose regimens in conjunction with other standard immunosuppressive agents. The incidence of acute rejection appears reduced without increasing the rates of infection or post-transplant lympho-proliferative disorders. The agent is generally well tolerated in adults and children and there is no need for additional monitoring. Daclizumab has also been used outside the transplant arena in a variety of immune-mediated diseases with limited success.

Anti-Tac (daclizumab, Zenapax) in the treatment of leukemia, autoimmune diseases, and in the prevention of allograft rejection: a 25-year personal odyssey

Twenty-five years ago, we reported the production of the monoclonal antibody, anti-Tac that identifies the IL-2 receptor alpha subunit and blocks the interaction of IL-2 with this growth factor receptor. In 1997, daclizumab (Zenapax), the humanized form of this antibody, was approved by the FDA for use in the prevention of renal allograft rejection. In addition, we demonstrated that daclizumab is of value in the treatment of patients with noninfectious uveitis, multiple sclerosis, and the neurological disease human T-cell lymphotropic virus I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Others demonstrated therapeutic efficacy with daclizumab in patients with pure red cell aplasia, aplastic anemia, and psoriasis. Thus, translation of basic insights concerning the IL-2/IL-2 receptor system obtained using the monoclonal antibody daclizumab provided a useful strategy for the prevention of organ allograft rejection and the treatment of patients with select autoimmune diseases or T-cell leukemia/lymphoma.

Pharmacologic approaches to composite tissue allograft

This article discusses the pharmacologic approaches and the most promising new compounds for composite tissue allograft tolerance. Although some approaches rely on a combination of immunosuppressive agents that act synergistically against rejection, other strategies use immunologic manipulation, including major histocompatibility complex matching, induction of chimerism, and use of monoclonal antibodies to abrogate the immune response. There is still a need, however, to reproduce these findings in species phylogenetically closer to humans. This may be the target of future research efforts, which may overcome the challenge of limb and face transplant rejection.

Two-dose basiliximab compared with two-dose daclizumab in renal transplantation: a clinical study

BACKGROUND

Addition of the interleukin-2 receptor (IL-2R) antagonists basiliximab or daclizumab to a calcineurin inhibitor-based regimen significantly reduces risk of acute rejection with a tolerability profile similar to a placebo. Use of a truncated two-dose regimen of daclizumab has been reported, but till date, there has been no controlled study of two-dose daclizumab vs. two-dose basiliximab.

METHODS

Deceased-donor renal transplant recipients were randomized to basiliximab (20 mg on days 0 and 4) or daclizumab (50 mg on days 1 and 14) with cyclosporine, mycophenolate mofetil and corticosteroids. Flow cytometry was used to calculate the proportion of CD25(+) T cells in peripheral blood.

RESULTS

Thirty patients were randomized to basiliximab and 28 to daclizumab. There was one patient death in each group, with no other graft losses. By six months, the incidence of biopsy-proven acute rejection was 0% with basiliximab vs. 21.4% with daclizumab (p < 0.05). Three patients in the daclizumab group required OKT3 for steroid-resistant rejection. There were no between-group differences in the incidence of infection. The proportion of CD25(+) T cells declined markedly during the first two wk in both groups, but was significantly lower in the basiliximab group during weeks six to eight.

CONCLUSION

Two doses of basiliximab are more effective than two 1 mg/kg doses of daclizumab in preventing acute rejection in de novo renal transplant patients receiving cyclosporine, mycophenolate mofetil and corticosteroid maintenance therapy. In patients receiving relatively low-level immunosuppression in order to minimize toxicity, basiliximab may be preferable to a truncated daclizumab regimen.

Daclizumab induction and maintenance steroid-free immunosuppression with mycophenolate mofetil and tacrolimus to prevent acute rejection of hepatic allografts

Steroid-free immunosuppressive regimens reduce corticosteroid-related side effects in liver transplant recipients although their efficacy is very variable. We evaluated the efficacy and safety of a steroid-free regimen in a 6-month, open-label, multicenter, pilot study, which involved 102 liver transplant patients treated with daclizumab (2 mg/kg within 6 h following transplant and 1 mg/kg on day 7), mycophenolate mofetil (MMF, 1 g b.i.d) and tacrolimus (trough levels of 5-15 ng/ml in the first month and 5-10 ng/ml thereafter). One intra-operative dose of methylprednisolone was administered. At 6 months, the acute rejection rate was 9.8%, and patient and graft survival rates were 96% and 95%, respectively. Acute rejection rates were similar for hepatitis C-positive patients (8.6%) and hepatitis C-negative patients (10.4%). Infections occurred in 22% of patients; most cases were considered mild or moderate. Post-transplantation hypertension and diabetes mellitus developed in 37% and 14% of patients, respectively, during the study period, but were markedly less frequent (8% and 6%, respectively) at 6 months. Hypercholesterolemia was observed in only 2% of patients. In conclusion, the steroid-free immunosuppressive regimen of daclizumab, MMF, and tacrolimus effectively prevents acute rejection after liver transplantation without decreasing safety.

Limited-dose Daclizumab versus Basiliximab: a comparison of cost and efficacy in preventing acute rejection

The purpose of this study was to compare the efficacy and cost of the limited-dose Daclizumab regimen to that of the standard-dose Basiliximab regimen. Two antibody induction regimens were compared in patients aged 18 years and older who received renal transplants from January 2002 to September 2003 and completed interleukin (IL)-2R antibody induction with standard-dose Basiliximab (20 mg x 2 doses) or limited-dose Daclizumab (1 mg/kg x 2 doses). The primary outcome measure was the incidence of acute rejection. Secondary outcomes included cost, changes in serum creatinine level, and delayed graft function. Of the 46 patients randomized, 42 patients completed the 6-month follow-up. Mean serum creatinine level at time of discharge was originally higher in the limited-dose Daclizumab group than the standard-dose Basiliximab group (1.89 vs 1.57, respectively). By 1, 3, and 6 months, mean serum creatinine values were similar between both groups, with a trend toward lower mean serum creatinine values in the limited-dose Daclizumab group. The incidence of acute rejection was also similar between the groups (6% vs 7%). The average cost difference between the 2 regimens was approximately $715. This study suggests that a limited-dose Daclizumab regimen may be an efficacious and less costly alternative to the standard-dose Basiliximab regimen for antibody induction therapy following renal transplantation.

Antibody induction therapy in renal transplant patients receiving calcineurin-inhibitor immunosuppressive regimens: a comparative review

Acute rejection during the first year post-transplant is a key predictor of graft survival after renal transplantation. Use of induction therapy with a lymphocyte-depleting agent or an interleukin-2 receptor (IL-2R) antagonist can provide effective protection against rejection in the first critical weeks and months post-transplant. Polyclonal lymphocyte-depleting antibodies are associated with a low incidence of rejection but evidence of their benefit in terms of graft survival is lacking. Thymoglobulin appears to offer superior graft outcomes compared with generic antithymocyte globulin (ATG). The most frequent adverse events are symptoms of cytokine release syndrome, leukopenia, thrombocytopenia, and tachycardia; data on whether polyclonal antibody use increases the risk of lymphoma are conflicting. Muromonab CD3 (OKT3), a monoclonal lymphocyte-depleting antibody, is efficacious but a high incidence of cytokine release syndrome and increased risk of post-transplant lymphoproliferative disease have limited its use. Following their recent introduction, the IL-2R antagonists basiliximab and daclizumab are now used widely, after randomized trials demonstrated that addition to calcineurin inhibitor-based therapy significantly reduced acute rejection by approximately 30-40%. Meta-analyses and registry analysis suggest that addition of an IL-2R antagonist may improve graft survival. The safety profile of IL-2R antagonists is indistinguishable from placebo, with no apparent difference in incidence of infection or post-transplant lymphoproliferative disease. IL-2R antagonists and polyclonal lymphocyte-depleting antibodies (with delayed cyclosporine) offer equivalent efficacy in standard-risk populations; in a trial of high-risk patients, acute rejection rate and graft outcomes were improved with Thymoglobulin. Tolerability is superior with IL-2R antagonists: cytokine release syndrome and hematologic disturbances (notably leukopenia) are significantly more frequent with polyclonal antibodies. Cytomegalovirus infection may also be more common with lymphocyte-depleting antibodies. Thus, in patients at high risk of graft loss, Thymoglobulin may be the preferred choice for induction therapy, while for all other patients, IL-2R antagonists should be considered first-line choice for induction therapy.

Daclizumab induction in solid organ transplantation

Antibody induction therapy is used in solid organ transplantation to prevent rejection in the early postoperative period. It is especially useful in high-risk groups such as retransplants, patients with delayed graft function to delay the initiation of nephrotoxic calcineurin inhibitors (tacrolimus, cyclosporin), highly sensitised recipients and African-American recipients. Historically, antibody induction has been associated with a high incidence of adverse effects and a complicated administration regimen. Daclizumab is a monoclonal antibody that exerts its effect by binding to the alpha subunit (CD25) of the human interleukin (IL)-2 receptor on the surface of activated lymphocytes, thus preventing the binding of IL-2. It is used for induction therapy and is well-tolerated with easy administration. Although originally studied as a five-dose regimen, there is a growing accumulation of data that fewer doses (two or three) are efficacious and less costly for preventing rejection.

Daclizumab is Associated With Decreased Rejection and No Increased Mortality in Cardiac Transplant Patients Receiving MMF, Cyclosporine, and Corticosteroids

BACKGROUND

Sparse published data exist on outcomes in daclizumab-treated cardiac transplant patients. One trial observed an increased mortality risk 6 and 12 months posttransplant in patients receiving daclizumab plus mycophenolate mofetil (MMF), cyclosporine, and steroids. This study further investigates the safety profile of daclizumab with this same immunosuppressive regimen from a large registry.

METHODS

Data obtained at hospital discharge on all adult cardiac transplants performed in the USA between January 1998 and October 2003 for patients receiving MMF plus cyclosporine and steroids were accessed from the Scientific Registry of Transplant Recipients. Patients were selected based on induction treatment: daclizumab (n = 684) or no induction (n = 2525). Outcomes were evaluated at 6 months, 12 months, and 3 years posttransplant. Univariate Kaplan-Meier and multivariate Cox models were used to evaluate the effect of treatment on outcomes. Patient survival and infectious death were the primary endpoints. Secondary endpoints included rejection within the first year posttransplant (acute rejection; AR) and total rejection episodes over time. The two treatment groups shared similar demographics and transplant procedure details.

RESULTS

Daclizumab (vs no induction) patients had no increased risk of patient death nor infectious death. Daclizumab patients had a lower incidence of AR at 6 months (P = .005) and 12 months (P < .001); the adjusted risk for AR at 12 months (hazards ratio [HR] = 0.77; P = .89) and over 3 years (HR 0.83, P = .006) was also lower in daclizumab-treated patients.

CONCLUSIONS

In cardiac transplant patients, daclizumab (vs no induction) does not result in increased mortality or infectious death, and is associated with a lower incidence of AR.

A Truncated-Dose Regimen of Daclizumab for Prevention of Acute Rejection in Kidney Transplant Recipients: A Single-Center Experience

Daclizumab can decrease the incidence of acute rejection (AR) in renal transplant (RTx) recipients. In this prospective study, 52 RTx patients were divided into two groups according to the dose of daclizumab: 1 mg/kg on day 0 and every 14 days for five doses (group 1, n = 30) or a truncated regimen of 2 mg/kg on day 0 and on the day of discharge (group 2, n = 22). The following variables were recorded: demographics; delayed graft function; AR at 3, 6, and 12 months; time to AR; chronic allograft nephropathy (CAN); and serum creatinine. The overall incidences of AR were 23% and 27% (P = 0.76) in groups 1 and 2, respectively, whereas at 6 months they were 21% and 18% (P = 1.0). Median time to AR was 10 days in group 1 and 94 days in group 2 (P = 0.09). The incidence of CAN was 6.6% in group 1 and 13% in group 2 (P = 0.63). These data suggest that the truncated dose of daclizumab is as effective as the standard regimen for AR prophylaxis.

Two-dose Daclizumab Induction Therapy in 209 Liver Transplants: A Single-Center Analysis

BACKGROUND

Patient and graft survival after liver transplantation are adversely affected by early posttransplant renal dysfunction. Therefore, our immunosuppressive strategies should be as "renal sparing" as possible. This is the largest published series to date using daclizumab induction therapy in a renal-sparing regimen.

METHODS

This is a retrospective, nonrandomized study comparing 209 adult liver transplants with daclizumab induction to 115 transplants with no induction.

RESULTS

Patient and graft survival were similar, despite higher pretransplant acuity of illness and older age in the induction group. Acute rejection within the first 6 months occurred less commonly in the induction group (25.4% vs. 39.1%, P=0.01), despite significantly delayed initiation and lower doses of a calcineurin inhibitor. Mycophenolate mofetil was used more commonly in induction patients, but the efficacy of daclizumab in preventing rejection was independent of this. Patients with a pretransplant creatinine concentration 1.5 mg/dL or less had less rejection if they received induction. Renal function worsened in noninduction patients but showed sustained improvement throughout follow-up in induction patients with a pretransplant creatinine concentration greater than 1.5 mg/dL. Induction therapy provided better rejection prophylaxis among those requiring temporary calcineurin inhibitor cessation because of renal dysfunction. The incidences of histologic hepatitis C recurrence and cytomegalovirus infection were similar in each group.

CONCLUSIONS

Liver recipients with and without pretransplant renal dysfunction have less acute rejection with daclizumab induction therapy. This is not associated with an increased risk of over-immunosuppression. Sustained renal improvement in recipients with pretransplant renal dysfunction is possible with daclizumab induction.

Early experience with two-dose daclizumab in the prevention of acute rejection in cardiac transplantation

BACKGROUND

Daclizumab is a human monoclonal antibody that binds to the interleukin-2 receptor. It has been used as induction therapy in heart transplantation with repeated administrations over several weeks. At our institution, we use a two-dose regimen of daclizumab based on its extended half-life. We sought to determine the incidence of acute rejection with 2-dose daclizumab in cardiac transplantation.

METHODS

Eighteen consecutive heart transplants performed at a single center were analyzed retrospectively. Patients received daclizumab (2 mg/kg) within 8 h of cardiac transplantation and a second dose (1 mg/kg) 2 wk thereafter. Maintenance immunosupression included mycophenolate mofetil, prednisone and either cyclosporine or tacrolimus, based on side-effect profile. The endpoint was the incidence of acute rejection as defined by a histologic grade >2 according to the classification of the International Society of Heart and Lung Transplantation.

RESULTS

Four patients had acute rejections (all were 3A) during the first 3 months post-transplantation. All four patients had rejection at the first biopsy and only two had rejection thereafter. None of the rejections were hemodynamically significant and no patients were hospitalized. All except one rejection was seen in the context of low 2-h cyclosporine levels. The two-dose regimen was easier to administer on an outpatient basis and resulted in lower cost.

CONCLUSIONS

This preliminary report suggests that induction therapy with a two-dose regimen of daclizumab appears to be safe and well tolerated in patients undergoing cardiac transplantation.

Comparative in vitro study of the immunomodulatory activity of humanized and chimeric anti-CD25 monoclonal antibodies

Humanized or chimeric monoclonal antibodies (MoAbs) directed against the interleukin-2 (IL-2) receptor alpha-chain, CD25, are promising immunosuppressive agents due to improved pharmacokinetic profiles and less toxicity. These MoAbs have been used effectively in preventing and/or treating rejection in solid organ transplantation and are currently under investigation for prevention/treatment of graft-versus-host disease (GvHD) in stem cell transplantation. We analysed the in vitro activities of the chimeric anti-CD25 MoAb basiliximab and the humanized anti-CD25 MoAb daclizumab in various test systems for alloimmune response and T cell activation in comparison to cyclosporin A (CsA) and prednisolone. Anti-CD3- and alloantigen-induced T cell proliferation were decreased significantly by the anti-CD25 MoAbs in a dose-dependent fashion. At a concentration of 10 ng/ml daclizumab and CsA synergistically decreased T cell proliferation of mixed lymphocyte cultures, whereas basiliximab showed only subadditive activity. Simultaneous addition of the anti-CD25 MoAbs and prednisolone did not result in combined activity. Addition of exogenous IL-2 completely overcame the inhibitory effect on T cell proliferation of both anti-CD25 MoAbs, but not that of CsA and prednisolone. Anti-CD25 MoAbs inhibited the generation of antigen-specific cytotoxic T lymphocytes in a limiting dilution assay, whereas they showed no effect on the cytolytic activity of established antigen-specific T cell clones. This in vitro study demonstrates strong immunosuppressive activity by both chimeric and humanized MoAbs against CD25. The combined activity with CsA justifies their early use for prevention rather than treatment of GvHD.

Anti-Interleukin-2 Receptor Antibodies in Transplantation

Two monoclonal antibody preparations against the alpha-chain of the interleukin-2 receptor (IL-2Ralpha) are available for use, basiliximab and daclizumab, a chimeric and a humanised antibody, respectively. The first clinical studies have demonstrated the efficacy of these agents as induction therapy to reduce the rate of acute rejection after organ transplantation. Basiliximab and daclizumab have a similar effect on prevention of acute rejection. Likewise, incidence of infections and malignancies are not different between the two treatment options. Anti-IL-2Ralpha therapy was very well tolerated in clinical trials. Phase III studies with basiliximab have been undertaken with a two-dose regimen, consisting of two doses of 20mg, in an attempt to saturate the IL-2Ralpha on peripheral blood T lymphocytes for an average of 4-6 weeks. In contrast, the daclizumab dose is corrected for bodyweight and the goal is to achieve IL-2Ralpha blockade for 12 weeks. Phase III efficacy trials with daclizumab have, therefore, been developed with five doses of 1 mg/kg every 2 weeks in the first 2 months after transplantation. Whether or not it is a benefit to have blockade of the IL-2Ralpha for 10-12 weeks (daclizumab) compared with 4-6 weeks (basiliximab) remains unknown. Assuming 4-6 weeks would be sufficient for prevention of acute rejection, many centres have changed the protocol of daclizumab administration to two doses, the first dose given at the time of transplantation, the second 10 or 14 days after, with good success. Therefore, it seems feasible to limit the dose of daclizumab, which increases the ease of administration and probably also the cost effectiveness of this agent. There are no controlled studies comparing basiliximab and daclizumab, nor have different dose regimens been directly compared in renal transplantation. The data available suggest the differences are small, if present at all, and it is unlikely that such a trial will ever be done. With both compounds, a significant reduction in the number of acute rejection episodes following solid organ transplantation can be obtained without an increase in adverse effects or infectious complications.

IL-2 receptor blockers in liver transplantation: initial experience with daclizumab in Chile

Monoclonal antibodies against the interleukin 2 receptor have been developed in an effort to decrease rejection rates and spare calcineurin inhibitors when renal dysfunction occurs after transplant. While success has been reported in kidney transplantation, its effectiveness in liver transplantation is less clear.

METHODS

This prospective nonrandomized study including adult patients was performed between October 2000 and April 2003. Two groups of immunosuppressive regimens were compared: group A received 2 g of methylprednisolone intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Cellcept was also given for 2 months in the absence or for up to 4 months in the presence of rejection. Group B received the same immunosuppressive regimen but, in addition, daclizumab 1 to 1.5 mg/kg on day 1 and day 5 posttransplant. Rejection diagnosis is made on histology basis. Protocol biopsies were performed in all the patients on day 7 and if indicated by biochemistry thereafter.

RESULTS

Both groups were similar in terms of preoperative CHILD score, serum creatinine, incidence of status I, donor and recipient age and ischemia times. The mean follow-up time was 20 months for Group B (n = 24) and 7 months for Group A (n = 10). The 1-month and 1-year rejection rates are 29.1% and 41% in Group A versus 20% and 30% in group B. Rejection severity was similar between both groups. One-year patient and graft survival rates were 96% and 92% in group A and 100% for both in Group B.

CONCLUSIONS

In this series, daclizumab induction therapy seems to display a trend toward a lower rejection rate without increasing infectious complications nor affecting graft survival rates.

Single-dose daclizumab induction therapy in patients with liver transplantation

AIM: To investigate the efficacy and safety of a single-dose daclizumab induction therapy in orthotopic liver transplantation (OLTx).

METHODS: A retrospective study was made for 54 cases of OLTx in recent three years. The daclizumab group consisted of 23 cases of OLTx who received single-dose of 2 mg/kg intravenously after postoperative 24 hours. The control group consisted of the remaining 31 patients. Additional immunosuppressors included steroids, mycomphenolate mofetil, facrolimus or microemulsion cyclosporine used in all patients. Meta-statistical analysis was made for general data, incidence of acute rejection and infection, postoperative clinical course, complications and prognosis between two groups.

RESULTS: Pretransplant demographies were not significantly different between two groups. In the induction group there were significantly less acute rejection episodes (5 of 23, 21.74%) than those in the control group (12 of 31, 38.71%), which were proved by pathologic diagnosis (P < 0.05). The incidence of infection at the early stage was not significantly different between two groups.

CONCLUSION: Induction therapy with single-dose of daclizumab is safe and effective and appears to be able to reduce the incidence of acute rejection.

Pediatric liver transplantation with daclizumab induction

BACKGROUND

A new class of monoclonal antibodies (non-T-cell depleting) has gained favor for induction therapy after transplantation. This study evaluated the non-T-cell depleting antibody to the CD25 cell, daclizumab, as a single-dose induction agent immediately after pediatric liver transplantation to spare the use of the calcineurin inhibitor, tacrolimus, for 7 days in respect to both efficacy and renal function.

METHODS

From January 1998 to November 2001, 81 pediatric orthotopic liver transplant recipients receiving 89 liver grafts were evaluated. The treatment arm (n=61) received daclizumab 1 mg/kg immediately after liver transplantation along with mycophenolate, steroids, and, on postoperative day 7, tacrolimus. The control group did not receive induction therapy, whereas tacrolimus, mycophenolate, and steroids were started immediately after surgery.

RESULTS

The induction group had fewer patients with rejection within the first 30 days after liver transplantation (9 [14.8%] vs. 10 [50%]; P=0.003). The mean time to first rejection was similar between groups (12.1 [+/-7.8] days vs. 18.5 [+/-8.1] days; P=not significant). There was a 3.39 increase in relative risk to develop rejection within the first 30 days after orthotopic liver transplantation if the patient did not receive induction therapy (relative risk=3.39; 95% confidence interval [1.61, 7.14]). Two-year actuarial survival for the induction group was 93.2% compared with 85% in the control; graft survival was also similar between groups (87.8% vs. 72.7%) at 2 years.

CONCLUSION

Daclizumab 1 mg/kg given immediately after pediatric liver transplantation and withholding tacrolimus, is safe, efficacious, and reduces rejections within the first 30 days after surgery.

Two-dose daclizumab regimen in simultaneous kidney-pancreas transplant recipients: primary endpoint analysis of a multicenter, randomized study

BACKGROUND

Controversy exists about the optimal immunosuppressive regimen in simultaneous kidney-pancreas transplant (SKPT) recipients. This study determined the safety and efficacy of two dosing regimens of daclizumab compared with no antibody induction in SKPT recipients receiving tacrolimus, mycophenolate mofetil, and steroids.

METHODS

A total of 297 SKPT patients were enrolled in this prospective, multicenter, randomized, open-label study. The patients were randomized into three groups: daclizumab 1 mg/kg per dose every 14 days for five doses (group I, n=107), daclizumab 2 mg/kg per dose every 14 days for two doses (group II, n=112), and no antibody induction (group III, n=78). All patients received tacrolimus, mycophenolate mofetil, and steroids as maintenance immunosuppression.

RESULTS

Demographic and transplant characteristics were similar among the groups. At 6 months, there were no differences in patient, kidney, and pancreas graft survival rates among the three groups. The probability of either kidney or pancreas allograft rejection at 6 months was 21%, 17%, and 32% in groups I, II, and III, respectively (P=0.042). The median time to first acute rejection of either the kidney or pancreas was 23 days in group I, 44 days in group II, and 20 days in group III (group I vs. II, P=0.078; group II vs. III, P=0.016). At 6 months, the actuarial event-free survival (no acute rejection, allograft loss, or death) rates were 66%, 77%, and 56% in groups I, II, and III, respectively (group I vs. III, P=0.119; group II vs. III, P=0.002). There were no differences in the incidence of serious adverse events including infectious complications among the groups. All three groups demonstrate excellent kidney and pancreas function at 6 months.

CONCLUSIONS

Daclizumab is safe and effective in reducing the incidence of acute rejection in SKPT recipients compared with no antibody induction. Moreover, the two-dose regimen of daclizumab (2 mg/kg on days 0 and 14) compares favorably with the standard five-dose regimen.