Immunoprophylaxis with a monoclonal anti-IL-2 receptor antibody in liver transplant patients

Maintenance immunosuppression for adults undergoing liver transplantation: a network meta-analysis

BACKGROUND

As part of liver transplantation, immunosuppression (suppressing the host immunity) is given to prevent graft rejections resulting from the immune response of the body against transplanted organ or tissues from a different person whose tissue antigens are not compatible with those of the recipient. The optimal maintenance immunosuppressive regimen after liver transplantation remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different maintenance immunosuppressive regimens in adults undergoing liver transplantation through a network meta-analysis and to generate rankings of the different immunosuppressive regimens according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until October 2016 to identify randomised clinical trials on immunosuppression for liver transplantation.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in adult participants undergoing liver transplantation (or liver retransplantation) for any reason. We excluded trials in which participants had undergone multivisceral transplantation or participants with established graft rejections. We considered any of the various maintenance immunosuppressive regimens compared with each other.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the odds ratio, rate ratio, and hazard ratio (HR) with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included a total of 26 trials (3842 participants) in the review, and 23 trials (3693 participants) were included in one or more outcomes in the review. The vast majority of the participants underwent primary liver transplantation. All of the trials were at high risk of bias, and all of the evidence was of low or very low quality. In addition, because of sparse data involving trials at high risk of bias, it is not possible to entirely rely on the results of the network meta-analysis. The trials included mainly participants undergoing primary liver transplantation of varied aetiologies. The follow-up in the trials ranged from 3 to 144 months. The most common maintenance immunosuppression used as a control was tacrolimus. There was no evidence of difference in mortality (21 trials; 3492 participants) or graft loss (15 trials; 2961 participants) at maximal follow-up between the different maintenance immunosuppressive regimens based on the network meta-analysis. In the direct comparison, based on a single trial including 222 participants, tacrolimus plus sirolimus had increased mortality (HR 2.76, 95% CrI 1.30 to 6.69) and graft loss (HR 2.34, 95% CrI 1.28 to 4.61) at maximal follow-up compared with tacrolimus. There was no evidence of differences in the proportion of people with serious adverse events (1 trial; 719 participants), proportion of people with any adverse events (2 trials; 940 participants), renal impairment (8 trials; 2233 participants), chronic kidney disease (1 trial; 100 participants), graft rejections (any) (16 trials; 2726 participants), and graft rejections requiring treatment (5 trials; 1025 participants) between the different immunosuppressive regimens. The network meta-analysis showed that the number of adverse events was lower with cyclosporine A than with many other immunosuppressive regimens (12 trials; 1748 participants), and the risk of retransplantation (13 trials; 1994 participants) was higher with cyclosporine A than with tacrolimus (HR 3.08, 95% CrI 1.13 to 9.90). None of the trials reported number of serious adverse events, health-related quality of life, or costs.

FUNDING

14 trials were funded by pharmaceutical companies who would benefit from the results of the trial; two trials were funded by parties who had no vested interest in the results of the trial; and 10 trials did not report the source of funding.

AUTHORS' CONCLUSIONS

Based on low-quality evidence from a single small trial from direct comparison, tacrolimus plus sirolimus increases mortality and graft loss at maximal follow-up compared with tacrolimus. Based on very low-quality evidence from network meta-analysis, we found no evidence of difference between different immunosuppressive regimens. We found very low-quality evidence from network meta-analysis and low-quality evidence from direct comparison that cyclosporine A causes more retransplantation compared with tacrolimus. Future randomised clinical trials should be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid postrandomisation dropouts or planned cross-overs; and use clinically important outcomes such as mortality, graft loss, renal impairment, chronic kidney disease, and retransplantation. Such trials should use tacrolimus as one of the control groups. Moreover, such trials ought to be designed in such a way as to ensure low risk of bias and low risks of random errors.

Antibody induction versus placebo, no induction, or another type of antibody 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 antibody induction for preventing rejection after liver transplantation.

OBJECTIVES

To assess the benefits and harms of immunosuppressive T-cell specific antibody induction compared with placebo, no induction, or another type of T-cell specific antibody 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) until September 2013.

SELECTION CRITERIA

Randomised clinical trials assessing immunosuppression with T-cell specific antibody induction compared with placebo, no induction, or another type of antibody induction in liver transplant recipients. Our inclusion criteria stated that participants within each included trial should have received the same maintenance immunosuppressive therapy. We planned to include trials with all of the different types of T-cell specific antibodies that are or have been used for induction (ie., polyclonal antibodies (rabbit of horse antithymocyte globulin (ATG), or antilymphocyte globulin (ALG)), monoclonal antibodies (muromonab-CD3, anti-CD2, or alemtuzumab), and interleukin-2 receptor antagonists (daclizumab, basiliximab, BT563, or Lo-Tact-1)).

DATA COLLECTION AND ANALYSIS

We used RevMan analysis 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 the risk of systematic errors (bias) using bias risk domains with definitions. We used trial sequential analysis to control for random errors (play of chance). We presented outcome results in a summary of findings table.

MAIN RESULTS

We included 19 randomised clinical trials with a total of 2067 liver transplant recipients. All 19 trials were with high risk of bias. Of the 19 trials, 16 trials were two-arm trials, and three trials were three-arm trials. Hence, we found 25 trial comparisons with antibody induction agents: interleukin-2 receptor antagonist (IL-2 RA) versus no induction (10 trials with 1454 participants); monoclonal antibody versus no induction (five trials with 398 participants); polyclonal antibody versus no induction (three trials with 145 participants); IL-2 RA versus monoclonal antibody (one trial with 87 participants); and IL-2 RA versus polyclonal antibody (two trials with 112 participants). Thus, we were able to compare T-cell specific antibody induction versus no induction (17 trials with a total of 1955 participants). Overall, no difference in mortality (RR 0.91; 95% CI 0.64 to 1.28; low-quality of evidence), graft loss including death (RR 0.92; 95% CI 0.71 to 1.19; low-quality of evidence), and adverse events ((RR 0.97; 95% CI 0.93 to 1.02; low-quality evidence) outcomes was observed between any kind of T-cell specific antibody induction compared with no induction when the T-cell specific antibody induction agents were analysed together or separately. Acute rejection seemed to be reduced when any kind of T-cell specific antibody induction was compared with no induction (RR 0.85, 95% CI 0.75 to 0.96; moderate-quality evidence), and when trial sequential analysis was applied, the trial sequential monitoring boundary for benefit was crossed before the required information size was obtained. Furthermore, serum creatinine was statistically significantly higher when T-cell specific antibody induction was compared with no induction (MD 3.77 μmol/L, 95% CI 0.33 to 7.21; low-quality evidence), as well as when polyclonal T-cell specific antibody induction was compared with no induction, but this small difference was not clinically significant. We found no statistically significant differences for any of the remaining predefined outcomes - infection, cytomegalovirus infection, hepatitis C recurrence, malignancy, post-transplant lymphoproliferative disease, renal failure requiring dialysis, hyperlipidaemia, diabetes mellitus, and hypertension - when the T-cell specific antibody induction agents were analysed together or separately. Limited data were available for meta-analysis on drug-specific adverse events such as haematological adverse events for antithymocyte globulin. No data were found on quality of life.When T-cell specific antibody induction agents were compared with another type of antibody induction, no statistically significant differences were found for mortality, graft loss, and acute rejection for the separate analyses. When interleukin-2 receptor antagonists were compared with polyclonal T-cell specific antibody induction, drug-related adverse events were less common among participants treated with interleukin-2 receptor antagonists (RR 0.23, 95% CI 0.09 to 0.63; low-quality evidence), but this was caused by the results from one trial, and trial sequential analysis could not exclude random errors. We found no statistically significant differences for any of the remaining predefined outcomes: infection, cytomegalovirus infection, hepatitis C recurrence, malignancy, post-transplant lymphoproliferative disease, renal failure requiring dialysis, hyperlipidaemia, diabetes mellitus, and hypertension. No data were found on quality of life.

AUTHORS' CONCLUSIONS

The effects of T-cell antibody induction remain uncertain because of the high risk of bias of the randomised clinical trials, the small number of randomised clinical trials reported, and the limited numbers of participants and outcomes in the trials. T-cell specific antibody induction seems to reduce acute rejection when compared with no induction. No other clear benefits or harms were associated with the use of any kind of T-cell specific antibody induction compared with no induction, or when compared with another type of T-cell specific antibody. Hence, more randomised clinical trials are needed to assess the benefits and harms of T-cell specific antibody induction compared with placebo, and compared with another type of antibody, for prevention of rejection in liver transplant recipients. Such trials ought to be conducted with low risks of systematic error (bias) and low risk of random error (play of chance).

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.

Basiliximab as therapy for acute rejection after liver transplantation for hepatitis C virus cirrhosis

Steroid bolus therapy for acute rejection after liver transplantation for hepatitis C virus (HCV) cirrhosis often results in graft loss due to adverse effects. The efficacy and safety of basiliximab for the treatment of acute cellular rejection (ACR) in adult liver transplantation has not been adequately evaluated. Three patients received basiliximab as rescue therapy for acute rejection. The outcome and biochemical parameters were recorded before and after treatment with basiliximab. These results were compared to 11 patients who received steroid therapy for ACR. The median time from transplantation to the development of ACR was 19 days (range, 9-49 days). The degree of ACR was mild or moderate. Resolution of rejection was obtained in all patients and the median time from the onset to resolution of ACR was 16 days (range, 6-41 days). A steroid resistant reaction occurred in 2 of 11 patients and OKT3 was used, and the rejection eventually resolved in all patients. Five patients died within 2 to 22 months after transplantation and four of them died from graft failure. In the basiliximab group, there were no significant immediate adverse effects. One patient died from pneumonia 8 months after transplantation.

IN CONCLUSION

Basiliximab can be safely used as rescue therapy for ACR without significant adverse effects in patients who underwent liver transplantation for HCV cirrhosis.

Daclizumab induction therapy in liver transplant recipients with renal insufficiency

BACKGROUND

The role of interleukin 2 (IL-2) receptor antibodies to avoid the nephrotoxic effects of calcineurin inhibitors in the early post-liver transplant (LT) period is not well defined.

AIM

To examine the use of daclizumab induction in LT recipients with renal insufficiency.

METHODS

Between 2002 and 2005, 62 patients (median pre-LT creatinine 2.4 mg/dL, IQR 1.9-3.7) received daclizumab induction with tacrolimus being administered when serum creatinine was <2.0 mg/dL. A concurrent comparison group (n = 221, 2002-2005) received tacrolimus-based immunosuppression without daclizumab (median pre-LT creatinine 1.1 mg/dL, IQR 0.9-1.4). A second historical comparison group (n = 103, 1995-2005) not receiving daclizumab was matched to the daclizumab patients by pre-LT serum creatinine (2.2 mg/dL, IQR 1.8-3.1). All patients received mycophenolate mofetil and steroids.

RESULTS

Serum creatinine improved in the daclizumab group (-1.0 mg/dL, IQR -2.2 to -0.4) and worsened in the concurrent comparison group (+0.2 mg/dL, IQR 0-0.5) from pre-LT to 4 months. However, there was no difference when daclizumab group was compared with the historical comparison group matched on pre-LT creatinine (median change: -0.8 mg/dL vs. -0.7 mg/dL). Daclizumab induction was not associated with improvement in renal function at 4 months (P = 0.34) after adjusting for pre-LT creatinine, age, gender, hepatitis C status and simultaneous liver kidney transplantation.

CONCLUSION

The incremental benefit offered by induction therapy with IL-2 receptor antibodies to preserve renal function is questionable.

Anti-interleukin 2 receptor antibodies and mycophenolate mofetil for treatment of steroid-resistant rejection in adult liver transplantation

BACKGROUND

Steroid-resistant rejection (SRR) results in significant morbidity and mortality from the adverse effects of rescue therapy and in graft loss from chronic rejection. In our knowledge, the efficacy and safety of anti-interleukin (IL) 2r antibodies (daclizumab and basiliximab) for the treatment of SRR in adult liver transplantation has not previously been evaluated.

METHODS

Twenty-five patients received either daclizumab or basiliximab as rescue therapy for SRR. Outcome and biochemical parameters were recorded before and after treatment with an anti-IL-2r antibody.

RESULTS

The median time from transplantation to SRR was 25 days. Secondary immunosuppression included mycophenolate mofetil in 18 patients. Twelve patients (48%) had complete resolution of SRR. Aspartate transaminase levels normalized at a median of 37 days (range, 1-168 days). In 13 patients (52%) progressive hepatic dysfunction developed. Four of these patients received another transplant, and 6 patients had chronic rejection. Three patients died with graft failure. Of 16 patients with acute cellular rejection, 12 (75%) had resolution, 2 had chronic rejection, 1 required a repeat transplantation, and 1 died with graft failure. In contrast, all 9 patients with established chronic rejection in their pretreatment biopsy continued to have significant graft dysfunction, with 4 having persistent chronic graft dysfunction, 3 requiring repeat transplantation, and 2 dying with graft failure.

CONCLUSION

Twelve (48%) of 25 patients who received an anti-IL-2r antibody because of SRR were successfully treated. All successfully treated patients had ongoing acute cellular rejection at liver biopsy (75%), whereas patients with histologic evidence of chronic rejection responded poorly.

Long-term results of basiliximab induction immunosuppression in pediatric liver transplant recipients

It has been shown that an induction therapy with the monoclonal anti-interleukin-2 receptor antibody basiliximab (Simulect) is capable to reduce the incidence of acute graft rejection in adult and pediatric liver transplantation (Ltx). However, data on long-term results using basiliximab in children post-Ltx are still pending. Therefore, the objective of our study was to report on the long-term results of basiliximab induction therapy in pediatric liver transplant recipients. A total of 54 children received two single doses of basiliximab in addition to cyclosporine and prednisolone following Ltx. We analyzed the incidence of acute and chronic graft rejection that of post-transplant lymphoproliferative disease (PTLD), and patient and graft survival. The follow-up was 22-46 months. The historical control group (matched controls) consisted of 54 patients treated with a cyclosporine and prednisolone dual therapy. Patient survival was 53 of 54 in the treatment group and 51 of 54 in the controls. One patient was retransplanted in the treatment group vs. three patients in the control group. The incidence of acute graft rejection was 16.6% compared with 53.7% in the control group (p < 0.001), that of chronic rejection was comparable in both groups (one of 54 vs. one of 54). The incidence of steroid resistant rejection was four of 54 vs. six of 54 that of PTLD were one of 54 vs. zero of 54. There were no adverse effects observed, which could be related to the antibody treatment. We conclude that basiliximab provides safe and effective induction immunosuppression in pediatric liver graft recipients. Short- and even long-term results are excellent.

Basiliximab-chimeric anti-IL2-R monoclonal antibody in pediatric liver transplantation: comparative study

Basiliximab is a monoclonal antibody that binds to the alpha subunit (CD(25)) of the interleukin-2 receptor of activated T lymphocytes. The advantage of basiliximab in organ transplantation is the reduce possibility to calcineurin inhibitor dosages to avoid nephrotoxicity. Basiliximab has significantly reduced the incidence of acute rejection (AR) in renal transplant recipients; however, the results are uncertain in liver transplantation (LT). The objective of this investigation was to assess the effect of basiliximab to prevent AR in the first 6 months after pediatric LT. From March 2000 to October 2001, 32 recipients of a primary orthotopic cadaveric or living donor LT were given basiliximab by intravenous bolus injection on the day of transplantation (day 0) and on day 4. Four children who received one dose were excluded from the study. The rate and the intensity of AR episodes, the incidence of chronic rejection, serum creatinine level, incidence of infections, adverse side effects, and daily oral dosage of cyclosporine (Neoral) to maintain the target blood level of 850 to 1000 mg/dL at C2, 2 hours after the administration, were analyzed in the remaining 28 recipients. Results were compared to those obtained from a matched historical group (n = 28) of similar age, weight, and hepatic diseases distribution. None of the analyzed parameters was statistically significant (P >.05) except for the daily oral dose of cyclosporine (7 to 13 mg/kg/dose, P <.05). In our series, the addition of basiliximab to the immunosuppressive therapy did not reduce the incidence of AR in pediatric LT.

Basiliximab monotherapy following B-cell lymphoma after pediatric liver transplantation and anti-CD20 therapy

The chimeric, monoclonal antibody basiliximab inhibits the proliferation and clonal expansion of activated T cells. To date basiliximab has been used only in combination with other immunosuppressive agents for rejection prophylaxis after solid organ transplantation. An infant underwent liver transplantion (LTx) at the age of 5 months because of biliary atresia. The primary immunosuppression consisted of cyclosporine and prednisolone. As a result of a steroid resistant rejection episode on day 26 post-LTx we had to switch the initial immunosuppressive regiment to tacrolimus and steroids. Because of severe cholestasis and assumed impaired enteral resorption we were forced to administer an unusually high dosage (2 mg/kg/day) of tacrolimus. Four months after LTx an intestinal B-cell lymphoma was diagnosed when the patient suffered from a small bowel perforation. After stopping the immunosuppressive medication we started treatment with the anti-CD20 monoclonal antibody rituximab for B-cell depletion. During the 12 wk no B cells were detectable in the peripheral blood by flow cytometry. In this setting we started a monotherapy with repetitive doses of basiliximab for immunosuppression. During the following course there was no further rejection and no recurrence of the tumor. From this experience we conclude that monotherapy with basiliximab after LTx and anti-CD20 treatment for B-cell lymphoma is efficient and safe.

Advances in the management of psoriasis: monoclonal antibody therapies

Psoriasis is a common skin disorder characterized by erythematous, scaling plaques. Until recently, therapies for this disease have been aimed at reducing keratinocyte proliferation. We have learned that psoriasis is not primarily a disorder of keratinocyte hyperproliferation, but is an inflammatory disease. This knowledge, especially our current understanding of the role of activated T cells in psoriasis, has led to new therapeutic options and new areas of research. Immunosuppressive agents such as cyclosporine have proven very useful in the treatment of psoriasis, but their use is limited by toxicity. Monoclonal antibodies directed against key components of the inflammatory process have been studied in an attempt to produce safer, more selective immunosuppressive agents. This review summarizes much of the available literature describing the use of monoclonal antibodies in the treatment of psoriasis.

Pharmacokinetics, pharmacodynamics, and immunodynamics of daclizumab in a two-dose regimen in liver transplantation

BACKGROUND

The humanized anti-interleukin 2 receptor (IL-2R) monoclonal antibody daclizumab (Zenapax) has been shown to be safe and effective for preventing acute allograft rejection in renal transplantation. The aim of this study was to evaluate pharmacokinetics and pharmacodynamics of daclizumab in a two-dose regimen (1.5 mg/kg total) after liver transplantation.

METHODS

Twenty-eight patients were enrolled in this study. Patients were evaluated for outcome, postoperative blood and ascites loss, serum levels of daclizumab, and corresponding changes in peripheral blood. Patients were also checked for development of anti-daclizumab antibodies.

RESULTS

CD25+ cells in patients' blood were significantly reduced for 28 days after daclizumab application. Elimination half-life of the antibody was 99 hr with a total body clearance of 57 ml/hr. Blood loss was not statistically significant and loss of ascites was weakly correlated to the monoclonal antibody clearance. One episode of mild acute rejection occurred. Although there was no significant decrease in absolute counts of CD3+, CD4+, and CD8+ lymphocytes, we were not able to show constant coating of IL-2Ralpha with daclizumab. IL-2Ralpha was not detectable on cell surface with two different antibodies and IL-2Rbeta was clearly reduced. Low titers of neutralizing anti-daclizumab antibodies in 3 of 13 patients were not of clinical significance and without influence on the pharmacokinetics.

CONCLUSIONS

A two-dose regimen with daclizumab in liver transplantation leads to effective blockade of the IL-2Ralpha for at least 14 days after transplantation. Daclizumab seems to affect not only IL-2Ralpha but also IL-2Rbeta and may lead to an impairment of other cytokine pathways, such as the IL-15 pathway.

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

A major thrust of transplantation research is to find more effective and less broadly toxic immunosuppressive agents. One potential way is the use of monoclonal antibodies directed to IL-2R alpha. Immunoprophylaxis with daclizumab, a humanized anti-IL-2R alpha monoclonal antibody, has been shown to be effective in the prevention of acute rejection in kidney transplant patients. These results encouraged us to initiate a pilot study in 28 liver transplant patients in 1997. Daclizumab was administered intravenously approximately 6 h after reperfusion (1 mg/kg) and on day 4 post-transplant (0.5 mg/kg). Additional immunosuppression consisted of cyclosporine A as well as of corticosteroids. Administration of daclizumab was not associated with any side-effects. We only experienced one acute rejection in a patient on day 17 post-transplant. It resolved immediately under therapy with prednisolone. The rate of opportunistic infections did not differ from results with conventional immunosuppressive regimens. At 4 years post-transplant no lymphoproliferative disease was observed. Patient survival at 12, 24, 36 and 48 months post-transplant was 88.5, 84.6, 80.8 and 73.1%, respectively. Immunoprophylaxis with a two-dose daclizumab regimen is safe, effective and well tolerated, and does not lead to increased opportunistic infections.

Improved treatment response with basiliximab immunoprophylaxis after liver transplantation: results from a double-blind randomized placebo-controlled trial

Basiliximab, a high-affinity chimeric monoclonal antibody, is effective in reducing acute rejection episodes in renal allograft recipients. We assessed the ability of this antibody to similarly improve the outcome in liver transplant recipients. Adult recipients of a primary cadaveric liver transplant were randomized to treatment, stratified by hepatitis C virus (HCV) seropositivity. Patients were administered 40 mg of basiliximab (n = 188) or placebo (n = 193) as two 20-mg bolus injections days 0 and 4, plus cyclosporine and steroids. Primary efficacy variables were biopsy-confirmed acute rejection and its composite end point, including death or graft loss, and were assessed at 6 and 12 months and by HCV cohort. Because of differential efficacy responses between HCV-positive and HCV-negative cohorts, an additional analysis incorporating HCV recurrence as a component of treatment failure, termed problem-free transplant, was introduced. Safety and tolerability were monitored over the 12 months of the study. All 381 patients were assessable, and no meaningful differences in background characteristics were apparent between treatment groups. Biopsy-confirmed acute rejection rates 6 months after transplantation were 35.1% in the basiliximab group versus 43.5% in the placebo group. For death, graft loss, or first biopsy-confirmed acute rejection, rates were 44.1% versus 52.8%, respectively. The reduction in rejection episodes was concentrated in the HCV-negative cohort (14.5% relative to placebo; P =.034), with a much smaller difference (2.9%) in the HCV-positive cohort. For HCV-positive patients, problem-free transplant was shown at 12 months in 26.6% of the basiliximab group versus 11.6% in the placebo group (P =.020) and for all patients at 12 months in 39.7% of the basiliximab group versus 30.1% in the placebo group (P =.035). The incidence of infection and other adverse events was similar across the two treatment groups. There were 56 deaths (25 deaths, basiliximab group; 31 deaths, placebo group) over the 12-month study. The intravenous bolus injection was well tolerated. Immunoprophylaxis with 40 mg of basiliximab, in combination with cyclosporine and steroids, reduces the incidence of acute rejection episodes with no clinically relevant safety or tolerability concerns. The influence of HCV recurrence on efficacy results can be accounted for in future trials by using the concept of problem-free transplant, incorporating recurrence as a component of treatment failure.

First experience with basiliximab in pediatric liver graft recipients

Several studies have shown a significant reduction of acute cellular graft rejection in adult liver and kidney graft recipients treated with monoclonal anti-interleukin-2 (IL-2)-receptor antibodies. The mechanism was inhibition of activated T-helper cells by blocking the alpha-chain (CD25) of the IL-2 receptor. The pilot study described here evaluated the use of basiliximab in pediatric liver transplantation (LTx), which is the first report on its use in children. Fifty-two liver-transplanted children were analyzed in this study. A matched-pair historical control group (n = 26) received cyclosporin A (CsA) and prednisolone, and patients in the basiliximab group (n = 26) were treated with low-dose CsA and basiliximab (after reperfusion and on day 4 post-transplant). The incidences were compared of acute graft rejections, infectious complications, and the adverse effects of immunosuppressive medication within the first 6 months post-transplant. The incidence of acute rejection was significantly higher in the control group (61.5% vs. 11.5%, p = 0.0004). The frequency of infectious complications was similar (46.1% vs. 53.8%). Patients in the basiliximab group showed less arterial hypertension; however, the differences were not statistically significant (30.7% vs. 7.7%, p = 0.07). Nephrotoxicity, hepatotoxicity or neurotoxicity were only seen in the control group (7.7%; 3.8%; 3.8%, respectively). Hence, the use of basiliximab in combination with CsA and steroids in pediatric liver transplant recipients is safe and reduces the incidence of acute graft rejection. Further studies are needed to confirm our preliminary results and to analyze long-term effects on post-transplant lymphoproliferative disease, chronic rejection, and patient survival.

Use of daclizumab as initial immunosuppression in liver transplant recipients with impaired renal function

The addition of daclizumab (a human immunoglobulin G1 monoclonal antibody that blocks interleukin-2 receptors on T lymphocytes) to mycophenolate mofetil (MMF) and steroids is a new option for initial immunosuppression in patients undergoing liver transplantation (LT) with impaired renal function. We evaluated the efficacy and safety of daclizumab in preventing rejection in 25 patients with impaired kidney function undergoing LT. Patients with serum creatinine (Cr) levels greater than 2 mg/dL immediately before LT were administered initial immunosuppression with daclizumab, 1 mg/kg, in addition to MMF, 2 g/d, and methylprednisolone. Tacrolimus was added after kidney function improved (when Cr levels improved by >25% of initial value). Daclizumab-treated patients were compared retrospectively with 2 other groups of patients who underwent LT with kidney impairment (Cr > 2 mg/dL): 56 patients were administered OKT3 induction, and 48 patients were administered low-dose tacrolimus. The incidence of rejection and infection (bacterial, fungal, and viral), need for preoperative and postoperative dialysis, Cr level immediately post-LT and at 3 months, and graft and patient survival were analyzed. There was no difference among the groups in 3-month Cr levels or the incidence of rejection or fungal or viral infection. The daclizumab group had fewer bacterial infections (n = 13) than the tacrolimus group (n = 28) and significantly fewer than the OKT3 group (n = 58; P =.006). Only 1 patient (4%) in the daclizumab group required dialysis post-LT versus 13 patients in each of the other groups (OKT3, 23.21%; P <.05; tacrolimus, 27%). In the daclizumab group, 2-year patient and graft survival rates were statistically significant compared with the low-dose tacrolimus group (89% and 81% v 73% and 69%, respectively; P =.06). There were no side effects related to daclizumab use, and all patients tolerated the drug well. In patients with impaired renal function before LT, daclizumab-based initial immunosuppression can be used safely to reduce the risk for infection and need for dialysis post-LT, with improved long-term graft and patient survival.

Quadruple tacrolimus-based induction therapy including azathioprine and ALG does not significantly improve outcome after liver transplantation when compared with standard induction with tacrolimus and steroids: results of a prospective, randomized trial

BACKGROUND

Tacrolimus in combination with prednisolone has been proven to be a safe and effective immunosuppressive induction therapy in solid organ transplantation. However, it remains unclear whether a tacrolimus-based quadruple induction regimen with azathioprine and an antilymphocytic preparation could further improve the results after orthotopic liver transplantation. Therefore, we designed a prospective, randomized study to compare the immunosuppressive efficacy of dual (tacrolimus and prednisolone) and quadruple (tacrolimus, azathioprine, ALG Merieux and prednisolone) induction after liver transplantation.

METHODS

After randomization, 120 consecutive patients of primary liver transplants were divided into the dual group (n=59) and the quadruple group (n=61) and followed for a minimum of 3 years.

RESULTS

Patient survival at 3 years was 88.2% in the dual versus 94.9% in the quadruple group. Overall 25 patients in each group (41 and 42%, respectively) developed acute rejection. There was no difference in the number and severity of rejections. In each group only four patients required OKT3-therapy, however, although three of four patients in the quadruple group responded to OKT3 and cleared rejection, none of the four patients in the dual group were treated successfully with OKT3 (P<0.02). Rejection in these patients resolved only after additional treatment with mycophenolate mofetil. Adverse events and infections were equally distributed in both groups. Asymptomatic Cytomegalovirus infections were more common in the quadruple group (P<0.02). As of today, only one patient developed posttransplant lymphoproliferative disease (dual group).

CONCLUSIONS

The data from our single-center study indicate that both tacrolimus-based dual and quadruple immunosuppressive induction regimens yield similar safety and effectiveness after liver transplantation.

Immunologic Aspects of Transplant Management: Pharmacotherapy and Rejection

The intensivist caring for the critically ill transplant patient must be knowledgeable in the management of immunosuppression or have expert help. Critical illness often has a major impact on the absorption and metabolism of immunosuppressive drugs, increasing or decreasing net immunosuppression. Too little immunosuppression brings the risk of graft loss, while too much increases the morbidity and mortality of serious infection. Optimum management often requires the skillful manipulation of dosage and/or routes of drug delivery. In many cases of life-threatening infection, immunosuppression must be discontinued altogether and restarted prior to significant graft injury. The cost of miscalculation is very high. Loss of a renal, pancreas, or small bowel transplant is tragic, while loss of a heart, lung, or liver is usually fatal. Unfortunately the management of immunosuppression is becoming more complex. As the field of transplantation matures, new immunosuppressants are being introduced. Also, more experience and growing numbers of clinical trials are making the required knowledge base ever larger. Each type of transplant has its own set of evolving immunosuppression strategies. This review presents the basic mechanisms of the most widely used drugs and the dangers of immunosuppression. The drugs are then discussed in the context of liver, small bowel, kidney, pancreas, heart, and lung transplantation. Finally, a brief section on the practical pharmacokinetics of the drugs is presented.

Reduction of the occurrence of acute cellular rejection among renal allograft recipients treated with basiliximab, a chimeric anti-interleukin-2-receptor monoclonal antibody. United States Simulect Renal Study Group

BACKGROUND

A double-blind, placebo-controlled phase III study was performed to assess whether basiliximab, a chimeric anti-interleukin-2 receptor monoclonal antibody, reduced the incidence of acute rejection episodes in renal allograft recipients.

METHODS

A total of 348 patients were randomized into two demographically matched, equally sized groups treated with either basiliximab or placebo. The dose of basiliximab-20-mg infusions on day 0 and day 4-was selected to block detection of interleukin-2 receptor on 97% of peripheral blood lymphocytes for 30-45 days. All patients received immunosuppressive therapy with cyclosporine microemulsion (Neoral) and steroids. An intent-to-treat analysis of 1-year data assessed the incidence of posttransplant acute rejection episodes, patient and graft survival rates, and the safety and tolerability of basiliximab.

RESULTS

Among the eligible 346 patients equally divided into the two treatment groups, basiliximab reduced the proportion of patients who experienced biopsy-confirmed acute rejection episodes by 28%: 61 (35.3%) basiliximab vs. 85 (49.1%) placebo (P=0.009). Graft losses occurred in 9 (5.2%) basiliximab-treated and 12 (6.9%) placebo-treated patients. Five (2.9%) deaths in the basiliximab group and seven (4.0%) in the placebo group occurred. Compared with placebo, a higher fraction of basiliximab patients produced urine in the operating room, and a significantly lower fraction had renal dysfunction in the first month (serum creatinine > or =5 mg(dl) and between 1 and 12 months (serum creatinine > or =3 mg/dl). During the first 12 months, 94 (54%) basiliximab-treated patients experienced serious adverse events, compared with 106 (61%) who received placebo.

CONCLUSIONS

Prophylactic basiliximab therapy is well tolerated, has an adverse event profile comparable to placebo, and significantly reduces the number of acute rejection episodes in renal allograft patients within the first year after transplantation.

Reduction of acute renal allograft rejection by daclizumab. Daclizumab Double Therapy Study Group

BACKGROUND

Acute rejection is still a major problem in renal transplantation and is one of the most important causes of chronic graft dysfunction and late graft loss. Selective immunosuppression with a humanized antibody against the alpha-chain of the interleukin (IL)-2 receptor (CD25) was evaluated to demonstrate the efficacy of this type of immunoprophylaxis in combination with dual immunosuppression.

METHODS

We studied the effect of daclizumab, a humanized monoclonal antibody against the alpha-chain of the IL-2 receptor, in a randomized double-blind, prospective phase III clinical trial in 275 patients receiving a first cadaveric renal allograft. Among them 111 (83%) in the placebo arm and 116 (82%) in the daclizumab arm received the full regimen of five doses (1.0 mg/kg) every other week. Baseline immunosuppression consisted of cyclosporine and corticosteroids.

RESULTS

At 6 months, 39 (28%) of the patients in the daclizumab group had biopsy-proven rejections, as compared with 63 (47%) in the placebo group (P=0.001). The need for additional antilymphocyte therapy, antithymocyte globulin, antilymphocyte globulin (ATG, ALG, OKT3) was also lower in the daclizumab group (8% vs. 16%, P=0.02), and they required significantly lower mean (+/- SD) cumulative doses of prednisone (3750+/-1981 mg vs. 4438+/-2667 mg in the placebo group, P=0.01). Graft function was significantly better (P=0.02) in the daclizumab group (graft function rate: 58 vs. 51 ml/min, mean) as was patient survival (P=0.01, 99% vs. 94%). No specific adverse events were observed in daclizumab-treated patients. Patients receiving daclizumab experienced fewer cytomegalovirus infections (18% vs. 25%), and none died from severe infectious complications, compared to four patients in the placebo arm. No patient in the daclizumab group had a lymphoproliferative disorder or any other form of immunosuppression-related tumor during the first year after transplant.

CONCLUSIONS

Administration of daclizumab in addition to dual immunosuppression therapy significantly reduced biopsy-proven acute rejection after renal transplantation, improved patient survival, and did not add to the toxicity of the immunosuppressive regimen.

Randomised trial of basiliximab versus placebo for control of acute cellular rejection in renal allograft recipients. CHIB 201 International Study Group

BACKGROUND

Currently available immunosuppressive regimens for cadaver-kidney recipients are far from ideal because acute-rejection episodes occur in about 30% to 50% of these patients. In the phase III study described here we assessed the ability of basiliximab, a chimeric interleukin (IL)-2 receptor monoclonal antibody, to prevent acute-rejection episodes in renal allograft recipients.

METHODS

380 adult recipients of a primary cadaveric kidney transplant were randomly allocated, in this double-blind trial, to receive a 20 mg infusion of basiliximab on day 0 (day of surgery) and on day 4, to provide IL-2-receptor suppression for 4-6 weeks (n=193), or to receive placebo (n=187). Both groups received baseline dual immunosuppressive therapy with cyclosporin and steroids throughout the study. The primary outcome measure was incidence of acute-rejection episodes during the 6 months after transplantation. Safety and tolerability were monitored over the 12 months of the study.

FINDINGS

376 patients were eligible for intention-to-treat analysis (basiliximab, n=190; placebo, n=186). No significant differences in patient characteristics were apparent. The incidence of biopsy-confirmed acute rejection 6 months after transplantation was 51 (29.8%) of 171 in the basiliximab group compared with 73 (44.0%) of 166 in the placebo group (32% reduction; 14.2% difference [95% Kaplan-Meier CIs 3% to 24%], p=0.012). The incidence of steroid-resistant first rejection episodes that required antibody therapy was significantly lower in the basiliximab group (10% vs 23.1%, 13.1% difference [5.4% to 20.8%], p<0.001). At weeks 2 and 4 post-transplantation, the mean daily dose of steroids was significantly higher in the placebo group (p<0.001 with one-way analysis of variance). The incidence of graft loss at 12 months post-transplantation was 23 (12.1%) of 190 in the basiliximab group and 25 (13.4%) of 186 in the placebo group (1.3% difference [-5% to 9%], p=0.591). The incidence of infection and other adverse events was similar in the two treatment groups. The acute tolerability of basiliximab was excellent, with no evidence of cytokine-release syndrome. 14 deaths (basiliximab n=9; placebo n=5; -2.0% difference [-6% to 2%], p=0.293) occurred during the 12-month study and a further three deaths (basiliximab n=1; placebo n=2) occurred within the 380-day cut-off period. One post-transplantation lymphoproliferative disorder was recorded in each group.

INTERPRETATION

Prophylaxis with 40 mg basiliximab reduces the incidence of acute rejection episodes significantly, with no clinically relevant safety or tolerability concerns.

A prospective randomized trial comparing interleukin-2 receptor antibody versus antithymocyte globulin as part of a quadruple immunosuppressive induction therapy following orthotopic liver transplantation

BACKGROUND

Quadruple immunosuppressive induction therapy has been shown to markedly reduce the incidence of acute rejection episodes without increasing the incidence of infectious complications after liver transplantation. However, the use of polyclonal antibody preparations (e.g. antithymocyte globulin [ATG]) is associated with side effects such as fever and tachycardia. To evaluate the efficacy and the safety of a monoclonal antibody directed against the interleukin-2 receptor (BT563) in comparison with ATG as part of a quadruple induction regimen, a prospective, randomized study was conducted.

METHODS

Eighty consecutive adult recipients of primary orthotopic liver transplants were randomized to receive either BT563 (10 mg/day; days 0-12; n=39) or ATG (5 mg/kg/day; days 0-6; n=41) in addition to the standard immunosuppressive protocol consisting of cyclosporine, and prednisolone, and azathioprine.

RESULTS

Patients treated with BT563 had a significantly lower incidence of steroid-sensitive rejection episodes (3 vs. 11; P<0.025) and also significantly fewer drug-related side effects (4 vs. 18, P<0.038) when compared with patients treated with ATG. The incidence of infectious complications was not different between the two groups. Patient survival did not differ significantly between the two groups (84.6% at 1, 2, and 3 years in the BT563 group and 90.2% at 1 year and 87.8% at 2 and 3 years for the ATG group). Analysis of graft function showed an advantage for the BT563 group in terms of postoperative bilirubin levels. However, no differences were observed in long-term follow-up between the two groups.

CONCLUSIONS

Our results indicate that treatment with anti-interleukin-2 receptor antibody as part of quadruple induction therapy after orthotopic liver transplantation is safe and effective and shows fewer steroid-sensitive rejection episodes as well as fewer side effects when compared with quadruple induction therapy including ATG.