Slide 1

Thank you Joseph. Ladies and Gentlemen as one of the last talks of this EDTA congress I will address a very controversial issue that has indeed been controversial all over the last 20 years.

Slide 2

This paper in the Lancet in 1982 was really the start of the use of cyclosporine and since then cyclosporine and later on also tacrolimus have remained the cornerstone immunosuppressive agents after organ transplantation. But at the time of that publication we were not aware of how these molecules interfered in the immune cascade and of course, as you all know nowadays we know that these agents interfere very early in the first stage of the lymphocyte activation by inhibiting the calcineurin pathway. But also at the time of the publication of this first European study we were even not aware that these agents could be nephrotoxic. Quite on the contrary, as you see in the conclusion, it was clearly stated that at 6 months post-transplant renal function is similar in patients receiving cyclosporine and in those receiving azathioprine and steroids.

Slide 3

However, a couple of years later this paper was published in The New England Journal of Medicine coming from Brian Meyer’s group in Stanford who did an analysis of the evolution of kidney function in their heart transplant patients and in fact, they found that among the 32 heart transplant recipients treated for at least 12 months with cyclosporine, end-stage renal failure developed in two of these patients.

Slide 4

With this information in mind the question has been formulated since then whether indeed there is a need to eliminate or to minimise calcineurin inhibitors.
In order to give you an answer to this I think still controversial question I will try to answer the following questions. First what are indeed the risks of eliminating calcineurin inhibitors from our immunosuppressive protocols? Second what are the benefits of eliminating CNIs or in other words to which extent will it be possible to improve the long-term outcome by eliminating CNIs from our immunosuppressive regimens? And of course, the same two questions have to be answered regarding minimisation instead of elimination.

Slide 5

Let’s first start with elimination. What are the risks of elimination of CNIs from our immunosuppressive protocols? I think we can make a distinction between 2 different approaches. First we can try to withdraw CNIs after initial use of them as part of the induction immunosuppressive therapy but there is another approach and that is complete avoidance of CNIs from the very beginning.

Slide 6

Let me first discuss with you withdrawal of cyclosporine and tacrolimus after an initial use during a couple of weeks or months or even years after transplantation. From the very beginning after more systematic use of cyclosporine and later on tacrolimus indeed several authors have tried to withdraw these calcineurin inhibitors. To give an answer on the safety of this approach Bertram Kasiske did 2 meta-analyses, the one he published, the first one in 1996 and then he published a second updated one in the JASN of 2000. You see here the studies that he analysed with the year of publication the number of patients included in the study and the end points he analysed either acute rejection and or graft survival.

Slide 7

This was the result of his analysis in terms of acute rejection, in fact by withdrawing cyclosporine at that time these studies indicated that the withdrawal was associated with indeed a significant risk of an acute rejection, the pooled difference was indeed 0.11 and you see that this difference was hardly statistically significant.
So, at that time Burt Kasiske concluded that up to that moment studies have shown that withdrawing cyclosporine from the maintenance immunosuppressive protocol was indeed associated with a significant increase of acute rejections.
However, most of the studies that Burt Kasiske had analysed in these meta-analyses were studies before newer immunosuppressive agents like mycophenolate acetyl were introduced. Therefore, I looked to more recent studies where indeed maintenance therapy was not just cyclosporine and steroids but also MMF.

Slide 8

This is a Dutch study published in the JASN of 2002 where you can see that patients were randomised 6 months after transplantation. During the first 6 months they all received a combination of cyclosporine, steroids and MMF. Then at 6 months they were randomised into 3 groups, in one group steroids were stopped, in the control arm triple drug therapy was continued, while in the third arm cyclosporine was stopped.

Slide 9

Despite the fact that all these patients were treated with MMF you can see that this did not protect the patients against the development of acute rejection. You see that in the group where cyclosporine was stopped indeed there was a significant appearance of acute rejections after the complete withdrawal of cyclosporine. Both in terms of biopsy proven acute rejection but also in terms of biopsy proven chronic rejection the incidence of chronic rejections was significantly higher in the patients where cyclosporine was completely withdrawn.

Slide 10

Another study, more recent study published in the JASN by Daniel Abramowicz is this study which from a point of view of the design was somewhat different from the Dutch study. As you can see, patients were included in the study who were transplanted between 12 and 30 months after transplantation. Some of these patients were only on cyclosporine or steroids or were on cyclosporine, azathioprine and steroids. So, before randomisation all patients were switched to a triple drug therapy of MMF, cyclosporine and steroids, the so-called run-in period of 3 months. After these 3 months patients were randomised. In group A cyclosporine was stopped and patients were maintained on a dual therapy with MMF and steroids, while in group B, the control arm patients went on with the triple drug therapy being cyclosporine, MMF and steroids.

Slide 11

These are the results of this study. What is shown here is the incidence of acute rejection or graft loss due to rejection. You see that there is 5 years after randomisation a huge difference in terms of these primary end points between the patients who were maintained on triple drug therapy and the patients who were weaned and stopped from cyclosporine.
So, again this study clearly showed that stopping cyclosporine was not without risk in terms of acute rejection and even in terms of graft loss, you see that the Gs are standing for graft loss due to acute or chronic rejection. 

Slide 12

So, MMF clearly did not protect patients against the risk of acute rejection after withdrawal of cyclosporine. Then came the new drugs, the so-called mTOR inhibitors. You all or most of you are familiar with this Wyeth 310 study. Just to summarise, patients were induced with a combination of sirolimus, cyclosporine and steroids and then after exclusion of some patients because they had either acute rejection, vascular rejections or inadequate renal function, 430 of these 525 patients were randomised at 3 months either to go on with the combination of sirolimus and cyclosporine or either the group where cyclosporine was progressively decreased and stopped and they were maintained on sirolimus and steroids.

Slide 13

What are the risks of doing this? Well, you see that the incidence of acute rejection was not statistically significant. It was 10.2% in the sirolimus arm, it was 5.6% in the arm maintained on triple drug therapy but as you can see, the significance was not statistically, or the difference was not statistically significant. However, one major drawback of this study was that at 4 years after transplantation only about 50% of the patients were still available for analysis, so there was a huge dropout in this study.

Slide 14

Finally we should not forget that the combination of sirolimus and cyclosporine is indeed very nephrotoxic. This was clearly shown in a study, a multicentre study published by Barry Kahan in the Lancet where you can see that creatinine clearance in the control arm was about 68 ml/min. In the group where patients were treated with cyclosporine and 2 mg of rapamune it was somewhat lower but lowest creatinine clearance was indeed seen in the patients who were maintained on a combination of cyclosporine and rapamune clearly indicating that this combination is indeed nephrotoxic.

Slide 15

So, what about the second question? Can we completely avoid calcineurin inhibitors form the very beginning after transplantation?

Slide 16

This was a multicentre study published by Flavio Vincenti in 2001. The design of this study is shown here. As you can see patients were induced with daclizumab an IL-2 receptor blocker with high doses of MMF, 3g/ day later on reduced to 2g and standard doses of steroids. So you see that these patients did not receive CNIs from the very beginning after transplantation.

Slide 17

100 patients were included in the study. 2 were not transplanted so the results are based on 98 patients. You see there was a mix of patients transplanted with kidneys from diseased donors and also a quarter of the patients received a living donor kidney. The results in terms of patients and graft survival at 1 year after transplantation were indeed excellent. However, there was a very high incidence of biopsy proven acute rejections, 53% as you can see and the time to rejection was in fact, the moment that the induction with daclizumab was no longer effective.
Some patients did indeed have re-rejection and 2 patients had re-rejections. As stipulated in the protocol the investigators were free to start calcineurin inhibitors after one or two rejections and as you can see, at the end of the study 62% of these patients were again on calcineurin inhibitors. So the conclusion of this study made by Flavio Vincenti was that this protocol was not safe enough to be considered as a standard protocol.

Slide 18

There were 2 pivotal studies one published by Karl Groth, a second by Henry Kreis 1 year later where also calcineurin inhibitors were not used and in both of these studies indeed, the incidence of acute rejections was considered top be too high.
This is the incidence of acute rejection in the arms where cyclosporine was not used as compared to the group where cyclosporine was used. Also these two studies concluded that probably the incidence of acute rejection was still too high.

Slide 19

Have more recently published trials changed this opinion? I went to the abstract book of the American Transplantation Society meeting last year in Boston and there were at least a couple of papers or presentations where indeed the authors have tried to completely avoid the use of calcineurin inhibitors. You see here the incidence of acute rejection for some of the abstracts I couldn’t find the data of incidence of acute rejection but for these 3 studies you see 36, 33 and 45% acute rejections, again figures quite comparable to what I have shown in the previous slides and considered by most authors as being too high.

Slide 20

There was one important and interesting multicentre French study presented by Yvon Lebranchu in which they compared the association of sirolimus and MMF to the standard therapy with cyclosporine and MMF. You see that in terms of patient and graft survival there were no problems and even the incidence of acute rejection for the first time was identical also in the group where CNIs were not used. As expected, GFR was somewhat higher indeed in the group where CNIs were not used but as you can see, there was a higher incidence of patients with proteinuria and the major problem here in this study was wound healing.

Slide 21

But during the same congress another French group presented, Denis Glotz presented the data of another study, also a randomised controlled trial in which they compared ATG injection with MMF and sirolimus as compared to a standard control arm with FK506 and MMF. You see that the results were quite similar in terms of patient and graft survival and also in terms of incidence of acute rejection but the withdrawal rate in the arm where CNIs were replaced by sirolimus was extremely high and in fact, during the study by analysing or doing an interim analysis the authors decided to interrupt this study because of the high withdrawal rate mainly due to a high incidence of unexpected side effects like wound healing problems, a high incidence of anaemia and also thrombocytopenia.

Slide 22

Let me say a few words on a completely different approach, instead of using mTOR inhibitors the so-called Belatacept study. As you know, Belatacept is a monoclonal antibody that blocks the costimulatory pathway which is needed after binding of the antigen to the T cell receptor to stimulate or to activate the calcineurin cascades.

Slide 23

The results of this study have been published by Flavio Vincenti last year in the New England Journal of Medicine and you see that in this study where the comparative group was a group treated with cyclosporine and 2 doses of Belatacept were used and you see that in these 2 arms where no cyclosporine was used, indeed the incidence of rejection was as low as the very low incidence of rejection already seen in the control arm. As expected and I’m sorry for this perhaps difficult to read slide but what I wanted to show is indeed that the avoidance of cyclosporine in this study indeed resulted in a significant improvement of kidney function, creatinine clearance going up from about 53 ml/min to 63 or 66 ml/min.

Slide 24

So at least this is I think one of the first studies that showed that it is possible by using other drugs to avoid CNIs but unfortunately, the results of these studies were not yet confirmed in another study and were also rather short-term results.

Slide 25

That brings me to the second question. What are indeed the benefits after having discussed with you the risks, what are the benefits of eliminating CNIs? Or in other words can we indeed improve the long-term outcome by eliminating or avoiding CNIs?

Slide 26

And I’ll go back to Bertram Kasiske’s metanalysis where you can see that in terms of graft survival there was no single difference between the patients who were withdrawn from steroids and the ones who were maintained on steroids, so at least in this analysis stopping cyclosporine could not show an improvement in allograft survival.

Slide 27

The only study that could indeed prove an improvement in graft survival was again the Wyeth 310 study when the authors analysed the results 4 years after transplantation, they could indeed see a significant improvement in graft survival in the patients where cyclosporine was stopped. But as I already said I think that everyone now really considers the combination of sirolimus and cyclosporine as being too toxic so it is not surprising that in fact patients who were maintained on this very nephrotoxic combination had indeed a worse graft survival.

Slide 28

That brings me to the last question, what about minimisation? What are the risks? What are the benefits?

Slide 29

This is the experience in our centre in Leuven and what I show you on this slide is the mean dose of cyclosporine. Our patients are receiving at the end of the first year after transplantation from 84-99. So when patients were transplanted in 1984,at the end of the first year after transplantation they received a mean of 7 mg/kg of cyclosporine. If they were transplanted in ‘99 they received at the end of the first year a mean dose of about 50% of what we initially used at the very beginning after the introduction of cyclosporine and even if we analyse the doses that these patients received 10 years after transplantation, even there you see that over the years we went progressively down and 10 years after transplantation the mean dose, the daily dose of cyclosporine our patients are receiving is as low as 2.5 mg/day.

Slide 30

So over the time we have progressively decreased the daily doses of cyclosporine. These are the overall results from our centre. In the blue line is the graft survival censored for death, for the patients transplanted in the pre-cyclosporine decade between 1973-82 and fortunately, only 340 patients. In the next decade we had a much higher activity you see 872 patients and these patients were all transplanted with maintenance cyclosporine based immunosuppressive therapy. As you can see, the major difference indeed is clearly seen in the early results after transplantation. But one year after transplantation you see that the attrition rate of the 2 groups is completely the same and the curves of the slope of the curves are completely parallel indicating that the attrition rate of patients maintained on cyclosporine is exactly the same as the attrition rate of patients who were maintained on the old classical therapy with azathioprine and steroids.

Slide 31

I think these figures at least are an indirect indication that using low doses of cyclosporine in the long run does not result in a progressive deterioration and a progressive loss of kidney function. More recently, Dirk Kuypers from my unit did a small study in which he compared two groups of patients, patients who were treated with what we call a standard immunosuppressive therapy based on tacrolimus, cellcept and steroids and the target trough levels for tacrolimus were between 10-15 μ/ml. The second arm of this study were patients in which we reduced the dose of tacrolimus with about 50% and in fact, the aimed trough levels were now between 5 and 10. We doubled the dose of cellcept to 2 g and these patients also received induction with daclizumab.

Slide 32

These are the results in terms of serum creatinine and you see that from the very beginning indeed, patients who received only 50% of the so-called standard doses of tacrolimus had indeed a significant lower serum creatinine as compared to the control arm.

Slide 33

To our surprise this was not associated with an increased incidence of acute rejections. You see that patients who were treated with the low dose cyclosporine indeed had a very low incidence of acute rejections.

Slide 34

Our single centre results were recently confirmed by the results of the so-called Caesar study. This is a study in which 3 different approaches were compared. In the first arm induction with daclizumab was given with low doses, 50% of the normal dose of cyclosporine and 3 months after transplantation cyclosporine was progressively weaned and stopped. The second arm was identical to the first arm but in this arm, cyclosporine was given at 50% of the normal dose but was not stopped.

Slide 35

This is the control arm where the normal doses of cyclosporine were given.

Slide 36

These are the results in terms of kidney function and as you can see, both at 12 months and at 18 months the patients who received 50% of the normal standard dose of cyclosporine had indeed the best GFR as compared to patients where cyclosporine was completely stopped or the control arm. Again, this approach was safe, if we are looking to the incidence of biopsy proven acute rejections, again you see that in group B where cyclosporine was given at 50% but not stopped in this group the incidence of biopsy proven acute rejections was indeed the lowest as compared to the stop arm or the control arm.

Slide 37

So that brings me to the conclusions. My answer to the question, whether calcineurin inhibitors should be minimised or eliminated is as follows. Elimination no and the reason for that is because long-term follow up data are not showing a positive risk/benefit ratio and second I think that for the time being long-term data on alternative approaches without cyclosporine CNIs are indeed not yet available. Minimisation I think I can say yes and the reason for that is that I have tried to show you that minimisation is efficient and less toxic. I thank you for your attention.