I think we should start with the statement that ALL is a very, very developmental area of research. We have more and more treatment options, one of which is haematopoietic stem cell transplantation. Ten, fifteen years ago the issue was rather clear, we knew that patients with high risk disease needed to be transplanted, the problem was to find a donor because relatively few patients had HLA matched sibling donors. Unrelated donor registries were growing but less than half of patients could find such a donor.

Now the situation is quite different, we have more effective baseline chemotherapy, we have novel immunotherapy agents like bispecific antibodies, immune conjugates and others; we have CAR T-cells on the horizon. So it may be assumed that the role of haematopoietic stem cell transplantation will be diminished but so far it’s not the truth. We have run a European survey to see the trends in the use of allogeneic and autologous haematopoietic stem cell transplantation and we demonstrated that up to the year 2012 the numbers of all allogeneic transplants from sibling donors, from unrelated donors, haploidentical donors were growing. So the utilisation of haematopoietic stem cells in acute lymphoblastic leukaemia, in adults with acute lymphoblastic leukaemia, is still very high.

The inverse trend was observed for autologous transplantation, in fact there were several studies comparing autologous transplant to conventional dose chemotherapy and none of them showed benefits from autologous transplant. But these studies were performed before the era of routine assessment of minimal residual disease. We now know that MRD status determines outcome of regular chemotherapy but also of autologous transplant and there is a trend to rejuvenate autologous transplant as a treatment option for patients with acute lymphoblastic leukaemia. Once again the issue is that we should look at MRD status and only MRD negative patients are believed to potentially benefit from autologous transplant. Second, we should optimally place this procedure in the treatment continuum. According to my belief, autologous transplant should not be a single event that ends the treatment of adults with acute lymphoblastic leukaemia but should be preceded by consolidation and followed by maintenance therapy. Such a study evaluating the role of autologous transplant in Ph negative ALL is currently being run in Poland by the Polish Adult Leukaemia Group and there are several other study groups testing autologous transplant in Philadelphia positive acute lymphoblastic leukaemia.

With regards to Philadelphia positive acute lymphoblastic leukaemia the landscape changed dramatically with the introduction of TKIs. We know that generally using TKIs, the introduction of TKIs, contributed to improved outcome of patients with Ph positive ALL but also a lot the incorporation of autologous transplant in the treatment algorithm. We have performed a study on behalf of a leukaemia working party of EBMT showing that in the era of TKIs the results of autologous transplant are quite comparable, if not better, than allogeneic transplant provided that the transplant is followed by TKI maintenance. The potential advantage of autologous transplant is that there is no risk of graft versus host disease which occurs in up to 40% of patients treated with allogeneic transplant.

How do you see the landscape changing for future treatments and therapies?

There is a hope to avoid transplant procedures generally in patients with Ph positive ALL. In fact, such a study is currently being conducted in the USA incorporating ponatinib with hyper-CVAD chemotherapy regimen. Those investigators believe that a cure is achievable without any transplant but this must be demonstrated and we will wait for the results of that study.