EHA 2024 | The long-term outcomes of consolidative alloSCT for BPDCN

Our presentation at EHA was basically about our experience at MD Anderson on allogeneic transplantation for BPDCN, the blastic plasmacytoid dendritic cell neoplasm, as you know. It’s a relatively rare blood disease with its own unique characteristics, and it’s considered incurable with standard treatments and the only curative treatment at this point is allogeneic transplantation.

So we looked at about 31 patients that underwent an allogeneic transplant, and these were the ones where we also had a decent amount of follow-up, almost two and a half years of follow-up for these patients. So we looked at their characteristics and outcomes. So as I said, there were 31 patients that we had, and they varied in age group because it was a retrospective analysis. So, ranging from 16 years old to as old as almost 76 years old patients and they all received allogeneic transplant.

The most common donor that we could find was an unrelated donor, so almost 40% of patients received an unrelated donor transplant. And, the most common regimen that we used before the transplant was a busulfan/fludarabine-based [regimen], used in almost 55% of patients. And, there were patients who were getting their transplant in their first remission, meaning they were diagnosed, they received some treatment, had a response, and then came for transplant. But there was also a small number of patients who had prior treatments and had disease progression.

So the bottom line, we wanted to look at their progression-free and overall survival. So when we took all comers, after about three years of follow-up, 50% of patients were alive and in remission and 60% of patients were alive even if they had a disease relapse. But what we also found was that patients who received their transplant in first remission, meaning they never had a relapse before, they did significantly better than the ones who had a prior treatment and their disease had come back. So just to give you the number, at three years, 60% of those who had never relapsed before were alive and in remission, and 70% of those patients were alive, which was the overall survival. Of course, an allogeneic transplant is associated with toxicities, so we saw that, including graft-versus-host disease. But with the regimen that we use for GvHD, post-transplant cyclophosphamide as well as tacrolimus and mycophenolate, we’ve seen a reduction in the incidence of graft-versus-host disease in our patients. So from 50% of patients getting graft-versus-host disease, now we only saw about 30% who had grade two or more graft-versus-host disease.

So, that basically summarizes that it is potentially curative. We could safely say that 50 to 60% of patients can potentially be cured with an allogeneic transplant. And that is basically the message.