A brief review of the identification and management of capillary leak syndrome in patients being treated for blastic plasmacytoid dendritic cell neoplasm.
Naveen Pemmaraju, MD: Turning back to Dr Gru, this may be more of a research-oriented question I’m going to ask you, but given all your work and thinking about these future directions, the most deadly aspect of some of these novel-targeted therapies is that of the capillary leak syndrome. It’s not restricted to tagraxofusp. We see it in other, particularly bacterial toxin, agents. We’ve never had a really good pathologic correlate or signal, either in the skin or in the bone marrow. So we’ve been relying on saying if you have a low albumin, you shouldn’t get the drug, or if you have an albumin of X, get the drug, but then you can supplement it later. I wanted to hear your thoughts at the level of pathology. Take us through that. Capillary leak has been around, you and I have heard about this for decades. It can be part of diseases such as paraproteinemia for multiple myeloma, or other diseases. What are your thoughts at the pathologic level or microscopic level? What insights can you give us? Endothelial damage, what do you think about this? It’s really a tough entity to deal with. Dr Gru?
Alejandro Gru, MD: It’s a great question, and unfortunately, I think there are very little data on why capillary leak syndrome happens in BPDCN [blastic plasmacytoid dendritic cell neoplasm]. I haven’t seen, in my own experience, biopsies taken for patients who have developed capillary leak syndrome to see what the pathologic findings are. It’s hard to determine what findings you might expect in patients who might develop it. A lot of the biopsies show very consistent and similar histopathologic findings where the epidermis is spared, and you have these diffused sheets of mononuclear cells infiltrating the dermis. I wish I could give you more information about capillary leak syndrome, but I think it’s an unmet need. To my knowledge, we don’t know anything about it at this point.
Naveen Pemmaraju, MD: You highlight a very nice point, which is that we’re starting to understand the pathobiology of the disease, but not as much with the capillary leak. I think you and I, and James, and others, we can collaborate over the years to do exactly what you said. I love what you were talking about: vivisections, biopsies, tissue at the time of these events. That’s brilliant. Nobody has done that, and that’s something we can strive to do together. I like that you said that.
Transcript edited for clarity.