Salman Fazal, MD: I do have a discussion with them about the fact that it is a rare disease, and that’s always something we need to talk with the patients about. I personally think the patient should be treated at centers that have some experience using these treatment options and using these agents. That’s a very important point, especially when we are assessing newly diagnosed patients. It is an aggressive malignancy and there is lack of second- or third-line options, and that’s something I talk with the patients about earlier on, and about whether I would refer them for a clinical trial at that point. Those are the things that I bring up talking with patients.
As we’ll talk about, it is a different time that we’re dealing with right now. There is COVID-19 [coronavirus disease 2019] and complications related to that, so we are worried about patients who can develop COVID-19. Usually we are worried about patients with hematologic malignancies and developing infections.
Gary Schiller, MD: I counsel patients that they need to show up. It’s hard to do telemedicine with a rare disease. You do need to look at the skin. We can’t do that through telemedicine very well. They’re going to be coming in for outpatient therapy. It’s an intravenous drug after all, so it has to be given in an infusion center. I have no experience with its administration in the home. I don’t even know if it can be dispensed that way. Again, you need to check blood counts, and you need to check albumin. There’s no way around this. COVID yes or COVID no, they’re going to have to come into the clinic and see a person. Because they keep getting cycles, and there is no end to it as long as patients respond, at least at the time of administration they can have a medical evaluation. They may not need to have an in-person evaluation midcycle. You could always get counts through home care or through a local laboratory that might be less busy than coming into a busy oncology clinic. But on the first day of the cycle, that’s the time when I see these patients.
Salman Fazal, MD: The first cycle is inpatient, so that helps in terms of COVID-19 because you’re admitting the patients. The outpatient administration is going to be challenging. You bring up a very important point, that once the patients are in remission and they are getting tagraxofusp on a maintenance schedule, I frequently get asked questions about whether they can stop it for a time period. As you can imagine, because this is an aggressive malignancy and we don’t have good second- or third-line options, I usually tell the patient that I would not stop the therapy, especially given that they’re working. There’s no reason in that circumstance to stop therapy and let the disease progress, and then you have a different problem in your hand.
Gary Schiller, MD: I agree. They continue to use drug until progression, at which time you either look for an alternative investigational agent or you can go to some acute leukemia–based regimen such as an ALL [acute lymphoblastic leukemia]–based regimen. Any other points to share?
Salman Fazal, MD: There are, of course, newer agents being evaluated in clinical trials. They’re all looking at the fact that the CD123 is highly expressed on this tumor, and there are at least 2 promising drugs that are in clinical trial. One is an antibody-drug conjugate, IMGN632, which is using an alkylating agent as a payload and could be used to target this disease. It’s enrolling patients right now. There is a bispecific targeting CD123 as well, and that is still promising. Our initial intuition was that patients who progress with tagraxofusp do not lose the expression of CD123, which allows us to target CD123 with these 2 options. That’s unique about this disease mechanism of resistance to tagraxofusp, in contrast with B-cell malignancies. When we use CD19 and CD22 therapies, the expression of CD19 or CD22 is altered. This allows us to enroll these patients in those clinical trials, and I remain cautiously optimistic about the outcome of those trials.
Gary Schiller, MD: Great. I appreciate your insights and both of our experiences with tagraxofusp and with BPDCN [blastic plasmacytoid dendritic cell neoplasm].
Salman Fazal, MD: Thank you. I thoroughly appreciate your insight as well.
Transcript Edited for Clarity