Recommendations regarding the appropriate number of cycles of induction therapy before sending a patient with multiple myeloma for stem cell transplantation.
Saad Z. Usmani, MD: I want to ask some questions based on a couple of points you made. When we think about induction, there’s no set number of cycles. We’ve traditionally done 3 in European studies and 4 in US studies. There’s no magic number. In your clinical practice, how do you guide the number of cycles of treatment? Are you looking for a response to plateau before you say, “We’ve had enough” and then we go to stem cell collection and transplant? What’s the decision-making process? Sham, you can start.
Sham Mailankody, MD: If you engage the transplant doctors early, the delay in taking a break for collection is usually not very long. The caveat is to have the patient see the doctors proactively and early. I plan for collection to be within 4 to 6 cycles, which means they’re seeing the transplant doctors after 2 or 3 cycles. I do that because with more treatments—in particular with quadruplets, etc—it may be a little tricky to get an adequate number of stem cells. This doesn’t occur often, but certainly it can happen. If you engage the transplant doctors early, you can take a brief break—say, 2 or 3 weeks between cycles—to collect cells, which takes somewhere 4 to 6 cycles. If you do a quadruplet regimen, I’ll probably leaning toward 4 cycles.
For the second point, if the patients decide, after all their consultations and discussions, to defer their transplant for logistical, medical, or other reasons, all the data we have suggest that even if you defer it the first time, we don’t have studies of transplant vs no transplant. We have studies of transplant vs delayed transplant. The idea is that if those patients defer for various reasons—and do relapse at 6 months, 6 years, whenever—then there would be a strong consideration for transplant. I’d probably resume some form of induction therapy for a few more cycles, after the collection, for those patients who decide not to do transplant up front. I do this to try to get as deep of a response as possible before maintenance therapy.
Saad Z. Usmani, MD: Urvi, what do you think?
Urvi Shah, MD: I agree with all that Sham said. I also ask if they’re plateauing, or what their response is to how many cycles. It’s a question about a defined number of cycles—which should range from 4 to 6, or 3 to 6 or even 8—but it should depend a little on the deepening of cycles for the individual, which we don’t see in clinical trials because they’re fixed in terms of the number of cycles. With a patient, I make sure that with every cycle there’s some added response. Once they’ve plateaued, do 1 more cycle. I don’t see a point in continuing cycles indefinitely, or for the certain number that I’ve defined. I refer them to transplant and think about whether they need to go to transplant sooner than later if necessary.
Saad Z. Usmani, MD: Those kinetics are very important. This is something we’ve discussed among ourselves: to look at our data on when that’s happening.
Transcript edited for clarity.