What is a tandem transplant? When are they used?

What is a tandem transplant? When would you consider a tandem transplant?

Tandem transplant is application of a stem cell transplant back to back within about 3 to 6 months of the first one, and the goal is to get people into a deep remission. So this was a relatively useful technique when we did not have such good induction and treatments pre-transplant in multiple myeloma. So, there were randomized clinical trials done in France which showed that, compared to one transplant, a second transplant can benefit at least the patients who were not in a very good partial remission or a complete remission after the first one. So if you had a first transplant and you are not in a great VGPR or complete submission, you could go and have a second transplant to get you there, and those patients who converted did very well. So that was the basis on which tandem transplants were popular, followed in the United States, there were several centers that did tandem transplant, but then the BMT CTN in the United States completed a large randomized trial, which randomized patients in the new era, which is the era of initial good initial therapy, three drug initial therapy transplant, and then maintenance. So with that standard, the tandem transplant did not add much, or a second transplant did not add much to the first transplant. So patients who had a second transplant, then land maintenance did the same as the patients who had one transplant. Then line maintenance. In the meanwhile, the European study still continued to show a small but clear benefit for tandem transplant. So right now the jury's divided on this, for us, the goalposts have moved, in my opinion, in the United States, we for young patients or transplant eligible, we actually need to get into a deep MRD negative remission. If that is not possible with one transplant. I think you could consider a second transplant at that point as a tandem. On the other hand, if you get a deep good induction response followed by a single transplant and you're already MRD negative to which most people are going to be in the future, you wouldn't need a second transplant. So therefore my policy is to be a response adapted for the second transplant question. I hardly have to do it in less than 10% of my patients these days. So I keep the stem cells for a second transplant at relapse if needed, or hopefully never use it. If the patient gets a really, really long remission. So the tandem transplant, believe it or not, you know, it became very popular in the 90s when we didn't have these new therapies. And so actually we had a study from France, showing that if you didn't have the maximal response after one transplant, the complete remission, and then you did another one and you achieved a complete remission, two was better than one. But there were some studies that were negative. They didn't show that. The second was, you know, advantageous. And, and there are new studies actually showing that for patients with high risk disease, two maybe better than one, but, I think we don't do routinely I personally don't do I keep enough stem cells for two. I use a sandwich. The transplant with this new targeted therapy before and after, occasionally, you know, I do it in certain situations where I think the therapy before didn't work. Well, if I have a patient, who struggled to achieve the response, who, you know, rapid progressive disease and the chemotherapy works, then yes, I said, you know, I'll give it a double dose. There is definitely a dose response. The there is a randomized studies comparing 100 to 200 Melphalan showing 200 better. But the idea is, you know, to achieve the deepest response fast if you have a rapidly proliferating myeloma, you know, you, you don't want your myeloma lingering there and developing the resistance. You want to just blasted, you want eliminate the clone. And so sometimes the tandem transplant change in the conditioning can be reasonable. But because the study were not all positive, it remained a controversial issues based on, situation, a patient, the genetic of the myeloma.