Treatment and Management of Multiple Myeloma
The following is a lightly edited transcript of a follow-up teleconference discussion on treating patients with multiple myeloma in the VHA. For more information and the original conversation, visit FedPrac.com/AVAHOupdates.
Bone Marrow Transplant
Dr. Ascensão. Do you transplant for 1 or 2 bone marrows? What’s the best maintenance regimen postallograft, and when do you start? Do you use lenalidomide the first month of the transplant or do you wait until day 100?
Dr. Chauncey. From my perspective, hematopoietic stem cell transplantation has never really lost prominence. It is true that the concept of marrow transplantation for MM has been around for more than 20 years for those patients with first best response (Note that I’ll use best response rather than first remission). The concept was developed in an era when we had much less effective therapy, and in comparative trials, progressionfree survival was consistently superior and occasionally, overall survival was better with transplantation. As treatments got better, responses got better, and there were regular questions as to whether we still needed transplantation. But the data show that as responses got better, the progression-free survivals continued to improve, and transplantation still adds something to initial therapy.
Probably the most current data are from the Dana Farber- IFM trial for which Nikhil Munshi, MD, is an investigator. The trial includes induction with lenalidomide/bortezomib/dexamethasone, which is one of the more aggressive induction regimens. When upfront transplant vs delayed transplant are compared, it seems the preliminary data still favor having an upfront transplant after initial induction therapy.
The consensus is that autologous transplantation adds to the better response that we see with better induction therapy. Overall survival has become a less accessible endpoint since the initial trials, and that’s really a consequence of having better salvage therapy, and the confounding effects of subsequent treatments. We have so many options for salvage therapy that it’s now very hard to look at overall survival as an endpoint in trials of initial therapy.
A sometimes contentious question when it comes to payers, and less so in the VA, is how many transplants to do as part of initial therapy? Little Rock and the French did some of the pioneering work on tandem transplants. The BMT CTN 0702–StaMINA trial looks at this directly, and is mature and should be presented soon [Editorial Note: Preliminary results were presented at the American Society of Hematology meeting on December 6, 2016]. 
The approach at VAPSHCS and most other transplant centers has typically been to harvest a sufficient quantity of peripheral blood stem cells to do 2 transplants. If less than a very good partial response is achieved after the first transplant, then we do a second transplant in tandem fashion.
One exception would be for plasma cell leukemia, which is very aggressive. In that case, we would routinely perform tandem transplantation. We are unlikely to ever have a randomized trial that compares 1 vs 2 transplants in that particular setting.
Another question is whether a second autologous transplantation can be useful in a nontandem fashion, and there is a large amount of retrospective data about its use as salvage treatment. In eras when there were not as many effective therapies, salvage autologous transplant was more attractive. As new therapies came along, its use has somewhat waned, but there’s been renewed interest because dose-intensive melphalan with autologous rescue is relatively safe and not cross-resistant to other therapies. It also offers the option of a drug holiday after the transplant, whereas salvage drug therapy is typically continuous.
There is no universal agreement on nontandem second transplantation, there are no consistent algorithms to say when it is appropriate, but it’s worth discussing with the transplant programs, especially if there is a lot of toxicity with current salvage therapy.
The last question is the role of allogeneic transplantation, and while I’m generally a proponent of allogeneic transplantation for many diseases, in spite of some really significant efforts, the majority of allogeneic data for MM has not been very positive. The large BMT-CTN 0102 trial compared tandem autologous transplant at first response to a single autologous transplantation followed by reduced-intensity autologous transplantation from a matched sibling. This study was limited in part by enrollment bias, but the published results did not favor an allogeneic approach.3 Although there was less relapse in the allogeneic setting, the mortality of allogeneic transplant was not overcome by the decrease in relapse. Neither progression-free or overall survivals at 3 years were better in the allogeneic group.
Despite small studies showing feasibility and promising results, it’s currently very hard to advocate for allogeneic transplantation in MM. There are certainly centers that continue to have their own approach, with some in the U.S. that are pioneering tweaks on allogeneic regimens and graft engineering, but the data are typically small and anecdotal. That doesn’t mean that there won’t ultimately be a better way to do allogeneic transplantation in MM, but rather that we don’t currently know the best way to approach this strategy.
