Carlos R. Bachier, MD
Even with recent significant advances in the treatment of hematologic malignancies, such as chimeric antigen receptor (CAR) T-cell therapy, investigators are still focused on improving one of the field’s longest-established therapies—stem cell transplant.
From discovering the peripheral blood as a source for stem cells to allowing a wider criterion for donors with the introduction of chemotherapy, there are growing opportunities for patients with hematologic malignancies to benefit from stem cell transplantation, according to Carlos R. Bachier, MD. Looking ahead, prior treatment with CAR T-cell therapy may even enhance outcomes in patients who are candidates for transplant, he adds.
In an interview during the 2018 OncLive®
State of the Science Summit™ on Hematologic Malignancies, Bachier, program director of Sarah Cannon Center for Blood Cancer, Sarah Cannon Research Institute, discussed the evolution of stem cell transplantation as a treatment for patients with hematologic malignancies.
OncLive: Please discuss the evolution of stem cell transplants.
There has been an evolution in the way that we treat transplant patients. Forty or 50 years ago, we started just using bone marrow as the source of stem cells. Now, we can obtain stem cells from the peripheral blood. This has benefited patients in the autologous setting, where the recovery of blood counts is much faster. It is the same in the allogeneic setting, where we use donors.
The most important space has been supportive care. When we do transplants, particularly allogeneic ones, these patients can develop reactions such as graft-versus-host (GVHD) disease and infections. Over the last few decades, we have developed much better therapies that have made transplant easier, less toxic, and have improved survival. We have made significant advances in supportive care; however, stem cell transplant is still associated with toxicities. We still struggle, especially in relapse. We still have patients who will relapse after allogeneic transplant. We are actively investigating and developing strategies that will decrease the relapse rate after transplant.
There has been a significant number of new drug discoveries in different blood cancers. We now have targeted therapies for leukemias and lymphomas, which has had a secondary effect on patients who go on to have transplant. For example, we now have this drug midostaurin (Rydapt), which is a targeted therapy for FLT3
mutations. What we have learned is that if you give midostaurin to patients prior to transplant, their outcome after transplant will be much better. We have had the beneficial influence of these new drugs, which have made transplant much better.
Can you address some of the common toxicities that patients may experience following stem cell transplant?
It is mostly related to toxicities in the allogeneic transplant setting. Patients receive a transplant through donors, and while these donors are immunologically similar to the recipient, there are still differences between them. When the cells are infused into the recipient, the immune cells may think, "What am I doing here? This is not my body.” They will then attack the recipient’s body. If that happens, patients will develop a complication called GVHD. This is one of the most serious complications that a patient can have after transplant. We have been looking at developing new therapies that can effectively prevent and treat GVHD, although it is still a problem that we face.