Umbilical Cord Blood Transplants Offer Lifeline for Leukemia Patients, But Expertise Gap Threatens Progress
Despite promising outcomes, the use of umbilical cord blood transplantation – a perhaps life-saving therapy for blood cancer patients – is declining due to a shortage of specialized expertise, according to leading researchers. This trend threatens to limit access to a crucial treatment option for those lacking traditional donor matches.
In 2016,Dr. Filippo Milano, MD, PhD, Associate Professor at the Fred Hutchinson Cancer Center in Seattle, published a landmark study demonstrating the viability of cord blood as an alternative stem cell source. The research, which reviewed outcomes for 582 patients with acute myeloid or lymphoid leukemia or myelodysplastic syndrome, showed that transplant recipients receiving cord blood had survival rates comparable to those receiving matched unrelated donors, and superior outcomes to those receiving mismatched donors.
The key lies in the unique properties of stem cells found in umbilical cord blood. Unlike adult stem cells, these cells are “naive” and less developed, requiring a less rigorous match to the patient’s human leukocyte antigen (HLA) type. This opens the door to potentially curative treatment for individuals who would or else be ineligible for a transplant. Cord blood transplantation has proven effective in treating over 80 diseases, including leukemia, lymphoma, sickle cell disease, and thalassemia.
However, despite its potential, the procedure remains relatively rare, with approximately 40,000 cord blood transplants performed worldwide. In the United States, the number of transplants has been steadily decreasing over the past decade.
All stem cell transplants are challenging for patients, but cord blood transplantation presents unique considerations. As cord blood contains a lower cell dose compared to adult stem cells, recovery of the immune and blood systems is frequently enough slower, increasing the risk of infection. This necessitates more intensive supportive care,which may contribute to the declining utilization rate.
Though, Dr.Milano emphasizes that with meticulous infection prevention strategies – including antibiotic, antiviral, and antifungal prophylaxis, as well as the use of letermovir to prevent cytomegalovirus activation – these risks can be mitigated. “With the right supportive care and infection prevention strategies, we can make sure patients tolerate this therapy well,” he affirmed.
A meaningful advantage of cord blood stem cells is their ability to adapt to the host, potentially reducing the risk of relapse and chronic graft-vs-host disease, a major concern for transplant recipients. The ultimate goal, Dr. Milano explains, is not just to cure cancer, but to restore patients to a high quality of life.
Augmenting Cord Blood with Dilanubicel
Recent advancements offer promising solutions to enhance the efficacy of cord blood transplantation. A phase II study led by Dr. Milano investigated the addition of dilanubicel, a novel cellular therapy, to improve outcomes for patients undergoing transplantation. The results were remarkable: combining dilanubicel with a matched cord blood unit led to prosperous transplants in 28 patients, with minimal side effects.
“Basically, we are developing a platform in which a single cord blood transplant is augmented with dilanubicel as a third-party donor transient graft to make the transplant safer and more effective for patients,” Dr. Milano explained. With a median follow-up of over 12 months, 27 patients remain alive and in remission, with only one case of relapse.Notably, the addition of dilanubicel did not increase the risk of graft-vs-host disease, and no instances of severe or chronic forms of the condition were observed.
The study also demonstrated positive outcomes for ethnic minorities, with 40% of participants falling into this category. This is notably significant, as it highlights the potential for equitable access to advanced cancer treatments. The research was supported in part by a $50,000 grant from a former patient, now thriving in college, who wished to help others benefit from the same life-saving chance.
“This is the beauty of my job,” dr.Milano reflected. “Sometimes I get discouraged and frustrated; then I see study results like these and say, okay, now I understand why I’m doing what I’m doing. It’s very rewarding.”
