Overview
The European Society for Blood and Marrow Transplantation (EBMT) has released its 2024 activity report, marking a historic milestone: more than one million hematopoietic cell transplants (HCTs) have now been reported to the survey since 1990. This achievement reflects more than three decades of sustained progress in transplantation medicine and cellular therapy, as well as the growing role of advanced treatments such as chimeric antigen receptor T-cell therapy, better known as CAR-T therapy.
The 2024 data show that EBMT centers across Europe and participating countries continued to deliver large volumes of complex care despite changing disease patterns, shifting donor strategies, and the lingering effects of the COVID-19 era on health systems. At the same time, CAR-T therapy continued its rapid expansion, reinforcing the transformation of hematology-oncology practice.
What the 2024 EBMT report captured
In 2024, the EBMT activity survey reported 47,204 HCT procedures in 43,791 patients across 688 centers in 53 countries. These included 21,023 allogeneic transplants, in which stem cells come from a donor, and 26,181 autologous transplants, in which patients receive their own previously collected stem cells.
Compared with 2023, overall HCT activity fell slightly by 1.1%. Autologous transplants declined by 3.9%, while allogeneic transplants increased by 2.6%, reaching the highest annual allogeneic activity recorded to date in the EBMT survey. This divergence is clinically meaningful because it suggests that donor-based transplantation remains highly relevant for many malignant and non-malignant diseases, even as some autologous indications are changing with newer therapies.
CAR-T therapy also expanded strongly. In 2024, 6,082 patients received CAR-T treatment, a 24.5% increase compared with 2023. Since 2018, more than 20,000 CAR-T treatments have been captured in the EBMT survey. This reflects the rapid adoption of cellular immunotherapy in routine practice, particularly for certain blood cancers.
Why hematopoietic cell transplantation remains important
HCT is a potentially curative treatment for many hematologic malignancies and some non-malignant disorders. In allogeneic HCT, the donor immune system can help eliminate residual disease, a phenomenon known as graft-versus-leukemia effect. In autologous HCT, high-dose chemotherapy is followed by reinfusion of the patient’s own stem cells to restore blood formation. Although supportive care, targeted agents, and immunotherapies have changed treatment pathways, HCT remains a key option for selected patients.
The EBMT report is valuable because it does more than count procedures. It helps clinicians, health systems, and policymakers understand how transplant medicine is evolving, where demand is increasing, and which patient groups are benefiting from advanced therapies.
Main indications for allogeneic transplantation
The leading indications for allogeneic HCT in 2024 remained myeloid malignancies, which accounted for 62% of procedures. This category includes diseases such as acute myeloid leukemia and myelodysplastic syndromes, where transplantation may offer the best chance of long-term disease control or cure in eligible patients.
Lymphoid malignancies represented about 24% of allogeneic transplants. These include disorders such as acute lymphoblastic leukemia, some aggressive lymphomas, and other high-risk lymphoid diseases. Non-malignant disorders made up approximately 17% of allogeneic transplants, highlighting the continuing importance of transplantation for inherited blood disorders, bone marrow failure syndromes, and selected immune or metabolic conditions.
This distribution shows that allogeneic transplantation is not limited to cancer care. It also plays an important role in pediatric and adult patients with serious non-cancer conditions where transplant may correct an underlying hematologic or immune defect.
Main indications for autologous transplantation
For autologous HCT, plasma cell disorders remained the dominant indication, accounting for 59% of procedures. This is largely driven by multiple myeloma, where autologous transplant remains an established part of treatment for many fit patients.
Lymphomas accounted for 22% of autologous transplants. In selected patients with relapsed or high-risk lymphoma, autologous HCT continues to be an effective consolidative or salvage approach. Solid tumors contributed about 6%, a smaller but still relevant segment of the transplant landscape.
The ongoing decline in overall autologous activity likely reflects the increasing use of targeted therapies, antibodies, bispecific agents, and novel immune-based approaches in some diseases, which may reduce the need for transplant in certain clinical settings.
Donor sources and changing transplant practice
One of the most notable trends in the report was donor selection. Unrelated donors accounted for 56% of allogeneic transplants and increased by 5%. This confirms the central role of international donor registries and cord blood banks in making transplant possible for patients who do not have a matched sibling donor.
HLA-identical siblings remained stable at 25%, and haploidentical donors, typically a partially matched family member, also remained stable at 19%. The steady presence of haploidentical transplantation is important because it has broadened donor access in many regions, especially where matched unrelated donors are harder to find or where time-sensitive treatment decisions must be made.
Cord blood use continued to decrease, falling by 6.2%. Cord blood transplantation once offered a valuable option for patients without other donors, especially children, but its use has been affected by slower engraftment, limited cell dose, and the increasing availability of alternative donor strategies such as haploidentical transplantation.
Pediatric transplantation trends
Pediatric HCT activity decreased slightly in 2024 by 1.7% overall. Allogeneic pediatric transplants fell by 1.9%, and autologous pediatric transplants by 1.1%. Although the changes were modest, they suggest a stabilization or slight reduction in transplant volume among children and adolescents.
This may reflect several factors, including improved non-transplant therapies, changes in disease epidemiology, earlier diagnosis, and evolving transplant indications. In pediatric practice, the balance between transplantation and newer treatments is especially sensitive because clinicians must weigh long-term disease control against the risks of treatment-related toxicity, growth and developmental effects, and late complications.
CAR-T therapy: rapid growth and expanding indications
CAR-T therapy continued to be one of the most rapidly expanding areas in cellular medicine. In 2024, lymphomas remained the leading indication, representing 70% of CAR-T treatments. These products have become a major option for certain relapsed or refractory B-cell lymphomas, especially when standard therapies have failed.
Multiple myeloma accounted for 18% of CAR-T use, reflecting the growing role of BCMA-targeted CAR-T products in this disease. Acute lymphoblastic leukemia represented 8% of treatments. These data show that CAR-T is moving beyond its original niche into a broader range of hematologic malignancies.
A notable increase was also seen in autoimmune disease indications, which rose by 67%. Although still a smaller part of the total CAR-T landscape, this growth signals an important research and clinical frontier. Early studies suggest that CAR-T targeting B cells may help induce deep remission in severe, treatment-resistant autoimmune diseases by resetting dysregulated immune activity.
What the numbers tell us about system resilience
The report notes that overall transplant and CAR-T activity continued to rise steadily over time, despite temporary declines during the pandemic period. Safety measures, altered workflows, and healthcare system adaptations helped reduce disruption. The 2024 data therefore reflect not just clinical progress, but also the resilience of transplant programs, donor networks, and cellular therapy infrastructure.
The report also highlights the variable contributions of different countries. This is important because access to HCT and CAR-T is not uniform across Europe and neighboring regions. Differences in funding, referral pathways, regulatory approval, laboratory capacity, donor availability, and specialized staff can all influence how many patients receive treatment.
A central message of the EBMT report is that activity data are a proxy for access. When used over time, they can reveal whether advances in therapy are reaching patients equitably or whether gaps remain between countries, age groups, and disease categories.
Why this milestone matters
Crossing one million reported HCTs is more than a symbolic achievement. It represents millions of clinical decisions, donor-recipient matches, nursing interventions, laboratory processes, and follow-up visits. It also reflects the maturation of transplantation as a discipline that has moved from an experimental therapy to a standard component of care for many diseases.
At the same time, surpassing 20,000 CAR-T treatments within a relatively short period shows how quickly cellular immunotherapy can move from trial settings into real-world use. This pace of growth is likely to continue as more products become available, eligibility expands, and manufacturing and referral pathways improve.
Looking ahead to 2025 and beyond
Starting in 2025, the EBMT survey will collect adult and pediatric activity separately. This is an important methodological improvement. Separate reporting should provide a clearer picture of age-specific needs, trends in disease burden, transplant access, and outcomes. It will also support more precise planning for workforce needs, hospital capacity, donor services, and long-term follow-up infrastructure.
Over time, this expanded database may help answer essential questions: Which patients are benefiting most from transplant or CAR-T? How do indications change as new drugs emerge? Are all countries and age groups receiving equitable access? Which donor strategies are most effective in different settings? These are not only academic questions; they directly affect treatment policy and patient survival.
Conclusion
The 2024 EBMT activity report marks a landmark moment in cellular therapy. With more than one million HCTs reported since 1990 and CAR-T therapy surpassing 20,000 treated patients since 2018, the field continues to expand in scope and importance. Allogeneic transplantation reached its highest annual level, donor strategies continued to evolve, and CAR-T therapy showed strong growth across lymphoma, myeloma, leukemia, and emerging autoimmune indications.
Taken together, the data show a field that is both established and rapidly changing. Hematopoietic cell transplantation remains a cornerstone of hematology-oncology care, while CAR-T is reshaping the future of cellular therapy. The EBMT’s ongoing surveillance will remain essential for tracking these trends, identifying unmet needs, and ensuring that more patients can benefit from these advanced treatments.