EHA 2026 Highlights New Directions in Post-Transplant Lymphoproliferative Disease
Post-transplant lymphoproliferative disease, or PTLD, is a rare but serious complication that can develop after a solid-organ or stem-cell transplant. It occurs when the immune system is intentionally suppressed to protect a transplant, allowing certain immune cells—often B cells infected with Epstein-Barr virus (EBV)—to grow out of control. At the 2026 European Hematology Association Congress, researchers highlighted advances across prevention, targeted immune-cell therapy, and CAR T-cell approaches that may expand options for people with this difficult-to-treat disease.
PTLD presents a unique clinical challenge. Physicians must control a potentially aggressive lymphoma-like disorder while preserving the transplanted organ or donor stem-cell graft. Reducing immunosuppressive drugs may help restore immune surveillance, but it is not always possible and can increase the risk of organ rejection or graft complications. Rituximab, an antibody therapy that targets CD20-positive B cells, is a common frontline treatment. However, some patients relapse or do not respond, creating a need for more effective approaches.
One major theme at EHA 2026 was prevention. In high-risk transplant recipients, clinicians may monitor blood for EBV DNA, looking for early evidence that the virus is becoming active. If viral levels rise, pre-emptive treatment with rituximab may reduce the likelihood that PTLD will develop. This strategy is particularly relevant after allogeneic hematopoietic stem-cell transplantation, when immune recovery can be slow and EBV-driven complications may emerge. Still, rituximab also depletes healthy B cells, so the decision to use it preventively requires careful risk assessment and ongoing monitoring.
For patients with relapsed or refractory EBV-positive PTLD, tabelecleucel is drawing attention as a more targeted form of immunotherapy. The treatment consists of partially HLA-matched, EBV-specific donor T cells designed to recognize and attack EBV-infected tumor cells. Unlike personalized cell therapies, tabelecleucel is an “off-the-shelf” product, meaning it can be selected from an established cell bank for an individual patient.
Data from the phase 3 ALLELE trial showed objective responses in 50% of patients who developed PTLD after hematopoietic stem-cell transplant and 52% of those who developed it after solid-organ transplant. The trial enrolled 43 patients with EBV-positive PTLD that had relapsed or failed to respond after rituximab-based treatment. Importantly, investigators reported no treatment-related organ rejection, graft-versus-host disease, cytokine-release syndrome, or neurotoxicity—side effects that can be major concerns with some immune-cell therapies.
Longer-term updates have continued to support that signal. In a broader cohort of 75 patients, tabelecleucel produced an overall response rate of 50.7%, including complete responses in 28.0% of participants. The reported median duration of response was 23 months, although this was not a randomized comparison against another treatment.
CAR T-cell therapy is another area of interest discussed at the meeting. CAR T treatment involves modifying a patient’s own T cells so they can recognize cancer cells, commonly through a target such as CD19. It has reshaped care for some blood cancers, but its use in PTLD requires extra caution because transplant recipients have complex immune risks and may be vulnerable to infection, organ rejection, and treatment-related inflammation. The EHA highlights signal growing research interest, not an established standard of care, for CAR T in this setting
Together, these developments illustrate a changing PTLD landscape. Earlier EBV surveillance and selective rituximab use may help prevent some cases, while EBV-targeted T-cell therapy offers a potential option after standard treatment fails. CAR T-cell research may eventually add another tool, but more evidence is needed to define which transplant recipients can benefit safely.
For patients and families, the key takeaway is that PTLD treatment is becoming increasingly individualized—guided by transplant type, EBV status, prior treatment response, and the delicate balance between controlling cancer and protecting the transplanted organ or graft.
