Leukemia-specific T-cells (mLSTs) are a safe and promising treatment for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (HSCT), according to research published in Blood.
Patients who relapse after HSCT have poor survival and few effective treatment options. Donor lymphocyte infusions (DLIs) or a second transplant have been more effective than chemotherapy alone in treating relapsed AML or MDS. However, less than 30% of patients have long-term remission after these treatments. DLIs induce severe graft-vs-host disease (GVHD) in up to 30% of patients.
The study authors used a T-cell therapy that attempts to mimic the graft-vs-leukemia effect. The therapy uses peripheral blood from hematopoietic stem cell donors and expands naturally occurring T-cells with receptors specific for leukemia-expressed antigens.
The study evaluated the safety and effectiveness of this therapy in 20 patients with AML or MDS who underwent HSCT. A total of 5 patients were treated twice, so the authors discussed the results of 25 enrollments.
A total of 17 enrollments (15 patients) received mLSTs while in complete response (CR) in the adjuvant arm. There were 8 enrollments enrolled in the active disease arm and had measurable active leukemia at the time of the infusion.
In the adjuvant arm, 6 enrollees relapsed a median of 9.5 months after infusion. There were 2 enrollees who switched to the active disease arm and received another mLST infusion. A total of 11 enrollees did not relapse after mLST infusion with a median follow-up of 1.9 years.
In the active disease arm, there was 1 complete response and 1 partial response. Across all enrollees, there were no cases of grade 3 or greater acute GVHD and no extensive chronic GVHD.
Overall, the study results suggest mLSTs are safe and effective in patients with chemoresistant AML or MDS who relapse after HSCT.
Disclosure: The study author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Lulla PD, Naik S, Vasileiou S, et al. Clinical effects of administering leukemia-specific donor T cells to patients with AML/MDS after allogeneic transplant. Blood. 2021;137(19):2585-2597. doi:10.1182/blood.2020009471