A study assessing the long-term impact of omidubicel, an ex-vivo expanded stem cell product derived from umbilical cord blood, found that it led to “durable long-term hematopoiesis and immune competence” in patients with hematologic malignancies.
While allogeneic hematopoietic stem cell transplantation (HSCT) with omidubicel can lead to faster engraftment and fewer infections compared with the use of umbilical cord blood, researchers had not previously studied the long-term impact of omidubicel.
Chenyu Lin, MD, of Duke University Medical Center in Durham, North Carolina, and colleagues conducted the research and presented their findings at the 10th Annual Meeting of the Society of Hematologic Oncology.
Dr. Lin and colleagues followed 116 patients who were transplanted with omidubicel in a randomized phase III trial and four single-arm trials between 2006 and 2020 at 26 international academic transplant centers. The researchers followed patients for up to 10 years after transplant, with a median follow-up of 22 months (range, 0.3-122.5 months.)
The most common hematological malignancy was acute myeloid leukemia (40.1%), followed by acute lymphoblastic leukemia (26.7%), myelodysplastic syndrome (13.3%), and sickle cell disease (7.6%). Around a third of patients (30.5%) had high or very high disease risk indices. The median patient age was 42 years (range, two to 62 years), with slightly more men (52.4%) than women in the study. Around a third of patients were non-white (30.5%).
Most patients received transplantation with omidubicel (n=92), with the remainder receiving omidubicel with supplementary umbilical cord blood (n=24). Many patients (83.6%) engrafted with omidubicel, while 9.5% engrafted with umbilical cord blood and 4.3% had primary graft failure. Two patients had mixed chimerism and one was unevaluable.
The three-year overall survival rate was 62.5% (95% CI, 53.4-73.2), while the three-year disease-free survival rate was 56.2% (95% CI, 47.0-67.1). The three-year cumulative incidence of relapse was 37.8% (95% CI, 16.1-33.3), with relapse causing death in 16 patients. Infection caused deaths in 11 patients.
“Durable trilineage hematopoiesis was observed for up to 10 years,” Dr. Lin and colleagues concluded. “Similarly, median numbers of lymphoid subsets, including CD3+, CD4+, CD8+ T cells, CD19+ B cells, and CD16+/CD56+ [natural killer] cells were maintained within normal range for up to eight years.”
Lin C, Schwarzbach A, Montesinos P, et al. Multicenter long-term follow up of allogeneic hematopoietic stem cell transplantation with omidubicel: a pooled analysis of five prospective clinical trials. Abstract #CT-314. Presented at the 10th Annual Meeting of the Society of Hematologic Oncology, September 28-October 1, 2022.