Most patients who received allogeneic hematopoietic stem-cell transplantation (HSCT) with omidubicel did not develop chronic graft-versus-host disease (GVHD), according to research presented at the Tenth Annual Meeting of the Society of Hematologic Oncology (SOHO).
Omidubicel, an ex-vivo expanded stem-cell product derived from umbilical cord blood, leads to faster engraftment and fewer infections compared with umbilical cord blood, but the long-term impact of omidubicel has not been studied.
Chenyu Lin, MD, of Duke University Medical Center in Durham, North Carolina, and colleagues conducted the research and presented their findings at the SOHO meeting.
Researchers followed 116 patients who were transplanted with omidubicel in a randomized phase 3 trial and 4 single-arm trials between 2006 and 2020 at 26 international academic transplant centers. Patients were followed for up to 10 years after receiving a 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%). Approximately one-third of patients (30.5%) had high or very high disease risk indices. The median patient age was 42 years (range, 2-62 years), with slightly more men (52.4%) than women in the study. Approximately one-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. A total of 2 patients had mixed chimerism and 1 was unevaluable. The researchers reported secondary graft failure in 5 patients, 3 of whom received a second transplant.
The 3-year cumulative incidence of chronic GVHD was 37.8% (95% CI, 27.9-47.6). The 3-year overall survival rate was 62.5% (95% CI, 53.4-73.2), while the 3-year disease-free survival rate was 56.2% (95% CI, 47.0-67.1). The 3-year cumulative incidence of relapse was 37.8% (95% CI, 16.1-33.3), with relapse causing death in 16 patients. Infection caused death in 11 patients.
“Durable trilineage hematopoiesis was observed for up to 10 years,” Dr. Lin and colleagues reported. “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 8 years.”
A donor-derived myeloid neoplasm occurred in 1 patient at 40 months after transplant. Posttransplant lymphoproliferative disorders occurred in 2 patients, 1 of whom died due to the disorder.
“Omidubicel demonstrated durable long-term hematopoiesis and immune competence,” Dr. Lin and colleagues concluded. “One case of donor-derived myeloid neoplasm was observed with both omidubicel and control [umbilical cord blood].”
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. Poster CT-314. Presented at the Tenth Annual Meeting of the Society of Hematologic Oncology; September 28-October 1, 2022; Houston, TX.
