Long-Term Follow Up Shows Potential of Omidubicel in Hematologic Malignancies

Chenyu Lin, MD, hematology/oncology fellow at the Duke Cancer Institute, discusses the results of a 10-year follow up of patients who underwent allogenic stem cell therapy with the novel cell therapy omidubicel.

The hematopoietic stem cell graft is derived from umbilical cord blood, composed of an ex vivo nicotinamide-expanded CD133-positive stem cell fraction, and a non-expanded CD133 T-cell-containing fraction. A previous phase 3 study (NCT02730299) showed that omidubicel fared better than other standard grafts derived from umbilical cord blood and reduced infections, leading to a FDA priority review of the drug’s biologics license application. However, there had not been a long-term analysis of the therapy.

At Duke Cancer Institute, Lin and his co-authors looked at 22 patients with hematologic malignancies given an omidubicel graft during the study period between November 2010 and January 2020. The most common disease types were acute myeloid leukemia (36%), myelodysplastic syndrome (32%), and acute lymphocytic leukemia (18%). Five patients were considered to have high risk disease, 13 were intermediate risk, 3 were low risk, and 1 was unevaluable. The estimated 10-years overall survival was 48.5% (95% CI, 31.0% - 75.7%) and estimated disease-free survival was 43.6% (95% CI, 26.8% - 70.9%). Eleven patients passed away due to disease relapse (64%), acute GVHD (27%), or infection (9%).

Lin highlights how these results show the long-term potential of adding this graft to allogenic stem cell therapy and how the complication profile of this therapy was also manageable.

Transcript:

0:08 | Since this was a novel therapy, we looked at some of the long-term transplant related complications. We found that the cumulative incidence of chronic GVHD was 32%, but most of these patients had mild to moderate GVHD and were successfully weaned off systemic immunosuppression at last follow up. There were no secondary hematologic malignancies in our cohort, which is always a theoretical concern with these ex-vivo expansion technologies.

0:39 | Notably, in terms of graph durability, we observed sustained trilineage hematopoiesis even at 10 years of follow up. This is also true for immune reconstitution. There were serial quantitative assessments that demonstrated the maintenance of normal levels of lymphocyte subsets for up to 8 years post-transplant. So, all this suggests that omidubicel can provide durable hematopoiesis and sustained immune competence, even on extended follow up, which does speak to the safety of the product in the long term. [This also] suggests that these expanded stem cells can retain their long-term repopulating ability.