Severe aplastic anemia (SAA) and myelodysplastic syndrome (MDS) are life-threatening bone marrow disorders. For SAA patients, long term survival can be achieved with immunosuppressive treatment. However, of those patients treated with immunosuppressive therapy, one quarter to one third will not respond, and about 50% of responders will relapse.
Combined haplo-cord transplant as an alternative to cord or haploidentical donor alone transplantation has recently been shown to be a viable transplant option for SAA patients lacking an HLA matched donor. In our ongoing protocol 08-H-0046, we have utilized this approach in 25 patients with SAA with 23/25 patients having sustained engraftment and long-term disease free/transfusion free survival. However, engraftment patterns have varied substantially and in some patients, cord engraftment was profoundly delayed or never occurred. A number of strategies to expand hematopoietic progenitor cells (HPC) in vitro to improve engraftment and prevent graft rejection have recently been studied. Nicotimanide (NAM) expanded umbilical cord blood/unrelated cord blood (UCB) can be successfully engrafted in NOD/SCID mice (1) and humans (2) where they appear to have long-term repopulating potential. CordIn(TM) is a cryopreserved stem/progenitor cell-based product of purified CD133+ cells composed of ex vivo expanded allogeneic UCB cells. CordIn(TM) comprises: 1) Ex vivo expanded, umbilical cord blood-derived hematopoietic CD34+ progenitor cellsU ( (CordIn(TM) cultured fraction (CF)); and 2) the non-cultured cell fraction of the same CBU (CordIn(TM) Non-cultured Fraction (NF)) consisting of mature myeloid and lymphoid cellsU. Both fractions, i.e. CordIn(TM) CF and CordIn(TM) NF are kept frozen until they are infused on the day of transplantation.
This research protocol is therefore designed to evaluate the safety and effectiveness of transplantation with ex vivo expanded UCB (CordIn(TM)) to overcome the high incidence of graft rejection associated with conventional UCB for aplastic anemia, where graft rejection occurs in up to 50% of subjects. We believe, based on preliminary data, that transplantation of CordIn(TM) will not only lead to rapid engraftment, but will also lead to sustained hematopoiesis, expedited immune recovery, and will reduce the chance of cord graft failure in this setting, potentially obviating the need for co-transplanting haploidentical CD34+ cells as a stem cell back-up. This phase II study is designed to have two cohorts: cohort 1 is intended to establish (in as safe a manner as possible) preliminary pilot data to support the capacity for the CordIn unit to engraft in patients with SAA in the presence of haplo CD34+ cells. For cohort 1, three to six subjects will be conditioned then will be transplanted with the thawed CordIn(TM) unit (consisting of the cultured fraction and the non-cultured fraction of the same CBU) and approximately 3 x 106 CD34+ cells/kg from a haploidentical donor which will serve as a backup stem cell source should cord graft failure occur. If 3 of the first 3 to 4 subjects or 4 of 6 subjects achieve early and sustained engraftment (defined as ANC >500 cells/ul by day 26 and a calculated cord ANC >500 cells /ul by day 42 sustained at day 100), the study will move to cohort 2 where up to 23 subsequent subjects will be transplanted with the CordIn(TM) unit alone.
The primary objective of the Phase II study is to evaluate the ability of the CordIn(TM) unit to achieve sustained early engraftment. Secondary endpoints will include 100 day and 200 day treatment related mortality (TRM), and standard transplant outcome variables such as non-hematologic toxicity, incidence and severity of acute and chronic GVHD, and relapse of disease. Health related quality of life will also be assessed as secondary outcome measure.
- aplastic anemia
- myelodysplastic syndromes (MDS)