At this ASH meeting, we are reporting preliminary data for a trial with this drug called UCART22, which is an off the shelf, allogeneic C22 targeting CAR for adult patients with relapsed/refractory B-ALL. This CAR-T product has a knockout of T-cell receptor, which allows it to be an allogeneic product to prevent graft versus host disease. And these cells are derived from healthy donor T-cells. But uniquely this product also has a knockdown of CD52, which allows alemtuzumab to be used as part of lymphodepletion...
At this ASH meeting, we are reporting preliminary data for a trial with this drug called UCART22, which is an off the shelf, allogeneic C22 targeting CAR for adult patients with relapsed/refractory B-ALL. This CAR-T product has a knockout of T-cell receptor, which allows it to be an allogeneic product to prevent graft versus host disease. And these cells are derived from healthy donor T-cells. But uniquely this product also has a knockdown of CD52, which allows alemtuzumab to be used as part of lymphodepletion.
At the last ASH meeting, we had reported data, early data with the use of fludarabine and cyclophosphamide as lymphodepletion. And what we saw was that patients’ host T-cells were not adequately suppressed with fludarabine cyclophosphamide, and we didn’t really see much expansion of the CARS. So we amended the study to allow alemtuzumab to be added to fludarabine and cyclophosphamide.
Now, with this regimen, we have now treated several patients. And what we see specifically is that the host T-cells are depleted much longer with that regimen. We also saw that we are seeing CAR-T expansion for some of these patients. And in fact, the two patients who had very nice CAR-T expansion also are the ones where we saw significant reduction in the bone marrow blast count to less than 5%, significantly implying that there is some clinical activity we are seeing for these patients. So at this time, this trial again continues to accrue patients. It’s a dose escalation study. We have just completed a dose level two, and we are now moving to the next dose level, which is five million cells per kilogram, along with the FC alemtuzumab lymphodepletion.