ASH 2022 | Phase I results of rapidly manufactured Prgn-3006 Ultracar-T in R/R acute myeloid leukemia

So again, in relapsed/refractory acute myeloid leukemia patients, there’s really not a standard of care. And although there’s been a paradigm shift in the utilization of CAR-T therapies for patients with other hematologic malignancies, that really has not been the case of AML. And the timing of treatment, these patients can progress rapidly, is quite critical. And so rapid manufacturing as well as, again, novel CAR-T therapy are somewhat urgently needed.

So this is a novel therapy that actually instead of a viral vector system uses a sleeping beauty plasmid. And actually, you can go from apheresis to infusion of the patient within two days. So very rapid from a manufacturing perspective. It’s also decentralized in that the CAR-T cells are actually made onsite.

So now we’re actually presenting completed Phase I data. Data from last year, we realized that, you know, you have to add lymphodepleting chemotherapy, as although that cohort was safe, we did not have any objective responses, although, saw some blast reduction in patients. We then focus on the totality of, again, the completed dose one phase escalation where patients do get fludarabine and cyclophosphamide. From a safety perspective, actually very well tolerated. We’ve only had a few grade three cytokine release syndrome events that were very transient, no dose-limiting toxicities. So from a CRS perspective, quite safe. When we then look at efficacy, almost a third of our acute myeloid leukemia patients have achieved response and including a patient bridge to transplant, who’s been alive for over 18 months at data cutoff. And several additional patients going into complete remission, although the durability has remained a challenge.

So really going forward, we’re quite excited in that we’re going through the expansion phase now of the trial. Actually, I think this is one of the only CAR-T trials to be in expansion. And what’s unique, again, because of this ability to rapidly manufacture, we are going to go with a two dosing regimen where patients, again, will get cells around day zero and around two weeks after, if they do not have any toxicity issues, will get their second dose. So that is being initiated as we speak and hope will further augment efficacy in this very challenging and tough to treat patient population.