Acute Myeloid Leukemia: Novel Therapy, excluding Transplantation: Immunotherapy

901  First-in-Human CLL1-CD33 Compound CAR T Cell Therapy Induces Complete Remission in Patients with Refractory Acute Myeloid Leukemia: Update on Phase 1 Clinical Trial

Fang Liu, MD, et al.

The Abstract concludes: Our first-in-human clinical trial demonstrates promising efficacy of cCAR therapy in treating patients with relapsed/ refractory AML. cCAR is able to eradicate leukemia blasts and leukemia stem cells, exerting a profound tumor killing effect that is superior to single target CAR T cell therapies. cCAR is also shown to induce total myeloid ablation in bone marrow, suggesting that it may act as a safer alternative to avoid the severe toxicities caused by standard bone marrow ablation regimens without sacrificing the anti-tumor efficacy. This strategy will likely benefit patients who are unable to tolerate total body radiation or high dose chemotherapies. In addition to AML, cCAR also has the potential to treat blast crisis developed from myelodysplastic syndrome, chronic myeloid leukemia, and chronic myeloproliferative neoplasm.


902  Remissions in Relapse/Refractory Acute Myeloid Leukemia Patients Following Treatment with NKG2D CAR-T Therapy without a Prior Preconditioning Chemotherapy

David A Sallman, et al.

The Abstract concludes: We have demonstrated the feasibility and safety of multiple injections of CYAD-01 without preconditioning chemotherapy. We evidenced promising anti-leukemic activity with 42% ORR in r/r AML with 5/7 pts having clinical benefit. Rates of G3/4 CRS were low and manageable. Updated safety, activity and correlative science data of the complete dose-escalation segment will be presented.


903  FLT3 Inhibitor Treatment Increases FLT3 Expression That Exposes FLT3-ITD+ AML Blasts to Elimination By FLT3 CAR-T Cells

Hardikkumar Jetani, et al.

The Abstract concludes: Collectively, the data show that FLT3 inhibitors augment cell surface expression of FLT3 in FLT3-ITD+ AML cells which leads to enhanced recognition and elimination by FLT3 CAR T cells. This is, to our knowledge, the first demonstration that small molecule inhibitors and CAR T cell immunotherapy can be used synergistically to treat a hematologic malignancy. We confirmed this principle with each of the FLT3 inhibitors in our panel, and observed the strongest antileukemia activity of FLT3 CAR T cells in combination with crenolanib. Our data encourage the clinical evaluation of this combination treatment in high risk patients with FLT3-ITD+ AML.


904  Oncogenic-Drivers Dictate Immune Responses to Control Disease Progression in Acute Myeloid Leukaemia

Rebecca Austin, et al.

The Abstract concludes: These data demonstrate that immune responses in AML are oncogene-specific and provide evidence that AE/NRAS AML cells undergo immunoediting over time in the presence of a competent immune microenvironment. Since AML is associated with alterations in T cell subsets, and changes in T cell activation and exhaustion states, these findings may inform translational strategies to use immunotherapies for patients with AML.


905  Results of a Phase 2, Open-Label Study of Idarubicin (I), Cytarabine (A) and Nivolumab (Nivo) in Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) and High-Risk Myelodysplastic Syndrome (MDS)

Rita Assi, et al.

The Abstract concludes: Addition of Nivo to (I+A) induction is feasible and safe in younger AML pts. Post-transplant severe GVHD is not significantly increased and is manageable. CD4+ T-effector cells display exhausted phenotype in non-responders that can be potentially reversed. Studies with earlier initiation of checkpoint inhibitor therapy are planned


906  Safety, Efficacy, and Biomarkers of Response to Azacitidine (AZA) with Nivolumab (Nivo) and AZA with Nivo and Ipilimumab (Ipi) in Relapsed/Refractory Acute Myeloid Leukemia: A Non-Randomized, Phase 2 Study

Naval G. Daver,et al.

The Abstract concludes: AZA+Nivo was effective in pts with AML in Salvage 1 or those with increased pretherapy CD3+ BM infiltrate by MFC or IHC. BM CD3 and CD8 are simple assays to select pts for future trials of AZA+PD1 inhibitors in AML. AZA+Nivo+Ipi had a encouraging CR/CRp/CRi rate (43%) and med OS (NR) in pts with salvage 1/2 AML and is enrolling.