NexImmune, Inc. announced results from its Phase 1/2 clinical trial of NEXI-001 in patients with relapsed/refractory acute myeloid leukemia (AML) post-allogeneic hemopoietic stem cell transplant (allo-HSCT). In this clinical trial to date, NEXI-001 is well tolerated with a favorable safety profile while eliciting an immune response to target antigens and a clinical effect in some patients. The data describing two patients from the dose escalation study of NEXI-001 are being presented in a poster session at the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting in Chicago on June 5, 2023 at 8 AM in Hall A. The goals of the NEXI-001 Phase 1 clinical trial are to evaluate the safety, tolerability, immune response, and clinical activity of the antigen-specific CD8+ NEXI-001 T cells, as well as to inform the range of patient characteristics and to determine the recommended Phase 2 dose.

The dose escalation phase of the study included patients who have relapsed acute myeloid leukemia (AML) post allo-HSCT and are refractory to salvage therapy. All patients in the study, except one, relapsed after, or were refractory to, subsequent salvage therapies (one to three prior therapies). A majority of patients had three-to-four adverse risk characteristics linked to poor prognosis in addition to poor prognostic patients with extramedullary disease.

Three dose-ascending cohorts of patients were enrolled in the study, with potential doses ranging from a single dose of 50 million NEXI-001 T cells to multiple doses of up to a total of 1.2 billion NEXI-001 T cells. To date, the maximum dose evaluated has been 600 million NEXI-001 T cells. The study includes a lymphodepletion chemotherapy (Flu /Cy 30/300) following a baseline bone marrow biopsy.

To date, 11 patients have completed the dose-limiting toxicity (DLT) period and one patient is currently ongoing in the first month of protocol treatment.