Nkarta, Inc. announced positive updated data from its Phase 1 dose escalation study of NKX019 as monotherapy to treat patients with relapsed or refractory (r/r) non-Hodgkin lymphoma (NHL). Seven of ten patients treated at the higher dose levels in a three-dose regimen showed a complete response (70% CR), including two patients with aggressive large B cell lymphoma (LBCL), one patient with mantle cell lymphoma (MCL), and one patient with marginal zone lymphoma (MZL). No dose limiting toxicity, neurotoxicity /ICANS, graft versus host disease (GvHD), or >Gr3 cytokine release syndrome (CRS) were observed in the study.

Nkarta plans to provide updates from the NKX019 program, including data from the dose expansion cohorts, in 2023. Evaluating NKX019 in r/r B cell malignancies: NKX019 is an allogeneic, cryopreserved, off-the-shelf cancer immunotherapy candidate that uses NK cells engineered to target the B-cell antigen CD19, a clinically validated target for B-cell cancer therapies. The NKX019 Phase 1 study is evaluating the safety and anti-tumor activity of NKX019 as a multi-dose, multi-cycle therapy in patients with r/r B cell malignancies.

As of November 28, 2022, 19 patients were enrolled and dosed. Fourteen patients entered the study with a diagnosis of non-Hodgkin lymphoma (NHL), 7 of which were aggressive large B cell lymphoma (LBCL). Patients had received a median of 4 prior lines of therapy (range of 2 to 10).

To date, enrollment has included patients with aggressive disease characteristics and extensive lesions throughout the body. Patients were enrolled at clinical trial sites in Australia (13) and the United States (6). Safety in NKX019: NKX019 was well tolerated.

No ICANS, GvHD, or >Gr3 CRS were observed in the study. No dose-limiting toxicities were observed. Five patients developed fever within 8 hours of NKX019 infusion, and each resolved within 24 hours.

2 of the 5 patients were assessed to have infusion-related reactions, 2 patients were assessed to have CRS, despite the rapid onset and rapid resolution not common in CRS, and one patient had both entities described in two separate cycles. The most common higher-grade adverse events were myelosuppression - a condition resulting in fewer red blood cells, white blood cells and platelets, which is common in this patient population post lymphodepletion. The emerging safety profile of NKX019 is positively differentiated from those of many cell therapies.