Nkarta Announces Clean Safety Profile for Cell Therapy Across Five Autoimmune Indications

Nkarta Inc. (NASDAQ:NKTX) announced Wednesday that its experimental NKX019 cell therapy showed encouraging initial safety results in 40 patients across five autoimmune diseases.

The company presented the findings at the American College of Rheumatology’s ACR Convergence 2026 conference in Orlando.

The biotech company demonstrated strong clinical tolerability for its off-the-shelf cell therapy candidate NKX019, showing zero deaths and no severe immune toxicities across 40 patients with refractory autoimmune conditions.

Strong Tolerability in Heavily Pretreated Patients

Nkarta manufactures NKX019 from healthy donor-derived natural killer cells. The off-the-shelf, cryopreserved approach eliminates patient leukapheresis and individualized manufacturing delays, ensuring convenient delivery across clinical sites.

The cumulative analysis, carrying a data cutoff of Sept. 18, 2026, evaluated patients battling active or progressive systemic sclerosis, myositis, lupus nephritis, rheumatoid arthritis, and ANCA-associated vasculitis.

Participants enrolled in the Ntrust Phase 1/2 clinical program after exhausting standard-of-care options.

Thirty patients, or 75% of the cohort, had undergone four or more prior treatments. The study population recorded a median disease duration of 4.7 years, spanning from 0.3 to 30.7 years.

Complete Absence of Severe Immune Toxicities

Participants received outpatient lymphodepletion using fludarabine and cyclophosphamide before receiving a three-dose cycle of NKX019.

Nkarta evaluated three dose cohorts: five patients received 1 billion cells per dose, seven received 2 billion cells, and 28 received 4 billion cells.

The integrated analysis revealed zero cases of cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, or graft-versus-host disease across all dosing tiers.

Furthermore, physicians reported no fludarabine-related leukoencephalopathy, and no patients discontinued treatment due to adverse events.

Manageable Adverse Events and Streamlined Delivery

Treatment-emergent adverse events occurred in 34 individuals, with 14 patients developing grade 3 or higher complications. Clinicians predominantly attributed these high-grade events to preconditioning chemotherapy.

Most hematologic abnormalities resolved within one to two months, though five patients experienced grade 3 or higher cytopenias persisting past 28 days. Adverse event frequency remained stable across all dose levels.

NKTX Price Action: Nkarta shares were up 3.70% at $1.40 at the time of publication on Wednesday, according to Benzinga Pro data.

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