Artiva Biotherapeutics (NASDAQ:ARTV) said data presented at the EULAR 2026 Congress support continued development of its investigational AlloNK regimen in refractory rheumatoid arthritis and other autoimmune diseases, while emphasizing that the data remain preliminary and AlloNK has not been approved for marketing.
On a webcast reviewing the EULAR presentations, Fred Aslan, chief executive officer of Artiva, said the company believes deep B-cell depletion is “arguably the most exciting mechanism in autoimmune disease today” and positioned AlloNK as a potentially scalable alternative to autologous CAR-T approaches. AlloNK is a non-genetically modified natural killer cell therapy used with rituximab to target CD20-positive B cells, along with low-dose cyclophosphamide and fludarabine conditioning.
Company Plans Registrational RA Trial
Artiva said it had a constructive end-of-phase 2 meeting with the U.S. Food and Drug Administration and aligned on a registrational strategy for refractory RA. The planned trial is expected to enroll approximately 150 patients who have had an inadequate response to two or more biologic or targeted synthetic DMARDs.
Patients will be randomized 2-to-1 to receive AlloNK plus rituximab or rituximab alone. The primary efficacy endpoint will be ACR50 at six months. Patients in the rituximab-only arm who do not achieve ACR50 at six months may cross over to the AlloNK plus rituximab arm.
Aslan said Artiva expects ACR50 responses at six months of 50% or higher in the AlloNK plus rituximab arm, compared with 20% to 25% in the rituximab-only arm. The company plans to use 4 billion cells per dose for two doses, or 8 billion cells total, in the registrational study. Aslan said the global trial will include more than 80 sites and is slated to begin in the second half of the year, with a readout expected in the second half of 2028.
EULAR Data Highlight Responses Across Autoimmune Diseases
The company reviewed five accepted EULAR abstracts, including an investigator-initiated trial in RA, a phase 2a basket trial in rheumatologic diseases, a Sjögren’s disease case presentation, translational data and a safety abstract.
In RA, Artiva said the investigator-initiated study enrolled six highly refractory patients, all of whom had received at least two prior targeted therapies. The company said patients showed rapid improvement in CDAI and DAS28-ESR scores at three months, with responses deepening by six months.
In the phase 2a basket study, Artiva said RA patients had high baseline disease activity and were also heavily pretreated, with 73% having received at least two prior distinct targeted therapies and 27% having received at least three. Among patients with six months of follow-up in the basket study, 71% achieved ACR50, while the remaining 29% achieved ACR20, according to the presentation.
Across 21 RA patients from the investigator-initiated and basket studies, the company said follow-up ranged from three months to more than 18 months. As of the data cutoff, Artiva said no patient had lost response, required high-dose steroids or started a new targeted therapy.
Artiva also reported initial findings in Sjögren’s disease and scleroderma. In Sjögren’s disease, the company said 11 patients had at least three months of follow-up and showed early responses across clinical and functional measures, including improvement in ClinESSDAI and ESSPRI scores. In scleroderma, Artiva said all four patients with six months of follow-up achieved ACR20, with 50% reaching ACR50.
Safety Profile Compared With Other Deep B-Cell Depletion Approaches
The safety abstract analyzed 55 patients treated with AlloNK and rituximab. Artiva said it observed no cytokine release syndrome, no use of tocilizumab and no use of IVIG for hypogammaglobulinemia. The company reported infections in 29% of patients, with severe infections in 2%.
Artiva also said only two of 55 patients required hospitalization during the first 28 days after treatment: one for dehydration from diarrhea and one for diabetic ketoacidosis. The company said neither hospitalization was related to treatment. The most common treatment-emergent adverse events were described as consistent with rituximab or cyclophosphamide/fludarabine.
Rheumatology Perspective
Dr. Paul Emery, Arthritis UK Professor of Rheumatology at the University of Leeds and director of the Leeds NIHR Biomedical Research Centre, said refractory RA patients represent “the largest current unmet need in RA management.” He said existing therapies do not offer a consistent chance of response for patients who have failed multiple targeted therapies.
Emery said rituximab experience suggests deeper B-cell depletion is associated with better clinical responses, but that rituximab alone is “a relatively poor B-cell depleter.” He said every RA patient treated with AlloNK plus rituximab in Artiva’s data achieved complete B-cell depletion using a high-sensitivity assay.
Emery cautioned that the results remain early and that the randomized controlled trial will be crucial. Still, he said the consistency of the findings — deep B-cell depletion, reconstitution with a naive B-cell phenotype and clinically meaningful responses in refractory patients — is encouraging.
Funding and Future Updates
Aslan said Artiva recently raised $300 million, extending its cash runway into 2029. He said the funding should give the company sufficient resources to read out the planned registrational RA trial.
The company expects additional RA data over the next 12 to 24 months, including a larger dataset from the ongoing basket study. Artiva also said it plans to share data from additional indications and provide updates on a potential registrational path for a second indication, though Aslan said the company has not yet identified which indication that will be.
About Artiva Biotherapeutics (NASDAQ:ARTV)
Artiva Biotherapeutics, Inc is a clinical-stage biotechnology company focused on the development of allogeneic “off-the-shelf” cell therapies for cancer. The company’s proprietary platform leverages natural killer (NK) cells engineered to express chimeric antigen receptors (CARs) or other targeting modalities, with the goal of delivering potent anti-tumor activity while minimizing the safety and supply limitations associated with patient-derived (autologous) approaches.
Artiva’s pipeline includes multiple lead product candidates designed to address both hematologic malignancies and solid tumors.
