Artiva Biotherapeutics initiates Phase 3 RA trial after RMAT designation
Artiva Biotherapeutics has announced it will initiate a Phase 3 registrational trial of its allogeneic natural killer cell therapy AlloNK in refractory rheumatoid arthritis during the second half of 2026, following FDA granting Regenerative Medicine Advanced Therapy (RMAT) designation to the AlloNK plus rituximab combination.
The San Diego company reported the milestone alongside second-quarter 2026 financial results, disclosing a cash position of $349.4 million as of 30 June 2026, largely reflecting a $300 million underwritten equity offering completed in May. The runway is expected to extend into 2029.
Clinical data and Phase 3 design
Phase 2a basket trial data presented at the European Alliance of Associations for Rheumatology (EULAR) 2026 conference underpinned the registrational move. In the refractory RA cohort, five of seven patients with six months of follow-up achieved an ACR50 response as of an April data cutoff, a rate of 71%. No patient had lost that response, required high-dose steroids, or started a new biologic or targeted synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) at the time of the cutoff.
The planned Phase 3 study will randomise approximately 150 patients to AlloNK plus rituximab or rituximab alone. The primary efficacy endpoint is ACR50 response at six months. Artiva is targeting a response rate above 50% in the combination arm against an expected 20% for rituximab monotherapy, based on published literature.
Safety data from 55 autoimmune patients treated across the basket trial showed no cytokine release syndrome, no immune effector cell-associated neurotoxicity syndrome, no AlloNK-related serious adverse events, and no treatment discontinuations attributable to the therapy. Grade 3 or higher infections occurred in 2% of patients, and no participant was hospitalised for infection in the first 28 days after dosing. The tolerability profile is positioned by the company as supportive of outpatient, community rheumatology settings, a meaningful differentiation point if it holds in the larger registrational study.
Beyond RA, the basket trial enrolled patients with Sjögren disease and systemic sclerosis. Sjögren patients showed improvements in stimulated salivary flow, while the small systemic sclerosis cohort demonstrated an average 9.5-point reduction in mean modified Rodnan skin score among those with six months of data.
Market context and competitive landscape
The RMAT designation carries practical benefits: it provides more frequent FDA interaction and can support rolling review of a biologics licence application, which may shorten the path to a potential approval. Several cell and gene therapy developers have leveraged RMAT status to accelerate late-stage regulatory discussions, though designation does not guarantee approval.
Artiva is operating in an increasingly active space. The broader field of B-cell depletion for autoimmune disease has attracted significant interest following early clinical signals from CD19-targeted CAR-T therapies in severe lupus and systemic sclerosis. AlloNK's off-the-shelf, non-genetically modified format distinguishes it from engineered CAR-T approaches, potentially offering a more scalable and lower-cost manufacturing profile. Whether that translates into commercial accessibility will depend on the Phase 3 outcome, the safety profile at scale, and pricing negotiations with payers.
Chief executive Fred Aslan said the company was "well capitalised to initiate and execute our planned Phase 3 trial in refractory RA and continue advancing AlloNK across B-cell-driven autoimmune diseases." Research and development expenses rose to $21.9 million in the second quarter, up from $17.9 million a year earlier, reflecting increased clinical activity.
Artiva also appointed Diego Miralles as president and head of research and development, adding more than 20 years of industry experience to the leadership team ahead of what is expected to be its most capital-intensive development period.