Artiva Biotherapeutics, Inc. 8-K

What Happened
On May 8, 2026 Artiva Biotherapeutics (ARTV) filed an 8‑K announcing its financial results for the quarter ended March 31, 2026 and releasing positive initial clinical data for AlloNK (AB‑101) combined with rituximab in B‑cell driven autoimmune diseases, including refractory rheumatoid arthritis (RA). The company furnished press releases and an updated corporate presentation and also notified Leerink Partners that it has suspended sales of common stock under its August 6, 2025 Sales Agreement (ATM) until a new prospectus supplement is filed.

Key Details

• Clinical dataset (data cutoff April 3, 2026): 21 refractory RA patients with ≥12 weeks follow‑up (13 with 6 months); broader autoimmune set includes 11 Sjögren’s (SjD) and 5 systemic sclerosis (SSc) patients. As of April 30, 2026, >70 autoimmune patients had initiated AlloNK and >40 sites were active.
• Efficacy: >50% of RA patients with six months’ follow‑up achieved ACR50 at six months; mean disease duration 14.8 years; 81% had failed ≥2 prior b/tsDMARD classes. Clinically meaningful reductions in CDAI (mean −37 at 6 months) and DAS28‑ESR (mean −2.8 at 6 months).
• Safety and biology: No reported CRS or ICANS, no treatment discontinuations due to AEs, and no SAEs related to AlloNK. Grade ≥3 infection rate 2% (1 patient). Uniform peripheral B‑cell depletion by Day 13; complete depletion in 28 RA patients tested; reconstitution showed predominance of naïve/transitional B cells.
• Registrational plan and timing: Company reports FDA alignment on a single Phase 3 randomized trial in refractory RA (~150 patients, 2:1 AlloNK+rituximab vs rituximab alone) with ACR50 at 6 months as the primary endpoint. Planned start in H2 2026, primary data expected H2 2028, potential BLA submission in 2029.
• ATM suspension: On May 8, 2026 Artiva suspended any sales under the Sales Agreement with Leerink; the agreement remains in effect but no sales will occur until a new prospectus supplement is filed.

Why It Matters
These filings report encouraging early efficacy and a clean initial safety profile for AlloNK plus rituximab in difficult‑to‑treat RA, and they document FDA alignment on a registrational Phase 3 design and timeline—key milestones for development value. The ATM suspension limits near‑term equity offers under the existing prospectus, which can affect the company’s immediate financing flexibility. The company’s statements are forward‑looking and subject to clinical, regulatory and financing risks described in the filing.