Shanghai – October 17, 2026 -- The U.S. Food and Drug Administration has granted Orphan Drug Designation to GT801, the lead in vivo CAR-T candidate of Vivacta Biotechnology (Shanghai) Co., Ltd., for autoimmune hemolytic anemia (AIHA). Vivacta Bio was spun out of Beijing Grit Biotherapeutics' in vivo CAR-T platform on June 25, 2025.
Designation opens tax credits, fee exemption and seven-year exclusivity
Sponsors of designated products may be eligible for tax credits on qualified clinical trial expenses and an exemption from marketing application user fees. They may also receive seven years of orphan drug market exclusivity after marketing approval, subject to applicable requirements.
Two AIHA patients reached complete response in early data
Preliminary results were presented in a poster at the 2026 American Society of Gene & Cell Therapy (ASGCT) Annual Meeting. Both AIHA patients treated with GT801 achieved complete response (CR). One reached CR at Week 4 and stayed in CR at Week 8 and Month 3. The other reached CR at Week 10.
The poster also reported sustained peripheral B-cell depletion and higher hemoglobin levels. Lactate dehydrogenase, indirect bilirubin and reticulocyte counts fell. The data cover only two patients and are preliminary.
GT801 generates CAR-T cells inside the body using mRNA and lipid nanoparticles
GT801 is an investigational anti-CD19 therapy that pairs mRNA with T-cell-targeted lipid nanoparticle (LNP) delivery. The mRNA encodes a CAR delivered into patients' T cells, which are designed to eliminate CD19-positive B cells in vivo. Vivacta Bio says the approach avoids cell isolation, ex vivo expansion and lymphodepletion, which it identifies as drivers of cost, treatment time and toxicity in conventional cell therapies.
The company targets AIHA patients who continue to have inadequate disease control despite multiple lines of therapy. CD19 CAR-T has recently been investigated in refractory AIHA through B-cell depletion. Simplifying treatment and improving access remain open development areas, according to the source's cited literature.
Yarong Liu, Founder, Chairperson and CEO of Grit Bio, called the designation an important milestone in GT801's global development in autoimmune diseases, particularly rare ones.