Designation for GT801
Vivacta Biotechnology (Shanghai), a company spun out of Beijing Grit Biotherapeutics' in vivo CAR-T platform, has been granted Orphan Drug Designation by the US Food and Drug Administration for GT801, its lead investigational product, in autoimmune hemolytic anemia, the company said. Vivacta said the designation was an important step in developing GT801 for autoimmune diseases and opens potential access to incentives supporting the product's further development in AIHA in the United States.
AIHA and the candidate
AIHA is an autoimmune disorder in which autoantibodies cause excessive destruction of red blood cells. Symptoms can include anemia, fatigue and shortness of breath, and severe cases can be life-threatening. GT801 is an investigational in vivo CAR-T therapy combining mRNA with T-cell-targeted lipid nanoparticle delivery; it is designed to carry mRNA encoding an anti-CD19 chimeric antigen receptor into patients' T cells so that CAR-T cells are generated in the body to recognize and eliminate CD19-positive B cells.
Preliminary findings
Preliminary clinical results in patients with autoimmune diseases were presented in a poster at the 2026 American Society of Gene and Cell Therapy annual meeting. Two patients with AIHA each achieved a complete response after treatment with GT801: one at week 4 who remained in complete response at the week 8 and month 3 assessments, and the other at week 10. Sustained depletion of peripheral B cells was also observed, together with increased hemoglobin levels and reductions in lactate dehydrogenase, indirect bilirubin and reticulocyte counts.
What the status provides
Orphan Drug Designation is intended to encourage development of treatments for rare diseases. Sponsors of designated products may, subject to applicable requirements, be eligible for incentives including tax credits for qualified clinical trial expenses, exemption from marketing application user fees and the potential for seven years of orphan drug market exclusivity after marketing approval. Yarong Liu, founder, chairperson and chief executive of Grit Bio, said the designation was an important milestone in the project's global development in autoimmune diseases and reflected continued progress in advancing therapies originated from Grit Bio's in vivo CAR-T platform, particularly in rare autoimmune diseases.