NEW YORK – The US Food and Drug Administration has granted Iaso Bio permission to start testing its autologous cell therapy equecabtagene autoleucel in patients with generalized myasthenia gravis, a rare and chronic autoimmune disease, the firm said Thursday.
Regulators in China cleared Iaso's investigational new drug application in January for the BCMA-targeted CAR T-cell therapy, allowing for the start of clinical testing there. In an investigator-initiated open-label study, the Nanjing, China-based company is evaluating equecabtagene autoleucel's safety and efficacy and has enrolled two patients with refractory myasthenia gravis.
Both patients' clinical symptoms improved over 18 months following a single infusion of the therapy. They experienced improvements in limb strength and vital capacity only three months after the infusion, according to the company. The patients sustained these improvements as measured by multiple scales including the Myasthenia Gravis-Activities of Daily Living Score and Myasthenia Gravis-Quality of Life Score. These patients' symptoms had not improved on multiple prior treatments.
According to Iaso, these initial data suggest the cell therapy may have long-term efficacy due to its ability to reconstitute B cells with a naive phenotype and clear plasma cells. Within two months of treatment, patients' B cells and plasma cells decreased to undetectable levels. After 18 months, patients' B cells returned to normal levels, about 80 percent of which were naive B cells, while plasma cells remained at a low level. After treatment, multiple antibodies, including anti-AChR, anti-Titin, and anti-MuSK, decreased rapidly and remained low in both subjects.
Researchers detected no new safety risks in these first patients on the cell therapy, and instances of grade III or higher hemocytopenia resolved within four weeks. One of the subjects developed grade I cytokine release syndrome.
"We are very pleased that equecabtagene autoleucel has been approved for clinical trial for myasthenia gravis in the US," Iaso Bio Founder, Chairman, and CEO Jinhua Zhang said in a statement. "We hope equecabtagene autoleucel will provide a more efficient and long-lasting therapeutic option for myasthenia gravis and potentially other autoimmune diseases."