Kidney transplantation is the treatment of choice for patients with end-stage renal disease (ESRD) who must otherwise remain on long-term dialysis. To prevent graft rejection, transplanted patients are treated with lifelong immunosuppressive therapy, which impacts the body’s immune system and is associated with multiple side effects.
These side effects include an increased risk of severe life-threatening infections, malignancies, cardiovascular disease, and other drug-related toxicities, such as nephrotoxicity, which can impact the function and survival of the newly transplanted kidney.
TX200 is composed of the patient’s own (autologous) regulatory T cells (Tregs) engineered to express a chimeric antigen receptor (CAR) designed to recognize the HLA-A2 protein present on a transplanted kidney and bind to it. TX200 is in development for the prevention of immune-mediated rejection in HLA-A2 mismatched kidney transplantation from a living donor.
HLA-A2 negative patients first undergo a leukapheresis procedure to collect their white blood cells, after which their Treg cells are isolated, genetically engineered and then cryopreserved. They subsequently undergo transplantation surgery to receive a kidney from an HLA-A2 positive living donor. Following a recovery period, the patient receives their personalized TX200 investigational cell therapy.
TX200 cells are expected to localize to the graft and activate upon binding to the HLA-A2 antigen. Through their ability to regulate the immune system, TX200 cells may protect the graft from immune-mediated rejection and may reduce or eliminate the need for lifelong treatment with immunosuppressants.
The STEADFAST study is a multicenter, open-label, single ascending dose, dose-ranging Phase 1/2 clinical study for the prevention of immune-mediated rejection in HLA-A2 mismatched kidney transplantation from a living donor.
The primary objective of the STEADFAST study is to evaluate the safety and tolerability of TX200. Key secondary objectives include the evaluation of the effect of TX200 on acute graft-related outcomes and on long-term safety outcomes, as well as the evaluation of the pharmacodynamic and pharmacokinetic effects of TX200.
Routine post-transplant biopsies will allow for the early detection of engineered CAR-Tregs in the kidney. The adjustment and tapering of standard immunosuppressive therapy will be at the discretion of the investigator.