Revisiting CD28 Superagonist TGN1412 as Potential Therapeutic for Pediatric B Cell Leukemia: A Review

Pediatric acute lymphoblastic leukemia (ALL) represents the most common pediatric cancer diagnosis, with numbers rising gradually every year. This paper proposes a novel therapeutic agent for pediatric ALL on the basis of a failed clinical drug trial in 2006. TGN1412 was a promising therapeutic agent that yielded outstanding results in both in vitro studies and animal trials. It is a CD28 superagonist monoclonal antibody that activates T regulatory (T_Reg) cells in the absence of costimulation of the T cell receptor (TCR) by an antigen-presenting cell. This drug was intended as a solution to T cell deficient diseases such as B cell leukemia and autoimmune diseases such as rheumatoid arthritis. When phase I clinical trials were conducted, all volunteers that received the drug experienced severe cytokine release syndrome (CRS) and faced multiple-organ failure within hours. TGN1412 was reassessed and re-entered clinical trials as a therapeutic for rheumatoid arthritis. A new assay was developed to better quantify T cell response, and volunteers in this trial experienced no pro-inflammatory cytokine release. This essay analyzes how misinformation contributed to the failure of TGN1412 in clinical trials and how revisiting this therapeutic could yield a novel treatment for pediatric B cell leukemia.