Chimeric antigen receptors: unleashing a new age of anti-cancer therapy

BACKGROUND: Chimeric antigen receptors (CARs) represent a novel facet of modern day synthetic biology that exemplifies personalized medicine at work through their ability to harness and redirect a patient’s immune system to fight cancer. BODY: By combining the target-specificity of antibodies to the effector capabilities of T cells, CARs have yielded high remission rates for many late staged and relapsed/refractory (r/r) hematological malignancies, including acute lymphoblastic leukemias (ALL) and Non-Hodgkin’s lymphomas. Despite toxicities of cytokine release syndrome and neurotoxicity, recent studies have uncovered their underlying mechanisms and devised effective therapies to manage and possibly prevent them. In 2017, CAR T cell therapy became a reality for the general public despite the high costs, when Novartis’s Kymriah, became the first product to receive FDA approval for pediatric r/r B cell ALL with Gilead’s Yescarta following several months later. Although effective in hematological malignancies, CAR response has been limited in solid tumors largely attributed to the heterogeneous and immunosuppressive tumor microenvironment along tumor defense mechanisms, such as antigenic escape. CONCLUSION: Despite the current challenges of CAR T therapy, this technology is still in its infancy and its promise will continue to grow as scientists continue to develop novel approaches to enhance its efficacy. As its prevalence continues to increase, institutions and pharmaceuticals worldwide are investing in this technology in hopes of driving therapeutic innovation, while providing greater access to their respective populations through clinical trials.