LAUSR

Simple Summary In 2017, two chimeric antigen receptor-T (CAR-T) therapies were approved by the FDA for advanced/resistant lymphoma and acute lymphoblastic leukemia. However, despite the breakthrough efficacy results, the safety of CAR-T treatment is still a concern for treating physicians and their patients. Moreover, the high rate of relapse in up to 60% of patients previously treated with CAR-T represents a major challenge. There is currently extensive research activity aimed at addressing these shortfalls; strategies include changing the administration plans of CAR-T, combining it with chemotherapy, and even developing new types of CAR-T therapies. This article will focus on new CAR-T strategies that are under investigation and the results of their studies. Abstract The year 2017 was marked by the Food and Drug Administration (FDA) approval of the first two chimeric antigen receptor-T (CAR-T) therapies. The approved indications were for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL) and for the treatment of patients up to 25 years of age with acute lymphoblastic leukemia (ALL) that is refractory or in a second or later relapse. Since then, extensive research activities have been ongoing globally on different hematologic and solid tumors to assess the safety and efficacy of CAR-T therapy for these diseases. Limitations to CAR-T therapy became apparent from, e.g., the relapse in up to 60% of patients and certain side effects such as cytokine release syndrome (CRS). This led to extensive clinical activities aimed at overcoming these obstacles, so that the use of CAR-T therapy can be expanded. Attempts to improve on efficacy and safety include changing the CAR-T administration schedule, combining it with chemotherapy, and the development of next-generation CAR-T therapies, e.g., through the use of CAR-natural killer (CAR-NK) and CAR macrophages (CAR-Ms). This review will focus on new CAR-T treatment strategies in hematologic malignancies, clinical trials aimed at improving efficacy and addressing side effects, the challenges that CAR-T therapy faces in solid tumors, and the ongoing research aimed at overcoming these challenges.