Advances in cellular therapies for children and young adults with solid tumors

Adoptive immunotherapy brings hope to children and young adults diagnosed with high-risk solid tumors. Cellular (cell) therapies such as chimeric antigen receptor (CAR) T cell, CAR natural killer (NK) cell, and T cell receptor (TCR) T cell therapy are potential avenues of targeted therapy with limited long-term toxicities. However, development of cell therapies for solid tumors is in its nascent stages. Here, we will review the current clinical experience, barriers to efficacy, and strategies to improve clinical response and patient access.

Cell therapies are shown to be generally safe and well tolerated. Strategies to optimize antitumor activity have now moved into early-phase trials. The immunosuppressive tumor microenvironment remains a major barrier to efficacy, and efforts are underway to gain better understanding. This will inform future treatment strategies to enhance the antitumor activity of cell therapies.

Clinical experiences to date provide important insights on how to leverage cell therapies against solid tumors. Key factors in advancing the field include a better understanding of immune cell biology, tumor cell behavior, and the tumor microenvironment. Lastly, improving access to novel cell therapies remains an important consideration in the conduct of clinical trials and for future implementation into standard practice.