Cancer immunotherapy is a field that garners significant interest, fueled by the clinical success of immune checkpoint inhibitors. In contrast to conventional cancer therapies, immunotherapies leverage the host's immune system by enhancing innate and adaptive immunity to control cancer progression. Despite these exciting advances, only a subset of patients respond to these drugs, and immunotherapies frequently result in immune-related toxicity. One approach to overcome these challenges is intratumoral administration of treatment to minimize systemic toxicities and maximize therapeutic effects. Intratumoral cancer therapies have shown similar or superior antitumor efficacy in both treated and distant untreated tumors, with a widely improved benefit-risk ratio over conventional therapeutic approaches. Herein, we review the current landscape of intratumoral cancer gene immunotherapy.
Keywords: cancer immunotherapy; gene therapy; immune checkpoint inhibitor; intratumoral immunotherapy; localized therapy.
Immunotherapies are drugs designed to activate a patient’s own immune system to fight cancer. Research in this field has soared following the US FDA’s approval of the first class of these drugs. They work by blocking cancer cells’ ability to hide from the body’s immune system. Unfortunately, only some patients respond and many experience side effects when the medicine is delivered to the whole body. One approach to overcome these problems is to deliver these drugs directly into a patient’s tumor to limit side effects while maintaining the positive effects. In this review we describe the benefits of giving these types of drugs directly into tumors over whole-body administration. We summarize the current clinical data and explain the mechanisms behind each drug.