Oncolytic viruses (OVs) have emerged as effective gene therapy and immunotherapy drugs. As an important gene delivery platform, the integration of exogenous genes into OVs has become a novel path for the advancement of OV therapy, while the herpes simplex virus type 1 (HSV-1) is the most commonly used. However, the current mode of administration of HSV-1 oncolytic virus is mainly based on the tumor in situ injection, which limits the application of such OV drugs to a certain extent. Intravenous administration offers a solution to the systemic distribution of OV drugs but is ambiguous in terms of efficacy and safety. The main reason is the synergistic role of innate and adaptive immunity of the immune system in the response against the HSV-1 oncolytic virus, which is rapidly cleared by the body’s immune system before it reaches the tumor, a process that is accompanied by side effects. This article reviews different administration methods of HSV-1 oncolytic virus in the process of tumor treatment, especially the research progress in intravenous administration. It also discusses immune constraints and solutions of intravenous administration with the intent to provide new insights into HSV-1 delivery for OV therapy.

Chimeric antigen receptor T (CAR-T)-cell therapy has revolutionized the treatment of hematological malignancies, yet long-term efficacy remains constrained by antigen escape and T-cell dysfunction. Recent advances have rapidly elucidated the molecular underpinnings of antigen escape mechanisms and intrinsic T-cell dysfunction, revealing novel vulnerabilities in current CAR-T paradigms. In this review, we discuss the limitations of CAR-T-cell therapy in hematological malignancies, particularly regarding antigen escape mechanisms and T-cell dysfunction. It is noteworthy that in recent years, multi-targeted CAR-T and engineered CAR-T cells have demonstrated promising clinical efficacy in overcoming drug resistance and relapse in hematological malignancies. Here, we also discuss emerging approaches to enhance the efficacy of CAR-T-cell therapy, including advanced CAR-T-cell engineering techniques, the identification of novel therapeutic targets, and the development of multi-targeted CAR-T-cell strategies.