Talimogene laherparepvec and novel injectable oncolytic viruses in the management of metastatic melanoma

Abstract

Talimogene laherparepvec (T-VEC) is an oncolytic virus (OV) therapy derived from the JS1 strain of herpes simplex virus one that was approved by the Food and Drug Administration in 2015 to be administered as direct injection therapy for patients with melanoma. The anti-tumor effects of T-VEC are due to viral-mediated tumor cell lysis at the site of administration and a local, and in some cases systemic, anti-tumor response via T cell-mediated host immune response pathways aided by GM-CSF. T-VEC has shown promising results for metastatic melanoma, particularly in patients with skin, lymph node, and soft tissue metastases (stages IIIB, IIIC, and IVa). Studies have explored the utility of T-VEC as monotherapy, neoadjuvant therapy, and in combination with other immunotherapies and targeted therapies. T-VEC has proven to improve durable response rates and overall survival with a very tolerable safety profile. More research is needed to better understand which patients are most likely to benefit from T-VEC therapy, which combination therapies are most effective, and how to sequence multimodality therapy. Additionally, new OVs are currently in development and/or being studied in clinical trials. In this review, we will discuss T-VEC as a monotherapy, neoadjuvant therapy, and combination therapy, in addition to future directions for melanoma therapy as it pertains to new OVs.