Dear Colleagues,

Oncolytic virus (OV), either naturally occurring or genetically modified, is relatively a new class of anti-cancer agent that selectively replicates in cancer cells (sparring healthy cells) while inducing anti-tumor immunity (i.e., in situ vaccine effect). Among all OVs, oncolytic herpes simplex virus (oHSV) armed with an immunostimulatory GM-CSF (designated T-VEC) is approved for the treatment of advanced melanoma. Besides oHSV, at least 15 other OVs are under clinical development and many more are being tested preclinically either alone or in combination with other anti-cancer agents or immunotherapies. T-VEC approval in 2015 was a crucial turning point that significantly fueled the field of OV-based cancer immunotherapy as evidenced by hundreds of OV trials that are currently running to combat cancer. Although oHSV is the furthest and a leading oncolytic agent in the clinic, it has limitations in treating advanced metastatic diseases, and, similarly, each OV has its own strengths/limitations, indicating further improvements are needed to obtain long-term treatment solutions for cancer patients. In this Special Issue on “Oncolytic Viruses in Cancer Therapy”, our goal is to provide a current understanding of OV in the field of cancer immunotherapy that includes current trend, future opportunities, and challenges to fight cancer.

Dr. Dipongkor Saha

Guest Editor