Ovarian cancer (OC) remains the most lethal gynecologic malignancy owing to late detection, intrinsic and acquired chemo-resistance and remarkable heterogeneity. There is an unmet medical need to develop new therapy modalities. In preclinical studies, GL-ONC1, has shown the ability to preferentially locate, colonize and destroy tumor cells in more than 30 different human tumors, including ovarian cancer. GL-ONC1 has been investigated in early stage clinical trials in the United States and Europe via systemic delivery as monotherapy and in combination with other therapies, and via regional delivery as monotherapy. GL-ONC1 treatment was well tolerated across different malignancies, routes of administration, and monotherapy as well as combination therapy protocols. The ability of GL-ONC1 to infect tumor tissue and kill tumor cells was demonstrated. In addition, virus-induced immune activation and favorable anti-tumor immune response have been observed. Evidences of anti-tumor efficacy and clinical benefits have also been documented.