RESUMEN
Oncolytic viral therapy has been accepted as a standard immunotherapy since talimogene laherparepvec (T-VEC, Imlygic®) was approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for melanoma treatment in 2015. Various oncolytic viruses (OVs), such as HF10 (Canerpaturev-C-REV) and CVA21 (CAVATAK), are now actively being developed in phase II as monotherapies, or in combination with immune checkpoint inhibitors against melanoma. Moreover, in glioma, several OVs have clearly demonstrated both safety and a promising efficacy in the phase I clinical trials. Additionally, the safety of several OVs, such as pelareorep (Reolysin®), proved their safety and efficacy in combination with paclitaxel in breast cancer patients, but the outcomes of OVs as monotherapy against breast cancer have not provided a clear therapeutic strategy for OVs. The clinical trials of OVs against pancreatic cancer have not yet demonstrated efficacy as either monotherapy or as part of combination therapy. However, there are several oncolytic viruses that have successfully proved their efficacy in different preclinical models. In this review, we mainly focused on the oncolytic viruses that transitioned into clinical trials against melanoma, glioma, pancreatic, and breast cancers. Hence, we described the current status and future prospects of OVs clinical trials against melanoma, glioma, pancreatic, and breast cancers.
RESUMEN
Oncolytic viruses (OVs) are opening new possibilities in cancer therapy with their unique mechanism of selective replication within tumor cells and triggering of antitumor immune responses. HF10 is an oncolytic herpes simplex virus-1 with a unique genomic structure that has non-engineered deletions and insertions accompanied by frame-shift mutations, in contrast to the majority of engineered OVs. At the genetic level, HF10 naturally lacks the expression of UL43, UL49.5, UL55, UL56, and latency-associated transcripts, and overexpresses UL53 and UL54. In preclinical studies, HF10 replicated efficiently within tumor cells with extensive cytolytic effects and induced increased numbers of activated CD4+ and CD8+ T cells and natural killer cells within the tumor, leading to a significant reduction in tumor growth and prolonged survival rates. Investigator-initiated clinical studies of HF10 have been completed in recurrent breast carcinoma, head and neck cancer, and unresectable pancreatic cancer in Japan. Phase I trials were subsequently completed in refractory superficial cancers and melanoma in the United States. HF10 has been demonstrated to have a high safety margin with low frequency of adverse effects in all treated patients. Interestingly, HF10 antigens were detected in pancreatic carcinoma over 300 days after treatment with infiltration of CD4+ and CD8+ T cells, which enhanced the immune response. To date, preliminary results from a Phase II trial have indicated that HF10 in combination with ipilimumab (anti-CTLA-4) is safe and well tolerated, with high antitumor efficacy. Improvement of the effect of ipilimumab was observed in patients with stage IIIb, IIIc, or IV unresectable or metastatic melanoma. This review provides a concise description of the genomic functional organization of HF10 compared with talimogene laherparepvec. Furthermore, this review focuses on HF10 in cancer treatment as monotherapy as well as in combination therapy through a concise description of all preclinical and clinical data. In addition, we will address approaches for future directions in HF10 studies as cancer therapy.
RESUMEN
Oncolytic virus therapy is a promising new therapeutic method, one of an eagerly anticipated class of biological therapies against cancer. There are many different classes of oncolytic virus. One of these, herpes oncolytic virus, is strongly oncolytic and has a large DNA genome as 150k bp. HF10 is a spontaneous mutant of herpes simplex virus -1 (HSV-1) that replicates within tumors and destroys cancers without damaging normal tissue and organs. Clinical trials of HF10 are underway in Japan and the United States. The first pilot study of HF10 was initiated in Japan in 2003. This study examined the safety and efficacy of HF10 in the treatment of breast cancer and head and neck cancers; the trial also included careful dose escalation studies. In 2005, a clinical trial using HF10 to treat pancreatic cancer was initiated. screened In this Japanese study, 17 patients received HF10 in their tumor sites. A clinical trial in the United States is also ongoing to evaluate safety, tolerability and evidence of antitumor activity in patients with refractory superficial solid tumors. Here, we report the evaluation of the 17 patients treated in Japan. Among the patients, 6 had recurrent breast cancer, 3 had recurrent head and neck cancer, and 8 had non-resectable pancreatic cancer. No severe adverse side effects have been observed, and some therapeutic potential has been reported based on pathological findings, tumor markers, and diagnostic radiography. Those results should encourage further clinical trials of HF10 around the world.
