As early as around 1800, doctors discovered that certain cancer patients would have their symptoms eased after being briefly infected with some viruses. Although the concept of using viruses to treat cancer was relatively early, the development of genetic engineering technology in the 1990s could transform viruses. Around 2005, the industry recognized that the true value of virus in cancer treatment is immunotherapy, and oncolytic viruses have gradually developed into a hot topic in the field of anti-tumor research.
Most tumor viruses can directly destroy host tumor cells. This mechanism mainly depends on the efficiency of cell receptor targeting, virus replication, and host cells’ antiviral response. The lytic potential of an oncolytic virus is related to the virus type, dose, natural or induced viral tropism, and the sensitivity of different tumor cells. The ways of cell death include apoptosis, necrosis, pyroptosis, autophagy.
Currently, the U.S. Food and Drug Administration (FDA) has only approved one oncolytic virus drug, Amgen’s IMLYGIC, for the treatment of melanoma.
Size of Global Market
BCG analysis believes that there will be 5 oncolytic virus-related products on the market in 2021-2025, and it is estimated that the 6 major products will reach sales of $1.3 billion by 2026.
- IMLYGIC, from Amgen, with herpes simplex virus (HSV) as the virus type, and melanoma as the indication, was marketed in 2015.
- RP1, from Replimune, with HSV as the virus type, and soft tissue sarcoma as the indication, is expected to be on the market in 2021.
- Reolysin, from Oncolytics Biotech, with Reovirus as the virus type, and pancreatic cancer, breast cancer, etc. as indications, is expected to be on the market in 2022.
- DS-1647, from Daiichi Sankyo, with HSV as the virus type, and glioblastoma as the indication, is expected to be on the market in 2022.
- Cavatak, from Merck, with Coxsackievirus as the virus type, and melanoma, bladder cancer, etc. as indications, is expected to be on the market in 2023.
- Oncos-102, from Targovax, with Adenovirus as the virus type, and ovarian tumor, rectal cancer, etc. as indications, is expected to be on the market in 2025.
IMLYGIC (talimogene laherparepvec) is an oncolytic virus approved by the FDA in 2015 for the treatment of melanoma. This product is a live, attenuated HSV that has been genetically modified to express human granulocyte-macrophage colony-stimulating factor (huGM-CSF), cultured by Vero cells. IMLYGIC replicates in the tumor to generate the immunostimulatory protein GM-CSF, which triggers the lysis of the tumor, and then releases tumor-derived antigens, and the antigens, together with GM-CSF, trigger an anti-tumor immune response. The precise mechanism claimed by the drug insert is not yet clear. The manufacturer is BioVex, a subsidiary of Amgen.