Talimogene laherparepvec, sold under the brand name Imlygic among others, is a biopharmaceutical medication used to treat melanoma that cannot be operated on; it is injected directly into a subset of lesions which generates a systemic immune response against the recipient's cancer.

The earlier stage group had a reduction in the risk of death of approximately 50% with one in four patients appearing to have met, or be close to be reaching, the medical definition of cure.

[7] Around half of people treated with talimogene laherparepvec in clinical trials experienced fatigue and chills; around 40% had fever, around 35% had nausea, and around 30% had flu-like symptoms as well as pain at the injection site.

[13] Around half of people treated with talimogene laherparepvec in clinical trials experienced fatigue and chills; around 40% had fever, around 35% had nausea, and around 30% had flu-like symptoms as well as pain at the injection site.

[5] The first oncolytic virus to be approved by a regulatory agency was a genetically modified adenovirus named H101 by Shanghai Sunway Biotech.

It gained regulatory approval in 2005 from China's State Food and Drug Administration (SFDA) for the treatment of head and neck cancer.

[10][9] BioVex was founded in 1999, based on research by Robert Coffin at University College London,[18] and moved its headquarters to Woburn, Massachusetts in 2005, leaving about half its employees in the UK.

[22] As of 2016, talimogene laherparepvec has been studied in early stage clinical trials in pancreatic cancer, soft-tissue sarcoma, and head and neck squamous-cell carcinoma; it had also been tested in combination with checkpoint inhibitors ipilimumab and pembrolizumab.