Talimogene Laherparepvec: A Review in Unresectable Metastatic Melanoma

Talimogene laherparepvec (Imlygic™) is a first-in-class oncolytic viral immunotherapy derived from herpes simplex virus type 1, which has been genetically modified to increase tumour selectivity and stimulate antitumour immune response. This article reviews the pharmacological properties of intralesional talimogene laherparepvec and its clinical efficacy and tolerability in patients with unresectable metastatic melanoma. In the phase III OPTiM trial, talimogene laherparepvec was more effective than subcutaneous human granulocyte-macrophage colony-stimulating factor (GM-CSF), both in patients with stage IIIB–IV melanoma [intention-to-treat (ITT) population] and in those with stage IIIB–IVM1a disease (in an exploratory subgroup analysis). Durable response rate (DRR) was significantly higher with talimogene laherparepvec in the ITT population; beneficial results in DRR were also observed in talimogene laherparepvec recipients in patients with stage IIIB–IVM1a disease. Talimogene laherparepvec was generally well tolerated in clinical trials. In conclusion, talimogene laherparepvec is a novel, effective and well tolerated option for the treatment of patients with unresectable metastatic melanoma.