Interim results from a pivotal Phase III trial show that Amgen's investigational agent talimogene laherpaepvec increased overall survival in patients with unresected stage IIIB, IIIC, or IV melanoma compared to granulocyte-macrophage colony-stimulating factor (GM-CSF). The study found that median overall survival was 23.3 months in the talimogene laherparepvec arm over 19 months in the GM-CSF arm. Moreover, differences in survival rates were pronounced in the subset of patients with stage IIIB, IIIC or IV M1a disease or who received talimogene laherparepvec as first-line treatment, each comprising approximately 50 percent of the study population. The most frequently observed adverse events were fatigue, chills and pyrexia. Serious adverse events, which included disease progression, cellulitis, and pyrexia, occurred in 26 percent of talimogene laherparepvec patients and 13 percent of GM-CSF patients. The results were presented during an oral session at the 2013 Society for Melanoma Research (SMR) Congress, in Philadelphia.