THOUSAND OAKS, Calif., April 4, 2014 /PRNewswire/ -- Amgen (NASDAQ: AMGN) today announced top-line results from the primary overall survival (OS) analysis of a Phase 3 trial in melanoma, which evaluated the efficacy and safety of talimogene laherparepvec for the treatment of unresected stage IIIB, IIIC or IV melanoma compared to treatment with subcutaneous granulocyte-macrophage colony-stimulating factor (GM-CSF). Results showed that, while the primary end point of durable response rate was met (as previously reported), the secondary endpoint of OS was not met, although there was a strong trend in favor of talimogene laherparepvec ( p=0.051). The estimated OS hazard ratio and improvement in median OS were similar to what was previously reported at the interim OS analysis. Talimogene laherparepvec is an investigational oncolytic immunotherapy designed to selectively replicate in tumors and to initiate an immune response to target cancer that has metastasized, or spread to other areas of the body. "We remain encouraged that the study met its primary endpoint of achieving durable responses in patients with metastatic melanoma," said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. "We missed statistical significance on the secondary endpoint of overall survival but the strong trend in survival benefit supports further research of talimogene laherparepvec to better understand its role in melanoma, both as a single-agent and in combination with other therapies." The global, randomized, open-label Phase 3 trial enrolled patients with unresected stage IIIB, IIIC or IV melanoma. Patients were randomized 2:1 to receive either talimogene laherparepvec every two weeks through direct tumor injection or GM-CSF subcutaneously for the first 14 days of each 28-day cycle, for up to 18 months. The most frequent adverse events observed in this trial were fatigue, chills and pyrexia. The most common serious adverse events include disease progression, cellulitis and pyrexia.