Amgen announced findings from a pre-specified retrospective analysis of patients with metastatic melanoma that showed talimogene laherparepvec reduced the size of injected tumors and also non-injected tumors that had metastasized to other parts of the body. The analysis recorded tumor-level responses from a pivotal Phase 3 study evaluating talimogene laherparepvec in patients with injectable unresected stage IIIB, IIIC or IV melanoma compared to granulocyte-macrophage colony-stimulating factor (GM-CSF).
Full results were presented Friday during an oral session at the Society of Surgical Oncology (SSO) 67th Annual Cancer Symposium in Phoenix, Ariz.
Talimogene laherparepvec is an investigational oncolytic immunotherapy designed to selectively replicate in tumor tissue and to initiate a systemic anti-tumor immune response.
Of the 295 patients treated with talimogene laherparepvec, almost 4,000 tumor lesions were tracked for this analysis. Half of these lesions were injected with talimogene laherparepvec at least once, while the rest were not injected, including visceral tumor lesions (tumors involving solid organs such as the lungs and liver). The results showed a 50% or greater reduction in tumor size in 64% of injected tumors. In addition, one-third of uninjected non-visceral tumors, and 15% of visceral tumors were also reduced by at least 50%. There were 35 melanoma-related surgeries performed during this trial of which 30% successfully removed all residual disease.
The most frequently observed adverse events in the Phase 3 study were fatigue, chills and pyrexia. The most common serious adverse events include disease progression in both groups, and cellulitis and pyrexia in the talimogene laherparepvec group. Serious adverse events occurred in 26% of talimogene laherparepvec patients and 13% of GM-CSF patients. Immune-mediated events were reported infrequently.
“These data add to the body of evidence supporting talimogene laherparepvec’s local and distant effect, and its potential ability to stimulate a systemic anti-tumor immune response,” said Sean Harper, executive vice president of Research and Development at Amgen. “Melanoma remains a devastating and difficult-to-treat disease, and talimogene laherparepvec continues to demonstrate encouraging results in this setting.”
Date: March 14, 2014