Amgen's Talimogene Laherparep?vec Reduced Size Of Melanoma Tumours in New Phase III Retrospect?ive Analysis

Amgen has announced findings from a pre-specified retrospective analysis of patients with metastatic melanoma that showed talimogene laherparepvec reduced the size of injected tumours and also non-injected tumours that had metastasized to other parts of the body.

The analysis recorded tumor-level responses from a pivotal Phase III study evaluating talimogene laherparepvec in patients with injectable unresected stage IIIB, IIIC or IV melanoma compared with granulocyte-macrophage colony-stimulating factor (GM-CSF). Full results were presented 14 March during an oral session at the Society of Surgical Oncology (SSO) 67th Annual Cancer Symposium in Phoenix.

Talimogene laherparepvec is an investigational oncolytic immunotherapy designed to selectively replicate in tumour tissue and to initiate a systemic anti-tumour immune response.

Of the 295 patients treated with talimogene laherparepvec, almost 4000 tumour 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 tumour lesions (tumours involving solid organs such as the lungs and liver). The results showed a 50% or greater reduction in tumor size in 64% of injected tumours. In addition, one-third of uninjected non-visceral tumours, and 15% of visceral tumours 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 III 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-tumour immune response," said Sean E. Harper, MD, 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."