FDA Approves Talimogene Laherparepvec for Unresectable Recurrent Melanoma
The U.S. Food and Drug Administration (FDA) has approved the biologics license application for talimogene laherparepvec (Imlygic), a genetically modified oncolytic viral therapy indicated for the local treatment of unresectable cutaneous, subcutaneous and nodal lesions in patients with melanoma recurrent after initial surgery. Talimogene laherparepvec has not been shown to improve overall survival or have an effect on visceral metastases. This is the first oncolytic viral therapy approved by the FDA based on therapeutic benefit demonstrated in a pivotal study.
Talimogene laherparepvec is a genetically modified herpes simplex virus type 1 injected directly into tumors where it replicates inside tumors and produces granulocyte-macrophage colony-stimulating factor (GM-CSF), an immunostimulatory protein. Talimogene laherparepvec then causes the tumor to rupture and die. The rupture of the tumor causes the release of tumor-derived antigens, which together with virally derived GM-CSF may promote an antitumor immune response. However, the exact mechanism of action is unknown and being further investigated.
OPTiM Study
The approval of talimogene laherparepvec is based on data from Study 005/05, referred to as OPTiM. OPTiM was a phase III, multicenter, open-label, randomized clinical trial comparing talimogene laherparepvec to GM-CSF in patients with advanced melanoma (stage IIIB, IIIC, or IV) that was not surgically resectable. The primary endpoint of the study was durable response rate, defined as the percent of patients with complete response or partial response maintained continuously for a minimum of 6 months.
OPTiM enrolled 436 patients. In the study, 16.3% of patients treated with talimogene laherparepvec achieved a durable response compared to 2.1% of patients treated with GM-CSF (P < .0001). Of the patients who experienced a durable response, 29.1% had a durable complete response and 70.8% had a durable partial response. In the study, the median time to response was 4.1 (range = 1.2–16.7) months in the talimogene laherparepvec arm.
The most common adverse drug reactions in talimogene laherparepvec treated patients were fatigue, chills, pyrexia, nausea, influenza-like illness, and injection site pain. Most adverse reactions reported were mild or moderate in severity and generally resolved within 72 hours. The most common grade 3 or higher adverse reaction was cellulitis.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
