FDA approves Imlygic for unresectable melanoma

The FDA has approved talimogene laherparepvec, an oncolytic viral therapy, for the local treatment of unresectable cutaneous, subcutaneous and nodal lesions in patients with melanoma who experienced recurrence after initial surgery.

Talimogene laherparepvec (Imlygic; BioVex, Amgen) — commonly referred to as T-VEC — is a systemically active oncolytic immunotherapy derived from herpes simplex virus type-1. T-VEC is the first FDA-approved oncolytic virus therapy.

After T-VEC is injected directly into the melanoma lesions, it selectively infects and replicates in tumor cells — causing the cells to rupture and die — and produces granulocyte-macrophage colony–stimulating factor. This process releases tumor-derived antigens, which with GM-CSF, may promote an anti-tumor immune response.

“Melanoma is a serious disease that can advance and spread to other parts of the body, where it becomes difficult to treat,” Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research, said in a press release. “This approval provides patients and health care providers with a novel treatment for melanoma.”

The FDA based its decision in part on results of the multicenter phase 3 OPTiM study, composed of 436 patients with unresectable metastatic melanoma. Patients received T-VEC or a comparator for 6 months, or until there were no remaining injectable lesions. More patients who received T-VEC than the comparator experienced a decrease in the size of their skin and lymph node lesions for at least 6 months (16.3% vs. 2.1%; P ˂ .0001).

However, T-VEC has not been shown to extend OS or improve outcomes in patients with disease that has metastasized to the brain, bone, liver, lungs or other organs.

The most common adverse events associated with T-VEC include fatigue, chills, fever, nausea, flu-like symptoms and pain at the injection site. Herpes virus infection can also occur, and thus, patients with suppressed immune systems or who are pregnant should not receive T-VEC.

“Advanced melanoma remains a complex disease to treat, requiring the use of several modalities over the course of a patient's therapeutic journey,” Howard L. Kaufman, MD, the principal investigator for the OPTiM trial, associate director for clinical science at the Rutgers Cancer Institute of New Jersey and president of the Society for Immunotherapy of Cancer, said in a press release. “As an oncolytic viral therapy, Imlygic has a unique approach, and provides another option for treating eligible patients with unresectable disease that has recurred after initial surgery.”