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FDA’s US approval of Imlygic is the first for a viral oncology therapy

WASHINGTON – Breaking what is new – and very likely fertile – ground, the U.S. Food and Drug Administration (FDA) in late October approved Amgen’s Imlygic (talimogene laherparepvec), 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. It is the first such approval by the FDA for an oncolytic viral therapy.

“Imlygic is the first clinical and regulatory validation of an oncolytic virus as a therapy. Not all melanoma patients currently benefit from available therapies, and Imlygic represents an important new option that can provide meaningful durable responses for patients with this aggressive and complex disease,” said Sean E. Harper, MD, executive vice president of research and development at Amgen in a press release. “Immunotherapy is an exciting area for cancer research, and we are currently studying Imlygic in combination with other immunotherapies in advanced melanoma and other solid tumors.”

Imlygic is a genetically modified live oncolytic herpes virus therapy used to treat melanoma lesions that cannot be removed completely by surgery. It is designed to replicate within tumors and produce an immunostimulatory protein called granulocyte-macrophage colony-stimulating factor (GM-CSF). The viral therapy causes cell lysis, which ruptures tumors, releasing tumor-derived antigens, which along with GM-CSF, may promote an anti-tumor immune response.

“This is huge for the whole field, and for cancer patients,” said John Bell, a senior scientist at the Ottawa Hospital Research Institute in Canada in a Boston Globe report. “The field is exploding, and this would be another arrow in the quiver that oncologists use.”

Skin cancer is the most common form of cancer in the United States. Melanom, most often caused by exposure to ultraviolet (UV) light, is a leading cause of skin cancer related deaths. According to the National Cancer Institute, roughly 74,000 Americans will be diagnosed with melanoma and nearly 10,000 will die from the disease in 2015.

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

According to the FDA approval:

The safety and efficacy of Imlygic were evaluated in a multicenter study of 436 participants with metastatic melanoma that could not be surgically removed. The participants’ melanoma lesions in the skin and lymph nodes were treated with Imlygic or a comparator therapy for at least six months, or until there were no remaining injectable lesions. The study showed that 16.3 percent of the study participants who received Imlygic experienced a decrease in size of their skin and lymph node lesions, lasting for a minimum of six months, compared to 2.1 percent of the study participants receiving the comparator therapy. However, Imlygic has not been shown to improve overall survival or to have an effect on melanoma that has spread to the brain, bone, liver, lungs, or other internal organs.

“Advanced melanoma remains a complex disease to treat, requiring the use of several modalities over the course of a patient’s therapeutic journey,” said Howard L. Kaufman, MD, the principal investigator for the pivotal trial (OPTiM), associate director for Clinical Science at the Rutgers Cancer Institute of New Jersey and president of the Society for Immunotherapy of Cancer. “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.”

The drug, which is being made available by Amgen almost immediately will – like most first-in-class cancer therapies – carry a steep price tag of nearly $65,000 per patient on average, according to company estimates. But Amgen also anticipates variability in dosing from patient to patient and the company has said it intends to work with the healthcare community to implement a program that helps limit the average cost of Imlygic therapy to $65,000 for eligible participating institutions.