T-VEC (Imlygic™)

Immunotherapy is cancer treatment that directly kills cancer cells and stimulates the body's immune system to fight cancer, such as melanoma.

Imlygic (talimogene laherparepvec, or T-VEC) is a local immunotherapy treatment that kills melanoma cells in the skin and lymph nodes. 

What Is T-VEC (Imlygic)?

T-VEC is an oncolytic virus therapy, a treatment that uses a virus to infect and kill cancer cells while avoiding normal, healthy cells. T-VEC is made from a genetically modified herpes virus, commonly known as the cold sore virus. The therapy is designed to replicate inside melanoma cells to kill those cells. It may also enhance the immune system's ability to fight cancer.

How Does T-VEC (Imlygic) Work?

Your physician injects T-VEC directly into melanoma tumors. The virus then replicates within the cells, causing them to rupture and die. T-VEC is a local treatment, which means that it is applied directly to melanoma lesions to treat those cells.

The exact way that T-VEC works in the immune system is not fully known. Cancer experts believe that, in addition to directly killing cells, the virus may also produce an immune response against melanoma by releasing:

  • Antigens (substances that promote an immune response) shed from the tumor cells
  • A protein (GM-CSF) that stimulates the immune system

Which Patients Benefit from T-VEC (Imlygic)?

In 2015, the U.S. Food and Drug Administration (FDA) approved T-VEC as the first oncolytic virus therapy. The FDA approved T-VEC for patients with advanced melanoma (Stage IIIB, IIIC or IV) that cannot be completely removed with surgery. The treatment is injected directly into tumors that are:

  • Cutaneous (in the skin)
  • Subcutaneous (under the skin)
  • Nodal (within lymph nodes)

T-VEC may not be right for certain patients, such as those who:

  • Are pregnant
  • Have a weakened immune system caused by an immune deficiency, blood or bone marrow cancer (such as leukemia or lymphoma), steroid use, or HIV/AIDS

Patients should discuss T-VEC and other immunotherapy treatments with their physicians to understand the potential risks and benefits of a particular treatment.

How Is T-VEC (Imlygic) Given?

Patients receive T-VEC as an intralesional (into the tumor) injection.

  • After the initial injection, patients receive a second dose three weeks later.
  • Patients receive subsequent doses every two weeks for at least six months, until no injectable tumors remain or other treatment is required.
  • You can receive T-VEC for 6 months or longer.
  • Patients usually continue to take this medication for a period of time, until their melanoma worsens or they experience unacceptable side effects.

What Are the Goals of T-VEC (Imlygic)?

T-VEC works as a targeted therapy to:

  • Destroy melanoma cells
  • Shrink melanoma lesions in the skin and lymph nodes

T-VEC has not been shown to improve overall survival or to shrink metastatic melanoma (melanoma that has spread to the brain, bone, liver, lungs or other organs).

Melanoma treatments, like T-VEC, have side effects, which can sometimes be serious. Patients should talk with their physician to learn more about the side effects of T-VEC and other melanoma treatment options. 

What Should I Ask My Doctor About T-VEC (Imlygic)?

If you are interested in finding out more about T-VEC, here are some questions you should ask your physicians:

  • Am I eligible for T-VEC?
  • What is your experience with T-VEC?
  • Is T-VEC a good option for my melanoma treatment?
  • Is there an alternative to T-VEC for me?
  • How successful has T-VEC been for patients like me?
  • What are the side effects of T-VEC?
  • Are there any clinical trials for T-VEC that I should consider?
  • What other treatments are FDA-approved for treating advanced melanoma?
  • What are the risks and benefits of the available treatment options?
  • What are the goals for my treatment?
  • How long will I stay on this treatment?

Need Help Paying for T-VEC (Imlygic)?

Patient Assistant Programs (PAPs) are designed so that you still have access to the treatments you need, in any financial circumstance. Learn more about the manufacturer’s patient assistance program and other options here.

Manufacturer’s Patient Assistance


Latest Treatments for Advanced Melanoma

Learn more about the latest, most effective treatments for patients who have advanced melanoma: 

Melanoma Research

The Melanoma Research Alliance is the largest, non-profit funder of melanoma research worldwide. Since 2007, we have directly funded over $131 million in innovative grants to improve prevention, detection, and treatment of melanoma. We have also leveraged an additional $415 million in outside funds for research. Learn more about our funded research.

Last updated: August, 2021