Talimogene laherparepvec (T-VEC), sold under the brand name Imlygic among others, is a biopharmaceutical medication used to treat melanoma that cannot be operated on; it is injected directly into a subset of lesions which generates a systemic immune response against the recipient's cancer. The final four-year analysis from the pivotal phase 3 study upon which T-VEC was approved by the FDA showed a 31.5% response rate with a 16.9% complete response (CR) rate. There was also a substantial and statistically significant survival benefit in patients with earlier metastatic disease and in patients who had not received prior systemic treatment for melanoma. The earlier stage group had a reduction in the risk of death of approximately 50% with one in four patients appearing to have met, or be close to be reaching, the medical definition of cure. Real world use of talimogene laherparepvec have shown response rates of up to 88.5% with CR rates of up to 61.5%.