General Information

Imlygic (talimogene laherparepvec) is a genetically modified oncolytic viral therapy.

Imlygic is specifically indicated for the local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in patients with melanoma recurrent after initial surgery.

Imlygic is supplied as a suspension for intralesional injection. Imlygic should be administered by injection into cutaneous, subcutaneous, and/or nodal lesions that are visible, palpable, or detectable by ultrasound guidance.

Imlygic is provided in single-use vials of 1 mL each in two different dose strengths: 10*6 (1 million) plaque-forming units (PFU) per mL (light green cap) – for initial dose only and 10*8 (100 million) PFU per mL (royal blue cap) – for all subsequent doses. The initial recommended dose is up to 4 mL at a concentration of 10*6 (1 million) PFU per mL. The recommended dose for subsequent administrations is up to 4 mL at a concentration of 10*8 (100 million) PFU per mL. Please see drug label for recommended dose schedule and dose volume determination.

Clinical Results

FDA Approval

The FDA approval of Imlygic was based on Study 005/05, referred to as OPTiM. OPTiM was a phase III, multicenter, open-label, randomized clinical trial comparing Imlygic to GM-CSF in 436 patients with advanced melanoma (Stage IIIB, IIIC, or IV) that was not surgically resectable. The subjects were randomized to receive either Imlygic (n = 295) or GM-CSF (n = 141). Imlygic was administered by intralesional injection at an initial concentration of 10*6 (1 million) PFU per mL on Day 1, followed by a concentration of 10*8 (100 million) PFU per mL on Day 21 and every 2 weeks thereafter, at a dose of up to 4 mL per visit. GM-CSF was administered subcutaneously in 28-day cycles, i.e., 125 µg/m2 daily for 14 days followed by 14 days without GM-CSF administration. The primary endpoint of the study was durable response rate (DRR), defined as the percent of patients with complete response (CR) or partial response (PR) maintained continuously for a minimum of six months. In the study, 16.3 percent of patients treated with Imlygic achieved a durable response compared to 2.1 percent of patients treated with GM-CSF (p <0.0001). Of the patients who experienced a durable response, 29.1 percent had a durable CR and 70.8 percent had a durable PR. In the study, the median time to response was 4.1 (range: 1.2 to 16.7) months in the Imlygic arm.

Mechanism of Action

Imlygic (talimogene laherparepvec) is a genetically modified oncolytic viral therapy. It was designed to replicate within tumors and to produce the immune stimulatory protein GM-CSF. Imlygic causes lysis of tumors, followed by release of tumor-derived antigens, which together with virally derived GM-CSF may promote an antitumor immune response.