Talimogene Laherparepvec: An Oncolytic Virus Therapy for Melanoma

Objective: To review the efficacy and safety of talimogene laherparepvec (T-VEC) as well as its pharmacology, pharmacokinetics, drug-drug interactions, handling procedures, cost considerations, and place in therapy. Data Sources: Searches of PubMed (1966 to February 2017) and Cochrane Library (1999 to February 2017) were conducted using the terms talimogene laherparepvec, T-VEC, OncoVEX, immunotherapy, melanoma, and oncolytic virus. Additional information was determined from bibliographies, manufacturer product labeling and website, meeting abstracts, Food and Drug Administration website, and clinicaltrials. gov. Study Selection and Data Extraction: A total of 79 English-language publications were identified. Articles that assessed T-VEC's pharmacokinetics, pharmacodynamics, mechanism, dosing, safety, and efficacy were included as well as narrative reviews that provided practical information. Data Synthesis: Clinical trials have confirmed the safety and efficacy of T-VEC as monotherapy for the treatment of advanced melanoma, with an overall response rate (ORR) of 26%. Relative to granulocyte-macrophage colony-stimulating factor, T-VEC significantly increased durable response rate (DRR; 16.3% vs 2.1%, P < 0.001); however, median overall survival was not improved (23.3 vs 18.9 months, P = 0.051). Phase 1b trials have combined T-VEC and immunotherapies with promising results. T-VEC's adverse effects are generally considered mild to moderate in severity. Conclusion: T-VEC is the first approved oncolytic virus for local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in melanoma recurrent after initial surgery. T-VEC improves ORR and DRR as a single agent, shows promise in combination therapy, and is well tolerated. Ongoing trials will determine if T-VEC has a role in early treatment or in combination therapy for melanoma or other malignancies.