Oncolytic Virus Targets Injectable Melanoma

Oncolytic immunotherapy shows promise for patients with advanced melanoma that is not amenable to surgery

medwireNews: Patients with inoperable, advanced melanoma may derive significant benefit from injections of the novel oncolytic virus talimogene laherparepvec (T-VEC), suggests research published in the Journal of Clinical Oncology.

T-VEC uses a genetically modified version of the herpes simplex virus type 1 to selectively replicate and lyse tumour cells without damaging healthy tissue. T-VEC is also engineered to express human granulocyte–macrophage colony-stimulating factor (GM-CSF) and induce a tumour-specific T-cell response, explain Howard Kaufman, from Rutgers Cancer Institute of New Jersey, New Brunswick, in the USA, and team.

The durable response rate (DRR), defined as a continuous, objective response lasting at least 6 months, was 16.3% for the 295 patients given open-label T-VEC compared with just 2.1% of the 141 patients given a subcutaneous recombinant GM-CSF control treatment, a significant difference.

The overall response rate was also significantly higher for the T-VEC group than control patients, at 26.4% versus 5.7%, with a trend towards higher median overall survival at 23.3 and 18.9 months, respectively.

T-VEC had the strongest impact in patients with less advanced, stage IIIB, IIIC or IVM1a disease, as well as those who had not previously been treated for their melanoma.

“It is encouraging that the treatment had such a clear benefit for patients with less advanced cancers – ongoing studies are evaluating if it can become a first-line treatment for more aggressive melanomas and advanced disease”, commented trial leader Kevin Harrington, from the Institute of Cancer Research in London, UK.

The team notes that T-VEC was “well tolerated”, with fatigue, chills and pyrexia the most commonly reported adverse effect. Cellulitis was the only grade 3 or 4 event reported in 2% of patients or more.

“T‑VEC treatment resulted in long lasting and complete responses suggesting T‑VEC could delay/prevent relapses or preclude progression to later stages of disease”, conclude the authors.

“T‑VEC represents a novel potential new treatment option for patients with injectable metastatic melanoma and limited visceral disease.”

Reference

Andtbacka RHI, Kaufman HL, Collichio F, et al. Talimogene laherparepvec improves durable response rate in patients with advanced melanoma. J Clin Oncol 2015; Advance online publication 26 May. doi: 10.1200/JCO.2014.58.3377

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