Epstein-Barr virus-targeted therapy in nasopharyngeal carcinoma.

Autor: Stoker SD; Department of Head and Neck Surgery and Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands, s.stoker@nki.nl., Novalić Z, Wildeman MA, Huitema AD, Verkuijlen SA, Juwana H, Greijer AE, Tan IB, Middeldorp JM, de Boer JP
Jazyk: angličtina
Zdroj: Journal of cancer research and clinical oncology [J Cancer Res Clin Oncol] 2015 Oct; Vol. 141 (10), pp. 1845-57. Date of Electronic Publication: 2015 Apr 29.
DOI: 10.1007/s00432-015-1969-3
Abstrakt: Purpose: Despite successful primary treatment of nasopharyngeal carcinoma (NPC), the incidence of distant metastasis remains 25-34 %. Treatment options are limited, and survival is poor. Intratumoural Epstein-Barr virus (EBV) was used as treatment target. In NPC, EBV is present in a latent state, expressing only few non-immunogenic viral products. Gemcitabine and valproic acid can trigger EBV to the lytic state, wherein viral kinases are expressed, making EBV-positive tumour cells susceptible for antiviral therapy with, i.e. valganciclovir, and inducing an EBV-specific immune response.
Methods: This drug combination was applied in eight patients with EBV-positive NPC, refractory to conventional treatment. The primary endpoints were safety, tolerability and clinical response. Secondary endpoint was to get proof of concept based on biomarkers, i.e. pharmacokinetics, EBV-DNA load in whole blood and nasopharyngeal brushes, EBV-RNA profiling for proof of lytic induction, EBV-IgG and EBV-IgA levels and diversity and EBV-specific T cell response.
Results: The best observed clinical response was partial in two patients (25 %) and stable disease in three patients (37.5 %). The median survival was 9 months (95 % confidence interval 7-17 months). Effective dose levels were reached. Peaking of EBV-DNA loads in blood and brush proved the biological effect on EBV during most treatment cycles. In one patient, RNA profiling confirmed lytic EBV induction. EBV-IgG and EBV-IgA antibody levels were already high before treatment and did not change during treatment. No changes in EBV-specific T cell response were detected.
Conclusion: The treatment was safe with manageable side effects, clinical response was observed, and viral activation corroborated.
Databáze: MEDLINE
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