Intratumoral recombinant GM-CSF-encoding virus as gene therapy in patients with cutaneous melanoma

Abstract

Seven immunocompetent, revaccinated patients with surgically incurable cutaneous melanoma underwent treatment of dermal and/or subcutaneous metastases with twice-weekly intratumoral injections of escalating doses (10 4 Ϫ2 ϫ 10 7 plaque-forming units (PFU)/lesion; 10 4 Ϫ8 ϫ 10 7 PFU/session) of a vaccinia/GM-CSF recombinant virus for 6 weeks. Patients with stable or responding disease were maintained on treatment until tumor resolution or progression. Systemic toxicity was infrequent, dose-related, and limited to mild flu-like symptoms that resolved within 24 hours. Local inflammation, at times with pustule formation, was consistently seen with doses of Ն10 7 PFU/lesion. Chronically treated lesions showed a dense infiltration, with CD4 ϩ and CD8 ϩ lymphocytes, histiocytes, and eosinophils. All seven patients developed an antivaccinia humoral immune response 14 -21 days following revaccination. Despite the presence of these antivaccinia antibodies, the reporter gene was expressed, as judged by the development of anti-␤-galactosidase antibodies in all patients. Passenger cytokine gene function was evidenced by the presence of virally encoded GM-CSF mRNA at injection sites both early (weeks 1 and 5) and late (week 31) in the course of treatment. Eosinophilia at treatment sites indicated that physiologically significant levels of functional cytokine were generated. However, there were no changes in the total number of peripheral white blood cells or in the numbers or percentages of polymorphonuclear leukocytes, monocytes, or eosinophils. GM-CSF was not detected in the sera. The two patients with the largest tumor burdens failed to respond even at treatment sites. Three patients had mixed responses, with regression of treated and untreated dermal metastases and progression of disease elsewhere. One patient had a partial response, with regression of injected and uninjected regional dermal metastases. Residual melanoma was excised, rendering the patient disease free. One patient with only dermal metastases confined to the scalp achieved a complete remission. Sequential administration of escalating doses of a GM-CSF recombinant vaccinia virus is safe, effective at maintaining passenger gene function, and can induce tumor regression.

Oncolytic virotherapy for ovarian carcinomatosis using a replication-selective vaccinia virus armed with a yeast cytosine deaminase gene

“…One way is to arm the virus with an immunostimulatory factor such as granulocyte-macrophage colony-stimulating factor. 29 Another method is to arm it with a gene-directed enzyme prodrug therapy (GDEPT). 7,30,31 Other investigators have shown that combined virus/prodrug treatment may enhance the replication/spread of oncolytic adenovirus in mouse tumor models.…”

Clinical development directions in oncolytic viral therapy

“…Vaccinia oncolysate has been studied as a vaccine in early stage melanoma. [156][157][158][159][160][161][162][163][164][165] Results suggested a good tolerability and survival advantage compared with historical controls. However, an unpublished prospective controlled trial failed to validate the use of vaccinia oncolysate.…”

Replication-defective recombinant Semliki Forest virus encoding GM-CSF as a vector system for rapid and facile generation of autologous human tumor cell vaccines

“…Medium was removed and cells were fixed with 0.5 ml fixation solution (2% paraformaldehyde, 0.2% gluteraldehyde) for 5 min RT. Fixed cells were washed three times with PBS and stained with 0.5 ml coloring solution (0.1% X-gal in 5 mm K 3 Fe(CN) 6 , 5 mm K 4 Fe(CN) 6 , 2 mm MgCl 2 ) at 37°C.…”

“…Possibilities that are already explored in the clinic involve immunization with autologous tumor cells, genetically modified with recombinant viral vectors to produce interferon-gamma, IL-4, IL-12, and GM-CSF. [1][2][3][4][5][6] At present, GM-CSF appears to be the most efficient cytokine for obtaining optimal immune responses. 7 Within the context of the use of cytokine gene-modified autologous tumor cell vaccines, currently, in the clinic retrovirus vectors are applied most widely for delivery of the cytokine gene to the tumor cells, [7][8][9][10][11] although other viral delivery systems are also under investigation.…”