Re-inventing intratumoral immunotherapy for melanoma

Immunotherapeutics have been applied intratumorally to manage accessible lesions and to induce systemic immunity in malignant melanoma. Intratumoral bacillus Calmette-Guérin (BCG) has been used for 40 years, and intratumoral BCG, IL-2, IFN-α and imiquimod are recommended as treatment options for patients with in-transit melanoma metastases. Regression of cutaneous metastases can be achieved. Subcutaneous metastases are more refractory, and regression of uninjected, visceral metastases is infrequent. Other microbial products, cytokines, chemicals, immune cells, antibody and viral and plasmid vectors expressing immunologically active molecules have been tested. Antitumor activity has not been demonstrated to be superior to that of intratumoral BCG. There are few controlled trials, and whether survival is impacted with any approach has not yet been established. The immunotherapeutics applied and the intratumoral administration procedure itself can activate responses that are immune inhibitory. More rigorous clinical testing and improved understanding and modulation of regulatory immune responses are necessary.

Immunologic therapy targeting metastatic melanoma: Allovectin-7®

In the USA, the incidence of cutaneous melanoma is increasing rapidly. It has been shown to be responsive to immune-stimulating drugs. Allovectin-7® allows the immune system to recognize metastatic melanoma lesions as foreign by incorporating a MHC class I complex into the tumor through direct injection. Once transfected, tumor biopsies have shown an increased presence of cytotoxic T lymphocytes in the tumor beds themselves. Phase I and II trials have shown local and systemic response to these tumors, with an excellent safety profile. Currently, a Phase III trial has completed enrollment and is set to determine the safety and efficacy of treatment in comparison with standard chemotherapy.

Allovectin-7 therapy in metastatic melanoma

BACKGROUND

Patients with metastatic melanoma are immunosuppressed by the growing tumor. Allovectin-7 therapy is a form of active immunotherapy that aims at immunization of the host with substances designed to elicit an immune reaction that will eliminate or slow down the growth and spread of the cancer.

OBJECTIVE

to describe the rationale for immunotherapy with Allovectin-7 and assess its safety profile and efficacy based on the results of completed melanoma clinical trials.

METHODS

we reviewed both the published medical literature and the results of trials pending publication.

RESULTS/CONCLUSION

Allovectin-7 is a safe and active immunotherapeutic agent. It induces local and systemic durable responses in patients with metastatic melanoma.