Results from a new study in the US have shown impressive long-term survival rates for patients with metastatic melanoma when treated with patient-specific cancer vaccines derived from a patient’s own cancer and immune cells.

The clinical study presented by Hoag Memorial Hospital Presbyterian showed that vaccines given to patients who already had their disease treated somewhat effectively by other therapies were well tolerated and resulted in longer-term survival rates.

During the study, 54 patients with regionally recurrent or distant metastatic melanoma were injected with a vaccine designed to stimulate the patient’s immune system to react against tumour stem cells or early progenitor cells that can create new depots of cancer throughout the body.

The vaccine included each patient’s own immune cells (dendritic cells) and 500 micrograms of granulocyte-colony stimulating factor (GM-CSF), an immune stimulator.

Data showed a five-year projected survival rate of 54% at a median follow up of 4.5 years (range 2.4 to 7.4) for the 30 surviving patients.

Eight patients in the dendritic cell vaccine study experienced remarkable long-term, progression-free survival after completing the vaccine therapy, even though they had widely metastatic disease and/or repeated appearance of new metastases despite various therapies. The vaccine treatment was also well tolerated, with most patients only experiencing mild skin irritation and redness at the injection site.

Hoag Cancer Centre executive medical and scientific director and lead investigator for the study Dr Dillman said that the one-year and projected five-year survival rates of 85% and 54% respectively are remarkable for melanoma patients with documented metastatic disease.

“This study was extremely encouraging and shows the potential these types of personalized cancer vaccines have for patients diagnosed with metastatic melanoma,” Dillma said.

The “Phase II Trial of Dendritic Cells Loaded with Antigens from Self-Renewing, Proliferating Autologous Tumor Cells as Patient-Specific Anti-Tumor Vaccines in Patients with Metastatic Melanoma” was sponsored by the Hoag Hospital Foundation.