Ras Vaccine Prolongs Survival in Patients With Advanced Disease.(Brief Article)

2001 JUN 6 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - A pancreatic cancer vaccine can stimulate potent immune responses even in patients with advanced disease - responses that translate to prolonged survival.

That's good news for a form of cancer with a dismal five-year survival rate, and one for which the conventional therapeutic arsenal is only marginally effective.

Observing that K-Ras mutations are common in adenocarcinomas of the pancreas, M.K. Gjertsen and colleagues in Norway proposed that a vaccine incorporating mutant ras peptides could be effective.

They vaccinated 48 pancreatic cancer patients by intradermal injection with synthetic mutant ras peptides in granulocyte-macrophage colony-stimulating factor adjuvant. The results of their phase I/II clinical trial were published in the International Journal of Cancer.

Ten of the patients had undergone surgery and 38 had advanced disease. Twenty-five of 43 evaluable patients (58%) generated peptide-specific immunity, and patients with advanced disease who demonstrated an immune response survived longer from the start of treatment than vaccine nonresponders (median survival 148 days versus 61 days, respectively).

A tumor biopsy provided evidence that the ras peptide vaccine encouraged ras-specific T cells to accumulate selectively in the tumor, generating a long-lived immunological memory ("Intradermal ras peptide vaccination with granulocyte-macrophage ...