Long-Term Follow-Up Data on M-Vax Cancer Vaccine

Avax Technologies, Inc., has released 9-year follow-up data of stage III melanoma patients from company-sponsored phase II studies of M-Vax, an individualized cell-based vaccine for cancer. Ernest W. Yankee, PhD, the company’s executive vice-president, presented the data at the 26th annual meeting of the Clinical Oncological Society of Australia in Melbourne. Australia has the highest incidence of melanoma in the world, three times the rate in the United States.

Long-Lasting Responses

David Berd, md, professor of medicine, Thomas Jefferson University, and the inventor of M-Vax, began studies of the vaccine in 1989 and now has data from a sufficient number of patients to conduct a long-term analysis. At the conference, Dr. Yankee highlighted the results from 71 patients who were melanoma free for at least 2 years following treatment with M-Vax and then were monitored for up to 9.8 years (median follow-up, 5.3 years). The 9-year overall survival rate was approximately 85% in this group of patients, demonstrating that the clinical response to M-Vax therapy is long lasting. The 9-year relapse-free survival rate in these patients was 80%. No serious or long-term toxic effects of M-Vax were observed in any patient.

Confirming earlier findings, a patient’s clinical outcome was strongly influenced by the development of cell-mediated immunity to the patient’s own melanoma cells. Cell-mediated immunity is measured by a simple skin test (delayed-type hypersensitivity [DTH] test) administered to the patient after the vaccine treatment is completed.

Of the 71 patients, all had received M-Vax after surgical debulking of bulky regional lymph node metastases, and over half had entered the studies with one or more widely recognized indicators of poor prognosis. These included in-transit metastases or metastases to multiple lymph nodes.

Immune Response and Survival

“There are several experimental vaccines administered post-surgically that claim prolonged survival rates in stage III melanoma patients,” said Dr. Yankee. “These survival rates are generally calculated on the basis of estimates and not on actual observations. We believe that AVAX is the only cancer vaccine company with strongly positive survival data that extend to 5 years and beyond in a group of patients that were given very little hope for cure.”

Characterizing the data as “extremely encouraging,” Dr. Yankee emphasized that the investigators have noted a direct correlation between the development of an immune response to the patients’ melanoma cells and survival. “We &ldots;.believe that these vaccines, which are made from a patient’s own tumor cells, provide potential therapies for patients with other cancers,” he said.