PHILADELPHIA—The autologous, dinitrophenyl (DNP)-modified vaccine M-Vax has previously been shown to produce a 5-year overall survival rate of 58% in melanoma patients with large, resectable metastases in one regional nodal site.
Now, an analysis of 40 patients who received M-Vax following surgery for resectable metastases in two regional nodal sites shows a predicted 5-year overall survival rate of 31%, David A. Berd, MD, principal investigator and inventor of the vaccine, said at the 90th annual meeting of the American Association for Cancer Research (AACR) in Philadelphia.
“We pulled out the 40 worst of 200 patients,” Dr. Berd said in an interview. Of those 40, each had metastases in two regional nodal sites—seven with bilateral axillary nodal metastases; eight with metastases in both axillary and neck nodes; 15 with both inguinal and pelvic node metastases; eight with two sites in the neck; and two with miscellaneous sites.
“Currently, we can say with confidence that 3-year overall survival for the melanoma vaccine treatment in these patients is 40%,” said Dr. Berd, professor of medicine, Kimmel Cancer Center, Thomas Jefferson University Hospital.
To prepare the vaccine, melanoma cells are dissociated from surgical specimens and cryopreserved. Before each vaccine administration, these cells are thawed and irradiated, then modified with DNP. The vaccine is mixed with BCG just before intradermal injection. Patients received one of four dosage schedules over a 2- to 6-month period.
No serious adverse events occurred. All patients developed inflammatory or pustular reactions at the injection site, which caused itching or mild discomfort.
At the time of the presentation, 17 of the 40 patients (43%) were alive with a median follow-up of 33 months. Twelve (30%) were continuously relapse-free with a median follow-up of 36 months. The Kaplan-Meier estimates for overall and relapse-free survival at 5 years were 31% and 27%, respectively.
For the subgroup of patients with metastases to pelvic nodes, who have an expected surgical cure rate of less than 10%, the estimates for 5-year overall and relapse-free survival were 47% and 38%, respectively.
“Although these results require corroboration in our ongoing multicenter randomized trial,” Dr. Berd said, “they provide additional evidence that M-Vax is an effective postsurgical adjuvant treatment for patients with regionally metastatic melanoma.”
The ongoing phase III trial, he said, conducted by the vaccine’s manufacturer, AVAX Technologies, Inc., Kansas City, Missouri, is comparing M-Vax with alfa-interferon in postsurgical stage III melanoma patients.
