INCREASED SURVIVAL OF PATIENTS TREATED WITH A VACCINIA MELANOMA ONCOLYSATE VACCINE - 2ND INTERIM ANALYSIS OF DATA FROM A PHASE-III, MULTIINSTITUTIONAL TRIAL

Objective The efficacy of vaccinia melanoma oncolysate (VMO) vaccine t o increase overall survival and disease-free survival of patients with surgically resected International Union Against Cancer (UICC) stage I I melanoma was studied in a phase III, randomized, multi-institutional trial, Summary Background Data Phase I and II trials with VMO showed minimal toxicity and clinical efficacy in patients with melanoma. In a recently completed phase Ill VMO trial, the first interim analysis pe rformed in April 1994 showed an increasing trend in the survival of pa tients treated with VMO. The second interim analysis was performed in April 1995. Methods Patients with surgically resected stage II (UICC) melanoma were treated with VMO (N = 104) or placebo vaccinia vaccine v irus (V) (N = 113) once a week for 13 weeks and then once every 2 week s for a total of 12 months. Patients' clinical data were collected as of May 1995 and analyzed for survival. Results In this second interim analysis, the mean follow-up time is 42.28 months. No survival differe nce was observed between VMO and V treatments. However, in a retrospec tive subset analysis, a subset or males between the ages of 44 and 57 years and having one to five positive nodes (at 2-, 3-, and 5-year int ervals, 13.6%, 15.9%, and 20.3% difference in survival in favor of VMO [N = 20] when compared to V [N = 18] [p = 0.037]) and another subset of patients with clinical stage I (at 3- and 5-year intervals, 30% and 7% difference in survival in favor of VMO [N = 20] when compared to V [N = 23], [p = 0.051]) showed significant survival advantage with VMO . Conclusions Although VMO vaccine therapy in surgical adjuvant settin g did not produce a significant survival benefit to all patients with melanoma, patients from the above two subsets had significant survival benefit.