Overview analysis of adjuvant therapies for melanoma--a special reference to results from vaccinia melanoma oncolysate adjuvant therapy trials.

A phase III, randomized, double-blind, multi-institutional vaccinia melanoma oncolysate (VMO) trial was performed for patients with stage III (AJCC) melanoma. When compared with the control vaccinia virus (V) therapy, VMO therapy did not show clinical efficacy in the final analysis of data from this trial. However, the data did allude to significant therapeutic efficacy with VMO therapy if it had been compared with an observation arm. Therefore, a comparative overview statistical analysis was performed to identify the therapeutic efficacy of VMO. This review compares VMO results with data from the treatment and observation arms of other prominent randomized anti-melanoma biologic trials (i.e., ECOG EST 1684; SWOG, IFN-gamma (J. Natl. Cancer Inst. 87 (1995) 1710); WHO IFN-alfa-2a (ASCO 14 (1995) 410); Mayo IFN-alfa-2a (J. Clin. Oncol. 13 (1995) 2776); French IFN-alfa-2a (ASCO 15 (1996) 437). The analysis was carried out comparing the disease-free interval (DFI) and overall survival (OS). The analysis shows that the VMO results are fairly comparable to the results of the treatment arms from the ECOG and Mayo trials at the 5-year mark; percent DFI 0.37, 0.37, and 0.4, percent OS 0.48, 0.46, 0.47, respectively. In some cases, VMO DFI is superior to the observation arms from other studies; ECOG, Mayo, and WHO; 0.37 versus 0.26, 0.3, 0.27 (4 years), respectively. These comparative results suggest that the vaccinia arm is not a true observation arm in the VMO trial, and the VMO could have shown an enhanced efficacy had the trial included a no-treatment observation control arm.