Clinical outcomes model in renal cell cancer patients treated with modified vaccinia Ankara plus tumor-associated antigen 5T4.

Abstract

We developed an outcomes model to select patients for renal cell cancer vaccine immunotherapy. We examined clinical data from 2 phase II studies of modified vaccinia Ankara as vector to express 5T4 (MVA-5T4), calculated progression-free survival (PFS) and overall survival (OS), and created risk groups based on the number of factors involved. Median OS was 12.4 months; median PFS was 3.6 months. Significant factors (p<0.05) included neutrophils (both), bone metastases (OS), ECOG performance status (OS), lactate dehydrogenase levels (both), prior therapy with tyrosine kinase inhibitors plus immunotherapy (OS), Fuhrman grade (OS), and 5T4-specific ELISPOT response (PFS). By group, median OS was not reached in patients with favorable risk (censored at cutoff), was 13.7 months in those with intermediate risk and 4.0 months in those with poor risk. Further validation of this model will identify the patients most likely to respond to MVA-5T4 and provide a framework for outcomes models for other vaccine therapies.