A randomized placebo-controlled phase II study with the cancer vaccine candidate IGN101 in patients with epithelial cancers

Abstract

2555 Background: IGN101 is a vaccine designed for therapeutic vaccination against cancers of epithelial origin. It consists of 0.5 mg alum-adsorbed murine monoclonal antibody 17-1A as vaccine antigen to trigger an immune response and has been shown in phase I to reduce the number of circulating EpCAM-positive tumor cells. Methods: A 1:1 prospective randomized double-blind placebo-controlled phase II trial was conducted in 240 patients (pts) with epithelial cancers Stage III or IV. Objectives were to assess effects of IGN101 on survival of the whole study population but also to analyse in an exploratory way the survival effects for the different tested indications. Primary endpoint was overall survival (OS), secondary endpoints included safety, tolerability and immunogenicity. Vaccinations with IGN101 or placebo (alum) were given on days 1, 15, 29 and 57 and in weeks 16, 24, 32, 40 and 68. Concomitant standard therapies were permitted. Pts were recruited from Sept. 01 until July 03. Results: On intention-to-treat (ITT), 239 pts were included. 163 pts had CRC, thereof 95 stage IV. 32 pts had stage III or IV upper GI-tract cancer, 38 pts had stage III or IV NSCLC, 6 pts had liver or bile-duct carcinoma. Groups were well balanced regarding age, sex, Karnofsky Index and concomitant therapies. For the whole ITT population, no difference in OS was seen. A trend for prolonged survival was seen in stage IV CRC pts (ITT) during the first year (12 months overall survival 48.8% Placebo vs. 60% IGN101, p = 0.28). A statistically significant survival prolongation was observed in the 53 stage IV rectal cancer pts (ITT): For the IGN101 group, median survival was 415 days, compared to 253 days for placebo (P = 0.037). 1-year survival was doubled from 29,5% for placebo to 62% for IGN101. Use of concomitant chemotherapy (CT) had no effect on survival. Vaccinations with IGN101 were well tolerated. Almost all pts of the IGN101 group mounted an antibody response to the vaccine antigen. Conclusions: Whereas the effect observed in the overall colorectal cancer stage IV group was not statistically significant (potentially due to sample size), vaccination with IGN101 however significantly prolonged survival of metastatic rectal cancer pts. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration igeneon AG igeneon AG igeneon AG