Clinical and immune responses in resected colon cancer patients treated with anti-idiotype monoclonal antibody vaccine that mimics the carcinoembryonic antigen

Purpose: We generated an anti-idiotype antibody, designated CeaVac, that is an internal image of the carcinoembryonic antigen (CEA). We previously dem onstrated that the majority of patients with advanced colorectal cancer gen erate specific anti-CEA responses. The purpose of the current study was to treat patients with surgically resected colon cancer with CeaVac ta determi ne the immune response and clinical outcome to treatment with vaccine. We a lso compared the immune responses between patients treated with fluorouraci l (5-FU) chemotherapy regimens plus vaccine versus vaccine alone. Patients and Methods: Thirty-two patients with resected Dukes' B, C, and D, and incompletely resected Dukes' D disease were treated with 2 mg of CeaVa c every other week for four injections and then monthly until tumor recurre nce or progression. Fourteen patients were treated concurrently with 5-FU c hemotherapy regimens. Results: All 32 patients entered onto this trial generated high-titer immun oglobulin G and T-cell proliferative immune responses against CEA. The 5-FU regimens did not have a qualitative or quantitative effect on the immune r esponse. Three of 15 patients with Dukes' B and C disease progressed at 19, 24, and 35 months, Seven of eight patients with completely resected Dukes' D disease remained on study from 12 to 33 months; one patient with resecte d Dukes' D disease relapsed a, 9 months. One patient with incompletely rese cted Dykes' D disease remained on study at 14 months without evidence of pr ogression; eight experienced disease progression at 6 to 31 months. Conclusion: CeaVac consistently generated a potent anti-CEA humoral and cel lular immune response in all 32 patients entered onto this trial, A number of very high-risk patients continue on study 5-FU regimens, which are the s tandard of care for patients with Dukes' C disease, did not affect the immu ne response. These data warrant a phase III trial for patients with resecte d colon cancer. (C) 1999 by American Society of Clinical Oncology.