Specific active immunotherapy in patients with adenocarcinoma of the colon utilizing tumor-associated antigens (TAA). A phase I clinical trial.

Twenty-two patients received specific active immunotherapy (TAA vaccine once per month for 3 months), with the duration of follow-up, as of July 1984, ranging from 3 months to 36 months (median, 21 months). Of these, seven had Dukes B2, seven had Dukes C, and eight had Dukes D lesions. All received surgical resection, and those with Dukes D disease underwent resection of all metastases where possible, with six clinically disease-free at the time of initiation of therapy. The age range of the 22 patients was 40 to 73 years (median, 60 years); sex distribution was 12 males and 10 females. All patients were monitored by physical examination and by laboratory parameters including complete blood count, liver and renal function tests, blood chemistries, urinalysis, chest x-ray, carcinoembryonic antigen levels, migration inhibition assays, complete immune complexes, serum chemistries, helper and suppressor and total T-cell and B-cell assays, and TAA antibody levels. As measured by delayed cutaneous hypersensitivity skin test and by migration inhibition assays (MIA), a strong postimmunization response is developed approximately 5 months after vaccination is completed. There were no clinical or biochemical manifestations of any type of systemic toxicity including hepatic, renal, gastrointestinal, respiratory, or neurologic during the period of follow-up. All patients developed skin ulcers at the vaccination and required 4 to 5 months to heal. With this small number of patients in a Phase I trial, survival is indicative of the safety of the vaccine only: 82% of the patients are alive (mean survival, 21 months) thus far, and 59% of the patients are without evidence of disease (NED) (mean NED, 22 months). These studies, therefore, justify a Phase II-III trial in a larger number of patients and have provided selection of appropriate monitoring tests for the larger trial.