An immunoscintigraphic evaluation of the engineered human monoclonal antibody (hCTMO1) for use in the treatment of ovarian carcinoma

OBJECTIVE: To assess the safety and targeting ability of the engineered human antibody (hCTMO1) in women with ovarian carcinoma. DESIGN: The monoclonal antibody labelled with Indium-111 was administered to women with suspected primary or recurrent ovarian carcinoma six days pre-operatively. The first group of women was given a dose of 0.1 mg per kg body weight of radiolabelled antibody. A second group of women received 1 mg per kg body weight and finally a third group was given 1 mg per kg body weight of unlabelled antibody followed one hour later by 0.1 mg per kg body weight of radiolabelled antibody. All the women were then imaged using a gamma camera one hour and up to 96 hours after injection. PARTICIPANTS: Fourty-four women in whom there was a high suspicion of primary ovarian carcinoma on the basis of ultrasound or CT imaging and serum CA125 and those in whom there was a suspicion of recurrent ovarian carcinoma after being treated for histologically confirmed carcinoma. SETTING: The Queen's Medical Centre, Nottingham and University Hospital Vrije Universiteit, Amsterdam, The Netherlands. RESULTS: At the low dose of antibody the sensitivity for detection of ovarian carcinoma was 70%. After increasing the dose of antibody and also after pre-dosing with unlabelled antibody the sensitivity increased to 100%, but there was a large number of false positive results at the higher dose, and therefore the specificity was low. The liver and bone marrow were the organs with the highest activities. CONCLUSION: The genetically engineered antibody hCTMO1 is safe for use in women. This antibody effectively targets ovarian carcinoma and has greater potential as a vector for therapeutic use than as a diagnostic agent.