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.