Human Anti-mouse IgM and IgG Responses in Ovarian Cancer Patients after Radioimmunotherapy with ⁹⁰Y-muHMFG1

Abstract

Background: Human anti-mouse antibody (HAMA)-IgM and IgG in ovarian cancer patients treated with intraperitoneal (i.p.) ⁹⁰Y-muHMFG1 as consolidating therapy were analyzed for a relationship with outcome of disease. Patients and Methods: Serial serum samples from 208 ovarian cancer patients participating in a phase III trial of i.p. ⁹⁰Y-muHMFG1 and 25 controls were analyzed for HAMA-IgM and HAMA-IgG. Results were correlated with time to, and location of, disease recurrence. Results: Patients receiving i.p. ⁹⁰Y-muHMFG1 developed a rapid HAMA-IgM peak (week 4 to 8), followed by a HAMA-IgG peak 2-4 weeks later. HAMA levels in the control group remained unchanged. Early maximum HAMA-IgG peaks were associated with early relapse [hazard ratio (HR), 0.975; 95% confidence interval (CI) 0.956 to 0.995; p=0.012]. Patients with a HAMA-IgG maximum before or at 8 weeks were at significantly higher risk for disease recurrence (HR, 1.6; 95% CI 1.1 to 2.5; p=0.021) as compared to patients with a HAMA-IgG maximum after 8 weeks. Conclusion: Besides time point of maximum HAMA-IgG, no evident relation could be found between HAMA-IgM or HAMA-IgG development and time to relapse or location of recurrence.