Utilization of ¹²⁵I monoclonal antibody in the management of primary glioblastoma multiforme

The objective of this study was to assess the toxicity and potential efficacy of the adjuvant administration of an iodine 125 (¹²⁵I)‐labeled monoclonal antibody 425 for primary glioblastoma multiforme. From January 29, 1987, to October 1, 1993, 60 patients with a diagnosis of glioblastoma multiforme received an average of three intravenous or intraarterial injections of ¹²⁵I‐labeled antiepidermal growth factor receptor monoclonal antibody (¹²⁵1425). All patients had biopsy or resection followed by postoperative radiation therapy. Patients were included who had either stereotactic irradiation or brachytherapy (5 patients), or who were not candidates for these treatments. Stratification was made by Karnofsky performance status (KPS) and age. Treatments were administered on an outpatient basis. The mean KPS was 78, and the total cumulative dose of ¹²⁵I 425 was approximately 150 mCi. Among this entire group were 6 patients who received 10–80 mg of unlabeled “blocking” 425 to block binding sites on non‐tumor cells prior to the second intravenous infusion of ¹²⁵I 425. No patients were excluded from the statistical analysis. The median actuarial survival for all patients treated adjuvantly for glioblastoma multiforme was 13 months. Both age and KPS correlated positively with survival, as would be expected. The toxicity from the administration of repeated doses of ¹²⁵I 425 was low. No patient had chronic toxicity attributed to the monoclonal antibody therapy. Acute toxicity was observed in 1 patient who received a single dose >60 mCi. We conclude that the repeated administration of ¹²⁵1425 is safe and may have some benefit in the management of primary glioblastoma multiforme. This may be especially true for patients who do not qualify for other forms of more aggressive management. A prospective randomized trial should be performed. © 1995 Wiley‐Liss, Inc.