Safety and Tolerability of Ultrasmall Superparamagnetic Iron Oxide Contrast Agent Comprehensive Analysis of a Clinical Development Program

Background: Because of its cellular uptake pattern, ferumoxtran-10 maybe potentially useful for the imaging of a variety of diseases (eg, atheroma, multiple sclerosis, stroke, renal graft rejection, glomerulonephritis and brain tumors, in addition to differentiation of metastatic and nonmetastatic lymph nodes). The aim of this article is to present a comprehensive review of the safety and tolerability of ferumoxtran-10 as reported during clinical development of the compound as an ultrasmall superparamagnetic iron oxide contrast agent for use in magnetic resonance imaging. Materials and Methods: The safety profile of ferumoxtran-10 was assessed using pooled data from 37 phase I to III clinical studies in 1777 adults (1663 received the contrast agent [1527 patients and 136 healthy volunteers], 75 received placebo, and 39 patients were enrolled but did not receive study medication). Results: At (cast one adverse event was reported in 23.2% of patients who received ferumoxtran-10. Adverse events were of mild-to-moderate severity in 86.3% of patients in the ferumoxtran-10 group. At least 1 event considered by the investigator to be related to study treatment was reported in 18.2% of patients in the ferumoxtran-10 group. The most commonly reported treatment-related adverse events were back pain, pruritus. headache, and urticaria. A total of 44 patients (2.6%) in the ferumoxtran-10 group reported 76 serious adverse event (SAE). Only 7 SAEs (0.42%) were considered to be treatment-related (anaphylactic shock, chest pain, dyspnea, skin rash, oxygen saturation decreased, and 2 cases of hypotension). There were 12 deaths, only one of which (anaphylactic shock) was considered to be related to ferumoxtran-10 which was administered by bolus injection of undiluted product, a mode of administration that is no longer recommended. Results in high-risk groups of patients including the elderly and those with hepatic, renal or cardiovascular disease seemed to show no cause for special clinical concern in these groups. Conclusions: Clinical experience to date therefore shows ferumoxtran-10 to be a well tolerated contrast agent.