[Phase I clinical study for 111In-DTPA-IgG].

A phase I study was performed in three health volunteers to evaluate the safety and biodistribution of 111In-DTPA-IgG, a newly developed imaging agent for inflammation/infection. No adverse effect was observed. There were no clinically significant changes in blood chemistry, hematology, and urinalysis parameters, physical examinations or vital signs. 111In-DTPA-IgG in blood exhibited a biexponential disappearance, consisting of a fast component (t1/2 alpha) ranging from 5.72 to 8.51 hours, and a slow component (t1/2 beta) ranging from 34.0 to 35.5 hours. Twelve percent of the injected dose was eliminated in the urine within 72 hours. Dosimetry estimates indicated that up to 80 MBq of 111In-DTPA-IgG can be safely administered to subjects without exceeding generally accepted absorbed dose for other scintigraphic procedures for inflammation/infection. The organs receiving the highest absorbed dose was the liver followed by the kidneys, heart, and lungs. Each of these organs received less than 40 mGy per 80 MBq administered. The safety data and dosimetry estimates indicated that it is safe to proceed with phase II studies with a 40-80 MBq dose of 111In-DTPA-IgG.