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FDA Approves Imaging Agent for Diagnosing Appendicitis

Christina Benner

NeutroSpec, a new diagnostic agent consisting of a radiolabeled murine immunoglobulin M monoclonal antibody, has been approved by the Food and Drug Administration, according to announcements Monday by Palatin Technologies and Mallinckrodt Imaging.

The agent, known by the generic name technetium Tc 99m fanolesomab, is indicated for the imaging of patients with equivocal signs and symptoms of appendicitis who are five years of age or older. NeutroSpec was formerly referred to as LeuTech in clinical trials and articles.

According to the product's labeling, the monoclonal antibody in NeutroSpec binds to CD15-bearing white blood cells, predominantly neutrophils, in the bloodstream. The neutrophils migrate to the infection site, labeling it with the radioactive tracer. Images can be collected by a gamma camera within 60 minutes after intravenous injection of the diagnostic agent, which does not require separate mixture with the patient's white blood cells.

Patients with a hypersensitivity to any murine proteins or other components of the product must not receive technetium Tc 99m fanolesomab.

During clinical studies, the most frequently reported adverse events were flushing and dyspnea.

No announcement was made regarding the product's availability.

NeutroSpec will be supplied as a preparation kit containing five vials of fanolesomab 0.25 mg and five 2-mL ampuls of ascorbic acid injection 500 mg/mL. After preparation with sodium pertechnetate Tc 99m injection, the dose is injected directly into the patient's bloodstream. Like other radiopharmaceuticals, technetium Tc 99m fanolesomab should be used by or under the control of licensed personnel who are qualified by specific training and experience in the safe use and handling of radionuclides.