About NeutroSpec ™
In July, 2004, the U.S. Food and Drug Administration gave approval to market and distribute NeutroSpec™ imaging agent [Kit for the Preparation of Technetium (99m Tc) fanolesomab], an in vivo radiopharmaceutical that labels white blood cells and myeloid precursors. The FDA approval specifically indicates NeutroSpec™ imaging agent for scintigraphic imaging of patients with equivocal signs of appendicitis who are five years of age or older.
NeutroSpec™ is a radiodiagnostic agent consisting of a murine IgM monoclonal antibody, formulated to be labeled with radioactive Technetium (Tc-99m). The labeled antibody binds, with high affinity and specificity, to circulating and sequestered neutrophils which congregate at the site of the infected appendix. NeutroSpec™ imaging agent can be visualized with images generated via a gamma camera in the Nuclear Medicine department – allowing the physician (usually a radiologist or nuclear medicine specialist) to quickly locate the site of infection.
Utilizing NeutroSpec™ imaging agent, 98% of positive appendicitis cases in the Phase 3 trial were diagnosed within one hour after injection. This rapid diagnosis eliminates the time delays and risks often associated with alternative white blood cell labeling procedures.
According to Frederick L. Weiland, M.D., F.A.C.N.P., Co-director of Nuclear Medicine, Sutter Roseville Medical Center and Clinical Associate Professor of Radiology, University of California, Davis, “Of the 700,000 patients with suspected appendicitis, about half will have clinical findings that are atypical or equivocal. There are many causes of abdominal pain, and it can be difficult to differentiate appendicitis from other causes. In addition, other non-invasive tests to diagnose appendicitis, i.e., spiral CT with contrast, are not available everywhere and can be difficult to perform and interpret. If a diagnosis of appendicitis is missed, there can be significant medical consequences such as perforation and peritonitis. Because of this risk, it is currently acceptable to have a 10-20% negative laparotomy rate in which a normal appendix is removed.”
Dr. Weiland also indicates that, “NeutroSpec™ is easy to read. Given the vast experience physicians have in reading other Tc-99m based infection imaging agents, the learning curve will be minimal. A NeutroSpec™ procedure can be done successfully on any gamma camera and does not require high tech imaging equipment or computer support.”
Drs. Weiland, Eric Rypins, and Samuel Kipper, in the journal, Annals of Surgery, published in February, 2002, reported, “A NeutroSpec™ image allows a physician to more rapidly obtain necessary diagnostic information to support patient management decisions. As a result of the in vivo systemic administration of NeutroSpec™, radioactivity becomes concentrated in areas of infection or inflammation; thus, the need to withdraw blood from a patient to label WBC’s ex vivo is eliminated and the time required to perform the test is reduced significantly.”
Drs. Rypins and Kipper also reported in the journal, The American Surgeon, published in September, 2000, that, “Accuracy, positive predictive value, and negative predictive value were 90, 81, and 98 percent, respectively. In patients with appendicitis and positive scans, more than 50 percent of the images were positive at 4 minutes, and all were positive by 1 hour. Mean time of first positive image was 15 minutes.”
These studies, clearly indicative of the rapid, safe, and simple nature of imaging procedures conducted with NeutroSpec™ imaging agent, are generating significant interest in the product among nuclear medicine physicians and radiologists.
Phase 2 studies of NeutroSpec™ in the diagnosis of osteomyelitis have been conducted. Additional Phase 2 studies have been conducted for the imaging and detection of other infections, such as fever of unknown origin, post-surgical abscess, and inflammatory bowel disease.
NeutroSpec™ [Technetium (99m Tc) fanolesomab] contains both murine antibodies and sodium hydrosulfite, each of which has been known to induce allergic reactions, including anaphylaxis. The most frequently observed adverse events seen in clinical studies were flushing and dyspnea.
See Prescribing Information
View the animation below to see how NeutroSpec™ functions.