NeutroSpec Life-Threatening Adverse Events. The Food and Drug Administration (FDA) today issued a Public Health Advisory to alert health care providers that the agency has requested the market withdrawal of the diagnostic imaging agent NeutroSpec [Technetium (99m TC) Fanolesomab] pending review of reported deaths and serious and life-threatening adverse events associated with use of the product.
The manufacturer, Palatin Technologies Inc. and marketing partner, Mallinckrodt, have agreed to implement an immediate voluntary market suspension making the product unavailable for approved or investigational uses.
The adverse event reports submitted to FDA as part of the Agency’s routine postmarket surveillance of all medical products revealed cases where NeutroSpec caused allergic type (hypersensitivity) reactions that occurred within minutes following NeutroSpec administration. These reactions led to the death of two patients, and to cardiopulmonary failure, central nervous system reactions, and infusion reactions in other patients.
In pre-market studies submitted to the Agency as part of the drug’s application for approval, NeutroSpec was administered to 523 patients. These studies revealed relatively few safety concerns. Most of the adverse events occurred in patients who were given the drug post-approval on an off-label basis. All of the reactions occurred immediately after NeutroSpec was administered. There is no evidence that patients who already safely received the drug face any long-term risk.
NeutroSpec, approved for marketing in July 2004, is a diagnostic imaging agent that is administered intravenously to help diagnose appendicitis in patients five years and older with possible appendicitis who lack its conventional signs and symptoms. FDA said the decision to suspend marketing was based on the life-threatening nature of the associated adverse events, the unpredictability of the reaction, and availability of other means of diagnosing appendicitis that do not carry these risks.
FDA urges health care providers to discontinue use of existing stocks of NeutroSpec and to contact Palatin Technologies regarding their return. FDA is conducting further investigation into the deaths and adverse events associated with NeutroSpec. The Agency is working closely with the manufacturers of the product to evaluate the risks and benefits associated with its use.
FDA also plans to convene an advisory committee meeting in early 2006 to discuss the existing data about the risks and benefits of NeutroSpec, what additional safety measures can be taken with its use, and what indications may exist where benefits of the product are outweighed by the known risks. The FDA will notify health care providers and patients in a timely manner following further scientific investigation of adverse event reports.