The FDA has approved Anascorp, the first specific treatment for a scorpion sting by Centruroides scorpions in the United States.
Venomous scorpions in the U.S. are mostly found in Arizona. Severe stings occur most frequently in infants and children, and can cause shortness of breath, fluid in the lungs, breathing problems, excess saliva, blurred vision, slurred speech, trouble swallowing, abnormal eye movements, muscle twitching, trouble walking, and other uncoordinated muscle movements. Untreated cases can be fatal.
Anascorp, Centruroides (Scorpion) Immune F(ab')2 (Equine) Injection, is made from the plasma of horses immunized with scorpion venom. Anascorp may cause early or delayed allergic reactions in people sensitive to horse proteins. The manufacturing process for Anascorp includes steps to decrease the chance of allergic reactions and to reduce the risk of transmission of viruses that may be present in the plasma.
The effectiveness of Anascorp was based on results from a randomized, double-blind, placebo-controlled trial of 15 children with neurological signs of scorpion stings. These signs resolved within four hours of treatment in the eight subjects who received Anascorp, but in only one of the seven participants who received the placebo. The most common side effects were vomiting, fever, rash, nausea, itchiness, headache, runny nose, and muscle pain. In total, safety and efficacy data was collected from 1,534 patients in both open-label and blinded studies.
Anascorp was designated as an Orphan drug by FDA and received priority review.