January 9, 2007 -- The US Food and Drug Administration (FDA) has granted orphan drug status for a proteinase inhibitor in the prevention and treatment of smallpox; an immediate release, oral administration version of 4-aminopyridine for the treatment of chronic functional motor and sensory deficits resulting from Guillain-BarrÃ© syndrome; and a small, orally available recombinant protein for the prevention of necrotizing enterocolitis.
Orphan Drug SIGA-246 for the Prevention and Treatment of Smallpox
On December 20, the FDA approved orphan drug status for a proteinase inhibitor ( SIGA-246, made by SIGA Technologies, Inc) in the prevention and treatment of smallpox. Fast-track status was also awarded to the product to expedite its review.
According to a company news release, the drug is the first ever to demonstrate 100% protection against human smallpox virus in a primate trial, which was conducted at the US Centers for Disease Control and Prevention (CDC). In addition, results of a human clinical safety trial completed in July 2006 demonstrated the drug's safety in humans.
Smallpox infection is highly infectious. Its morbidity rate is 90%, and mortality rates for smallpox range from 30% to 60%. Although the disease was declared eradicated in 1980 after worldwide vaccination programs, smallpox is currently classified as a category A agent by the CDC. These agents are believed to pose the greatest potential threat to public health and have a moderate to high potential for large-scale dissemination.
Although US citizens have not been vaccinated against the disease since 1972, mass immunization is not advised due to the risk for serious adverse events such as encephalitis, myocarditis, disseminated vaccinia, viral infection, and death. As with prevention, there is currently no treatment for smallpox that can be safely administered to the general population without significant risk of adverse reactions.
The company notes that the US Department of Homeland Security has designated smallpox a "material threat" to our national security, rendering SIGA-246 eligible for purchase for the Strategic National Stockpile under Project Bioshield.
SIGA-246 is also currently being evaluated for the treatment of monkeypox virus, another orthopox virus strain that causes disease similar to smallpox in both monkeys and humans. In 2 primate trials, the agent completely protected nonhuman primates from lethal doses of monkeypox virus even when treatment was started 3 days after infection and at doses equivalent to the potential human dose.
Orphan Drug 4-Aminopyridine ( Ampydin) for Chronic Motor and Sensory Deficits of GBS
On December 20, the FDA granted orphan drug status for an immediate release, orally administered version of 4-aminopyridine ( Ampydin, made by Neurorecovery, Inc) in the treatment of chronic functional motor and sensory deficits resulting from Guillain-BarrÃ© syndrome (GBS).
According to a company news release, 4-aminopyridine is currently on the FDA's compounding for compassionate use list for treatment of certain neuropathies and for spinal cord injury and multiple sclerosis.
An international phase 3 trial of the product for the GBS indication is expected to begin in the United States, Canada, and the European Union during the first half of 2007.
Orphan Drug TTI-1612 for the Prevention of Necrotizing Enterocolitis
On December 19, the FDA approved orphan drug status for a small, orally available recombinant protein (TTI-1612, made by Trillium Therapeutics, Inc) in the prevention of necrotizing enterocolitis.
The majority of necrotizing enterocolitis cases (75%) occur in premature infants, particularly if prolonged rupture of the membranes with amnionitis or asphyxia occurred at birth. Although its etiology remains unclear, incidence rates for necrotizing enterocolitis may also be increased in infants fed hypertonic formulas, those small for gestational age, infants with cyanotic congenital heart disease, and those who have undergone exchange transfusion. There are no effective treatments for necrotizing enterocolitis, which is associated with a mortality rate ranging from 20% to 40%.
According to a company news release, TTI-1612 has demonstrated strong cytoprotective and anti-inflammatory effects in preclinical animal models of necrotizing enterocolitis and intestinal ischemia/reperfusion injury, and it may have additional utility in the treatment of other intestinal disorders, such as short bowel syndrome, inflammatory bowel disease, and chemotherapy-induced mucositis.
The product was also recently granted orphan drug status in the European Union.
Medscape Medical News © 2007
Cite this: Yael Waknine. New FDA Orphan Drugs: SIGA-246, Ampydin, TTI-1612 - Medscape - Jan 09, 2007.