First drug therapy for frostbite has been cleared by FDA

People at risk of losing a finger or toe to frostbite now have the first FDA-approved treatment that could prevent a life-changing amputation.

The US regulator has cleared Aurlumyn (iloprost) injection from CiVi Biopharma subsidiary Eicos Sciences as a treatment for severe frostbite, caused by prolonged exposure to extreme cold, after a priority review.

The incidence of severe frostbite injury in the US is estimated at 0.8 out of 100,000 people, meaning that there are approximately 2,800 cases a year, with cases disproportionately affecting the homeless in urban areas, but also seen in military personnel, industrial workers, and people who engage in outdoor sports like mountaineering, skiing, and hiking.

There are thought to be around 14,000 cases of frostbite overall per year, and most are mild and do not require medical intervention or cause permanent skin damage.

Around one in five cases are severe enough to result in the freezing of tissue and loss of blood flow that can result in disability from amputation, costing health systems an estimated $75,000 to $200,000-plus to treat.

Iloprost administered as an injection into the affected area can help to open up blood vessels and prevent blood clotting, reducing the risk of permanent damage.

The drug was tested in an open-label trial involving 47 people with severe frostbite who had been rescued by the emergency services between 1996 and 2008.

They all received standard care, including aspirin injections and rewarming of the affected limb. One group received intravenous iloprost for six hours a day for up to eight days, while another group was treated with the vasoactive agent buflomedil and a third got iloprost and clot-dissolving drug t-PA. Both buflomedil and t-PA have been considered as possible therapies for frostbite because they also may help restore blood flow.

The study found there were no cases of amputation in 16 subjects treated with iloprost alone, three of 16 in the iloprost plus t-PA group, and nine of 15 treated with buflomedil alone. There was also a significantly lower risk of abnormal bone scans in the two groups receiving iloprost.

Iloprost is a well-established drug treatment, having been approved by the FDA 20 years ago as an inhaled treatment for pulmonary arterial hypertension (PAH) under the Ventavis brand, sold by CoTherix.

Eicos reformulated the drug as an injection and is also developing the drug for additional indications, including rare autoimmune disease systemic sclerosis and to support patients undergoing extracorporeal membrane oxygenation (ECMO) because of life threatening respiratory or cardiac failure.