Good news for rare disease?

The mother of young twins with a rare genetic disease is seeking approval from the U.S. Food and Drug Administration to administer linkurl:a non-prescription compound;http://www.the-scientist.com/blog/display/55377/ directly into the brains of her girls based on recent findings showing the compound dramatically improves cats with the disease. It may seem unusual for a parent to fill out such an application to the FDA, but Chris Hempel, who has two 6-year old children suffering from Niemann-Pick Type C (NPC), has practice. Last month, the FDA approved her orphan drug designation application for the compound in question, cyclodextrin, widely employed by the food and chemical industries, and used as a drug solubilizer. "I'm so excited," Hempel told The Scientist. "It's been a long process."

Addi and Cassi getting their intravenous infusions
Image: Chris Hempel

Hempel has been giving her twin girls regular intravenous infusions of cyclodextrin to stop or stall the progression of NPC, a rare fatal disease that disrupts cholesterol trafficking (linkurl:see the twins' story;http://www.the-scientist.com/article/display/55136/ in our November, 2008 issue). She sought orphan status in order to obtain tax credits towards human research, enable scientists to obtain grants to move clinical trials forward, and help get the word out about cyclodextrin to other families with NPC kids. "Cyclodextrin needs to have the visibility," she said. The compound works, in theory, by depleting cells of cholesterol. Indeed, linkurl:recent evidence has suggested;http://www.the-scientist.com/blog/display/55807/ it may help in other diseases that depend on cholesterol to progress, such as HIV. Hempel hopes cyclodextrin will stop or reverse some of the effects of NPC, such as dementia, and difficulty walking and speaking. Hempel's twins Addi and Cassi are test subjects of sorts, as each receive a "whopping dose" of cyclodextrin every week -- 2500 milligrams per kilogram over 8 hours. The FDA-approved infusions have taken place over the course of a year, and the girls haven't shown signs of kidney toxicity or hearing damage (some animals that receive high doses go deaf), and their lungs seem clear. And the compound is doing something -- when the girls had to skip 3 weeks' worth of infusions, their walking was so bad they had to stay in bed. After their infusions, their walking improves, their appetite is better, and they generally seem more engaged, Hempel said. "I feel that it is helping them." Still, the girls continue to deteriorate, so Hempel plans to ask for approval to deliver cyclodextrin directly into their brains. This could require a much smaller dose, and get the drug right where it needs to go, she reasoned, adding she plans to submit the new protocol and an approval request to the FDA in a few weeks. Hempel's optimism stems from recent findings out of Charles Vite's lab at the University of Pennsylvania, where the neuroscientist studies NPC positive cats, which typically die of the disease at 24 weeks old. But when Vite injected cyclodextrin directly into the spinal fluid of 3 NPC cats, "at 24 weeks of age, they looked clinically normal," he said. Vite is now examining their brains, and applying for an R01 to see how long the NPC cats can live when given these infusions. "I think it's kind of astonishing that giving it directly in spinal fluid has such a positive effect," Vite told The Scientist. For now, Hempel is still celebrating the victory of cyclodextrin's designation as an orphan drug. "In giving us their approval, the FDA is agreeing that this is a drug."
**__Related stories:__***linkurl:Twin Disorders;http://www.the-scientist.com/article/display/55136/
[November 2008]*linkurl:Take drug additive, not drug?;http://www.the-scientist.com/blog/display/55377/
[26th January 2009]*linkurl:New non-drug fix for HIV?;http://www.the-scientist.com/blog/display/55807/
[30th June 2009]