FDA approves first-ever drug for Alexander disease

Alexander disease is a rare, often-fatal brain disorder that has never had a real treatment. That changed Sept. 3. The FDA approved Zanvastro, made by Ionis Pharmaceuticals. It's the first drug that actually changes the disease's course, not just its symptoms. It's approved for both children and adults. Patients get it as an injection into the fluid around the spinal cord, roughly once every three months.

Alexander disease is caused by a broken gene called GFAP. That mutation makes a protein build up and damage the brain over time. It usually leads to lost mobility and independence, and is often fatal. Because it's so rare, no company had ever built a treatment for it before Ionis did. The approval also came with a Rare Pediatric Disease priority voucher. That's a reward the FDA gives, which a company can use to speed up review of a future drug. Ionis already sold the rights to sell this drug outside the US to an Italian company, Recordati. The deal was worth $30 million upfront, plus a share of future sales.

Keep reading — what to watch

When will patients actually be able to get it? Ionis says Zanvastro should reach US patients within weeks. The bigger question is what this means for other rare diseases like it. Alexander disease affects only a small number of families worldwide, and drug companies often skip conditions that small. Ionis didn't, and that's the part worth watching.