The U.S. Food and Drug Administration has approved Zanvastro, the first drug designed to directly treat Alexander disease, an extremely rare neurological disorder that progressively damages the nervous system and can be fatal. Until now, patients had no options beyond managing individual symptoms, which can include seizures, difficulty walking, speaking, and swallowing, as well as dangerously elevated pressure inside the brain.
The drug's development traces back to a discovery in the late 1990s, when researchers Albee Messing and Michael Brenner identified mutations in the GFAP gene as the underlying cause of the disease. That work led to a strategy: use an antisense oligonucleotide to reduce production of the GFAP protein, whose abnormal buildup forms damaging deposits in brain cells. Zanvastro was developed in collaboration with Ionis Pharmaceuticals and tested in clinical trials beginning in 2021.
According to the University of Wisconsin-Madison, which announced the approval, patients receiving Zanvastro generally experienced stabilization of motor function, and some showed improved movement. Messing, who helped lead the foundational research, called the approval "a wonderful and long-awaited day for the Alexander disease community." The disease affects fewer than one in a million people worldwide, with symptoms that can emerge in infancy, childhood, or adulthood.