The FDA has approved ZANVASTRO™ (zilganersen) as a prescription medicine to treat Alexander disease in children and adults

This is the first approved treatment for AxD, and the first medicine designed to act on the disease itself rather than its symptoms. For a community that has spent decades being told there was nothing, this is a different kind of day.

We want to be careful about how we say thank you, because this approval does not belong to any one group of people.

It belongs to the individuals and families who enrolled in the clinical trials. It belongs to everyone who gave their data — often through procedures that were not easy or comfortable, including spinal fluid, blood, and tissue collection — long before there was any treatment on the horizon, and with no promise that it would ever help them. And it belongs to the children and adults who are no longer here. Their data is part of this approval. They are part of this approval.

We are holding all of you today.

What ZANVASTRO is

Alexander disease is caused by mutations in the GFAP gene, which lead to too much GFAP protein and the buildup of Rosenthal fibers in the brain.

ZANVASTRO is an RNA-targeted medicine that reduces the production of GFAP in the brain. The recommended dose is 50 mg, given quarterly by intrathecal injection via lumbar puncture.

The approval is based on FDA review of safety and efficacy data from a Phase 1–3 clinical trial of zilganersen. Ionis has said the trial results will be published in a peer-reviewed journal. No publication date has been announced.

What happens now

If you are in the U.S. and want to learn more, start with your doctor. That conversation is the first step for everyone.

Ionis has a support program called Ionis Every Step™ for people prescribed ZANVASTRO. It includes a dedicated Patient Education Manager who checks in regularly, answers questions, and connects families to resources through each stage of treatment. More information is at ZANVASTRO.com.

If you are enrolled in the clinical trial at a U.S. site — Stanford Neurosciences Health Center, Lucile Packard Children's Hospital, Children's Hospital of Atlanta, Massachusetts General Hospital, or Children's Hospital of Philadelphia — your study team will be in touch about how to transition from the trial to commercial product.

If you are accessing zilganersen through the U.S. Expanded Access Program, your treating physician will be in touch about that same transition. We also want to be straightforward about one piece of this: Ionis has stated that no additional individuals will be enrolled into the U.S. EAP. If you were hoping that was your path forward, please talk with your care team about what this approval means for you specifically.

If you are outside the United States

This is a U.S. decision and it applies to the United States only.

Outside the U.S., Ionis has licensed zilganersen to Recordati, a global rare disease company based in Italy. Questions about access outside the U.S. should go to them: recordati.com/contact-us-rare-diseases-medical-information

If you are enrolled in the trial at a site outside the U.S., you will continue to receive zilganersen through the trial per the study protocol.

We know this is not the news our international families were hoping to read today, and we will keep advocating alongside you.

About safety

Like any medicine, ZANVASTRO carries risks and possible side effects, including serious ones. The full Important Safety Information is in the community statement from Ionis, linked at the bottom of this page, and at ZANVASTRO.com.

Please read it, and bring your questions to the people who know your situation — your neurologist and your care team.

What we cannot tell you yet

We do not know what ZANVASTRO will cost. We do not know how insurance will handle it. We do not know exactly when it will be on pharmacy shelves beyond "in the coming weeks."

We would rather tell you we don't know than guess. As we learn more, we will share it here and in our newsletter.

Hear it directly

Ionis is hosting a community webcast on Friday, September 4 at 10:00 a.m. ET. If you have questions, this is the place to ask them. LINK

Our community was in the room

“As a mom to a young boy living with Alexander disease and an advocate for this community, I have seen firsthand the profound impact this disease has on individuals and their families. Today’s approval represents a fundamental shift, changing the conversation from ‘How do we manage this disease’ to ‘How can we treat it,’” said Emily Petty, president, End Alexander Disease. "For far too long, receiving a diagnosis of Alexander disease was accompanied by uncertainty and the difficult reality that there were no available treatments. Today, that begins to change. ZANVASTRO marks a defining moment and brings a new sense of possibility to our community."

United we are unstoppable. Together we will End AxD. ❤️

Read the full announcement from Ionis here.

This document contains the complete details, including the full Important Safety Information.

Read the Alexander disease Community Statement from Ionis here.

FDA announcement here.