The first and only approved treatment to target a genetic cause of amyotrophic lateral sclerosis (ALS)

Approved under FDA accelerated approval pathway. See What is QALSODY?







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Learn about QALSODY

SOD1 (superoxide dismutase 1)-ALS is a type of ALS that involves a change, or genetic mutation, in the SOD1 gene. This mutation leads to a harmful buildup of toxic SOD1 protein in the brain and spinal cord.

QALSODY is specifically approved to treat adults with SOD1-ALS.

QALSODY is a type of antisense therapy. By binding to messenger RNA associated with the SOD1 gene, QALSODY can help reduce the production of harmful SOD1 protein.

QALSODY-treated participants had a 55% reduction in plasma NfL levels on average at Week 28 in Study 1, compared to participants on placebo who had a 12% increase.


Clinical study design

QALSODY was evaluated in Study 1, a clinical trial enrolling 108 people ages 23 to 78 years with weakness due to ALS and a SOD1 mutation. A total of 72 participants received QALSODY 100 mg, and 36 received placebo. Participants received 3 loading doses and 5 maintenance doses of their assigned treatment over the course of 24 weeks. Participants were also allowed to take riluzole and/or edaravone during the study. The results for QALSODY and placebo were compared at 28 weeks.

After completing Study 1, participants were given the option to enroll in an open-label extension (OLE) study. All participants received QALSODY in the OLE, including those who had received placebo in Study 1. Results for the OLE were evaluated at 52 weeks, and the study is still ongoing.

Study 1 results

The primary outcome of Study 1 was change from baseline to Week 28 in ALS Functional Rating Scale–Revised (ALSFRS-R) score in a subgroup of 60 participants who had faster-progressing disease. The ALSFRS-R measures 12 aspects of physical function. Participants treated with QALSODY experienced less decline from baseline in the ALSFRS-R compared to placebo, but the results were not statistically significant.* Other clinical secondary outcomes for QALSODY-treated participants were not statistically significant compared to participants on placebo.

Study 1 also measured changes in a biomarker called plasma neurofilament (NfL).

  • Plasma NfL is a blood-based marker of axon injury and degeneration of neurons
Comparison of plasma NfL levels in QALSODY and placebo groups by study week

A complex mathematical formula called the least-squares geometric mean ratio to baseline was calculated for the y-axis and baseline starting point at Week 0 for both the placebo and QALSODY groups.

*Because there was no significant difference in the primary outcome of Study 1, change from baseline in ALS Functional Rating Scale–Revised score, these data should be interpreted with caution. For more information, talk to your doctor.

Reduction in neurofilament levels with QALSODY was consistently seen regardless of participants’ sex, time since symptom onset, site of symptom onset, and use of other medication (riluzole and/or edaravone).


The FDA approved QALSODY under the Accelerated Approval Program based on these neurofilament results

Accelerated approval allows for drugs to be approved based on a marker that may predict a clinical benefit but is not itself a clinical benefit. Treatment with QALSODY reduced the level of neurofilament in the blood, which may predict the slowing of disease progression. However, verification of this clinical benefit may be required for QALSODY to remain approved in the US.

Safety and side effects

It is important to talk with your doctor about the potential benefits and risks of any medication. Some people who use QALSODY to treat their SOD1-ALS may experience side effects.

QALSODY can cause serious side effects

  • Inflammation of the spinal cord (myelitis) and/ or irritation of the nerve roots (radiculitis), including serious cases, have been reported in patients treated with QALSODY. Contact your healthcare provider to learn more about symptoms associated with myelitis or radiculitis, and/ or if you believe you are experiencing either of these conditions. QALSODY may need to be interrupted or discontinued.
  • Swelling of the optic nerve (papilledema) and increased pressure inside the skull (elevated intracranial pressure), including serious cases, have been reported in patients treated with QALSODY. Contact your healthcare provider to learn more about symptoms associated with papilledema or elevated intracranial pressure, and/ or if you believe you are experiencing either of these conditions.
  • Inflammation of the brain linings (aseptic meningitis), including serious cases, have been reported in patients treated with QALSODY. Contact your healthcare provider to learn more about symptoms associated with aseptic meningitis, and/ or if you believe you are experiencing this condition.

Most common side effects associated with QALSODY seen in Study 1 were:

Talk to your doctor for
more information


QALSODY should be administered by your healthcare provider as soon as possible in the event that you miss a dose.

  • Treatment with QALSODY begins with 3 initial loading doses that occur every 14 days
  • After these doses, QALSODY is administered once every 28 days

QALSODY is an intrathecal injection, or an injection into the fluid of the spine, given by a healthcare provider experienced in performing lumbar punctures.

Find a treatment center

There are QALSODY treatment centers across the US

QALSODY is given through a procedure called intrathecal injection and should be administered at a treatment center by or under the care of healthcare professionals experienced in performing lumbar punctures.

This map may help you find treatment centers near you

Please note that new centers are added regularly and may not be in this locator tool yet. For additional treatment centers, please call Biogen Support Services at 1-877-725-7639, Monday-Friday, 8:30 AM to 8:00 PM ET.

Biogen does not receive payment for this service and does not endorse or recommend treatment facilities that have chosen to be listed. Further, Biogen does not have oversight of and is not responsible for the actions of any treatment center.

Biogen does not guarantee availability at any particular treatment center. Every individual is unique, and only after careful medical evaluation can a course of treatment be determined.

Biogen Support Services
is here for you

Biogen Support Services is here to support patients receiving QALSODY. As soon as you’re prescribed QALSODY, we can provide help with financial, insurance, or treatment education. Remember, your healthcare team is always your best source of information.

To get started,
call 1-877-725-7639
8:30 AM to 8:00 PM ET

Biogen Support

Get one-on-one phone support,
access to resources, and helpful

Financial and insurance assistance

From understanding insurance
coverage to exploring financial
assistance options, we will connect
you with the appropriate support. 


Access additional resources to
learn more about QALSODY.