Tofersen injection is used to treat a certain type of amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease; a condition in which the nerves that control muscle movement slowly die, causing the muscles to shrink and weaken) in adults with a certain genetic make-up. Tofersen injection is in a class of medications called antisense oligonucleotides. It works by decreasing the production of a harmful protein that builds up in the brain and spinal cord in ALS patients.

Tofersen injection comes as a solution (liquid) to inject intrathecally (into the fluid-filled space of the spinal canal). Tofersen injection is given by a doctor in a medical office or clinic. It is usually given as 3 initial doses (once every 2 weeks) and then is given once every 28 days thereafter.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Before receiving tofersen injection,

• tell your doctor and pharmacist if you are allergic to tofersen, any other medications, or any of the ingredients in tofersen injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.
• tell your doctor if you have or have ever had any other medical conditions.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving tofersen injection, call your doctor.

If you miss an appointment to receive tofersen injection, call your doctor right away to reschedule your appointment. Your doctor will probably tell you to resume your previous schedule to receive tofersen injection, with at least 14 days between the 3 initial doses and 28 days between the later doses.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Unless your doctor tells you otherwise, continue your normal diet.

Tofersen injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• fatigue
• muscle or joint pain

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• weakness, numbness, burning, or tingling in the hands, arms, feet, or legs
• back or neck pain
• loss of control of your bowels or bladder
• headaches, including those that are unusual or will not go away
• blurred vision, double vision, loss of vision, or other visions changes
• buzzing or ringing in the ears
• fever, headache, nausea, vomiting, sensitivity to light, confusion, stiff neck

Tofersen injection may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor and the laboratory.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Qalsody®