Qalsody Side Effects

Generic name: tofersen

Medically reviewed by Drugs.com. Last updated on Feb 26, 2025.

Note: This document provides detailed information about Qalsody Side Effects associated with tofersen. Some dosage forms listed on this page may not apply specifically to the brand name Qalsody.

Applies to tofersen: intrathecal solution.

Serious side effects of Qalsody

Along with its needed effects, tofersen (the active ingredient contained in Qalsody) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking tofersen:

More common side effects

• arm, leg, or back pain
• difficulty in moving
• joint pain or swelling
• muscle aches, cramps, pains, or stiffness
• nerve pain
• unusual tiredness or weakness

Less common side effects

• back numbness, tingling, or weakness
• blurred vision
• change in ability to see colors, especially blue or yellow
• confusion
• fever
• headache
• severe nausea or vomiting
• stiff neck

For healthcare professionals

Applies to tofersen: intrathecal solution.

General adverse events

The most common adverse reactions occurring in 10% of patients or greater included pain, fatigue, arthralgia, increased cerebrospinal fluid white blood cells, and myalgia.^[Ref]

Immunologic

• Very common (10% or more): Anti-drug antibodies (58.4%)^[Ref]

Musculoskeletal

• Very common (10% or more): Arthralgia (14%), myalgia (14%), musculoskeletal stiffness (6%)^[Ref]

Nervous system

• Very common (10% or more): Cerebrospinal fluid white blood cells increased or pleocytosis (14%)
• Common (1% to 10%): Cerebrospinal fluid proteins increased (8%), neuralgia (6%), myelitis and radiculitis (4%), elevated intracranial pressure and/or papilledema (2.7%), aseptic meningitis (1.4%)^[Ref]

Other

• Very common (10% or more): Pain including extremity and back pain (42%), fatigue (17%)
• Frequency not reported: Pyrexia^[Ref]

Further information

Qalsody side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer