Tofersen: uses, dosing, side effects & brands
Tofersen is a medicine sold in the U.S. under one brand, for amyotrophic lateral sclerosis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Amyotrophic Lateral Sclerosis
- Available as
- Injectable
- Sold as
- Qalsody
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
How tofersen is dosed
From the FDA label for Qalsody (application NDA215887). Other tofersen products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
QALSODY is administered intrathecally ( 2.1 ) Dosing Information ( 2.1 ) Recommended dose: 100 milligrams (15 mL) per administration Initiate QALSODY treatment with 3 loading doses administered at 14day intervals. A maintenance dose should be administered once every 28 days thereafter. Preparation and Administration Instructions ( 2.2 ) Allow to warm to room temperature prior to administration Administer within 4 hours of removal from vial Prior to administration, remove approximately 10 mL of cerebrospinal fluid Administer as an intrathecal bolus injection over 1 to 3 minutes 2.1. Dosing Information Recommended Dosage Administer QALSODY intrathecally using a lumbar puncture by, or under the direction of, healthcare professionals experienced in performing lumbar punctures. The recommended dosage is 100 mg (15 mL) of QALSODY per administration. Initiate QALSODY treatment with three (3) loading doses administered at 14-day intervals. Administer a maintenance dose every 28 days thereafter. Missed Dose If the second loading dose is missed, administer QALSODY as soon as possible, and administer the third loading dose 14 days later. If the third loading dose or a maintenance dose is missed, administer QALSODY as soon as possible, and administer the next dose 28 days later. 2.2. Preparation and Administration Instructions Use aseptic technique when preparing and administering QALSODY…
Tofersen side effects
The following clinically significant adverse reactions are discussed elsewhere in the labeling: Myelitis and/or Radiculitis [see Warnings and Precautions ( 5.1 )] Papilledema and Elevated Intracranial Pressure [see Warnings and Precautions ( 5.2 )] Aseptic Meningitis [see Warnings and Precautions ( 5.3 )] The most common adverse reactions ( ≥ 10% of patients treated with QALSODY and greater than placebo) were pain, fatigue, arthralgia, cerebrospinal fluid white blood cell increased, and myalgia. (Section 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Biogen at 1-877-725-7639 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1. Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of QALSODY cannot be directly compared to rates in clinical trials of other drugs and may not reflect the rates observed in practice. The safety of QALSODY 100 mg was evaluated in 147 patients with SOD1-ALS. The median patient exposure was 119.4 weeks (range from 4 to 212 weeks). QALSODY was evaluated in the placebo-controlled Study 1 and in the open label extension Study 2. In Study 1 Part C, approximately 43% were female; 57% were male; 64% were White and 8% were Asian. The mean age at entry in Study 1 Part C was 49.8 years (range from 23 to 78 years). The most common adverse reactions (≥ 10%…
Who shouldn’t take tofersen
None. None ( 4 )
Every tofersen product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Qalsody.
What people report to the FDA about tofersen
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 112 reports naming tofersen, and the FDA flagged 90% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- amyotrophic lateral sclerosis28 reports
- pneumonia13 reports
- respiratory failure9 reports
- fall8 reports
- csf protein increased7 reports
- post lumbar puncture syndrome7 reports
- headache4 reports
- acute respiratory failure3 reports
Read these as a signal, not a rate. A report does not mean tofersen caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 26, 2026.
Related calculators
Frequently asked questions
What is tofersen?
Tofersen, an antisense oligonucleotide, is a 20-base residue (20-mer) 5-10-5 MOE gapmer mixed backbone oligonucleotide. Of the nineteen internucleotide linkages, fifteen are 3′-O to 5′-O phosphorothioate diesters, and four are 3′-O to 5′-O phosphate diesters. Ten of the twenty sugar residues are 2-deoxy-D-ribose and the remainder are 2′-O-(2-methoxyethyl)-D-ribose (MOE). The residues are arranged so that there are five MOE nucleosides at the 5′ and 3′-ends of the molecule flanking a gap of ten 2′-deoxynucleosides. The cytosine and uridine bases are methylated at the 5-position.
Can you take tofersen with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run tofersen against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does tofersen come in?
Across the brands we track, tofersen is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic tofersen?
We do not currently list a generic-labelled tofersen product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Tofersen: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/tofersen
- MLA
- “Tofersen: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/tofersen.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for tofersen on DailyMed (NIH) ↗.