The goal of this clinical trial is to evaluate whether tofersen is safe and effective in adults with non-SOD1 ALS. Tofersen is currently approved by the U.S. Food and Drug Administration to treat SOD1-ALS. The main questions it aims to answer are:
* Does tofersen lower the levels of neurofilament light chain (NfL) in the blood and CSF of adult participants with non-SOD1 ALS?
* Is tofersen safe and tolerable for adult participants with non-SOD1 ALS?
* Does tofersen affect other measurements such as clinical outcomes and quality-of-life measures in participants with non-SOD1 ALS?
Participants will :
* Receive 100mg tofersen via lumbar puncture for 24 weeks. The doses are at the following time points: Weeks 0, 2, 4, 8, 12, 16, 20, and 24.
* Complete 2 follow-up visits following the end of the dosing period at Weeks 28 and 32.
* Complete a variety of questionnaires and outcome measurements such as strength and breathing testing.