Tofersen in Non-SOD1 ALS

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.