Related Experiment Video
Updated: Jun 14, 2026

Characterizing Exon Skipping Efficiency in DMD Patient Samples in Clinical Trials of Antisense Oligonucleotides
Published on: May 7, 2020
Optimizing Research Operations and Resource Utilization in ALS Care: Insights From the Tofersen Antisense
Alison Wheeler1, Kush Mehta1, Danica Sanders1
1Sean M. Healey and AMG Center for ALS and the Neurological Clinical Research Institute, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Introduction/Aims:
Tofersen is a gene-targeted therapy for individuals with superoxide dismutase 1 (SOD1) (+) amyotrophic lateral sclerosis (ALS). Prior to U.S. Food and Drug Administration (FDA) approval, tofersen was made available through expanded access protocol. This study describes the clinical and operational experience of administering tofersen through expanded access protocols at a single academic medical center in the U.S.
Methods:
Individuals with symptomatic SOD1(+) ALS (≥ 18 years), who were ineligible for traditional ALS clinical trials, received tofersen via bedside lumbar punctures at Massachusetts General Hospital. Treatment was provided through single-patient and intermediate-sized expanded access protocols prior to FDA approval. Demographic and clinical characteristics, referral-to-treatment timelines, safety outcomes, and operational costs were collected.
Results:
Eleven individuals with SOD1(+) ALS received monthly intrathecal tofersen over a two-year period (July 2021 to July 2023). Most participants were female, and 81.8% had leg-onset ALS. The mean (SD) referral-to-first dose duration was 36 (22.4) days. A total of 120 doses were administered over a two-year period. Tofersen was safe and well tolerated, with no treatment-related serious adverse events. Operational costs totaled $336,620, supported by philanthropy and insurance. The company provided the drug for free.
Discussion:
This experience demonstrates the feasibility of implementing a resource-intensive expanded access protocol within an academic medical center using a mixed funding model to facilitate early access to emerging ALS therapies.
