Dear ALS Community,

We are writing to let you know that Biogen and Ionis Pharmaceuticals announced topline results from the Phase 1 study of BIIB078/Ionis-C9RX. This asset was an investigational antisense oligonucleotide (ASO) in development for people with C9orf72-associated amyotrophic lateral sclerosis (ALS).

BIIB078 was generally well-tolerated. BIIB078 did not meet any secondary efficacy endpointsand it did not demonstrate clinical benefit. In the dose cohorts up to 60 mg there were no consistent differences between the BIIB078 group and the placebo group. Participants in the BIIB078 90 mg dose cohort trended toward a greater decline than those in the placebo group across secondary endpoints. Based on these results, the companies have made the decision to discontinue the BIIB078 clinical development program, including its ongoing open-label extension study. BIIB078 will not be provided through compassionate use or early access programs for any indication. While the results of this study are disappointing, we are committed to sharing the data and learnings with the medical and scientific community so that it can inform future ALS research.

We are deeply grateful for the commitments and contributions of the more than 100 people with C9orf72-associated ALS, their caregivers and families, and the investigators and staff who were involved in this global Phase 1 study across a network of 24 sites in six different countries.

For more than a decade, Biogen has been committed to advancing ALS research and will continue to pursue ALS therapy development with multiple programs in our pipeline.

Sincerely,
Biogen