Rare Daily Staff

Roche presented positive pivotal phase 3 study results for satralizumab as a monotherapy for neuromyelitis optica spectrum disorder (NMOSD), a rare autoimmune disease affecting the central nervous system.

NMOSD is an autoimmune disease of the central nervous system that mainly affects the optic nerves and spinal cord. It is characterized by unpredictable attacks that often lead to severe, irreparable disability including blindness and paralysis. The condition disproportionately strikes young women in the prime of their lives, with the average age of first onset at just 39 years. NMOSD affects more than 10,000 people in Europe, 15,000 people in the United States and up to hundreds of thousands of people worldwide.

Patients with the condition have antibodies that bind to a protein called aquaporin-4 (AQP4). Binding of the anti-AQP4 antibody appears to activate other components of the immune system, causing inflammation and damage to the central nervous system. About two thirds of patients with NMOSD test positive for the AQP4 biomarker.

Satralizumab is a humanized monoclonal antibody that inhibits IL-6 signaling, which is believed to play a key role in the inflammation that occurs in people with NMOSD, leading to damage and disability. People with NMOSD experience unpredictable, severe relapses that directly cause cumulative, permanent neurological damage.

Results from the SAkuraStar study, which were presented at the 35th Congress of the European Committee for Treatment and Research in Multiple Sclerosis, show that satralizumab monotherapy achieved a 55 percent reduction in the risk of relapses compared to placebo in the overall population representative of NMOSD patients. In the large subgroup of patients seropositive for AQP4-IgG antibodies, the effect was higher with a 74 percent reduction in risk of relapses About 67 percent of NMOSD sufferers are AQP4-IgG seropositive, and they tend to experience a more severe disease course.

The SAkuraStar study recruited 95 NMOSD patients from the ages of 20 to 70. Satralizumab was administered every four weeks by subcutaneous injection. The therapy performed better in NMOSD patients who are AQP4-IgG seropositive. Data from the AQP4-IgG seropositive subgroup showed that 82.9 percent of treated patients were relapse-free at 48 weeks compared to 55.4 percent in the placebo group, and 76.5 percent were relapse-free at 96 weeks compared to 55.4 percent and 41.1 percent with placebo.

In the overall satralizumab-treated population, 76.1 percent of treated patients were relapse-free at 48 weeks compared to 61.9 percent in the placebo group, and 72.1 percent were relapse-free at 96 weeks compared to 51.2 percent in the placebo group.

“While first described 125 years ago, the underlying biology of NMOSD has only recently been understood. The positive results from the pivotal SAkuraStar and SAkuraSky studies support the hypothesis that IL-6 plays a key role in this devastating disease that can take away people’s independence,” said Sandra Horning, Roche’s chief medical officer and head of Global Product Development. “We are encouraged by these results and look forward to working with regulators over the coming months to bring satralizumab to people living with NMOSD as soon as possible.”

The SAkuraStar trial results back up results of the SAkuraSky of satralizumab reported in 2018 as an add-on therapy. Satralizumab was created at Roche majority-owned Chugai Pharmaceutical using its proprietary antibody engineering technologies. It was granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration in December 2018.

Roche’s drug faces increasing competition: Alexion Pharmaceuticals’ Soliris was recently granted marketing approval as a treatment for seropositive NMOSD patients in the United States and Europe; and U.S. biotech Viela Bio, which recently presented positive results from a pivotal study of inebilizumab in patients with NMOSD, expects to file a new drug application with the FDA before the end of the year.

Photo: Sandra Horning, Roche’s chief medical officer and head of Global Product Development

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