Vielo Bio Reports Positive Pivotal Results of Treatment for Rare CNS Disorder

Viela Bio reported positive results from a pivotal study of its anti-CD19 monoclonal antibody, inebilizumab, in patients with neuromyelitis optica spectrum disorder, or NMOSD, a rare autoimmune disease characterized by unpredictable attacks that often lead to severe, irreparable disability including blindness and paralysis.

The results were presented at the 2019 American Academy of Neurology annual meeting held in Philadelphia.

“NMOSD is a devastating disease that can result in severe muscle weakness and paralysis, loss of vision, respiratory failure and neuropathic pain. There is currently no approved treatment, and patients today are relegated to off-label therapies with uncertain benefit,” said Jorn Drappa, chief medical officer and head of research and development at Viela Bio.

The N-MOmentum trial, the largest global, placebo-controlled study in NMOSD, achieved the primary and key secondary endpoints, demonstrating significant reduction in risk of NMOSD attack, and impacting measurements of worsening disability, hospitalizations and new central nervous system MRI lesions. Inebilizumab showed a favorable safety and tolerability profile, with an adverse event rate similar to placebo.

The double-blind international trial enrolled 231 NMOSD patients, including patients with and without the AQP4-IgG antibody, a key biomarker for the disease. Patients were randomized to receive either two introductory doses of inebilizumab monotherapy or placebo on the first day and the fifteenth day. The patients were followed for a total of 28 weeks, after which time they were given the option to enter an open-label extension period, in which they receive inebilizumab every 6 months.

Inebilizumab met the primary efficacy endpoint with a 77 percent reduction in risk of developing an NMOSD attack when compared to placebo in AQP4-IgG seropositive patients after 28 weeks of treatment. There was a similar effect on attack risk in AQP4-IgG seronegative patients with a 73 percent reduction in risk of NMOSD attack. At the end of 28 weeks, 89 percent of seropositive patients treated with inebilizumab were attack-free, compared to 58 percent in the placebo group.

“Inebilizumab is the first and only biologic in NMOSD to use CD19 as a target for B cell depletion without the confounding effects of background drug therapies,” said Bruce Cree, lead investigator for the N-MOmentum study and professor of clinical neurology at the University of California San Francisco Weill Institute for Neurosciences. “Inebilizumab substantially reduced the risk of attacks when given as a monotherapy, successfully measuring a strong treatment effect in both attacks and worsening disability.”

Based on the safety and efficacy data from this pivotal study, the company plans to file for a Biologics License Application with the U.S. Food and Drug Administration mid-2019. Inebilizumab has Orphan Drug designation in the United States and the European Union and Breakthrough Therapy designation in the United States.

Other companies with late-stage therapies targeting NMOSD include Chugai Pharmaceuticals and Alexion Pharmaceuticals. Alexion’s application to expand the use of its drug Soliris is under review by the FDA with a decision expected by June 28.

Photo: Jorn Drappa, chief medical officer and head of research and development at Viela Bio