With promising pivotal data, Viela Bio's lead autoimmune drug heads for FDA filing

Viela Bio spun out of AstraZeneca last year with six autoimmune and inflammation-aimed programs and $250 million. Now, the biotech is reporting positive pivotal data for its lead drug in a rare, autoimmune disease, teeing it up for an FDA filing later this year. 

Viela tested the drug, a CD19-targeting antibody called inebilizumab, in patients with neuromyelitis optica spectrum disorders (NMOSD), a disease in which the immune system attacks the optic nerves, spinal cord and brain. Current treatments fall into two groups: those used when a patient is having an attack and those used to ward off attacks. There is no treatment approved specifically for NMOSD, so the steroids and immunosuppressants prescribed to prevent attacks are used off-label. 

The data, presented Tuesday at the annual meeting of the American Academy of Neurology, showed the treatment reduced the risk of attacks by 73%. 

“Neuromyelitis optica attacks can be quite devastating. They can result in a rapid loss of vision up to and including blindness and paralysis. The key is to stop attacks from happening,” Viela Bio Chief Medical Officer Jorn Drappa, M.D., Ph.D., told FierceBiotech. 

“None of the currently used drugs have been studied in a rigorous fashion in NMOSD—there has not been a controlled clinical trial that establishes these treatments are effective. Ours is the largest clinical trial done in neuromyelitis optica,” Drappa said. 

The study enrolled 231 patients with varying severities of disease, said Viela Bio CEO Bing Yao. Most of the patients had autoantibodies against a protein called aquaporin-4 (AQP4), while a small number of them did not. These AQP4 antibodies are a biomarker of NMOSD and are believed to trigger NMOSD attacks when they bind to the nervous system. 

“We are trying to prevent attacks by attacking the cells that make the pathogenic antibody that causes NMOSD … Those cells express CD19, so we are targeting CD19-expressing B cells to trigger destruction,” Drappa said. 

The 231 patients were randomized to receive either two doses of inebilizumab or placebo, two weeks apart. They were then followed for six months. Though the overall reduction in risk of attacks was 73%, this figure was slightly higher in the patients who had AQP4 antibodies: 77%. And, the data showed, 89% of this group had no attacks during the six-month period, compared to 58% of the patients taking placebo. After the six months, patients could sign up for an extension period, during which they will receive additional doses of inebilizumab every six months. 

Though the treatment did not meet a secondary endpoint of visual acuity, it did meet the others, including a reduction in hospitalizations due to NMOSD attacks and a decrease in the number of new brain lesions seen on an MRI. A smaller percentage of patients taking inebilizumab had worsening disability than those on placebo—a 15.5% worsening from baseline in their Expanded Disability Status Scale score versus 33.9%. 

That scale, Drappa said, is widely used in multiple sclerosis trials and measures how well patients are functioning, ranging from no impairment to being wheelchair- or bedbound. 

“I think inebilizumab is going to be an attractive option for patients, provided it gets approved,” Drappa said. The treatment is given twice a year through an intravenous infusion that takes 90 minutes.