Rare Daily Staff

Biogen said it will discontinue development of its experimental therapy gosuranemab for progressive supranuclear palsy after the treatment failed to meet the endpoints of a mid-stage clinical trial.

Progressive supranuclear palsy, which is also known as Steele-Richardson-Olszewski syndrome, is a rare disease that involves the gradual deterioration of brain cells. Symptoms include loss of balance with unexplained falls, stiffness, difficulty moving the eyes, particularly up and down, personality changes, and dementia (loss of intellectual function). The disease usually starts in people aged over 60 years and gradually gets worse over time.

Progressive supranuclear palsy is a rare and life-threating neurologic disease. Patients with the condition have tangles of tau protein in their brain, which are believed to cause neurodegeneration. The condition leads to parkinsonism, paralysis, and premature death.

Gosuranemab is a humanized monoclonal antibody that targets N-terminal tau. Gosuranemab-mediated removal of N-terminal tau is being studied to evaluate whether it slows the progression of disease in tauopathies.

The company said the primary endpoint of the PASSPORT study, as measured by the PSP rating scale (PSPRS) at week 52, was not statistically significant. In addition, the study did not demonstrate efficacy on key clinical secondary endpoints.

Safety results of the study were generally consistent with previous studies of gosuranemab. Detailed results of this study will be made available in a future scientific forum.

While the company said it will discontinue development of gosuranemab for PSP and other primary tauopathies, it is continuing its ongoing study of the therapy for mild cognitive impairment due to Alzheimer’s disease given differences in disease pathology.

“We are disappointed with the efficacy results of the phase 2 PASSPORT study,” said Alfred Sandrock Jr., executive vice president of research and development and chief medical officer at Biogen. “We remain unwavering in our commitment to advancing therapies that have the potential to address the significant unmet medical needs of people with neurodegenerative diseases who are faced with limited to no treatment options.”

Photo: Alfred Sandrock Jr., executive vice president of research and development and chief medical officer at Biogen

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