Well, at least they have Aduhelm.
Biogen reported another failure in what has been a roller coaster week for the biotech, this time for a phase 2 study of the anti-tau antibody gosuranemab in Alzheimer’s disease patients. The trial missed its primary efficacy endpoint, failing to halt the rate of clinical progression in patients. The biotech has now terminated the study and will cease clinical development of the candidate. Biogen paid $300 million upfront to license the drug from Bristol Myers Squibb back in 2017.
No matter, though. Biogen is still flying high after persuading the FDA to approve its amyloid drug Aduhelm despite the opposition of outside experts convened to assess the application. But, barring another Lazarus-like resurrection, the attempt to get gosuranemab to market is over. The decision to dump the prospect follows a clinical trial that appears to be devoid of reasons for optimism about its prospects.
Investigators randomized 654 subjects with mild cognitive impairment due to Alzheimer's or a mild form of the disease to receive one of three doses of gosuranemab or placebo every four weeks. The primary efficacy endpoint looked at whether the therapy could slow clinical progression of dementia at week 78.
Gosuranemab, also known as BIIB092, failed to beat placebo on that measure of efficacy. Biogen said no treatment benefit was seen on exploratory efficacy endpoints, either. The exploratory endpoints included whether the therapy could impact cognitive dysfunction or improve daily life.
The across-the-board failure happened despite Biogen linking gosuranemab to the lowering of N-terminal tau in cerebrospinal fluid, which is present in Alzheimer's disease. The finding, which is consistent with prior studies, suggests the antibody is engaging with its target. Yet, the engagement failed to translate into a statistically significant treatment effect on tau-PET at week 78.
Biogen is continuing to analyze biomarker data but has stopped the study and will discontinue clinical development of gosuranemab. The failure of the Alzheimer’s trial follows the termination of another gosuranemab study in progressive supranuclear palsy because it also missed the primary goal.
The midphase flops mean the bet Biogen placed in 2017 is unlikely to pay off. Back then, Biogen put up $300 million to license gosuranemab, then known as BMS-986168, from Bristol Myers. The bet was based on early-phase results Bristol Myers generated after acquiring the asset in its takeover of iPierian and by evidence extracellular tau contributes to the spread of pathology in tauopathies.
Roche dampened expectations for anti-tau antibodies last year, when its AC Immune-partnered drug failed a phase 2 clinical trial. Talking to investors earlier this year, Al Sandrock, M.D., Ph.D., head of R&D at Biogen, said the Roche failure made him think “it's tough to target tau with an antibody,” but hope remained for gosuranemab.
While the phase 2 results extinguish those hopes, Biogen retains an interest in treating Alzheimer’s by targeting tau. The company is preparing to move tau-targeted antisense oligonucleotide BIIB080 into a phase 2 trial. The therapy is designed to reduce production of both intracellular and extracellular tau.