Benzinga | Jun 24, 2021 08:32AM EDT

Prothena Announces Bristol Myers Squibb Opt-In Of Anti-Tau PRX005 As First Program From Global Neuroscience Research And Development Collaboration

Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical company with a robust pipeline of novel investigational therapeutics built on protein dysregulation expertise, today announced that Bristol Myers Squibb exercised its option under the global neuroscience research and development collaboration to enter into an exclusive U.S. license for PRX005 and will pay Prothena $80 million. PRX005 is designed to be a best-in-class anti-tau antibody by specifically targeting an area within the microtubule binding region (MTBR) for the potential treatment of Alzheimer's disease (AD). Phase 1 study with PRX005 has initiated.

"Our continued collaboration with Bristol Myers Squibb on PRX005 allows us to further leverage our combined expertise to accelerate the development of therapies with the potential to transform the lives of those affected by neurodegeneration," said Gene Kinney, PhD, President and Chief Executive Officer of Prothena. "Mounting scientific evidence suggests the MTBR of tau is most closely associated with the pathogenic spread of tau. The presence of MTBR fragments in cerebrospinal fluid have also been shown to correlate with dementia stages in Alzheimer's disease to a higher degree than fragments of other tau regions. These recent biological understandings support the further development of PRX005, which uniquely targets a key region within the MTBR of the tau protein. In our studies, we have found that targeting specific regions within the MTBR reduce pathogenic tau uptake into neurons, an attribute that was not achievable with antibodies targeting other regions of tau."

"We are pleased that our collaboration with Prothena has successfully identified and developed PRX005, a novel, differentiated anti-tau antibody that we believe has the potential to provide a meaningful disease modifying treatment option for the millions of patients that suffer from Alzheimer's disease," said Richard Hargreaves, Senior Vice President and Head of Bristol Myers Squibb's Neuroscience Thematic Research Center. "We look forward to our continued partnership with Prothena."

Tau is a microtubule associated protein, which aggregates and hyper-phospohrylates in the brains of individuals with AD to form pathological neurofibrillary tangles. Tau tangles, along with amyloid beta plaques represent the pathological hallmarks of AD. The presence of tau pathology strongly correlates with neurodegeneration and cognitive impairment in AD and its pattern of progression throughout the brain suggests that tau pathologyspreads through anatomically connected pathways via cell-to-cell transmission, a hypothesis supported by multiple preclinical studies. This propagation of pathology is thought to be mediated by tau "seeds" containing the MTBR of tau. PRX005 has demonstrated superior ability to bind, intercept and block cellular internalization of pathogenic tau, and mitigate downstream neurotoxicity compared to other anti-tau antibodies in multiple preclinical studies.