Prothena (Nasdaq: PRTA) is an Irish clinical-stage biotechnology company that develops novel monoclonal antibodies directed towards misfolded proteins or improper cell adhesion.

The company’s work in protein misfolding aims to deliver therapies to treat several neurodegenerative diseases, including AL (primary) and AA (secondary) forms of amyloidosis (NEOD001), Parkinson's disease and related synucleinopathies (PRX002).

Prothena’s novel cell adhesion development activities aim to generate new therapies to treat inflammatory diseases and metastatic cancers (PRX003).

In December 2013 Prothena entered into a worldwide collaboration with Swiss drug major Roche (ROG: SIX) to develop and commercialize antibodies that target alpha-synuclein.

Included in the collaboration is PRX002, Prothena's monoclonal antibody for the treatment of Parkinson's disease, which is currently in preclinical development and is expected to enter Phase I clinical trials in patients with Parkinson's disease in 2014.

In March 2018, a deal was signed with Celgene that could be worth up to $2 billion to the Dublin-headquartered company, focused on three proteins: tau, TDP-43 and another, undisclosed target, each of which is implicated in the pathogenesis of neurodegenerative diseases such as Alzheimer's.