Roche and Prothena have agreed to jointly develop and commercialize new antibodies that target alpha-synuclein, including PRX002, Prothena's monoclonal antibody for the treatment of Parkinson's disease (PD).

Currently, PRX002 is in preclinical development and is scheduled to enter Phase I clinical trials in patients with PD in 2014.

Synuclein proteins are a family of charged proteins found throughout the body and alpha-synuclein is one protein from this family and is found extensively in neurons.

Alpha-synuclein is a major component of pathological inclusions that characterize several neurodegenerative disorders, including Parkinson's disease, dementia with Lewy bodies, neurodegeneration with brain iron accumulation type 1, and multiple system atrophy, which collectively are termed synucleinopathies.

As part of the deal, both the firms will jointly develop PRX002 for Parkinson's disease and potentially other synucleinopathies.

In the US, Prothena also has an option to co-promote PRX002, while the development, commercialization costs and profits will be shared a 70/30 basis by Roche and Prothena, respectively.

Roche will have sole responsibility for developing and commercializing PRX002 outside the US and will also pay Prothena up to double-digit royalties on net sales.

The deal will see Prothena receive an upfront payment and near-term clinical milestone totalling $45m as well as it is eligible to receive additional payments of about $380m upon the achievement of development, regulatory and first commercial sales milestones plus up to an additional $175m in ex-US commercial milestone payments.

According to the companies, the total worldwide upfront and milestone payments may amount up to $600m.

The firms will also start a research collaboration focused on optimizing early stage antibodies targeting alpha-synuclein including incorporation of Roche's proprietary Brain Shuttle technology to increase delivery of therapeutic antibodies to the brain.