Prothena’s stock surged more than 40% after-hours yesterday as early-stage data sparked hope that the firm’s Roche-partnered experimental monoclonal antibody PRX002 could offer a new approach to treating Parkinson’s disease.

The Dublin, Ireland-based biotech released data from a Phase I clinical trial showing that PRX002 was not only safe and well tolerated but also massively lowered levels of a protein linked with the onset and progression of the disease, inducing a “highly-significant” mean reduction of free serum alpha-synuclein levels of up to 96%. 

This reduction “may translate into a clinically meaningful delay or reversal of disease progression in patients with Parkinson’s disease,” noted Gene Kinney, PhD, Chief Scientific Officer and Head of Research and Development at Prothena, commenting on its potential.

Results from an ongoing, multiple ascending dose study in patients with Parkinson’s are expected in the first half of 2016, during which researchers will measure levels of PRX002 in the cerebrospinal fluid and assess additional biochemical, imaging and clinical biomarker endpoints. 

Prothena and Roche entered into a worldwide collaboration to develop and commercialise antibodies that target alpha-synuclein, including PRX002, in December 2013.