Prothena Soars on Positive Phase I Results Of Parkinson's Drug PRX002

Published: Mar 24, 2015

Prothena (PRTA) Soars on Positive Phase I Results Of Parkinson's Drug PRX002
March 20, 2015
By Riley McDermid, Breaking News Sr. Editor

Irish late-stage clinical biotech Prothena Corporation Plc soared more than 26 percent in morning trading Friday after the company today debuted stunning results from a Phase I trial of its experimental drug for Parkinson’s disease.

In the trial, researchers found a single ascending dose study of leads to mean reduction of free serum alpha-synuclein levels of up to 96 percent—or, in layman’s terms, managed to slow the onset or progression of the disease by a majorly statistically significant amount,

The drug, PRX002, is a monoclonal antibody for the potential treatment of Parkinson's disease and other related disease or symptoms, known as synucleinopathies. The drug is the focus of a worldwide collaboration between Prothena and Roche .

"There is genetic and pathological evidence that supports a causal role of alpha-synuclein in Parkinson's disease," said Todd Sherer, chief executive of the Michael J. Fox Foundation for Parkinson's Research. "We applaud Prothena and Roche for their pioneering work in developing a potentially disease-modifying therapy for this progressive neurodegenerative disease that affects millions worldwide."

The Phase 1 double-blind, placebo-controlled, single ascending dose study enrolled 40 healthy volunteers. All volunteers enrolled were randomized 3:1 into five escalating dose cohorts (0.3 mg/kg, 1 mg/kg, 3 mg/kg, 10 mg/kg or 30 mg/kg) to receive either PRX002 or placebo. No hypersensitivity reactions or drug-related serious adverse events were reported. PRX002 demonstrated favorable pharmacokinetic properties, supporting the current dosing frequency in the on-going Phase 1 multiple ascending dose study in patients with Parkinson's disease.

"We are extremely pleased with the results of the Phase 1 single ascending dose study as the mean reduction of free serum alpha-synuclein of up to 96% demonstrates the pharmacodynamic effects of PRX002," said Gene Kinney, chief scientific officer and head of Research and Development at Prothena.

"Importantly and for the first time in humans, we demonstrated that this robust, rapid and dose-dependent reduction of free serum alpha-synuclein was safe and well-tolerated. Thus, this approach may translate into a clinically meaningful delay or reversal of disease progression in patients with Parkinson's disease,” he said.

“We look forward to building upon these data with results from the on-going, multiple ascending dose study in patients with Parkinson's disease expected in the first half of 2016, where we will also be measuring levels of PRX002 in the cerebrospinal fluid and assessing additional biochemical, imaging and clinical biomarker endpoints,” said Kinney.

The company will co-host a symposium with Roche on March 21 at the 12th International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders.

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