Early Clinical Trial Results of Parkinson’s Therapy Published, Phase 2 Study Planned

Prothena’s drug candidate PRX002, under development for the treatment of Parkinson’s disease, is safe and well-tolerated, according to publication of results of a Phase 1 clinical trial (NCT02095171) in healthy volunteers.  A Phase 2 clinical trial of the potential Parkinson’s therapy in expected to start in 2017.

PRX002 is an antibody against alpha-synuclein, a protein found in nerve cells and a major factor linked to Parkinson’s disease. The normal function of alpha-synuclein is not well understood, however in certain neurodegenerative diseases including Parkinson’s disease, the protein missfolds and forms aggregates in neurons causing their death.

Research has shown that these misfolded proteins can propagate from one nerve cell to another, causing neurons to die in a spreading, infection-like manner. Targeting the misfolded alpha-synuclein with antibodies such as PRX002 could potentially stop such a spread.

Results of this Phase 1 study were presented in 2015 as part of the late-breaking oral session at the 19th International Congress of Parkinson’s Disease and Movement Disorders.

A total of 40 healthy volunteers were enrolled in the study. The participants received either an escalating dose of PRX002 or a placebo. Although some mild adverse side effects, including headache, nausea, pain on the site of injection, viral infection, and viral upper respiratory tract infection, were observed, the drug candidate was deemed generally safe and well-tolerated. No antibodies against the drug were detected in the blood of the participants.

Results showed that PRX002 reduced the levels of free alpha-synuclein in the blood by up to 96.5 percent within one hour of treatment administration.

Prothena, which is developing PRX002 in collaboration with Roche, announced the publication of the report, “First-in-human assessment of PRX002, an anti–α-synuclein monoclonal antibody, in healthy volunteers” in a press release. It was published in the journal Movement Disorders.

Parkinson’s disease is the second most common neurodegenerative disease after Alzheimer’s disease, affecting 1 in 100 people over the age of 60. It is estimated that 7 million to 10 million people live with the disease worldwide. There is currently no treatment that addresses the underlying cause of Parkinson’s disease.