Prothena’s Prasinezumab Advances to Phase III for Parkinson’s

Prothena ( (PRTA) ) has issued an announcement.

On June 15, 2025, Prothena Corporation announced that its partner Roche will advance prasinezumab into Phase III development for early-stage Parkinson’s disease. This decision follows data from the Phase IIb PADOVA study and ongoing open-label extensions, which suggest potential clinical benefits of prasinezumab, a first-in-class anti-alpha-synuclein antibody. The studies indicated positive trends towards reduced motor progression and provided biomarker evidence of prasinezumab’s impact on disease biology. This advancement could position prasinezumab as a potential disease-modifying treatment for Parkinson’s, addressing a significant unmet need for over 10 million affected individuals globally.

The most recent analyst rating on (PRTA) stock is a Buy with a $84.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Spark’s Take on PRTA Stock

According to Spark, TipRanks’ AI Analyst, PRTA is a Neutral.

Prothena’s stock score is primarily driven by financial performance and technical analysis, both reflecting significant challenges. The recent corporate event further highlights operational difficulties, contributing to a weak overall outlook.

To see Spark’s full report on PRTA stock, click here.

More about Prothena

Prothena Corporation plc is a clinical-stage biotechnology company specializing in protein dysregulation. It is advancing a pipeline of investigational therapeutics for neurodegenerative and rare peripheral amyloid diseases, including Parkinson’s disease, Alzheimer’s disease, and ATTR amyloidosis with cardiomyopathy.

Average Trading Volume: 1,397,941

Technical Sentiment Signal: Sell

Current Market Cap: $273.4M

See more insights into PRTA stock on TipRanks’ Stock Analysis page.