Prothena Shares Surge Despite Clinical Trial Setback
Investing.com -- Prothena Corporation plc (NASDAQ:PRTA) shares rose by 43% today, marking the largest daily increase since September 2022. This surge occurred despite the announcement from the company's partner Roche that the Phase IIb PADOVA study did not reach its primary endpoint in a trial for an experimental Parkinson's disease drug. Nevertheless, the increase in stock price reflects investors' optimism regarding other positive trends of the drug and expectations for future developments.
The Dublin-based biotechnology company stated that the prasinezumab study showed a numeric delay in motor progression in patients with early-stage Parkinson's disease, along with positive trends in multiple secondary and exploratory endpoints. The drug was well tolerated, and no new safety signals were observed. Although the primary endpoint was not met (with a hazard ratio (HR) of 0.84 and a p-value of 0.0657), results were more pronounced in the pre-defined analysis of levodopa-treated patients, showing a nominal p-value of 0.0431.
Prothena's President and CEO, Dr. Gene Kinney, noted that the results of the PADOVA study represent a significant step in the potential to offer the first disease-modifying treatment for Parkinson's disease. The company looks forward to discussing study results with health authorities to determine the most appropriate advancement path.
Analysts provided mixed reactions to the news. BofA Securities analyst Tazeen Ahmad lowered the price target on Prothena from $26.00 to $22.00 while maintaining a Neutral rating. Ahmad pointed out the uncertainty regarding the program's future due to a lack of definitive evidence for clinical benefit following two failed Phase 2 trials. On the other hand, Oppenheimer analyst Jay Olson reduced the price target from $62.00 to $58.00 but maintained an Outperform rating, emphasizing that the upcoming AFFIRM-AL study is a more significant catalyst for the company.
In light of today's developments, BofA Securities commented: "Today's data announcement could be a cleanup phase for investors now turning their focus to PRTA's AL amyloidosis data release – which is the largest driver of NPV for PRTA shares."
Investors appear to be reacting positively to the potential of prasinezumab and Prothena's broader drug portfolio. Notably, Phase 3 results for birtamimab in AL amyloidosis are expected in the first half of 2025, alongside data updates for PRX012 in Alzheimer's disease anticipated around mid-2025. The full results of the PADOVA study are set to be presented at an upcoming medical meeting.