Source: Prothena Corp. Plc

Compelling early stage trial data for Prothena Corp. Plc's (PRTA -2.71%) PRX002 as a therapy for Parkinson's disease sent the company's shares soaring 33.5% in June.

Offering new hope
Prothena is developing PRX002 with Roche Holding under a collaboration deal inked in December 2013.

Roche has already paid Prothena $45 million of the deal's potential $600 million in regulatory and sales milestone payments. Based on results from PRX002's phase 1 trial, it could be money well spent.

In that trial, levels of free serum alpha-synuclein, a protein that might contribute to the onset and progression of Parkinson's disease, a central nervous system disorder affecting up to 1 million Americans, dropped by a mean 96% following treatment with PRX002.

The two companies reported that PRX002 was generally well tolerated by patients, and that no serious adverse events were associated with the treatment.

Looking ahead
Admittedly, these results occurred in the first stage of human clinical trials, and PRX002 might not put up similar results in large late-stage trials. 

However, Roche has considerable experience in developing and commercializing monoclonal antibody drugs like PRX002. The Switzerland-based company funded researchers who discovered the science behind monoclonal antibodies in the 1970s, and Roche already racks up billions of dollars in sales from monoclonal antibody drugs, including Rituxan, Herceptin, and Avastin. This all suggests Roche has plenty of experience it can leverage to successfully develop PRX002.

Overall, while we're still miles away from finding out if PRX002 can be a similar commercial success, the potential opportunity makes Prothena a top stock to watch over the coming year or two.