Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

Source: Prothena Corporation Plc

What: Shares in Prothena Corporation Plc (PRTA) sky-rocketed by more than 40% today after the company reported promising early stage results for PRX-002, a drug for the treatment of Parkinson's disease.

So What: Parkinson's disease is notoriously tough to treat, and developing new treatment options has proven to be incredibly difficult. As a result, current treatments for Parkinson's disease focus on disease symptoms, rather than the cause of the disease itself.

It's for that reason that investors are so excited about the potential opportunity for PRX-002.

PRX-002 represents an entirely new approach to treating the disease. It's a monoclonal antibody that helps reduce the spread of an unnatural buildup in alpha synuclein, a protein found in brain tissue that is thought to be a cause of Parkinson's disease.

During Prothena's phase 1 trials, patients taking PRX-002 saw a mean reduction in alpha synuclein of as much as 96%. The was significantly better than placebo and could suggest that this drug may be able to slow, or potentially even reverse, disease progression.

Now What: Prothena's results were from a phase 1 study that involved just 40 patients, so these results should be taken with a grain of salt. After all, 90% of drugs entering phase 1 end up in the dust-bin, rather than on pharmacy shelves.

Regardless, the study results are intriguing and suggest that Prothena is one to keep a close eye on, particularly given that Prothena is developing PRX-002 with the deep-pocketed Roche Holdings (RHHBY -1.70%).

As part of that partnership, Roche has already handed over $45 million to Prothena, and Prothena could earn up to an additional $555 million in milestones if this drug pans out. Regardless, the spike in shares means that Prothena has a market cap of more than $1 billion. That's not sky-high, but given that the company's work remains in its early stages, it might make more sense for all but the most speculative investors to wait for a pull-back or for the additional phase 1 results that are expected in 2016, before considering this one for portfolios.