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.

What's happening: Shares in Alnylam Pharmaceuticals (NASDAQ:ALNY) are surging higher by as much as 10% earlier today after data from an ongoing phase 2 trial for patisiran as a treatment for familial amyloidotic polyneuropathy, or FAP.

Why it's happening: Patisiran is Alnylam's most advanced clinical drug and a big reason that Sanofi (NASDAQ:SNY), Alnylam's partner on the drug, took a 12% equity stake in Alnylam last year.

The updated patisiran data show that patients who have taken patisiran had a 2.5 point decrease in modified neuropathy impairment score after 12-months. That is better than the typical 13 to 18 point increase for untreated FAP patients.

FAP is a rare genetic disorder that can cause a buildup of the amyloid protein in tissue and organs. Patients have few treatment options and typically live five to 15 years after symptoms appear.

The tough-to-treat nature of this disease means that patisiran's phase 2 results are encouraging; however, it will be far more important to see patisiran succeed in ongoing phase 3 trials.

If patisiran puts up similarly strong results in those late stage trials, then it could clear the way for a filing for FDA approval. It would also help validate Alnylam's RNA targeting approach, which is being leveraged across a pipeline of drug prospects for other indications, including cardiovascular conditions.

Regardless, investors may want to keep an eye toward later this year when 18-month phase 2 data will be presented. That 18-month data could provide insight into the phase 3 results given that the endpoint for phase 3 is a drop in impairment score at the 18 month mark.