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: Shares of Enanta Pharmaceuticals (NASDAQ:ENTA), a small-molecule drug developer targeted at infectious disease, soared as much as 20% after clinical partner AbbVie (NYSE:ABBV) reported positive results from its second phase 3 trial of six (known as Sapphire-II) in treating experienced genotype 1 hepatitis-C patients.

So what: According to Enanta and AbbVie's press release, AbbVie's direct-acting antiviral combo, which consists of Enanta's ABT-450, as well as ABT-267 and ABT-333, demonstrated a sustained virologic response after 12 weeks of an incredible 96% in chronically infected genotype 1 patients who had been previously treated with and failed to respond to pegylated interferon and ribavirin. Also according to the release, nearly half of those patients were null responders under pegylated interferon and ribavirin treatment. The DAA combo was also well-tolerated with just 1% of the patient population dropping out due to adverse events.

Now what: These results are incredible -- that's all I have to say! Genotype 1 is by far the most common form of the disease, and this combo drug, in a matter of 12 weeks has practically eradicated it in nearly every patient! Furthermore, it did so without the use of interferon which can cause nasty flu-like side effects in patients. With Gilead Sciences (NASDAQ:GILD) getting Sovaldi approved on Friday as an interferon-free treatment for genotype 2 & 3 hepatitis C (as well as in conjunction with interferon in type 1 and 4 genotypes), we're rapidly seeing the potential for improving hepatitis-C patients' quality of life go up. As for Enanta, the potential for this DAA combo's approval is going to be huge because, at the moment, the data would signify it could be a monster drug. Even following its near doubling over the past couple of weeks, I would suggest, if approved, that Enanta could have more upside.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

The Motley Fool recommends Gilead Sciences. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.