What: Shares of Concert Pharmaceuticals (CNCE), a small-cap biopharmaceutical company focused on developing novel small-molecule drugs for the treatment of a variety of central nervous system and genetic disorders, finished the Wednesday trading session higher by a whopping 23% after reporting impressive phase 1 results for experimental drug CTP-656 as a treatment for cystic fibrosis.

So what: According to the midday press release, Concert's CTP-656 "achieved a superior pharmacokinetic profile to Kalydeco," which is Vertex Pharmaceuticals (VRTX 1.25%) heralded cystic fibrosis drug, and one of the components of its recently approved CF combo drug Orkambi.

As noted in the release, CTP-656 led to a reduced rate of clearance, a longer half-life, and greater plasma levels at the 24-hour mark. Concert also notes that the plasma exposure in the CTP-656 cohort was due to its "parent drug," whereas this wasn't the case with Kalydeco, where the greater plasma amounts were attributed to "a less-active metabolite and an approximately equivalent amount of an inactive metabolite." It should be noted the cross comparison between both drugs was only based on a relatively small nine-person patient pool.

Additionally, all three doses tested (75 mg, 150 mg, and 300 mg) were demonstrated to be safe with no serious adverse events reported. Concert intends to push CTP-656 into phase 2 studies next year.

Source: Centers for Disease Control and Prevention.

Now what: It's extremely early and the sample size was very small, but this is good news in the early going for Concert Pharmaceuticals. Of course, investors should understand that phase 1 studies are predominantly focused on dose-finding and safety rather than drug efficacy. Even though we've obviously been given a hint to CTP-656's potential, it'd be wise not to get too wrapped up in its clinical data until we have a larger and more substantive patient pool to examine.

On the flipside, Concert's data also points out how dangerous a valuation Vertex Pharmaceuticals may currently be carrying. With the exception of a few early stage oncology products, Vertex's revenue stream is wholly reliant on CF. While that's not a bad thing right now, if another competitor like Concert comes along as displaces Kalydeco or Orkambi, then Vertex could be in a world of hurt.

Also, with Vertex valued at more than six times its projected 2018 sales, it's not as if the company is in anyway "inexpensive." As such, my suggestion would be to keep your distance from both companies at present, but to have Concert Pharmaceuticals on your radar for when it does report its midstage results.