What happened Shares of Concert Pharmaceuticals (NASDAQ: CNCE) were cratering 28.9% as of 3:26 p.m. EST on Monday. The steep decline came after the company announced that experimental drug CTP-692 had failed to meet the primary and secondary endpoints in a phase 2 study as an adjunctive treatment for schizophrenia. So what It's always bad news for a clinical-stage biotech stock when a candidate fails in clinical testing. What's even worse for Concert is that CTP-692 was one of only two candidates in its pipeline. Image source: Getty Images. Note the use of the past tense in that last statement. Concert is completely throwing in the towel on its CTP-692 program after the dismal phase 2 results. The company stated that the drug, a deuterated form (where hydrogen is replaced with deuterium) of the D-serine amino acid, didn't show a statistically significant improvement over placebo at any dose level for any of the endpoints of the study. Concert Pharmaceuticals CEO Roger Tung said, "The body of evidence in the field supporting D-serine as an adjunctive treatment for schizophrenia was compelling and led us to advance CTP-692 into a Phase 2 proof of concept study. Unfortunately, we didn't see the results we hoped for to support continuation of this program." Now what What's next for Concert? All of its chips now ride on CTP-543. The experimental drug is currently being evaluated in late-stage testing for the treatment of alopecia areata, an autoimmune disorder that results in hair loss. However, the drugmaker is also evaluating other potential candidates that could advance into clinical testing. 10 stocks we like better than Concert PharmaceuticalsWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Concert Pharmaceuticals wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of November 20, 2020 Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source