Ardelyx's topline results from the Phase 3 Phreedom trial were positive, with the study hitting the key primary endpoint of phosphate lowering, Piper Jaffray analyst Christopher Raymond tells investors in a research note. The analyst says that while concern is likely over the higher than anticipated 16% discontinuation rate due to diarrhea, he continues to view the previously disclosed safety data from the Phase 3 Amplify as better representative of real-world results, which saw a discontinuation rate of just 2.6%. With another positive trial, the analyst continues to view tenapanor's path to approval as "significantly derisked." He remains a buyer of Ardelyx shares with an Overweight rating and $15 price target. The stock in morning trading is down 3% to $6.97.