 RADNOR, Pa., Sept. 17, 2021 PRNewswire -- The law firm of Kessler Topaz Meltzer Check, LLP alerts investors that a securities fraud class action lawsuit has been filed against Ardelyx Inc. NASDAQ: ARDX Ardelyx on behalf of those who purchased or acquired Ardelyx securities between August 6, 2020 and July 19, 2021 , inclusive the Class Period. 