Kessler Topaz Meltzer & Check, LLP: Investor Class Action Filed Against Ardelyx Inc. for Securities Fraud Violations

Notice is hereby given that a class action lawsuit has been filed on behalf of those who purchased or acquired Ardelyx Inc. (“Ardelyx”) (NASDAQ: ARDX) securities between August 6, 2020 and July 19, 2021, inclusive (the “Class Period”).    

Ardelyx investors may receive additional information about the case by clicking the link "Submit Your Information" above.  If you are a member of the class described above, you may no later than September 28, 2021 move the Court to serve as lead plaintiff of the class, if you so choose.

Ardelyx is a specialized biopharmaceutical company that focuses on developing first-in-class medicine to improve treatment for people with cardiorenal disease. This includes patients with chronic kidney disease (“CKD”) on dialysis suffering from elevated serum phosphorus, or hyperphosphatemia; and CKD patients and/or heart failure patients with elevated serum potassium, or hyperkalemia.

In June 2020, the defendants submitted a New Drug Application (“NDA”) to the U.S. Food and Drug Administration (“FDA”) for Ardelyx’s lead product candidate, tenapanor, a supposedly first-in-class medicine for the control of serum phosphorus in adult patients with CKD on dialysis. According to Ardelyx, tenapanor has “a unique mechanism of action and acts locally in the gut to inhibit the sodium hydrogen exchanger 3, or NHE3.” If approved, tenapanor “would be the first therapy for phosphate management that blocks phosphorus absorption at the primary pathway of uptake[,]” and “could greatly improve patient adherence and compliance with one single pill dosed twice daily in contrast to current therapies where typically multiple pills are taken before every meal.” Thus, tenapanor was widely touted by the defendants.

The Class Period commences on August 6, 2020, when Ardelyx issued a press release announcing that it submitted an NDA to the FDA for the review of tenapanor as a first-in-class therapy to control serum phosphorus in adult patients with CKD on dialysis.

The FDA accepted Ardelyx’s NDA in September 2020 and set a Prescription Drug User Fee Act date of April 29, 2021. Ardelyx repeatedly lauded this development, highlighting the FDA’s acceptance and review of the NDA, supported by so-called “successful” Phase 3 studies.

However, the truth was revealed after the markets closed on July 19, 2021, when the defendants announced that Ardelyx received a letter from the FDA on July 13, 2021, stating that “the FDA has identified deficiencies that preclude discussion of labeling and post-marketing requirements/commitments.” In particular, the FDA noted that “a key issue is the size of the treatment effect and its clinical relevance.”

The complaint alleges that throughout the Class Period, the defendants made materially false and misleading statements regarding tenapanor and the likelihood that it would be approved by the FDA. The complaint further alleges that the defendants possessed, were in control over, and, as a result, knew, or had reason to know, that the data submitted to support the NDA was insufficient in that it showed a lack of clinical relevance of the drug’s treatment effect, making it foreseeably likely, if not certain, that the FDA would not approve the drug.

A lead plaintiff is a representative party that acts on behalf of other class members in directing the litigation. In order to be appointed lead plaintiff, the Court must determine that the class member’s claim is typical of the claims of other class members, and that the class member will adequately represent the class. Your ability to share in any recovery is not, however, affected by the decision whether or not to serve as a lead plaintiff. Filling out the online form above or communicating with any counsel is not necessary to participate or share in any recovery achieved in this case.  Any member of the purported class may move the court to serve as a lead plaintiff through counsel of his/her choice, or may choose to do nothing and remain an inactive class member.

If you wish to discuss this action or have any questions concerning this notice or your rights or interests with respect to these matters, please contact Kessler Topaz Meltzer & Check, LLP:  James Maro, Esq. (484) 270-1453; toll-free at (844) 887-9500; or via e-mail at  If you would like additional information about the suit, please click on the link "Submit Your Information" above and fill out the form as promptly as possible.

Please complete this form relating to your transactions for Ardelyx Inc. (NASDAQ: ARDX) securities between August 6, 2020 and July 19, 2021, inclusive (the “Class Period”).    

You may also contact James Maro, Esq. (484) 270-1453; or toll free at (844) 887-9500; or you may submit your information via email at; or you may click here to print a PDF of this form.

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The submission of this form does not create an attorney-client relationship, nor an obligation on the part of Kessler Topaz or you to file a lead plaintiff motion in this matter. Any information you submit will be maintained as confidential. If Kessler Topaz, in its sole discretion, believes that you might be an appropriate lead plaintiff candidate, Kessler Topaz will contact you to discuss the matter and whether to establish an attorney client relationship. By signing this form you are authorizing us to contact you regarding this case and/or future cases.
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