The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has issued a positive opinion recommending the approval of ZS-9 (sodium zirconium cyclosilicate) to treat hyperkalaemia, AstraZeneca, the maker of ZS-9, announced.

The recommendation is based on data from three double-blind placebo-controlled trials and one ongoing 12-month open-label trial in adults with hyperkalaemia, representing more than 1,600 patients treated to date.

The CHMP’s opinion will now be advanced to the European Commission for a final decision on marketing authorization of the medicine. The final decision will be applicable to all 28 European Union member countries plus Iceland, Norway and Liechtenstein.

The U.S. Food and Drug Administration has accepted for review AstraZeneca’s re-submission of a new drug application for ZS-9. AstraZeneca announced in May that the FDA had rejected the new drug application for ZS-9 due to observations arising from a pre-approval manufacturing inspection.

Study data

Results from a Phase III study showed that in patients with hyperkalaemia, sodium zirconium cyclosilicate (oral suspension) significantly reduced blood serum potassium to normal levels (normokalaemia) within 48 hours, which was maintained during 12 days of maintenance therapy.

Normal levels of potassium in the blood serum were also achieved within 48 hours in an additional study, with a higher proportion of patients maintaining normokalaemia for up to 28 days on treatment versus placebo.

In these trials, sodium zirconium cyclosilicate was shown to significantly lower serum potassium levels quickly and effectively in patients with acute and chronic hyperkalaemia.1,2


  1. Kosiborod M, Rasmussen HS, Lavin P, et al. “Effect of Sodium Zirconium Cyclosilicate on Potassium Lowering for 28 Days Among Outpatients With Hyperkalemia.” JAMA. 2014. doi:10.1001/jama.2014.15688.
  2. Packham D, Rasmussen HS, Lavin P, et al. “Sodium Zirconium Cyclosilicate in Hperkalemia.” New Engl J Med. 2015;372:222-31. doi: 10.1056/NEJMoa1411487.