AstraZeneca's Sodium Zirconium Cyclosilicate Powder (ZS-9) Approved in China for Hyperkalemia Treatment

Original: Vernacular Chinese

On December 31, AstraZeneca’s sodium zirconium cyclosilicate for oral suspension (ZS-9) received approval from the National Medical Products Administration for marketing in China, for the treatment of hyperkalemia in adults.

Hyperkalemia is a common complication in patients with chronic kidney disease; if left untreated, it can lead to arrhythmias and even sudden cardiac death. It is estimated that there are approximately 2 million patients with end-stage renal disease worldwide, and despite undergoing dialysis treatment, the majority still exhibit elevated serum potassium levels. Currently, commonly used clinical treatments include patiromer sorbitex calcium and sodium/calcium polystyrene sulfonate. However, only sodium/calcium polystyrene sulfonate has been approved for marketing in China, leaving an unmet clinical need.

ZS-9 (sodium zirconium cyclosilicate) is a potassium binder developed by ZS Pharma in the United States. In November 2015, AstraZeneca acquired ZS Pharma for $2.7 billion in all-cash transaction (a 42% premium), thereby bringing ZS-9 into its portfolio. Studies have shown that ZS-9 exhibits nearly 100% selectivity for potassium ions, whereas sodium polystyrene sulfonate (SPS) shows a greater affinity for calcium ions compared to potassium and magnesium ions. The potassium-binding capacity of ZS-9 is ten times that of SPS. Analysts predict that peak sales of this drug could reach $1 billion.

Results from DIALIZE, a randomized, double-blind, placebo-controlled Phase IIIb clinical trial, demonstrated that 41.2% of patients in the ZS-9 treatment group maintained normal pre-dialysis serum potassium levels in at least three out of four dialysis sessions, compared with only 1% in the placebo group, thereby meeting the primary endpoint.

Source: PharmCube NextPharma

AstraZeneca’s New Drug Application for ZS-9 submitted to the U.S. FDA was rejected twice, both times due to manufacturing issues. The drug first received approval from the European Union on March 21, 2018, and obtained FDA approval two months later.

In May this year, sodium zirconium cyclosilicate for suspension was included in the "Second Batch of Clinically Urgent Overseas New Drugs List." The marketing application for this drug submitted by AstraZeneca was accepted by the CDE on July 10, 2019.