FDA approves new hyperkalemia drug Lokelma

The FDA approved oral sodium zirconium cyclosilicate (ZS-9), to be marketed as Lokelma, for the treatment of hyperkalemia.

The drug seems to work better than sodium polystyrene sulfonate (Kayexalate), reducing serum potassium levels within an hour and restoring normal levels after about 2 hours in most patients. The drug was tested against placebo (not Kayexalate) in the clinical trials that resulted in its approval.

Zirconium silicates are widely used in medical and dental settings and are believed to be generally safe. ZS-9, delivered orally, captures potassium ions in the GI tract through its chemical similarity to endogenous potassium channels. The potassium complex is then excreted in stool. Lokelma is not absorbed into the bloodstream. Edema was a common side effect of Lokelma.

AstraZeneca bought Lokelma's maker in 2015 but could not ramp up drug production until 2018. Lokelma's primary brand-name competitor, Veltassa (patiromer) had a black box warning about drug interactions, which was removed in 2016.

In 2017, the FDA warned against giving Kayexalate within three hours of other drugs, to avoid impaired absorption of medications.

The European Union's regulatory agency also approved Lokelma for use in the EU.

The hyperkalemia drug market has been predicted to increase sixfold over coming years to >$2 billion, if drugmakers can successfully convince physicians to maintain patients with kidney disease on renin-angiotensin-aldosterone system inhibitors, and then treat their chronic hyperkalemia with Lokelma or Veltassa.

Sources: Fierce Pharma, DRG