[Corrected 11/22/13, 1:55 pm. See below.] Chronic kidney disease affects 26 million patients in the U.S., and they spend a lot of money trying to manage the condition. Fort Worth, TX-based ZS Pharma is betting that it might have one more new option to help many of these patients.
ZS Pharma reported earlier this month that preliminary data from its Phase III trial 0f 753 patients showed its experimental drug was able to reduce excess amounts of potassium in the blood of patients with hyperkalemia. The finding–if confirmed in another big study—could be medically important. That’s because people with failing kidneys are often left with too much potassium in the blood, which can lead to potentially deadly arrythmias—an irregular heart rhythm.
“The thing we’re most excited about is that the drug is shown to be active and extremely safe,” says Robert Alexander, ZS’s executive chairman. “As potent as this drug is, we are thrilled to learn that it can be well tolerated.”
ZS Pharma made its announcement about ZS-9—a white odorless, tasteless powder that can be combined with water to make a suspension—earlier this month at Kidney Week, the American Society of Nephrology’s annual meeting. The study randomly assigned patients to get one of four doses—1.25 grams, 2.5 grams, 5 grams, and 10 grams—or a placebo, three times a day for two days. The company reported that the drug led to declines in potassium in 48 hours and that the drug appeared to be safe over the two-day period. [An earlier version of this story misstated the number of days that patients in the study were treated in the acute phase of the trial. We regret the error.]
ZS Pharma did not disclose the baseline levels of potassium of patients who entered the study, so the preliminary results do not show if the patients’ potassium levels were brought down to a normal range. The ZS-9 trial enrolled patients with mild to moderate hyperkalemia.
A spokeswoman for the company would only say that the full report would be available “in the coming months.”
“We wanted to really understand how the drug works across a range of doses,” Alexander says. “The main reason for hyperkalemia is high potassium, but there is a range of hyperkalemia. It’s’ a matter of making sure you get the right dose for the right patient.”
What would be key to know is how the drug fared against sodium polystyrene sulfonate (Kayexalate), which has been the mainstay in care for patients with hyperkalemia since the 1960s. Alexander says ZS Pharma did not conduct trials comparing ZS-9 with Kayexalate
