More than one in seven U.S. adults is living with chronic kidney disease, a condition that is linked to high blood pressure, per the U.S. Centers for Disease Control and Prevention. A new medication aims to help lower blood pressure levels.
According to new research from the American Heart Association’s Hypertension Scientific Sessions, Baxdrostat, developed by AstraZeneca, helped lower hard-to-control blood pressure in people with chronic kidney disease.
Dr. Jordana B. Cohen, immediate past chair of the American Heart Association’s Hypertension and Kidney Cardiovascular Science Committee, who was not involved in the study, noted that the study is significant because “patients with chronic kidney disease were historically often excluded from drug studies.” She said the new medication could be a “game changer.”
Kidney disease and blood pressure are linked together in a treacherous loop. Chronic kidney disease, a condition where the kidneys are damaged and cannot filter blood properly, can cause or worsen high blood pressure. At the same time, high blood pressure can cause or further kidney damage.
“High blood pressure is the second leading cause of kidney failure in the U.S. after diabetes,” according to the National Kidney Foundation. Other risks associated with chronic kidney disease and high blood pressure include heart attack, stroke, and heart failure.
To study the potential benefits of baxdrostat in patients who suffer from chronic kidney disease and uncontrolled high blood pressure, 195 patients were enrolled in the FigHTN Phase 2 clinical trial, and 192 were eventually included in the results. They had already been treated with either an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB), but still had high blood pressure.
For the clinical trial, the participants were given either a placebo, a low dose of the medication, or a high dose of the medication. These were administered over the course of 26 weeks.
Baxdrostat works by inhibiting the production of a hormone called aldosterone that is made by the adrenal glands. This hormone plays a role in both chronic kidney disease and high blood pressure. It causes the body to retain sodium, which then increases water retention and can lead to high blood pressure.
“Over time, an excess of the hormone can lead to stiffening and thickening of blood vessels, which can contribute to heart damage and cause scarring in the kidneys, thereby playing a role in both high blood pressure and chronic kidney disease,” the American Heart Association explained.
At the start of the study, the average systolic blood pressure (pressure against the walls of arteries when blood is pumping) for the group was 151 mm Hg. Normal systolic measurements are typically below 120 mm Hg. By the end of the trial, the average systolic blood pressure had fallen 8.1 mm Hg more in participants receiving either dose of baxdrostat than in those receiving the placebo, representing an approximately 5% reduction.
Another way the researchers measured the efficacy of baxdrostat was to measure levels of the protein albumin, a marker of kidney and cardiovascular risk. Albumin levels decreased by 55% for those who took the medication compared to the placebo group.
“The reduction in urine albumin gives us hope that baxdrostat may also help delay kidney damage. This potential is now being tested in two large Phase 3 trials to determine if baxdrostat delays the progression of kidney disease,” said Dr. Jamie P. Dwyer, professor of medicine in the division of nephrology and hypertension at University of Utah Health in Salt Lake City and lead author of a study on the trial published Saturday in the Journal of the American Society of Nephrology.
In the future, adding baxdrostat to standard care for these patients may improve their health outcomes.
“These findings are encouraging for people living with chronic kidney disease and high blood pressure, two conditions that often go hand-in-hand and create a dangerous cycle,” Dwyer of the research. “High blood pressure can worsen kidney function and declining kidney function can further elevate blood pressure, and these outcomes can be life-altering for patients.”
However, the American Heart Association noted that the medication is not yet approved by the U.S. Food and Drug Administration. It also said that high potassium levels in the blood occurred in 41% of participants on baxdrostat compared to 5% of those on placebo.
“Most cases were mild to moderate,” the association added. No deaths or unanticipated adverse events were reported during the trial, though 9% of participants taking baxdrostat and 3% of those in the placebo group experienced a serious adverse event.