A new analysis suggests acoramidis may improve kidney health over time in people with transthyretin amyloid cardiomyopathy (ATTR-CM). BridgeBio Pharma, the company that markets the drug, announced the findings, which appear in Circulation: Heart Failure.
The U.S. Food and Drug Administration (FDA) approved acoramidis (marketed as Attruby) for adults with wild-type or hereditary ATTR-CM to reduce cardiovascular death and cardiovascular-related hospitalization. It is not approved specifically as a kidney-protective treatment, but the study explored whether kidney-related effects may be part of its broader clinical profile.
People with ATTR-CM are at risk for heart failure, and heart and kidney function are closely related. For that reason, kidney health is often an important part of care for people being treated for heart disease. “Kidney dysfunction is pervasive in this population and an independent predictor of mortality from ATTR-CM,” said Dr. Jeffrey Testani, first author of the manuscript.
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Researchers analyzed data from randomized, double-blind, placebo-controlled trials, including the phase 2 AG10-201 study and the phase 3 ATTRibute-CM study.
The authors found that shortly after treatment began, there was an initial dip in estimated glomerular filtration rate (eGFR), which measures how well the kidneys filter blood.
Although a drop in eGFR usually raises concern about worsening kidney function, this dip was reversible. Researchers said it may reflect a treatment-related change in kidney blood flow rather than kidney injury, a characteristic already seen with other drugs people with heart failure use as treatment.
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They also reported a decrease in urinary albumin-to-creatinine ratio (UACR), a urine test that shows how much protein is being lost in the urine. A lower UACR can suggest less kidney stress or damage.
Through Month 30, acoramidis showed a more favorable chronic eGFR slope, or pattern of kidney filtration over time, and a sustained reduction in UACR.
The early eGFR dip was also linked to cardiovascular outcomes. Among participants who took acoramidis, those with larger-than-median eGFR dips had a 58% lower risk of death or cardiovascular hospitalization in the first year. They also had a 66% lower risk of hospitalization alone. However, this finding applied only to a subgroup. Not everyone who takes acoramidis will see the same risk reduction.
This news adds useful information about a drug doctors already use to treat ATTR-CM. However, the trials did not specifically test kidney outcomes, which may have affected the results. Future studies would need to test kidney effects as a planned outcome, including in people with different levels of kidney function at the start of treatment.
