Breakthrough or Band-Aid? New Drug for Primary Aldosteronism Sparks Debate

TAMPA, Fla., Oct. 16, 2025 /PRNewswire/ -- A new drug aimed at treating primary aldosteronism—the most common but often overlooked cause of high blood pressure—is making waves in the medical community. But according to one of the world's top adrenal surgeons, Dr. Tobias Carling, while innovation is always welcome, the real cure for many patients already exists: removing the aldosterone-producing tumor through a quick, low-risk operation.

Dr. Carling, Director of the Carling Adrenal Center at the Hospital for Endocrine Surgery in Tampa, co-authored a correspondence published today in The New England Journal of Medicine (NEJM), offering a multidisciplinary perspective on the evolving landscape of primary aldosteronism treatment [1].

A New Drug for Primary Aldosteronism: Promise and Caution

The NEJM publication responds to the recent Phase 2a SPARK trial of baxdrostat, an experimental aldosterone-synthase inhibitor designed to suppress aldosterone production in patients with primary aldosteronism. The study, led by Turcu et al., found that the drug reduced aldosterone and blood-pressure levels in 15 patients.

However, Dr. Carling and his co-author, Dr. Ute Scholl of Charité–Universitätsmedizin Berlin, raised concerns about the study's limitations—most notably, that it did not determine whether patients had unilateral or bilateral disease, a key distinction in deciding between medical and surgical treatment [1].

"Unilateral aldosterone-producing tumors are best managed surgically, an approach that leads to high cure rates," the authors noted, emphasizing that without subtyping, it remains unclear which patients actually benefit from drug therapy [1].

Baxdrostat, an investigational aldosterone-synthase inhibitor for treatment-resistant hypertension, is produced by AstraZeneca and was acquired through its $1.3 billion purchase of CinCor Pharma in 2023. The acquisition highlights growing pharmaceutical interest—and investment—in long-term drug therapies for conditions that can, in many cases, be cured surgically.

Understanding Primary Aldosteronism: A Curable Cause of Hypertension

Primary aldosteronism (also known as Conn's syndrome) occurs when one or both adrenal glands produce excess aldosterone, leading to high blood pressure, low potassium, and damage to the heart and kidneys. Studies suggest that up to 10 percent of people with hypertension may actually have primary aldosteronism, yet fewer than 1 percent are properly diagnosed [2].

Because the condition often mimics essential hypertension, most patients spend years taking ever-increasing doses of blood-pressure medication that never address the true cause.

"When one adrenal gland is overproducing aldosterone, surgical removal of that gland is not just effective—it's curative," said Dr. Carling. "In expert hands, surgery can restore normal hormone balance, eliminate the need for blood-pressure medication, and prevent long-term cardiovascular damage."

At the Carling Adrenal Center, Dr. Carling and his team perform more than 600 adrenal surgeries each year, making it the highest-volume adrenal-surgery program in the world [3]. Many patients travel from across the U.S. and abroad after being misdiagnosed or unsuccessfully managed with medication.

Safety Concerns in the Baxdrostat Trial

While baxdrostat shows potential for patients with bilateral primary aldosteronism without tumors, the trial's safety profile raised concern.

According to the NEJM correspondence, five of fifteen patients withdrew due to adverse events, including hyperkalemia (high potassium), acute kidney injury, and increased serum creatinine levels [1]. On average, kidney function declined during treatment, and in some patients, it did not return to baseline even after stopping the drug.

"Baxdrostat holds promise for select patients," said Dr. Carling, "but it also underscores why we must continue to emphasize precision in diagnosis and treatment selection. The goal is not just to manage symptoms temporarily—it's to cure the disease safely and definitively."

Why Surgery Remains the Gold Standard for Primary Aldosteronism

For patients with unilateral primary aldosteronism—meaning only one adrenal gland is affected—surgery remains the gold standard and often results in complete cure. Surgery as the first-line treatment was reaffirmed by the new July 2025 Endocrine Society Guidelines [5].

A minimally invasive adrenalectomy, performed by an experienced endocrine surgeon, typically takes less than 20 minutes, requires only small incisions, and allows most patients to return home the next day [3].

Dr. Carling has perfected advanced techniques that allow selective removal of diseased tissue while preserving healthy adrenal function when possible. This individualized approach has dramatically improved outcomes for patients with complex or bilateral disease.

"Modern adrenal surgery is extremely safe, and for many patients, it completely eliminates the need for medication," said Dr. Carling. "When performed by a high-volume adrenal surgeon, cure rates exceed 95 percent for unilateral disease."

The broader message, Carling adds, is that while multi-billion-dollar drug deals may promise incremental control, his focus remains on curing patients in a safe 20-minute operation—not keeping them dependent on lifelong medication.

The Road Ahead: Research and Individualized Care

The original SPARK investigators have since launched a Phase 3 trial (BaxPA) to further evaluate baxdrostat's long-term safety and effectiveness. But as Dr. Carling's commentary makes clear, rigorous, controlled studies that include proper disease subtyping are essential to defining the drug's true role in treating primary aldosteronism [1].

Dr. Carling's work continues to drive global awareness of primary aldosteronism and its curable nature. Through research, surgical innovation, and patient education, he and his team aim to ensure that fewer patients fall through the cracks of misdiagnosis and missed opportunities for cure.

About the Carling Adrenal Center

The Carling Adrenal Center at the Hospital for Endocrine Surgery in Tampa, Florida, is the world's leading center for adrenal surgery, performing more adrenal operations than any other hospital globally. The center treats patients with primary aldosteronism, Cushing's syndrome, pheochromocytoma, adrenal cancer, and other complex adrenal disorders.

Under the direction of Dr. Tobias Carling, former Chief of Endocrine Surgery at Yale University, the center is internationally recognized for its innovation in minimally invasive adrenal surgery and dedication to personalized, patient-centered care [2–4].

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References

1. Carling T, Scholl UI. More about the Phase 2a Study of Baxdrostat in Primary Aldosteronism. N Engl J Med. 2025 Oct 16;393(15):1550. doi: 10.1056/NEJMc2512324.
2. Primary Aldosteronism (Conn's Syndrome). Adrenal.com.
3. Conn's Syndrome Surgery and Cure Rates. Adrenal.com.
4. Hyperaldosteronism Symptoms and Diagnosis. Adrenal.com.
5. Adler GK et al. Primary Aldosteronism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2025 Aug 7;110(9):2453-2495. doi: 10.1210/clinem/dgaf284.

SOURCE Carling Adrenal Center