Baxdrostat: New 'game changer' daily pill could reverse high blood pressure for millions

A new daily pill has been hailed as a “game changer” to tackle high blood pressure for millions of Brits.

A global trial showed the new class of drug slashed blood pressure in people resistant to all other treatments in what has been hailed as “a triumph of scientific discovery”. In the UK about 14 million people have high blood pressure and for half it is “uncontrolled” as existing drugs don’t work against it. They are at much higher risk of heart attacks and strokes.

Breakthrough drug baxdrostat, developed by University College London in partnership with AstraZeneca, was unveiled at the world’s biggest heart conference in Madrid. It could be rolled out on the NHS as early as next year.

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Speaking to reporters at the European Society for Cardiology’s annual conference, trial lead Prof Bryan Williams, of UCL, said: “I've never seen blood pressure reductions of this magnitude with a drug. High blood pressure is hard to control. Despite many treatments and a lot of discussion it's still the single most important preventable cause of premature death globally. This drug development is really a triumph of scientific discovery.”

Baxdrostat was trialled in 796 patients at 214 clinics worldwide and caused blood pressure to drop by 9-10mmHg more than those taking a placebo in three months.

About four in 10 patients taking the new class of drug reached a healthy blood pressure level compared with fewer than two in 10 taking a placebo.

Prof Williams said: “This is a potential game-changer for patients because, despite the best efforts of clinicians and the drugs they have available, at least 50% of patients even in the most developed healthcare systems don't have their blood pressure controlled.

“We saw almost a 10mmHg reduction in blood pressure, from a baseline of 149. That is a big drop in blood pressure. That would reduce [the chance of a] stroke by about 40% and heart disease by about 25%.”

How does it work?

Baxdrostat works by blocking the production of a hormone called aldosterone, which helps the kidneys regulate salt and water.

Some people produce too much aldosterone, which increases their blood pressure. With baxdrostat blocking the production of this hormone, scientists were able to directly address the “core problem” behind high blood pressure.

While previous drugs have blocked aldosterone receptors, these had undesirable side effects and did not act on the hormone directly.

Prof Williams described the process as a “formidable challenge” to affect this singular hormone requiring the creation of a “very, very designer” drug. He added: “This should provide a treatment that's more effective because it targets the core mechanism, helping to reduce their future risk of heart disease, stroke, kidney disease and potentially dementia.”

Professor Paul Leeson, top cardiologist at Oxford University, who was not involved in the trial, said: “Patients with uncontrolled blood pressure often struggle to find the right tablets to reduce their risk of heart attacks or strokes.

“Increased levels in the blood of a substance called aldosterone are known to be a cause of difficult to control blood pressure. For many years, we have had medications that are able to block aldosterone working but they do not actually lower levels of aldosterone, so patients may still experience adverse effects of the substance.

“Baxdrostat is one version of a new range of medications that work differently, and directly reduce the levels of aldosterone. The medication also worked even when added on top of other tablets. This new type of medicine may therefore be a potentially valuable additional treatment to tackle high blood pressure.”

The phase three BaxHTN trial showed the drug also reduced blood pressure by as much as 16.9mmHg, when readings were taken over a 24-hour period with a continuous monitor.

Regarding this result, Williams said: “It's just amazing. I've never seen anything like it. So we may be even underestimating the effect of the drug in the clinic, and actually over the whole 24 hour period the effect was huge.” He added that this result wasn’t the primary outcome of the study, but a larger scale study is currently underway to prove this observation.

The findings are published in the New England Journal of Medicine and AstraZeneca is now in the process of applying for regulatory approval to sell the drug in Britain. If it gets the green light, the NHS could start offering it next year.

Sharon Barr, Executive Vice President at AstraZeneca’s BioPharmaceuticals research and development branch, said: “These findings provide compelling evidence of baxdrostat’s potential to address a critical unmet need by targeting aldosterone dysregulation, bringing a novel mechanism to a field that has seen little innovation in over two decades.

“We look forward to advancing our regulatory filings for baxdrostat with health authorities in the months ahead.”

What is high blood pressure and what is a healthy level?

Blood pressure is measured with two numbers. The first number is systolic pressure - pressure when your heart beats - and the second number is diastolic pressure - when your heart rests between beats.

Among people aged under 80 the NHS considers high blood pressure to be 140/90mmHg or higher when measured in a clinic, or 135/85 mmHg or higher when measured at home, when you are likely to be more relaxed.

For over-80s you are usually considered to have high blood pressure if your reading is either 150/90 or higher when checked by a healthcare professional, or 145/85 or higher when checked at home.

The reduction in blood pressure observed in the BaxHTN trial refers to the first measure of systolic pressure.