The First New Way to Lower Blood Pressure in Over a Decade Just Got Approved
The FDA just approved the first new mechanism for lowering blood pressure in over a decade. Baxfendy shuts off your body's "salt thermostat" instead of just blocking it, and it could reshape treatment for millions of patients whose numbers won't budge.
Millions of Americans take three or more blood pressure pills every single day, and their numbers still won't budge. For these patients, the medicine cabinet has looked basically the same since the 1990s. That changed last week.
On May 18, the FDA approved Baxfendy (baxdrostat), a once-daily pill from AstraZeneca that attacks high blood pressure through a mechanism no approved drug has ever used before. It's the first aldosterone synthase inhibitor to reach the market, and it's designed for the patients who need help the most: people whose blood pressure stays stubbornly high despite already being on multiple medications.
Why Your Body's Salt Thermostat Matters
To understand why this drug is a big deal, you need to know about aldosterone. Think of aldosterone as your body's salt thermostat. It's a hormone that tells your kidneys to hang on to sodium and water, which raises blood pressure. In many patients with hard-to-control hypertension, that thermostat is cranked way too high.
Doctors already have a drug that targets this problem: spironolactone, a cheap generic that blocks the receptor where aldosterone does its work. It's effective, and guidelines recommend it as the go-to add-on for resistant hypertension. But spironolactone has a brutal side-effect profile. Because of its chemical structure, it also messes with sex hormone receptors. Men can develop breast tenderness and gynecomastia. Women can experience menstrual irregularities. Many patients simply stop taking it.
Baxdrostat takes a completely different approach. Instead of blocking the receptor, it shuts off the factory. It inhibits the enzyme (called CYP11B2) that produces aldosterone in the first place. Less aldosterone means less sodium retention, less fluid buildup, and lower blood pressure. And because it doesn't touch androgen or progesterone receptors, those awkward hormonal side effects shouldn't show up.
It's like the difference between putting earplugs in to block a fire alarm versus actually putting out the fire.
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The approval was built on a Phase 3 trial called BaxHTN, which enrolled adults whose blood pressure remained above 140 mmHg systolic despite taking two or more medications. At 12 weeks, patients on the 2 mg dose saw their systolic blood pressure drop 9.8 mmHg more than placebo. The 1 mg dose delivered an 8.7 mmHg reduction. Both hit statistical significance with p-values below 0.0001.
Those numbers might not sound dramatic in isolation, but context matters enormously here. These are patients who were already on multiple drugs and still couldn't get their pressure under control. Cardiologists will tell you that squeezing out an extra 10 points of systolic reduction in this population is genuinely hard.
The ambulatory blood pressure data was even more impressive. When researchers strapped 24-hour monitors on patients taking the 2 mg dose, the placebo-adjusted drop in average systolic pressure hit 16.9 mmHg over a full day. Nighttime readings, which many cardiologists consider the most predictive of cardiovascular events, fell 11.7 mmHg versus placebo for the pooled 1 mg and 2 mg doses.
The trial also included a clever withdrawal phase. After all patients spent time on baxdrostat, some were randomly switched back to placebo. Their blood pressure crept back up, while those who stayed on the drug saw an additional 3.7 mmHg drop. That's strong evidence the drug is doing real pharmacological work, not just riding the placebo wave.
The Side Effects to Watch
No free lunches in pharmacology. Because baxdrostat reduces aldosterone (which normally helps your kidneys excrete potassium), hyperkalemia is the main safety concern. In the Phase 3 trial, about 2–3% of patients on either dose had potassium levels spike above 6.0 mmol/L, and roughly 1.5% on the higher dose discontinued due to high potassium. Hyponatremia, low blood pressure, dizziness, and muscle spasms also showed up more often than placebo.
The good news: serious adverse events were rare (3.4% on the 2 mg dose versus 2.7% on placebo), and importantly, there were no cases of adrenal insufficiency. That was the fear with earlier attempts at this drug class; older compounds couldn't tell the difference between the enzyme that makes aldosterone and the one that makes cortisol. Baxdrostat appears to have solved that selectivity problem. Patients will still need regular potassium and sodium monitoring, but the overall safety profile looks manageable.
A $5 Billion Ambition With Some Asterisks
AstraZeneca paid up to $1.8 billion to acquire CinCor Pharma, the company that originally developed baxdrostat, back in early 2023. That's a big check, and AstraZeneca has publicly floated peak sales potential of $5 billion for the drug across multiple indications.
That $5 billion figure, though, requires a lot to go right. The current approval covers add-on use in uncontrolled hypertension only. Reaching blockbuster territory means winning in broader populations: monotherapy, chronic kidney disease, and potentially heart failure prevention. AstraZeneca is also testing a combination pill with its SGLT2 inhibitor Farxiga, which could create a powerful cardiorenal franchise if the data cooperate.
Analysts are cautiously optimistic but realistic. One independent valuation model pegged US revenue for the resistant hypertension indication alone at about $89 million by 2035, a far cry from $5 billion. The gap between those numbers represents everything AstraZeneca still needs to prove: cardiovascular outcomes data, superiority over cheap generics in head-to-head comparisons, and enough evidence to convince skeptical payers to cover a branded specialty drug when a $4 bottle of spironolactone is sitting right there.
The Race Is Already Getting Crowded
Baxfendy has a first-mover advantage, but it's a slim one. Mineralys Therapeutics has submitted its own NDA for lorundrostat, another aldosterone synthase inhibitor targeting the same patient population. In cross-trial comparisons (with all the usual caveats about indirect matchups), baxdrostat's 14 mmHg ambulatory reduction looks stronger than lorundrostat's 7.9 mmHg. Baxdrostat also has a longer half-life (26 to 30 hours versus lorundrostat's 10 to 12), which could translate to smoother 24-hour blood pressure control.
But payers could easily turn this into a commodity fight, preferring whichever drug offers better contracting terms. Key opinion leaders have already told analysts that being first won't guarantee long-term dominance in this class.
The Bottom Line
For the millions of patients who've run out of good options for controlling their blood pressure, Baxfendy represents something rare in hypertension: a genuinely new idea. It won't replace the cheap, proven generics that form the backbone of treatment. But for the patients those generics have failed, having a new tool that attacks the problem from a different angle is meaningful.
Whether it becomes a $5 billion drug or a niche rescue therapy depends on data that hasn't been generated yet. The approval is the beginning of the story, not the end.
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