A Tuesday in South San Francisco, and someone is staring at a million heartbeats.
It is an unremarkable morning at 131 Oyster Point Boulevard. A data scientist is scrolling through cardiac waveforms collected from real patients - not test subjects, not idealized averages, but actual people walking around with actual hearts. A clinician three desks away is reading molecular profiles of dilated cardiomyopathy patients. Somewhere down the hall, a chemist is closing in on a compound that might, against all the dreary precedent of cardiology, do something about the underlying disease instead of merely the symptoms.
This is Kardigan. It launched in January 2025, closed a $254 million Series B nine months later, and has been moving with the unsentimental speed of people who have done this before. Which they have.
Heart disease is a 20th-century franchise still running on a 20th-century script.
Cardiology has been managing symptoms since the moon landing.
If you have heart failure today, your doctor will hand you a tidy bundle of pills - beta blockers, ACE inhibitors, diuretics - most of which were discovered before the internet. They will keep you alive longer. They will not, in any meaningful sense, fix anything. The disease will keep doing what it was always going to do.
It is not the cardiology profession's fault, exactly. Cardiovascular disease is a category, not a disease. Dilated cardiomyopathy alone has dozens of molecular subtypes. Acute severe hypertension and calcific aortic valve stenosis sit in roughly the same place - common, brutal, and almost entirely untreated at the disease-driver level. There are no approved disease-modifying therapies for any of the three indications Kardigan has picked.
This is the tension the company is built around: a field that has solved survival but not cure. A patient population the size of a small country, and a treatment manual that essentially says good luck and please come back in six months.
Five co-founders who already did this once before.
The founding team has the kind of resume that biotech recruiters keep in a separate file. Tassos Gianakakos, the CEO and chair, spent seven years running MyoKardia. Jay Edelberg is the chief medical officer. Bob McDowell is the scientific adviser. Leslie Leinwand and Beth McNally - both serious cardiovascular scientists in their own right - round out the co-founder roster.
MyoKardia is worth lingering on for a second. The company developed mavacamten, the first cardiac myosin inhibitor and arguably the most consequential cardiovascular drug in a generation. Bristol Myers Squibb bought it in 2020 for $13.1 billion. The MyoKardia team did not, as a group, take the money and retire to Sonoma. They regrouped, looked at the rest of cardiology, and apparently decided the work was not finished.
Then they did something interesting. Instead of building yet another drug-discovery boutique, they acquired Prolaio - an FDA-cleared cardiovascular data and connected-care platform - and folded it into the company in March 2025. The result is unusual: a clinical-stage biotech with a real-world data engine bolted into its chest cavity.
A short history of moving quickly
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2020MyoKardia sells to Bristol Myers Squibb for $13.1BMavacamten changes the standard of care in hypertrophic cardiomyopathy. The team scatters - briefly.
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2024Kardigan quietly foundedStealth mode. Capital, talent and pipeline get assembled in the background.
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January 2025$300M Series A and public launchPerceptive, ARCH and Sequoia Heritage anchor. Three late-stage programs revealed simultaneously.
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March 2025Acquires ProlaioCardiovascular data platform becomes a subsidiary. 'Cardiac intelligence' becomes the operating thesis.
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October 2025$254M Series BFidelity and T. Rowe Price join the cap table. Total funding pushes past half a billion dollars.
Three drugs, one platform, and a particular kind of obsession.
The clinical pipeline targets the underlying drivers of three indications: dilated cardiomyopathy (DCM), acute severe hypertension (ASH), and calcific aortic valve stenosis (CAVS). All three are common. All three are deadly. None has an approved disease-modifying treatment.
Wrapped around the pipeline is the cardiac intelligence platform - real-world clinical data, FDA-cleared software, and AI-driven analysis inherited from Prolaio. The point is not vague tech-bro 'AI for healthcare.' The point is matching the right disease driver to the right responder so that trials enrich for patients who actually have the molecular problem the drug actually addresses.
Roughly the budget of a mid-sized indie film studio. Considerably more useful, on a per-dollar basis, if the drugs work.
Money is not data, but it is a useful proxy for who is convinced.
Pre-revenue biotech is a strange thing to evaluate from the outside. The drugs are not approved. The trials are not finished. The only signals available are the team, the science, and the willingness of unusually careful investors to write unusually large checks.
On the third metric, Kardigan is doing fine. Perceptive Advisors, ARCH Venture Partners and Sequoia Heritage led the Series A. Fidelity and T. Rowe Price - both decidedly not in the business of speculative venture bets - showed up for the Series B. That second list is the more interesting one. Crossover funds tend to arrive when they can plausibly imagine a public-market exit, which means somebody at a very large mutual fund has read the data room and decided the pipeline is real.
The Prolaio acquisition adds something money cannot: an installed base of real-world cardiovascular data, FDA-cleared software, and a connected-care channel that lets the drug arm and the data arm inform each other in ways that traditional biotechs simply cannot.
To make cardiovascular disease preventable, curable, and no longer the leading cause of death.
Mission statements are usually best ignored. This one is worth reading because it is unusually specific. It does not say 'improve outcomes' or 'transform care.' It says preventable, curable, no longer the leading cause of death. Those are testable claims with binary answers. Either heart disease drops off the top of the WHO mortality list in the next few decades or it does not.
The team has put real money behind that kind of literalness. The culture, by the available accounts, is patient-driven and capital-efficient - a phrase that in biotech often means 'we do not believe in spending $2 billion to fail a phase three trial.' The hiring has been deliberate. The pipeline is narrow on purpose.
It would be unwise to predict success. Most biotechs do not work. Most ambitious cardiovascular drugs do not work. But it would be equally unwise to dismiss what this team has built, because if any group is going to make the bet pay off, the people who already shipped mavacamten are a reasonable place to start looking.
Back to the Tuesday morning, and the million heartbeats.
A few years from now, the data scientist will not be looking at waveforms in the abstract. She will be looking at outcomes - which patients with which molecular subtypes responded to which compound. The clinician will not be reading molecular profiles for their own sake. He will be matching them, in something close to real time, to enrollment criteria for a trial whose endpoint is actual disease modification.
If Kardigan is right, the cardiology of 2035 will look less like a refill schedule and more like an oncology clinic in 2025: targeted, molecular, occasionally curative. The world's leading killer would, finally, start to retreat.
And if Kardigan is wrong, at least it will be wrong in a way that produced better data, better tools, and a clearer map of where the next attempt should aim. Which is more than most biotechs leave behind.
Where to look next
- Websitekardigan.bio
- LinkedInlinkedin.com/company/kardigan-inc
- Leadershipkardigan.bio/leadership
- Pipelinekardigan.bio/development-pipeline
- Series B NewsFierce Biotech coverage
- Crunchbasecrunchbase.com/organization/kardigan
- Press KitSeries B press release