Breaking
Kardigan raises $254M Series B • Led by Fidelity & T. Rowe Price Tonlamarsen Phase 2 data at ACC.26 • 67% mean reduction in angiotensinogen • Published in JACC MyoKardia sold to Bristol Myers Squibb for $13.1 billion in 2020 Kardigan acquires Prolaio • Integrating cardiac AI data with drug pipeline Total funding: $554 million • Three late-stage cardiovascular programs Danicamtiv • Tonlamarsen • Ataciguat • Kardigan's precision cardiology pipeline Kardigan raises $254M Series B • Led by Fidelity & T. Rowe Price Tonlamarsen Phase 2 data at ACC.26 • 67% mean reduction in angiotensinogen • Published in JACC MyoKardia sold to Bristol Myers Squibb for $13.1 billion in 2020 Kardigan acquires Prolaio • Integrating cardiac AI data with drug pipeline Total funding: $554 million • Three late-stage cardiovascular programs Danicamtiv • Tonlamarsen • Ataciguat • Kardigan's precision cardiology pipeline
Tassos Gianakakos, Co-founder and CEO of Kardigan
Founder & CEO • Kardigan

Tassos
Gianakakos

The man who sold a heart company for $13 billion — then walked out the door and built a bigger one.

Biotech Founder Precision Cardiology MIT '94 HBS MBA Serial Builder
$13.1B
MyoKardia Exit
$554M
Kardigan Raised
3
Late-Stage Programs
Profile Co-founder, CEO & Chair at Kardigan • South San Francisco, CA • Menlo Park, CA • tassos@kardigan.bio
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The Heart Has Its Own Intelligence

Tassos Gianakakos doesn't announce his next move. He just makes it. When Bristol Myers Squibb acquired MyoKardia - the cardiovascular precision medicine company he co-founded and led as CEO - for $13.1 billion in October 2020, most founders would have taken a long exhale. He was "shown the door," as he put it, with characteristic lightness, and immediately started thinking about what comes next.

What came next was Kardigan. Co-founded in 2023 with Jay Edelberg and Bob McDowell - the same core leadership team from MyoKardia - Kardigan launched publicly in January 2025 with $300 million in Series A funding and a pipeline of three late-stage cardiovascular drugs. By October 2025, the company had added another $254 million in a Series B backed by Fidelity Management & Research and T. Rowe Price. Total raised: $554 million. Time elapsed since launch: nine months.

The pattern is not accidental. Gianakakos has been building, buying, and exiting biotech companies since the late 1990s. He helped spin Codexis out of Maxygen in 2001, led the business through to its IPO, then moved to MAP Pharmaceuticals as Chief Business Officer before Allergan acquired it in 2013. MyoKardia, the company he is best known for, was where precision medicine finally met the heart - and where he spent eight years turning a thesis about cardiac biology into one of the largest biotech acquisitions ever.

"In many ways, CVD is where oncology was 20 years ago - there were no precision medicines and non-specific treatments such as chemotherapy and radiation were used regardless of cancer type."

- Tassos Gianakakos, Co-founder & CEO, Kardigan

That analogy shapes everything he does. The cardiovascular space has long been treated as a monolith - statins for everyone, beta-blockers for everyone - while cancer treatment has fragmented beautifully into molecular subtypes and targeted therapies. Gianakakos is making the same bet in cardiology: that the heart, too, has its own intelligence, and that understanding it genetically and mechanistically will yield drugs that work dramatically better for specific patient populations.

$13.1B
MyoKardia acquisition by BMS (2020)
$554M
Total funding raised for Kardigan
67%
Mean reduction in AGT with tonlamarsen (Phase 2)

Kardigan: Cardiac Intelligence as a Drug Factory

Kardigan is not your standard biotech. Its founding premise - "cardiac intelligence" - is a synthesis of real-world patient data, AI analysis, and deep cardiovascular biology applied to drug discovery. When Kardigan acquired Prolaio in March 2025 (Gianakakos's own prior company, which had been building a cardiac clinical intelligence platform), the move merged a live data layer with an active drug pipeline. Two separate efforts, one integrated machine.

The company is headquartered in Menlo Park with operations in South San Francisco and Princeton, and by October 2025 had grown to approximately 120 people. It operates three late-stage programs, each targeting a different corner of cardiovascular disease with a drug matched to the specific biological mechanism driving it.

Why This Matters

Gianakakos's bet: biopharma companies need to "fundamentally embrace real-world data and AI-based tools in a way that is fully integrated across R&D." Kardigan was built as proof of that thesis from day one - not a retrofit of an old model, but a new architecture for drug discovery.

The Pipeline

Danicamtiv
Cardiac Myosin Activator
Genetic Dilated Cardiomyopathy (DCM) - licensed from Bristol Myers Squibb; originally discovered at MyoKardia. Targets the same cardiac myosin biology that made MyoKardia famous.
Phase 2/3
Tonlamarsen
AGT-Targeted Therapy
Acute Severe Hypertension (ASH) - Phase 2 (KARDINAL trial) showed statistically significant 67% mean reduction in angiotensinogen. Presented at ACC.26, published in JACC.
Phase 2b
Ataciguat
sGC Activator
Calcific Aortic Valve Stenosis (CAVS) - potential first-in-class oral treatment. An alternative to watchful waiting for patients with no current drug options.
Phase 2

How He Built MyoKardia - and Sold It for $13.1 Billion

MyoKardia was founded on a single, counterintuitive observation: that many forms of heart disease are fundamentally genetic, and that targeting the underlying molecular mechanism - rather than managing symptoms - could change outcomes for patients who had no other options.

The centerpiece drug was mavacamten, a cardiac myosin inhibitor designed specifically for obstructive hypertrophic cardiomyopathy (HCM) - a genetic condition where the heart muscle grows abnormally thick, obstructing blood flow. Traditional treatments managed the downstream symptoms. Mavacamten went upstream, quieting the overactive myosin that causes the thickening in the first place.

Bristol Myers Squibb's acquisition of MyoKardia in October 2020 valued the company at $13.1 billion in cash. The deal - one of the largest in biotech that year - required negotiation. BMS's initial bid reportedly came in lower; the final price of $225 per share reflected the scientific value the company had built over eight years. Mavacamten was subsequently FDA-approved as Camzyos in 2022 and is now available to HCM patients in the US.

After the acquisition closed, Gianakakos was out. "I started thinking about this pretty much the day after BMS bought MyoKardia," he said, "because I was... shown the door." The ellipsis is part of the story. There was no long farewell tour.

"The heart is a fount of information."

- Tassos Gianakakos

Thirty Years of Building Things That Work

1990-1994
Earns two bachelor's degrees from MIT simultaneously - Chemical Engineering and Economics. Class of '94.
1994-1995
Process Engineer at Merck & Co., vaccine division. First encounter with the practical machinery of drug manufacturing.
1994-1995
M.Sc. in Biotechnology from Northwestern University. Bridges engineering background with biological science.
1997-1999
MBA from Harvard Business School. The strategic toolkit that would define how he'd build companies.
1995-2001
Director of Business Development at Maxygen. Leads vaccine and bio-industrial platforms through the company's IPO financing.
2001
Co-founds Codexis as a Maxygen spin-off. Serves as President and SVP Business Development. Codexis goes public as a leading biocatalysis firm.
~2010-2013
SVP and Chief Business Officer at MAP Pharmaceuticals. Company is acquired by Allergan in March 2013 for approximately $958M.
2012-2020
Co-founds and serves as CEO of MyoKardia. Leads development of mavacamten. Company acquired by BMS for $13.1 billion in October 2020.
2021-2025
Co-founds Prolaio - a cardiac clinical intelligence platform focused on real-world cardiovascular data and AI.
2023
Co-founds Kardigan with Jay Edelberg (CMO) and Bob McDowell (CSO) - the MyoKardia core team, reassembled.
January 2025
Kardigan launches publicly with $300M Series A. One of the largest biotech Series A rounds in history.
March 2025
Kardigan acquires Prolaio, merging the cardiac data intelligence platform with the drug pipeline.
October 2025
Kardigan raises $254M Series B led by Fidelity and T. Rowe Price. Total raised: $554M.
March 2026
Positive Phase 2 data for tonlamarsen presented at ACC.26 as a late-breaker. Published simultaneously in the Journal of the American College of Cardiology.

One Size Fits Nobody

The philosophy at the core of everything Gianakakos has built: most patients with cardiovascular disease are being treated with drugs designed for someone else. Not their genetic subtype, not their specific disease mechanism. Just a drug that works on average, for a population that is defined statistically rather than biologically.

"Our approach is transformative," he has said. "Approaches today are one size fits all. For many diseases we're targeting, there are no approved therapies in the U.S., and all patients are treated with drugs approved for other conditions."

Kardigan's "cardiac intelligence" platform - built in part through the Prolaio acquisition - is the infrastructure that makes precision matching possible. High-density real-world patient data analyzed with AI tools allows the company to identify which patients carry which disease drivers, match them to the mechanisms its drugs target, and design clinical trials around patient subpopulations where the treatment effect is most likely to be meaningful. It's the oncology playbook. It's just being applied to the heart, twenty years later.

"Our approach is transformative. Approaches today are one size fits all. For many diseases we're targeting, there are no approved therapies in the U.S., and all patients are treated with drugs approved for other conditions."

- Tassos Gianakakos

Greek Roots, MIT Rigor, Mediterranean Table

Tassos Gianakakos is the son of Greek immigrants - a detail that surfaces quietly in both his name and his lifestyle. He is a committed advocate of the Mediterranean diet, citing olive oil, Greek salad, antioxidant-rich foods, and the occasional glass of red wine as his personal approach to the very disease he is working to cure. He avoids processed food and stays physically active.

The name "Kardigan" is itself a signal: a portmanteau of "kardia" - the Greek word for heart - and a nod to the precision and sophistication the company aspires to. It is both technically descriptive and personally resonant. That kind of detail is not accidental in a founder who holds degrees in chemical engineering, economics, and biotechnology, and who trained at three of the most demanding institutions in the world.

He serves as a Director at LianBio and as a Strategic Advisor at Evelo Biosciences, alongside John Maraganore. His board at Kardigan includes Paul Berns (ARCH Venture Partners), Doug Giordano (Perceptive Advisors), David Meeker, and Kim Popovits - a roster that reflects both the company's scientific ambition and its institutional credibility.

Five Things About Tassos Gianakakos

01
He holds two simultaneous MIT bachelor's degrees - Chemical Engineering and Economics - plus a Northwestern MS and a Harvard MBA. Four degrees. Fifteen-odd years of world-class education compressed into less time than it sounds.
02
The drug he helped create at MyoKardia - mavacamten, now sold as Camzyos - is FDA-approved and treating HCM patients today. He left to build Kardigan before the approval came through. He licensed danicamtiv, another MyoKardia drug, back from BMS to continue its development at Kardigan.
03
He co-founded Prolaio in 2021 - a cardiac data intelligence company - and then acquired it into Kardigan in 2025. He essentially built the data platform his drug company needed, then merged them.
04
His $300M Series A for Kardigan's launch in January 2025 was one of the largest biotech Series A rounds in history. He followed it with a $254M Series B nine months later. In a year when biotech funding was cautious, Kardigan ran a different playbook.
05
"The heart is a fount of information." That sentence - short, declarative, quietly radical - is the thesis behind everything he's built. The heart is not just a pump. It's a data source. And Gianakakos is reading it.