Pomegra
Soufflé Therapeutics raised a $135M Series B led by Juvia Group to move extrahepatic RNA drugs for muscular dystrophy and heart failure into human trials.
Key Takeaways
- Soufflé closed an oversubscribed $135M Series B on October 13, 2026, led by Juvia Group.
- Funds will carry three siRNA programs, in FSHD, heart failure and muscle or metabolic disease, into clinical studies.
- Valuation was not disclosed. The round follows a $200M Series A announced in October 2025.
Lead
Soufflé Therapeutics, a Boston RNA medicine developer, announced on October 13, 2026 that it closed a $135M Series B financing. Juvia Group led the round. The company will use the money to take its three lead programs into clinical studies and to extend its pipeline into other cell types and tissues. Soufflé did not disclose a valuation.
Who Else Put Money In?
New institutional investors joined Juvia: TCG Crossover Management, BB Biotech, Fidelity Management & Research Company, Balyasny Asset Management and an unnamed sovereign wealth fund. Crossover-style names in a private round usually signal that investors expect a public listing to follow.
Existing backers returned as well. They include Amgen Ventures, ARCH Venture Partners, Bessemer Venture Partners, Breyer Capital, The Invus Group, Janus Henderson, Leaps by Bayer, Polaris Partners, Safar Partners, TAS Partners, Temasek and Vida Ventures. Insider participation at this scale suggests the early investors have seen data they like.
What Is Soufflé Building?
Soufflé develops siRNA therapies that reach tissue other than the liver, which is where most approved RNA drugs act. Its REMEDY platform, short for Receptor Mediated Delivery, pairs cell-selective ligands with potent siRNA to target specific cell types.
Three programs lead the pipeline. The most advanced targets striated muscle for facioscapulohumeral muscular dystrophy (FSHD). The second silences the phospholamban (PLN) gene in cardiomyocytes to treat heart failure with reduced ejection fraction. The third addresses an undisclosed target in muscle and metabolic disorders.
How Does This Round Compare With the Series A?
The Series B is smaller than the $200M Series A the company announced in October 2025, when it emerged from stealth. Together the two rounds total $335M. A smaller second round is not a warning sign in itself, since the Series A was unusually large for a first institutional raise. The cheque size does show that investors are paying for clinical entry, not for an expanded platform pitch.
The Series A launch had pointed to a clinical start in 2026. The press release for this round describes the money as supporting the programs' move into clinical studies, without giving dates for first dosing. Investors are therefore funding the transition from preclinical work to human data, and the first readouts are the real test.
Why Does Delivery Beyond the Liver Matter?
Delivery outside the liver matters because siRNA drugs have largely stalled at the liver, where lipid and sugar-based carriers send them easily. Muscle and heart tissue are harder to reach, and a drug that gets there selectively could treat diseases that current RNA products cannot touch. FSHD has no approved disease-modifying therapy, and heart failure affects a far larger patient population.
Competition is real. Several companies are chasing muscle and cardiac delivery with antibody-oligonucleotide conjugates and peptide carriers, and early human data in this field has been uneven. Soufflé's ligand approach remains unproven in patients.
What Partners Does Soufflé Have?
Soufflé has built ties with large drugmakers, including AbbVie, Amgen, Bayer and Novo Nordisk. In January 2026 Bayer and Soufflé announced a strategic collaboration on a cell-specific, heart-targeted siRNA therapy, and Leaps by Bayer is also an investor. Amir Nashat is chief executive and Becky Stevenson is chief financial officer. Co-founders include Moderna co-founder Robert Langer, Daniel Anderson and Victor Kotelianski.
Pharma partners reduce some risk and add validation of the delivery technology. They also mean that some of the value in the heart program may be shared.
Outlook
Soufflé now holds fresh capital on top of its Series A, a pharma partner base and a lead investor in Juvia. The undisclosed valuation leaves the price of that confidence unclear. What matters over the next 12 to 18 months is whether REMEDY-delivered siRNA shows target engagement in human muscle and heart tissue. Positive early data would likely open a larger private round or a public listing, while weak delivery results would test how much patience the crossover investors have.
