Soufflé Therapeutics Raises $135M Series B for RNA Trials

A molecular address can determine which patients a medicine is designed to reach. At Soufflé Therapeutics, that address is a receptor on a particular cell, making the route into muscle or heart tissue part of the therapeutic design itself.

The Boston-area biotechnology company announced an oversubscribed $135M Series B on October 13, 2026, led by Juvia Group. The proceeds will support 3 lead clinical programs and further preclinical development, putting a larger institutional syndicate behind a company trying to extend RNA delivery beyond the liver.

Soufflé's current website says clinical-trial enrollment has begun in 2026. For investors and pharmaceutical partners, the financing supports a portfolio with several places to learn: skeletal muscle, heart muscle and additional tissues, each carrying its own development questions.

A financing syndicate around a clinical portfolio

The Series B brings TCG Crossover Management, BB Biotech, Fidelity Management & Research Company, Balyasny Asset Management and an unnamed sovereign wealth fund into Soufflé's investor group. Returning participants 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. Their inclusion establishes participation in the financing; the announcement supplies neither individual check sizes nor a valuation.

Juvia Group was founded in 2026, but its connection to Soufflé has an earlier history. In a testimonial on Juvia's website, CEO Amir Nashat describes Stefan Vitorovic as a thought partner on the pipeline, people and fundraising, and says Sujal Shah joined Soufflé's board 2 years ago. That account gives the lead investor a relationship with the operating business that predates the name on this round.

There is a useful distinction between financing a platform and allocating its next experiments. Soufflé's product engine creates the possibility of work across multiple tissues. The capital still has to be used in specific programs, with teams deciding how to advance the first indications while maintaining the broader research agenda. A larger syndicate expands the group backing those decisions without disclosing how the budget will be split.

Why the destination belongs inside the drug design

Soufflé calls its product engine REMEDY, short for Receptor Mediated Delivery. The company describes identifying receptors that take material into particular cells, then developing binders, including antibodies or other ligands, to carry oligonucleotide therapies along that route. Its focus on delivery outside the liver places tissue selection near the beginning of the design process.

That approach asks a drug developer to consider the payload and its passage into the relevant cell together. A molecular target gives a program its biological purpose; a delivery strategy determines how the intended tissue encounters the therapy. The resulting development work has to connect those choices in a way that can be evaluated in people. Laboratory delivery claims alone leave the clinical question open.

The company is led by founder and CEO Amir Nashat, Founding CTO Vadim Dudkin, and CBO and Founding President Susan Langer. Its scientific founders include Victor Kotelianski, Daniel Anderson, Robert Langer, Marino Zerial and Brad Pentelute. Leaps by Bayer's portfolio profile independently identifies several of those founders and describes the receptor, ligand and siRNA engineering approach. Together, the leadership and founding record explain the concentration of expertise behind the development plan, while clinical studies will supply evidence about the medicines emerging from it.

Three programs give the engine different questions

Soufflé's most advanced program addresses facioscapulohumeral muscular dystrophy, or FSHD, through delivery to striated muscle. The second targets the phospholamban gene, PLN, in cardiomyocytes for heart failure with reduced ejection fraction. A third pursues an undisclosed target for muscle and metabolic disorders. The funding announcement keeps that third molecular target private, and the public record should preserve the same boundary.

For the FSHD program, Soufflé enters an active field of development. The FSHD Society's drug-development pipeline tracks investigational approaches across several mechanisms and stages. That context matters because a delivery platform is arriving in a disease community already engaged with clinical research. Funding supports another development effort within that community; the announcement gives no comparative clinical outcome against other programs.

The portfolio also makes the word “replicable” more demanding than it sounds in a presentation. Applying a delivery approach to another tissue introduces another set of biological and clinical questions. Evidence from an early program can inform company decisions without automatically settling the prospects of the rest. Operators following Soufflé can therefore read progress both by individual program and by what the company learns about its broader delivery engine.

Partnership economics remain a separate account

In January, Bayer and Soufflé announced a collaboration and global license for a heart-targeted siRNA therapy addressing a form of dilated cardiomyopathy. The partners did not disclose financial terms. Bayer's relationship provides a distinct development connection alongside Leaps by Bayer's participation in the venture syndicate, with each arrangement serving a different function.

For historical capital context, WSJ Pro reported in October 2025 that Soufflé had raised just under $200M across seed and Series A financing, with Bessemer Venture Partners leading the Series A. The company had not publicly broken out those rounds. That historical figure and the new $135M financing offer context, but they do not justify an exact lifetime total or converting potential partnership economics into cash already received.

The next investment decisions at Soufflé will sit close to the clinical portfolio: where to commit people, how to balance the lead studies with work in additional tissues, and how partner programs fit beside company priorities. Nashat and Dudkin have an enlarged group of backers around that work. As enrollment proceeds, participants and investigators will add evidence that can change the next allocation, one program at a time.