About SonoThera
SonoThera develops gene therapies for serious genetic diseases without using viruses. Doctors would infuse plain DNA or RNA together with imaging microbubbles, then aim a standard ultrasound machine at the target organ. The sound waves help the genetic material enter that organ's cells. Its lead programs target Duchenne muscular dystrophy and autosomal dominant polycystic kidney disease (ADPKD).
Kenneth Greenberg, Steve Feinstein and Michael Davidson founded the company, which launched with a $60.75 million Series A in December 2022. Greenberg is CEO, Feinstein is chief scientific officer and Davidson is executive chairman. SonoThera is based in South San Francisco. It holds microbubble rights from GE HealthCare and Lantheus and signed a research deal with Janssen in 2023. In June 2026 it closed a $125 million Series B led by Vida Ventures, and it plans its first clinical trial, in Duchenne, for 2027.
Funding Rounds (SEC Form D)
| First sale | Filed with SEC | Amount sold | Investors | Avg. check | Terms | Filing |
|---|---|---|---|---|---|---|
| Jun 8, 2026 | Jun 30, 2026 | $125,450,218fully sold | 22 | $5.7M | EquityRule 506(c) | Form D ↗ |
| Apr 29, 2022 | Dec 29, 2022 | $30,375,000of $60.7M target | 12 | $2.5M | EquityRule 506(b) | Form D ↗ |
| Total, two offerings | $155,825,218 | |||||
First sale is the date the first investor in the offering committed to invest. Companies must file Form D within 15 days of that date, so filing dates run later.
Rounds announced by SonoThera
What the company said publicly about its funding. Announced amounts can differ from Form D figures: an announcement can combine several closings, and some money is raised without a Form D.
| Announced | Round | Amount | Investors | Source |
|---|---|---|---|---|
| Jun 10, 2026 | Series B | $125M | Vida Ventures (lead), ARK Invest, CureDuchenne Ventures, Leaps by Bayer, Otsuka Pharmaceutical, SymBiosis, UCB Ventures SA, Vivo Capital, ARCH Venture Partners, Alexandria Venture Investments, Duquesne Family Office, Illumina Ventures, Johnson & Johnson Innovation – JJDC, Medical Excellence Capital, RA Capital, Vertex Ventures HC | sonothera.com ↗ Press release ↗ |
| Dec 5, 2022 | Series A | $60.75M | ARCH Venture Partners (lead), Illumina Ventures, Johnson & Johnson Innovation – JJDC, Vertex Ventures HC, Medical Excellence Capital, Eli Lilly & Company, Alexandria Venture Investments, Lifespan Investments, Formic Ventures, Foothill Ventures, Wilson Sonsini | sonothera.com ↗ |
Why Investors Backed SonoThera
Investors backed SonoThera for a new way to deliver gene therapies, without the viral carriers they usually rely on. Viral carriers cannot hold very large genes, and doctors rarely give them twice. SonoThera instead uses standard ultrasound machines and imaging microbubbles to push bare DNA into chosen organs. Vida Ventures, which led a $125 million round in June 2026, said this could reach diseases other genetic medicines cannot.
The problem it targets
Gene therapies most often ride inside AAV, an engineered virus. The full-length dystrophin gene that Duchenne muscular dystrophy patients need is too large to fit inside it. The immune system also reacts to the virus, so doctors rarely give a second dose. CEO Kenneth Greenberg told Inside Precision Medicine this matters in Duchenne, because the patients are young, growing boys. SonoThera chose diseases where these limits bite hardest. Greenberg puts its Duchenne payload at about 13 kb and its ADPKD payload at about 22 kb, both too big for AAV.
What the product does
Patients would get an IV infusion of bare DNA along with microbubbles, the tiny gas-filled spheres doctors use in ultrasound imaging. A standard ultrasound system then aims sound waves at the target organ. SonoThera's RIPPLE wave patterns open brief gaps in blood vessels and cell membranes, so the DNA gets into cells. A second platform, PORE, designs the DNA and RNA payloads. The outpatient procedure takes about an hour or less. SonoThera's case is that because nothing wraps the DNA, it avoids the immune reactions that viruses trigger, so doctors could dose patients again.
Progress so far
So far, all of SonoThera's data come from animal studies. In monkeys, SonoThera found full-length human dystrophin in skeletal muscle at up to 290% of normal levels. In rodent models of Duchenne, muscle strength returned to normal within six weeks. Greenberg told Inside Precision Medicine that gene expression from a single treatment has lasted a year so far. GE HealthCare granted it exclusive global rights to two microbubble products in February 2023. Janssen began a research collaboration with it that May.
Who backs it
ARCH Venture Partners led the $60.75 million Series A in December 2022. Illumina Ventures, Johnson & Johnson Innovation and Eli Lilly also invested. Vida Ventures led the $125 million Series B in June 2026. New backers included Leaps by Bayer, Otsuka, UCB Ventures and CureDuchenne Ventures. Vida's Rajul Jain, a former Kite Pharma chief medical officer, then joined the board with Leaps' Rakhshita Dhar. The board also includes ARCH's Steven Gillis, a founder of Immunex, and Brian Halak of Medical Excellence Capital. Jain said Vida was “deeply impressed by SonoThera's scientific rigor, pace of execution, and vision.”
How the market is moving
In October 2025, Novartis agreed to buy Avidity Biosciences for about $12 billion, Reuters reported. Avidity makes RNA drugs aimed at muscle diseases, and Novartis closed the deal in February 2026. Meanwhile, Sarepta's Elevidys, an approved viral gene therapy for Duchenne, has hit safety trouble. The FDA added a boxed warning and limited it to patients who can walk, BioSpace reported in June 2026. Those steps followed patient deaths from liver injury.
We wrote this summary from public statements by SonoThera and its investors. It is not investment advice.
SonoThera in the News
- Endpoints 11: SonoThera is making waves in a bold new approach to non-viral gene therapy
- Can ultrasound unlock the power of gene therapy? A startup makes big claims
- SonoThera Targets 2027 for First Clinical Trial of Duchenne Gene Therapy
- Have Microbubbles Burst Through the Barriers of Genetic Medicine Delivery?
- SonoThera bags $125M series B to advance safer gene therapies
- SonoThera raises $125M for non-viral gene therapy approach
- Big Pharma-backed SonoThera sounds off with $125M series B for bubble-based genetic delivery
- With $125 million, 'microbubble' startup looks to launch gene therapy trial next year
Leadership Team
Executive officers and directors listed on SonoThera's Form D filed Jun 30, 2026.
Earlier filings also listed Tom Willis (director, last listed Dec 2022), Lori Hu (director, last listed Dec 2022) and Asish Xavier (director, last listed Dec 2022).
Sources
- SECSonoThera, Inc. filing history
- Companysonothera.com, about, history and team page
- Companysonothera.com, science and pipeline page
- Companysonothera.com, Series B launch release with preclinical data (2026-01-08)
- Companysonothera.com, GE HealthCare microbubble license release (2023-02-27, PDF)
- Companysonothera.com, Janssen research collaboration release (2023-05-15)
- Companysonothera.com, chief medical officer appointment (2026-09-14)
- PressLantheus, microbubble rights for SonoThera (2022-12-12)
- InvestorARCH Venture Partners, Steve Gillis bio
- InvestorVida Ventures, team page (Rajul Jain)
- InvestorMedical Excellence Capital, team page (Brian Halak)
- PressReuters, Novartis to acquire Avidity Biosciences (2025-10-26)
- PressNovartis, Avidity acquisition completed (2026-02-27)