Instead of using viral vectors, SonoThera’s genetic medicines are delivered through an ultrasound-mediated technology that could help sidestep key safety issues with conventional delivery methods.
Following the completion of its oversubscribed series B, San Francisco’s SonoThera will have $125 more in capital that it can use to advance its pipeline of genetic medicines that don’t use virus vectors for delivery.
The money will go toward SonoThera’s lead programs in Duchenne muscular dystrophy (DMD) and autosomal dominant polycystic kidney disease (ADPKD), which the biotech plans to take into clinical development, according to a Wednesday news release. The series B proceeds will also allow SonoThera to broaden its pipeline across other organ systems.
“Many diseases remain beyond the reach of today’s genetic medicines,” the biotech’s CEO Kenneth Greenberg said in a prepared statement. SonoThera’s goal is “to take a fundamentally different approach” to genetic medicines, with a platform that enables “more precise, durable, safer, and repeatable therapies for patients,” he added.
Traditionally, gene therapies are packaged into viruses that have been engineered to be inert and non-infectious. The objective here is to be able to take these genetic payloads to their target cells and safely integrate them into the host’s DNA, in turn establishing stable expression of the payload gene in the patient.
Adeno-associated viruses (AAVs) are the most common vector of choice and have been established as largely safe when used at low doses. The FDA has approved certain AAV-based gene therapies, such as Sarepta Therapeutics’ DMD treatment Elevidys.
Notably, however, these products carry warnings for safety concerns, particularly those that affect the liver. That’s because AAVs are still immunogenic and accumulate in the liver, where they can trigger a potentially dangerous immune reaction.
This particular safety hitch came to a head in March last year, when a patient on Elevidys died due to acute liver failure. Another Elevidys-linked death followed months later, followed by the death of a patient in a clinical trial for an investigational gene therapy from Sarepta for limb-girdle muscular dystrophy that uses the same vector platform as Elevidys. The FDA ultimately hit the drug with a boxed warning and narrowed its use to ambulatory patients.
SonoThera wants to do away with AAVs entirely and instead use a proprietary ultrasound-mediated approach, avoiding off-target effects and liver issues, as well as opening up the delivery of DNA or RNA constructs “of unlimited size,” according to the biotech’s website.
Many big names have thrown their support behind this approach, with Wednesday’s series B raise involving investors such as Leaps by Bayer, Otsuka, RA Capital, Vida Ventures, ARCH Venture Partners, Johnson & Johnson Innovation and Vertex Ventures.
Correction (June 11): This story has been edited to remove a mention of Vertex Pharmaceuticals and CRISPR Therapeutics’ Casgevy, which is not an AAV-based therapy but was listed as such. BioSpace regrets the error.
