Betting a company on the virus the industry overlooked
Joel Schneider runs a biotech that starts from an uncomfortable question. Nearly every gene therapy on the market or in the clinic rides on the same class of delivery vehicle, the adeno-associated virus. It is small. It tends to end up in the liver. And many people already carry antibodies that neutralize it. At Carbon Biosciences, the company Schneider founded in 2022, the working premise is that the standard vector was never the best one.
Carbon is based in Waltham, Massachusetts, and it builds its vectors from parvoviruses, a different viral family than the AAVs that dominate the field. The pitch is concrete: carry more genetic cargo, aim at specific tissues such as the lung and the heart, and avoid the pre-existing immunity that limits how, and how often, current gene therapies can be given. Schneider frames it as a delivery problem the industry has not finished solving.
Our vision is to enable a new generation of genetic medicines with differentiated vectors that have the potential to address the immunological, targeting and payload limitations inherent in current viral and non-viral delivery technologies.
The company came out of stealth in June 2022 with a $38 million Series A led by Agent Capital. The syndicate read like a statement of intent: the Longwood Fund, Astellas Venture Management, Solasta Ventures, the University of Tokyo Innovation Platform, Camford Capital, and the Cystic Fibrosis Foundation, which is both a scientific partner and an investor. That last name matters, because Carbon's lead program points straight at cystic fibrosis.
The scientist behind the operator
Schneider did not arrive at viral engineering by the obvious route. He holds a Ph.D. from Rutgers University and an undergraduate degree from Brandeis University, and he trained as a stem cell biologist. His postdoctoral fellowship at Harvard, in the Department of Stem Cell and Regenerative Biology, focused on small molecules that enhance skeletal muscle regeneration. He is the author of numerous peer-reviewed articles tied to Duchenne muscular dystrophy and stem cell biology. Muscle, not viruses, was where he started.
The pivot came through company building. Schneider was the first employee at Solid Biosciences, the Duchenne-focused gene therapy company, and rose to chief operating officer. Being employee number one is a rare vantage point. It meant he watched a gene therapy company assemble itself from a single day forward, learning where the science meets the money, the manufacturing, and the operational grind. That experience is the through line to Carbon: a founder who knows both the bench and the building.
Why a different vector
More than a kilobase of extra room. In gene therapy, cargo space decides which diseases you can even attempt.
The cystic fibrosis bet
Carbon's lead candidate, CGT-001, is built on the CBN-1000 vector, a non-AAV parvovirus designed to deliver genes that exceed the capacity of traditional AAV. The target is the lung. In preclinical work the vector showed transgene expression and tolerability in the lungs and airways of nonhuman primates when delivered by nebulization, and Carbon has reported functional correction of the CFTR gene in bronchial epithelial cells from cystic fibrosis patients. The company has also described a cardiac vector, CBN-1100, that expresses in heart cells while avoiding the liver.
As the first jointly funded program launched under a collaborative agreement between the Cystic Fibrosis Foundation and Longwood Fund, we are motivated by the potential impact our research may have in significantly improving care for cystic fibrosis patients.
Cystic fibrosis is a pointed choice. The disease has better therapies than it did a decade ago, but no cure, and the lung has long been a hard place for gene therapy to reach and hold. A vector that can be nebulized, target airway tissue, and potentially be redosed is exactly the kind of tool the field has wanted and struggled to build.
The partnership at the core
Schneider did not build the science alone. Carbon was co-founded with Robert M. Kotin, a professor of microbiology and physiological systems at the University of Massachusetts Chan Medical School and a recognized pioneer in gene therapy. The split is a familiar and effective one: the academic founder who knows the virology, and the operator who knows how to turn it into a company. Kotin sits on Carbon's board alongside a slate that includes board chair Chen Schor.
Through 2024 the company kept adding weight to the effort. Carbon presented four times at the American Society of Gene and Cell Therapy's 27th Annual Meeting, a signal that the platform was generating data worth showing, and it expanded both its board of directors and its scientific advisory board with clinical and translational-medicine veterans. For a preclinical company, the work is measured in candidates nominated and milestones cleared rather than product launches.
What he is really building
Strip away the vector names and the science, and Schneider's ambition is a platform bet. One cystic fibrosis program is the proof point. The larger goal is a family of vectors that fix three limits at once - targeting, payload, and immunity - and unlock diseases that today's delivery tools cannot reach. As he put it, Carbon's platform has the potential to expand the role of gene therapy in treating some of the world's most devastating and difficult to treat diseases. It is a big claim from a small company, made by someone who has already helped build one gene therapy startup from its first day and decided to do it again, this time around a virus almost no one else was using.