HexemBio Has Raised $15.5 Million in Total for a Therapy That Temporarily Returns Aging Blood-Forming Stem Cells to a Lab-Made Replica of Their Embryonic Birthplace, Targeting a First-in-Human Trial in 2027
HexemBio Has Raised $15.5 Million in Total for a Therapy That Temporarily Returns Aging Blood-Forming Stem Cells to a Lab-Made Replica of Their Embryonic Birthplace, Targeting a First-in-Human Trial in 2027
On September 15, new investor Happiness Capital joined the round alongside existing backers Draper Associates and Boost VC. The same core method, a synthetic copy of the embryonic yolk sac niche, forms the basis of all three of the company's products: a bone marrow transplant therapy, an injectable treatment, and a skin product.
Blood-forming stem cells produce every cell type in the blood and the immune system. With age, they skew their output toward certain lineages at the expense of others, weakening immunity and driving chronic low-grade inflammation throughout the body. These cells spend all of adult life in the bone marrow, but they originate in the yolk sac, a transient structure in the early embryo that forms within the first weeks of development and disappears well before birth. In the yolk sac, the cells receive environmental signals that shape their regenerative potential; after birth, they migrate to the bone marrow, that environment vanishes, and they age without it for decades. Complete reprogramming of a cell to a primitive state followed by re-maturation is an approach that already exists: in July 2026, one such method twice restored blood formation in mice, but it involves cellular stress and partial loss of the cell's original identity. HexemBio chose a gentler alternative: briefly return an aged patient cell to a laboratory copy of its native environment, let it restore itself, and then reinfuse it into the body by standard infusion.
The idea is rooted in the founders' own research. Before the company was founded, its future co-founders published a model of an artificial early-stage human embryo in Nature that spontaneously formed a yolk sac structure and generated blood-forming cells. Gene expression in this synthetic tissue matched that of the real human yolk sac to a statistically significant degree, and it is on that match that the therapy is built.
The method is aimed primarily at bone marrow transplantation, a procedure that, according to the company, leads to severe complications in at least 30% of cases and, in a meaningful fraction of patients, does not fully restore blood cell production. HexemBio's lead program is designed to close that gap: in July 2025, the FDA granted it orphan drug designation, a preferential regulatory pathway for treatments of rare diseases; in January 2026, the company completed a pre-submission meeting with the regulator; and it plans to enroll its first patient in early 2027. The injectable and skin products remain in preclinical testing, in the laboratory and in animals, and have not yet reached human trials.
The round features a venture capital dynasty: Draper Associates belongs to Tim Draper, whose early bets include Tesla, SpaceX, and Coinbase, while the other longstanding investor, Boost VC, is led by his son Adam Draper.
"Our first-generation product and lead transplant program remain the top priority on the path to human trials in 2027. Our goal is to create accessible therapies that extend years of healthy life," said Gabriel Lévêque Tremblay, CEO and co-founder of HexemBio.
"We invested in HexemBio's first therapy and are thrilled by their progress. [...] Their fundamental breakthrough technology has expanded into three new product categories, and there may be more to come," added the elder Draper.