Bay Area Scientist Launches Preventive to Study Gene Editing in Human Embryos to Prevent Inherited Disease

Lucas Harrington, a UC Berkeley–trained biochemist and co‑founder of Mammoth Biosciences, has launched a public benefit company called Preventive to pursue laboratory research into gene editing in human embryos as a potential way to prevent severe inherited diseases before birth. The company announced nearly $30 million in private backing from prominent technology investors.

What Preventive aims to do

Harrington says Preventive's mission is to assess whether the latest generation of gene‑editing tools can be applied "safely and responsibly to correct devastating genetic conditions for future children." Organized as a public benefit corporation, the firm says its work will be limited to preclinical laboratory research unless independent regulators and outside experts conclude clinical use is safe and appropriate.

Scientific approach

Experts note that embryo editing can occur only in the context of in vitro fertilization (IVF), because embryos must be accessible in a dish for testing and manipulation. In laboratory studies, scientists would identify embryos carrying disease‑causing variants, then test tools such as CRISPR to correct those sequences and observe how well edits persist and whether embryos develop normally over experimental windows used in research.

"Our goal is straightforward: to determine through rigorous preclinical work whether preventive gene editing can be developed safely to spare families from severe disease," Harrington wrote in a blog post announcing Preventive.

Ethical, legal and regulatory context

Leading scholars caution the field is ethically fraught and tightly regulated. Stanford law professor Henry (Hank) Greely explained that while laboratory research on embryos is permitted in many U.S. states (including California), some states restrict or ban it. Federal oversight becomes central if an edited embryo were ever implanted into a person — the Food and Drug Administration has authority over interventions in people, and current congressional restrictions limit the agency's ability to authorize clinical trials that could result in gene‑edited births.

Preclinical steps and challenges

Greely and other experts expect careful preclinical milestones: repeated laboratory studies of human embryos to characterize editing accuracy and developmental outcomes, followed—if justified—by extensive testing in relevant animal models such as non‑human primates. Primate studies, they note, are costly, technically challenging and raise additional biosafety and public‑relations considerations.

Potential benefits and cautions

Proponents argue that intervening at the embryonic stage could prevent disease more effectively than treating adults because fewer cells are involved and early correction might avoid irreversible damage. Critics counter that alternatives exist—such as embryo selection during IVF or advancing therapies for affected people—and that heritable changes raise profound ethical questions about future generations.

Harrington has emphasized his team’s intention to prioritize safety: if research determines the approach cannot be made acceptably safe, he says that conclusion will be treated as a valuable outcome. Outside experts urge that any safety claims be validated by independent regulators and broader expert review.

As Preventive begins its work, the debate it touches—between the potential to prevent devastating inherited conditions and the need for strict ethical safeguards—will remain central to how, where and whether embryonic gene editing advances toward clinical use.