Two years after Casgevy received commercial approval, only around sixty people with sickle cell disease or thalassemia have been able to benefit from it, due to a technical hurdle that the next generation of treatments will attempt to overcome
Imagine throwing a trillion darts and having every single one hit the bullseye. Achieving this level of precision in gene editing would require highly intelligent delivery of the molecular machinery for DNA repair (CRISPR or one of its variants) into patients’ bodies, reaching only defective cells while bypassing healthy tissues. The benefits would be substantial: maximum therapeutic efficiency, zero waste, and reduced risks in terms of toxicity, immunogenicity, and unwanted mutations. How can such precise targeting be achieved? By acting on multiple levels, explain Jennifer Doudna and three researchers from her Innovative Genomics Institute. See their review article, Targeted delivery of genome editors in vivo in Nature Biotechnology.
Jennifer Doudna and Fyodor Urnov have founded a company that will take on the challenge of editing rare diseases, starting with phenylketonuria.
The problem is well known: many diseases are theoretically treatable by correcting the corresponding genetic defects with the help of CRISPR tools, but doing so risks being difficult or even impossible because of regulatory rigidity and economic unsustainability. The case of the first newborn treated with a bespoke therapy developed in record time (KJ Muldoon) was a splendid proof of principle. But it left many parents of children with rare diseases asking: when will it be our turn? At the same time, specialists have long been asking: will investors return to viewing gene editing as a profitable approach worth investing in?
Every December, Nature selects the 10 people of the year, those who have most shaped the year that is coming to an end. For 2025, the little KJ Muldoon, about whom we have written many times, could not be left out. The first newborn to receive a CRISPR treatment developed specifically for him, the inspiration for new rules on the testing of advanced therapies for rare diseases, the mascot that patients, families, doctors, and scientists needed to look to the future of medical editing with renewed confidence.
Inspired by the Baby KJ case, the agency proposes a flexible framework allowing personalized treatments for individual patients to contribute to shared, platform-based approvals.
The announcement appeared on November 12 in the New England Journal of Medicineunder a seemingly cautious title: “The FDA’s New Plausible Pathway.” Yet the article, written by two senior figures at the Food and Drug Administration, reveals vision and leadership. For once, it is worth starting from the end, which reads like a strong statement of intent: “Nearly 30 years after the sequencing of the human genome, bespoke therapies are close to reality. The FDA will work as a partner and guide in ushering these therapies to market, and our regulatory strategies will evolve to match the pace of scientific advances.”
New Approach Methodologies (NAMs) have a bright future ahead, but they should be seen as complementary rather than alternative to classical experimentation.
Regulatory and funding agencies in the U.S. and Europe are promoting ambitious initiatives to foster the development and adoption of advanced systems capable of testing the effects of drugs and other substances without using animal models. The hope is that biomedical research can become more ethical, safer, and cheaper. But the challenge is complex, and the requirements vary depending on the application. As a result, some voices urge a faster “transition,” while others warn that rushing the process could be risky. Recently published articles in leading scientific journals capture this polarized debate, but they also hint at a possible middle ground.
The FDA is set to authorize “umbrella” clinical trials for rare diseases; the new approach will make the process faster and more sustainable by combining data from similar protocols, cutting redundant procedures, and reducing animal testing.
The progress achieved in Japan through experiments on mice has shown the way forward, but replicating these results in humans will pose technical, ethical, and legal challenges
Gametogenesis is the process by which gametes — male and female sex cells — are formed. In nature, it occurs inside the testes and ovaries, starting from progenitor cells that receive a variety of signals. Replicating the process in vitro is already possible in mice, albeit with low efficiency. Some specialists expect that within a decade, knowledge and technology will have advanced enough to apply these methods to humans, producing both sperm and eggs from cells taken from other parts of the body, and from individuals of either sex. This could allow infertile couples to have genetically related children without external donors, but it would also open the door to troubling new scenarios.
We have written extensively about this baby, who has become the mascot of tailor-made editing, thanks to a treatment developed in record time specifically for him. We are delighted to see him in excellent shape, dressed for the occasion at the STAT summit!
The coordinated effort that last spring saved the life of little KJ Muldoon earned widespread and enthusiastic media coverage. But between the invention of the treatment and its delivery to the patient lay a lesser-told story: an unprecedented manufacturing sprint. Genetic Engineering & Biotechnology News organized an online roundtable led by its deputy editor in chief, Julianna LeMieux, to discuss how therapeutic components were produced quickly, cost-effectively, and to clinical-grade standards.