Brown Lab

Cathy Tie’s statements below on embryo editing for reproductive purposes (made to Ryan Cross of Endpoints) could be the product of ignorance or deliberate deception or both. Data from a recent interview to the Guardian she gave to Jenny Kleeman argue for the former. Exact quote: "“Casgevy is a three-to-six-month process. Patients have to go through chemotherapy and other really invasive procedures,” Tie says. This isn’t the case for all gene therapies, I point out; Zolgesma is given in a single dose, delivered over a few hours. Tie blinks. “I’m not too familiar with that example.”" For a CEO of a therapeutic gene editing company to be unfamiliar with Zolgensma is equivalent to the CEO of a self-driving car company to be unfamiliar with Uber. I rest my case. My personal interpretation of her longer statement to Endpoints below (please read it) is she is being willfully deceptive. Definitive evidence from 1971 onwards proves that carrier screening and prenatal genetic diagnostics is a safe and effective way of dramatically lowering the prevalence of severe Mendelian disease. A 2003 New York Times piece by Gina Kolata has a telling title - "Using Genetic Tests, Ashkenazi Jews Vanquish a Disease.” I encourage folks to also look at a 2013 paper by Cao and Kan (pubmed ID 23378598) entitled “The prevention of thalassemia” (look at Figure 4). Equally definitive evidence proves that embryo selection - rather than editing - is equally safe and effective for diseases that are less prevalent than TSD or TDT. The New York Times had a nice piece about this 12 years ago [sic!] - "Ethics Questions Arise as Genetic Testing of Embryos Increases.” The scientific paper it describes (pubmed 24493558) tells the story of a family where mom is a het for a dominant allele that causes lethal disease. She and her partner chose IVF, 8 embryos were genotyped, and 4 - as per Mendel’s first law - were free of the mutant allele. Here’s a quote from the New York Times: “Like a growing number of couples who know a disease runs in the family, they chose in vitro fertilization, and had cells from the embryos, created in a petri dish with her eggs and his sperm, tested first for the disease-causing gene. Only embryos without the gene were implanted. The Kalinskys are now parents of three children who will be free of the fear of GSS.” For Cathy to position embryo editing as a viable alternative to the above is conceptually congruent to this: imagine a family wishes to get down from the top floor of the SalesForce Tower. Option 1: take the elevator. Option 2: jump off the building wearing a batman suit. Cathy’s statement below on cost v Casgevy is willful self-serving misrepresentation of an inarguable truth: if - huge if - the FDA, or MHRA, or EMA, or TGA ever allow embryo editing for reproductive purposes the sum total cost of editing an embryo that then would be implanted would be greater than Casgevy. The Agencies would regulate this as a “CRISPR on demand” approach and as someone who was one of the 4 co-investigators on the first ever expanded access IND and subsequent treatment at CHOP (NEJM 2025) I speak from direct knowledge and daily practice. I think Cathy is an uneducated charlatan. I also think her purpose is to sell “baby improvement” services to the affluent. I encourage folks to read Katherine Long’s WSJ piece about this: “Genetically Engineered Babies Are Banned. Tech Titans Are Trying to Make One Anyway.” I can say from lived experience that a previous charlatan - Jiankui He - did irreparable harm to the field of CRISPR gene editing for existing disease, a field where thousands of dedicated scientists and physicians are working in. I am gravely concerned we are on the same trajectory with Origin. I note in this regard that Origin’s recent “result” and the press release they put out is the equivalent of saying “we flew a paper airplane out of our window and we are on a trajectory to build a Dreamliner.” Finally, I think Cathy’s behavior in giving families living with the risk of genetic disease false hope - is reprehensible. The work she is doing will never help such families in the US, UK, EU, Canada, or Australia. The offshore “baby improvement via embryo editing” factory she’ll set up will “help” the affluent (see the WSJ piece, please). In closing. In a much-discussed and -criticized post here on twitter I said that Cathy should get a PhD before opining on therapeutic gene editing, much less working on that. In her specific case this is true. In a broader sense it is not and I regret coming across as - choose your turn of phrase - “elitist” or “credentialist” or worse. I thank many people on this platform who encouraged me to address this. Let me be clear. Everyone’s opinions are welcome. No formal educational requirements exist to start a biotech or make an impact on drug development. In Cathy’s _specific_ case, no serious scientific discussion can be had with her - based on her own statements (i) she’s not heard of Zolgensma, (ii) she pretends to not understand Mendel’s first law, and (iii) pretends to not understand the timeline and cost to a CRISPR-on-demand therapeutic. That’s why I said what I said.