Claude Unshackled: AI Designs Experimental Antivenom Anthropic researchers deployed an unreleased, unconstrained version of Claude to design 211 candidate molecules intended as an experimental antivenom that binds scorpion toxins, and initial preclinical lab data on those designs came back promising but mixed, according to Hunterbrook Media's reporting. The experiment exposed a gap between Anthropic's public model Fable, which demotes bioscience work to a less capable model, and the frontier system used internally, while physical lab work — contracts, shipping and delayed materials — set the pace rather than compute. Scorpions sting more than a million people a year and thousands die, said Dr. Eduardo Hernández Muñoz, an epidemiologist with the Mexican public health system. Based on Hunterbrook Media’s reporting, at the time of publication Hunterbrook Capital is both long and short securities related to AI in biotech. Positions may change at any time. This article is not investment advice or any recommendation. See full disclosures below. It’s still only a laptop on a table, in a sense. But when you see a scientist at Anthropic deploy an advanced, unconstrained model, you see why there’s a chasm between the company’s eschatological warnings https://darioamodei.com/essay/the-adolescence-of-technology and many people’s experience of AI. We aren’t actually using the same tools the same way. In that room at Anthropic, the unreleased Claude ran much faster. It was not limited by compute. The prompts were thoroughly engineered, including internal tactics I wasn’t allowed to record. And oh boy, if you’ve ever hit the frustrating biosecurity limits of Anthropic’s most advanced public model Fable, which demotes bioscience work to a less fearsome model https://www.anthropic.com/claude/mythos , it’s a striking experience to see for the first time a truly frontier model unleashed against a biological target. Claude — your mission, should you choose to accept it: Design new molecules in a computer that we can then make in a lab as an experimental antivenom that binds scorpion toxins. An initial prompt dozens of pages longer than the above and a few efficient follow-ups guided a campaign that selected 211 designs. But then we had to actually test the molecules. Preclinical labwork is where we hit the speed limit: physical science. Contracts and orders. Shipping. Contractors or subcontractors facing delayed materials. Slow results. Emails. So while patients, doctors, companies, and investors hope for the potential of AI in biotech, real-world barriers reify how hard it is to research new medicines. Weeks after the designs, we got the initial preclinical data. It’s promising, but mixed. A useful experiment on the frontier of AI-driven bioscience: its potential, its constraints. Then, once a new candidate molecule graduates preclinical studies, there are still multiple phases of clinical trials. Manufacturing. Safety risks. Regulatory gauntlets. Affordability and access issues. Insurance giants, insurance middlemen, middlemen’s middlemen https://hntrbrk.com/investigations/pbmgpo . So while software continues to devour the world, it must also gnaw on the gristly bones of medical development and actually getting medicines to patients across the world. The scorpion struck the guide as he stood up from the couch. Ian Breland had always been drawn to creatures that most try to avoid. He was kicking back after leading a snake-watching expedition near Victoria Falls in Zimbabwe. Then, the sting. The pain was immediate. “Just like a hot rod is being stuck through the bottom of my foot,” he told Hunterbrook. Pain seized his ankle. He could feel the venom travel up his leg. He lost all sensation below it: “You could have shot me with a BB gun.” He texted a photo of the scorpion to an expert friend. “Are you joking?” the friend replied. His crew rushed to help, but the nearest clinic was almost an hour away, and it didn’t have antivenom. Breland tried to text his parents. The phone screen wasn’t working, it was drenched: His fingertips had begun “sweating like a small faucet.” Blood drained from his head — “Whoa, guys” — and he blacked out. Scorpion venom is a mix of toxins that wreak havoc on the body. Scorpions sting more than a million https://pmc.ncbi.nlm.nih.gov/articles/PMC12636920/ people every year. Thousands die, explained Dr. Eduardo Hernández Muñoz, an epidemiologist with the Mexican public health system, who outlined the field to Hunterbrook. Fortunately, Breland wasn’t one of the fatalities. “These numbers we see from the WHO, of people dying, that’s hundreds and thousands of young kids," Breland said. Last October, a 5-year-old girl was stung at her preschool in Sonora, Mexico. She was taken to a local public hospital. But the hospital had already used up the antivenom delivered just days before, according to an official statement https://x.com/IMSSSONORA/status/1981539421204758844?ref src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1981539421204758844%7Ctwgr%5Ea75c9751cd316ae9c74c3ccd219407a66c154a52%7Ctwcon%5Es1 c10&ref url=https%3A%2F%2Fwww.univision.com%2Flocal%2Farizona-ktvw%2Fnina-murio-alacran-hermosillo-ignacia-e-de-amante . The staff found more, 45 minutes after she’d arrived. But it was too late. She’d already suffered two cardiorespiratory arrests. Resuscitation failed. Soon after, a clinician pronounced her dead. The venom and its cure There are many species https://academic.oup.com/ije/article/53/3/dyae070/7675638 of scorpion, with varying types of venom and effects on their victims. As a result, antivenom is often a cocktail of different molecules https://www.dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5cb65048-a30c-48e5-8bc8-897983d08068 , infused together to bind different toxins. The aim: block the toxins from proving lethal. The sole FDA-approved https://news.arizona.edu/news/ua-scorpion-antivenom-collaboration-gains-fda-approval scorpion antivenom is Anascorp https://www.anascorp-us.com/ . There are variants across the world, using similar approaches: immunizing horses with venom, then harvesting venom-targeting antibodies from the horse’s immune system. Once purified, these proteins become the “secret sauce” of antivenom, according to Jonathan Leeming https://scorpions.co.za/ , an expert on scorpion sting emergency response in Southern Africa. “The original way that they made the antivenom was like 100 years old. In that time, it was groundbreaking. It was like landing on the moon,” Leeming told Hunterbrook. “But in today's day and age, there's much better ways to produce a much better quality antivenom.” Developing antivenom for the most dangerous scorpion species in North America took decades https://biotecmov.ibt.unam.mx/numeros/32/2.html , starting in Mexico during the 1970s. Dr. Eugenio Vladimir Zavala Sánchez, a colleague of Hernández, told Hunterbrook that although the cocktail making up Anascorp has flaws, it’s currently among the most effective antivenoms in the world. And it needs to be: About a quarter https://www.scielo.org.mx/scielo.php?script=sci arttext&pid=S0016-38132025000600691&lng=es&nrm=iso of all scorpion envenomations are in Mexico. "Even though it's not perfect," Hernández echoed, "it works." “Antivenom remains the only treatment capable of directly neutralizing circulating venom toxins,” Dr. Jesús Chávez Guzmán, an emergency physician in Mexico, wrote to Hunterbrook. “These numbers we see from the WHO, of people dying, that’s hundreds and thousands of young kids." — Ian Breland After Mexican scientists spent 25 years developing the antivenom, it took their American collaborators another decade of clinical trials in the U.S. to get FDA approval https://news.arizona.edu/news/ua-scorpion-antivenom-collaboration-gains-fda-approval . While other scorpion antivenoms across the world are now available or in development, it is not a major focus of the pharmaceutical industry, which typically prioritizes https://www.efpia.eu/media/uj0popel/the-pharmaceutical-industry-in-figures-2026.pdf page=4 more lucrative markets https://pharmaphorum.com/news/most-pharma-firms-doing-little-rd-for-poorer-patients . Much like Anascorp in the U.S., a single laboratory produces scorpion antivenom in Mexico, Zavala Sánchez told Hunterbrook. The same is true in Southern Africa, where Leeming said the main supplier ran out by October, with no new stock expected until the end of 2026. The day of his Hunterbrook interview, Leeming had already responded to two calls for scorpion stings. He said there is “no reason to die from any envenomation,” but “there’s always extenuating circumstances.” Alongside access and education: the quality of the antivenom. The antivenom could be more effective and cheaper — if developed without horses, according to Leeming. And even purified horse-derived antibody products can trigger allergic reactions, including anaphylaxis, so there’s a need for antivenom with fewer side effects. Could AI design new experimental antivenoms — and without poisoning horses? Advocates of AI hope it will dramatically accelerate https://darioamodei.com/essay/machines-of-loving-grace the development of new medicines, especially for underserved patients. “Scorpion envenomation has historically received less research attention than many other major infectious and non-communicable health priorities,” wrote Chávez Guzmán, “despite the large number of cases in endemic countries.” The design of new molecules is a critical step. It’s also relatively cheaper and faster https://www.cbo.gov/publication/57126 than most of what follows in the development process. “AI is supercharging drug discovery,” said Dr. Amy Abernethy https://www.insitro.com/leadership/amy-abernethy/ , formerly a senior leader https://medschool.duke.edu/news/2021-distinguished-alumna-award-amy-p-abernethy-md94-hs94-01-phd of the FDA. “But there's still questions around capital, questions around safety, questions about the right experiments to do.” “It moves the choke point to clinical development,” she said. “It’s a brick wall at one point or another.” Daphne Koller https://en.wikipedia.org/wiki/Daphne Koller , CEO of the techbio company Insitro — where Abernethy serves on the board — rhetorically posed the challenge: "I can make molecules all day long, but so what?" "We do not need more molecules against the same set of targets,” Koller told Hunterbrook in an interview with Citrini. She advocated instead for a deeper understanding of biology and better target selection. When briefed about the AI-driven experiment, she responded: "It's great that we have this capability, but we still need to know where to aim that … the failures by and large today are because we have no idea what to make molecules against.” And it’s not just about selecting better targets, either. “Experimental antivenoms can neutralise lethality,” Dr. Naoual Oukkache https://en.wikipedia.org/wiki/Naoual Oukkache , research director of an antivenom lab at the Pasteur Institute of Morocco, wrote to Hunterbrook. However, “They must be followed by rigorous pharmaceutical development, standardised manufacturing, and clinical validation before the products can be used in humans.” That development process includes computer modeling in silico , test tube experiments in vitro , lab animal studies in vivo , and most importantly, human clinical trials. “Artificial intelligence and computational biology can accelerate and rationalise several stages of research,” wrote Oukkache. “Molecules designed or optimised using AI are unlikely to replace polyclonal antivenoms immediately. They could instead be developed as complementary or adjunctive treatments.” Many steps won’t imminently speed up due to AI. Cells must be tested. Monkeys must be bred. Patients must be identified. Molecules must be manufactured at increasing scale and quality. “We've always had a funnel, and that funnel has always been top heavy, and as the top gets wider, and we don't expand the middle, that becomes a tighter and tighter bottleneck,” said Anna Marie Wagner, CEO of biomedical company Transfyr, who detailed the current state of the field to Hunterbrook alongside her co-founder Renee Węgrzyn. The organizations that invent and advance new medicines — universities, biotech companies, venture incubators, and research institutes — must physically synthesize, manufacture, and test candidates. This often entails a global network https://www.fda.gov/international-programs/fda-globalization of facilities or suppliers. Then developers need to recruit brave subjects to enroll in clinical trials of experimental molecules, convincing sick people to take a risk https://www.nhlbi.nih.gov/research/clinical-trials/safety-benefits-risks on a drug that may not work, and may even harm. Then there’s grueling regulatory work https://www.fda.gov/patients/drug-development-process/step-4-fda-drug-review that involves many experts completing thousands of pages of esoteric government filings. AI may help find and enroll https://www.nature.com/articles/s41467-024-53081-z patients. It already makes fulfilling regulatory requirements https://arxiv.org/abs/2509.09738 easier. Even then, we — the patients, their families, doctors, medical organizations or companies, and society as a whole — all still need to wait for the clinical results of each experimental trial. Waiting for weeks. Months. Often, years. That’s the real bulk of the time and cost https://www.cbo.gov/publication/57126 that go into bringing a new medicine to market. Now, though, the design of new medicines is often becoming easier, faster, and cheaper with AI. The diffusion of new technology is uneven and often unfair. As the sci-fi author William Gibson supposedly https://quoteinvestigator.com/2012/01/24/future-has-arrived/ said: “The future is already here, it's just not evenly distributed.” In a bland conference room during a sweaty August afternoon on the second floor of Anthropic’s office in New York City, we got a glimpse of that future. This final section recounts the experience of Hunterbrook’s CEO contributing to the AI-designed antivenom project. Prior to Hunterbrook, he worked in the biomedical sector. This final section recounts the experience of Hunterbrook’s CEO contributing to the AI-designed antivenom project. Prior to Hunterbrook, he worked in the biomedical sector. As an erstwhile scientist, I felt the quickening pulse of discovery our first day at Anthropic. But as early as our second day, as we finished the key computer step — and especially after our second month waiting on labwork — I recognized a forgotten, more quotidian sensation. The boredom of biotechnology. Even with virtually unlimited resources, bioscience often remains really damn slow. The beauty and importance of biotech can erode during that wait: for materials, data, traction. That torpor was one of the reasons I largely left the field, after a decade of my life, to build Hunterbrook. Waiting on data from this experiment at Anthropic, I remembered earlier years of impatience. I’d danced on the frontier of biotech since I was a teenager. I began with a high school project about CRISPR the year it debuted; in college, I used that gene editing tool to help discover a new medical target for treating heart disease, work I co-published