Unleashing machine learning to solve medicinal chemistry

Salt Lake City, UT
Joined August 2021
Leash Bio retweeted
Pretty clever idea from @allmeasures and @Andrewdblevins at @leashbio to use a dense combinatorial set of experimental data like a DEL screen as an environment to test how well agents can optimize in chemical space. Medchem optimization in the real world isn't so constrained, but it's plausible to me that ability at the DEL task would transfer to the real world. I wonder where else the idea can be applied to build RL environments for science. Blog post: leashbio.substack.com/p/maki… Preprint: github.com/Leash-Labs/minos-… The preprint nicely addresses the biggest question I had from reading just the blog post by performing a "shuffle" ablation suggesting that it was measuring actual chemical reasoning ability instead of just "Mastermind" ability. I would also be interested in seeing some other baselines beyond random, like a fingerprint-based optimizer.
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Leash Bio retweeted
To improve agentic drug discovery, we created physical interrogation at compute speed. We can now ask questions that'd be hard with a lab-in-the-loop. One question we had was whether agents had existing drug knowledge baked into their weights that could help. 1/
Agentic models can act, observe consequences, and decide what to do next. This is great for coding, but if you want them to do science, lab experiments take forever. To fix this, we made a lab-in-the-loop with zero latency! 1/10
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From Wet Lab to RL Env: 10,000 Drug-Discovery Campaigns in a Weekend @LeashBio’s @allmeasures explains how DNA-encoded libraries generate billions of protein–molecule measurements, why no team in Leash’s Kaggle competition beat chance on an unseen chemical library, how public datasets can teach AI to recognize the chemist instead of understand the chemistry, why engineering protein mutations exposes model memorization, and how replayable experimental worlds let agents run over 10,000 medicinal chemistry campaigns in a weekend. Plus: Hermes vs. Boltz, moving from DEL hits to mouse studies in six months, and why experimental rigor and the Bitter Lesson of scaling could unlock a new generation of AI-driven drug discovery.
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Leash Bio retweeted
Agentic models can act, observe consequences, and decide what to do next. This is great for coding, but if you want them to do science, lab experiments take forever. To fix this, we made a lab-in-the-loop with zero latency! 1/10
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Leash Bio retweeted
BoltzGen, Protenix, ProteinMPNN — all trained on PDB. When your reward is also PDB-derived, you're learning "structure a crystallographer would deposit," not what a "good binder" is @leashbio showed the same failure in: ChEMBL models learn what chemists make, not what binds. 1/6
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Nature encodes function in many languages—from protein sequences shaped by evolution to animal communication and the chemistry of smell. Each is expressed through high dimensional patterns that are experimentally accessible yet resist neat, human-legible interpretation. In our upcoming livestream from the annual Flagship AI Summit, panelists @seemaychou (@ArcadiaScience ), @JCoolScience (@AnthropicAI), @gibsmk (Flagship Pioneering), @allmeasures (@leashbio) will explore how modern AI can decode these patterns and re-encode them into new designs. Stay tuned for details on how to watch on March 25th.
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Leash Bio retweeted
Current protein models seem to only memorize their wild-type training sets and lack physics understanding. One nice way forward is physically engineering mutations and then taking more ground-truth measurements. It works. We've already shown this! (1/n)
Adversarial Sequence Mutations in AlphaFold and ESMFold Reveal Nonphysical Structural Invariance, Confidence Failures, and Concerns for Protein Design 1. A new adversarial study systematically evaluates AlphaFold 3's robustness by introducing point mutations (up to 70%) and deletions (up to 10%) across 200 proteins, revealing striking structural invariance that raises fundamental questions about the model's biophysical reasoning capabilities. 2. The most concerning finding: AlphaFold 3 maintains virtually identical predicted structures even when 40% of residues are mutated with deliberately destabilizing substitutions, or when 10% of residues are deleted—perturbations that would catastrophically destabilize real proteins. 3. This structural invariance persists even for experimentally validated fold-switching proteins, where specific mutations are known to induce alternative conformations. AlphaFold 3 fails to capture these biologically critical transitions, suggesting limited sequence-structure coupling. 4. Confidence metrics prove unreliable: AlphaFold 3's ranking score selects the most accurate structure only ~25% of the time, and these scores correlate more strongly with template availability in the training set than with actual prediction quality. 5. Comparative analysis with ESMFold reveals that the protein language model-based approach shows significantly greater sensitivity to mutations, with structures diverging more rapidly as sequence perturbations increase—suggesting superior learned sequence-structure relationships despite lower absolute accuracy. 6. The study's template analysis provides quantitative evidence that AlphaFold 3's confidence reflects structural similarity to training-set exemplars (Pearson r=0.39) rather than genuine biophysical assessment, indicating heavy reliance on memorized patterns over learned principles. 7. These findings have profound implications for the entire AlphaFold ecosystem: protein design tools like RFdiffusion, binder design methods like BoltzGen and BindCraft, and drug discovery pipelines may inherit these fundamental limitations, potentially generating non-physical sequences or missing viable candidates. 8. The work identifies critical gaps in current structure prediction—models trained primarily on stable, wild-type proteins lack exposure to destabilized mutants and misfolded states, limiting their ability to generalize beyond the training distribution. 📜Paper: biorxiv.org/content/10.64898… #AlphaFold #AlphaFold3 #ProteinStructurePrediction #StructuralBiology #ProteinDesign #MachineLearning #Bioinformatics #ComputationalBiology #AIforScience #ProteinEngineering #DeepLearning #Biophysics
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Leash Bio retweeted
This week we showed near protein-ligand binding prediction SOTA on our lightweight model, Hermes. Unlike other models, Hermes has no way to think about protein or molecule structure. Never seen *any* public data. How did we do it? endpoints.news/leash-bio-war…
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Leash Bio retweeted
Is your Drug Discovery AI actually learning chemistry, or is it just “profiling” the chemist? 🕵️ New research from @leashbio highlights a "Clever Hans" failure mode in AI: models can predict molecular activity with high accuracy simply by identifying who synthesized the molecule. The paper shows a classifier can guess the author of a molecule (among 1,815 options) with 60% top-5 accuracy. Just like human chemists, if the AI knows it’s a “Schreiber molecule”, it already knows the likely target! It’s memorizing human bias, not physics. 🧪 Why does this matter? If you’re developing a "Me-too" drug in a well-trodden space, these "shortcut" models work fine. But for the future of biotech—new targets, new scaffolds—we need models that can’t "cheat". They must learn the essence of binding. The @leashbio Path: By building massive, consistent internal datasets (DEL-based), Leash is removing "human intent" from the equation. The goal? True Zero-shot drug design that generalizes to the unknown by learning from billions of data points, not just the "favorite" molecules of famous PIs. 🚀 Is "cheating" acceptable for Me-too drug development? What's your take? Let's discuss! 👇 @owl_posting @leashbio @Andrewdblevins @IsomorphicLabs @BoWang87 @BiologyAIDaily #AI #AI4S #AIDD #DrugDiscovery #Leashbio #Chemistry #CleverHans #Benchmarking #DataLeakage [Original Text: leashbio.substack.com/p/ai-f…]
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Had the pleasure of interning at @leashbio - genuinely great team with a serious commitment to rigor. Cool to see their work getting attention!
An ML drug discovery startup trying really, really hard to not cheat owlposting.com/p/an-ml-drug-… on the 12-person, Utah-based startup @leashbio, their culture of rigor, and the many ways small molecule models accidentally learn the wrong thing
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We’re happy to share some of Leash’s latest ML results. Our model, Hermes, is competitive with Boltz-2 on binding prediction. Importantly, Hermes is trained exclusively on Leash DEL data. In other words, the plan is working. leashbio.substack.com/p/good…
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Leash Bio retweeted
Drug discovery: 🥇 Aikium 🥈 @serna_bio 🥉 @leashbio Biotech: 🥇 @Ataraxis_AI 🥈 @Feeltherapeutic 🥉 Nostics Genomics & multiomics: 🥇 @transcriptabio 🥈 @Converge_Bio 🥉 @infinimmune Healthtech: 🥇 MetaSight Diagnostics 🥈 @slingshotai_inc 🥉 @isonohealth
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Love the momentum behind @Polaris_HQ right now and super excited to see @leashbio's massive BELKA dataset up on the platform.
Curious to learn more about the work that went behind making BELKA accessible through Polaris? Learn more about Dataset v2.0 and how we’re helping scientists focus on research, not on data wrangling. 👇🧵 Read the blog: polarishub.io/blog/dataset-v… Access BELKA: polarishub.io/datasets/leash…
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We just released 4.25B small molecule-protein measurements - real, physical ones from our lab - on @Polaris_HQ. It's the biggest such public collection ever, please use it! leashbio.substack.com/p/belk…
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We invite everyone interested in this problem to check out our ligand prediction Kaggle competition, which includes more physical measurements than all of Pubchem Bioassays. Open source FTW! kaggle.com/competitions/leas…
AlphaFold3 is out with improvements on structural models that include DNA/RNA and small molecules. Unfortunately, there is no code, no binary to run at scale and only a limited webserver. Why even publish? nature.com/articles/s41586-0…
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Started in the basement of Ian Quigley’s Utah home, Leash Bio has launched with an open challenge to the AI-bio world The startup is betting there's a need for more data to fuel the next AI breakthroughs in biology My latest: endpts.com/exclusive-ex-recu…
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We are also launching our inaugural machine learning Kaggle competition, Big Encoded Library for Chemical Assessment (BELKA), leveraging a dataset of unprecedented scale: kaggle.com/competitions/leas… #MachineLearning #AI #ML #TechBio #kaggle
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