Nearly two years ago, Isomorphic Labs dropped AlphaFold 3, the latest generation of its
Nobel Prize-winning
, structure-predicting AI model.
Now the company claims it has another major advance on its hands. While it hasn’t released extensive details, Tuesday’s news could put Isomorphic significantly ahead of the rival startups and researchers who have built their own clones and advancements on AlphaFold 3 in recent years.
In a
blog post
and
technical paper
, the London-based startup detailed the performance of what it calls the Isomorphic Labs Drug Design Engine, or IsoDDE. Despite the clunky name, the company claims it has more than doubled the success rate for accurately predicting protein-drug and antibody-antigen structures, compared with AlphaFold 3.
The company called the new engine a “step-change improvement” over AlphaFold 3.
“These sorts of capabilities are quite profound for us,” Isomorphic’s president Max Jaderberg said in an interview with
Endpoints News
. “They literally unlock new targets, new potential solutions to patients.”
Tuesday’s report is full of results on a range of benchmarks, including for biomolecular structure predictions, binding affinity predictions, and discovering new pockets on target proteins.
But the paper is also light on certain technical details, multiple scientists and industry executives outside of Isomorphic said. That includes specifics on what improvements — be it training data, new AI model designs, or something else — drove the gains.
In an interview with
Endpoints News
, Isomorphic’s director of machine learning Michael Schaarschmidt credited the gains to a “combination of everything.” That included major changes to the underlying model, he said, without divulging specifics.
“There’s some real changes to the architecture,” Schaarschmidt said. “So it’s a lot of small wins, but also some real big changes.”
These types of claims, with few scientific and technical details, have led to criticisms of AI companies conducting “science by press release,” rather than releasing full, peer-reviewed research papers that can be scrutinized by others.
Pat Walters, a longtime computational biotech veteran, said the lack of certain methodological details makes it difficult to interpret some of the results. Often, when researchers build models, they use some data to train the model while reserving some data to use as a test. Because of the complexity and size of these datasets, there’s always the risk that data can “leak” between those two groups, possibly letting the model cheat on the exam.
“It’s very easy to get data leakage when training an activity prediction model,” Walters said in an email. “The Iso team doesn’t describe how they did their train/test splits, so it’s tough to gauge performance.”
But the secrecy trend has become increasingly common as AI startups have grown more competitive and more protective of commercially valuable research.
AlphaFold2, for example, was fully open-sourced, while AlphaFold 3 came with more restrictions on its usage. Now with IsoDDE, it’s not clear what models even comprise its drug design engine, making it difficult for independent researchers or competing labs to vet and compare performance.
Isomorphic isn’t alone in that. Chai Discovery’s Chai-2, Nabla Bio’s JAM, and Iambic’s NeuralPLexer3 are among many recent models that have been kept proprietary. That makes it harder to directly compare their performance.
Despite the caveats, the progress seems to place Isomorphic at the top of the AI biotech world.
It has been a leader in the field since its 2021 founding, led by CEO Demis Hassabis, who is also CEO of Google DeepMind. The company has raised $600 million, grown past 300 employees, and polarized the field with
grandiose goals of solving all diseases
.
The breadth of Tuesday’s performance gains — across structures, affinities, and novel protein pockets — is early evidence of traction in Hassabis’ ambition to upend the industry with an AI-first approach to drug design.
In prior interviews, Hassabis has described much of the AI bio field as building models specific to an individual task or particular target. His goal has been to see if AI models can generalize, or make accurate predictions on scenarios that fall outside of training data.
Tuesday’s report shows progress on generalization, which has largely evaded the field. On protein-molecule structures, Isomorphic says it achieved a 50% success rate on a category of difficult programs, specifically designed to test if AI models are actually learning biology, or just memorizing from their training data.
AlphaFold 3, for instance, scored 23% on that metric, which still beats models like Boltz-1 and Chai-1. Isomorphic’s newest version more than doubled the AlphaFold 3 performance.
James Fraser, a bioengineering professor at the University of California, San Francisco, acknowledged the results as impressive, saying they were “something that has seemed far beyond other groups.”
“It will likely take some time (and likely hints of ‘how’ it improved) for the field to catch up,” Fraser wrote in an email.
Much of the technical paper directly compares Isomorphic’s latest model with
Boltz-2, a popular open-source protein model
. A new startup, called Boltz, launched last month with $28 million from investors like a16z and Amplify Partners to sell software to life sciences customers around models like Boltz-2.
IsoDDE was more than twice as good as AlphaFold 3 in predicting antibody-antigen structures. And it was about 20 times better than Boltz-2 on that task, according to Tuesday’s release.
Boltz CEO Gabriele Corso called the results “definitively impressive” in an email, adding his team has also seen further predictions improvements beyond Boltz-2, which was released last June.
A driver in starting Boltz, which is headquartered across the street from Isomorphic in London, was the desire to keep leading AI models open and accessible to scientists. So far, Isomorphic has signed partnership deals with a handful of large drugmakers like Eli Lilly, Novartis, and Johnson & Johnson.
“The rest of the field will also have access to a significantly better model soon!” Corso wrote.
Isomorphic also said its AI models meet or beat an industry gold standard of physics-based simulations. Ramy Farid, the CEO of Schrödinger, a longtime seller of physics-based software, said Isomorphic’s report lacks enough detail and transparency behind how they reported those results, which “could easily lead to incorrect conclusions.”
Ultimately, the companies will still have to prove that all of their work can lead to new drugs being tested in patients. Isomorphic is “pushing really hard toward the clinic,” Jaderberg said, without any delays.
Hassabis has recently said he expects to start clinical trials by the end of 2026, an apparent pushback to a previous timeline by the end of 2025. (Hassabis previously told Endpoints he had misspoken on that prior timeline, referring to when Isomorphic would select its first preclinical drug candidate.)