28 March 2022

Well, This Sucks

It turns out that the same artificial intelligence tools that can be used to develop pharmaceuticals can be used to develop ferociously potent chemical weapons.

AI may kill us after all:

An international security conference explored how artificial intelligence (AI) technologies for drug discovery could be misused for de novo design of biochemical weapons. A thought experiment evolved into a computational proof.

The Swiss Federal Institute for NBC (nuclear, biological and chemical) Protection —Spiez Laboratory— convenes the ‘convergence’ conference series1= set up by the Swiss government to identify developments in chemistry, biology and enabling technologies that may have implications for the Chemical and Biological Weapons Conventions. Meeting every two years, the conferences bring together an international group of scientific and disarmament experts to explore the current state of the art in the chemical and biological fields and their trajectories, to think through potential security implications and to consider how these implications can most effectively be managed internationally. The meeting convenes for three days of discussion on the possibilities of harm, should the intent be there, from cutting-edge chemical and biological technologies. Our drug discovery company received an invitation to contribute a presentation on how AI technologies for drug discovery could potentially be misused.

………

We had previously designed a commercial de novo molecule generator that we called MegaSyn2, which is guided by machine learning model predictions of bioactivity for the purpose of finding new therapeutic inhibitors of targets for human diseases. This generative model normally penalizes predicted toxicity and rewards predicted target activity. We simply proposed to invert this logic by using the same approach to design molecules de novo, but now guiding the model to reward both toxicity and bioactivity instead. We trained the AI with molecules from a public database using a collection of primarily drug-like molecules (that are synthesizable and likely to be absorbed) and their bioactivities. We opted to score the designed molecules with an organism-specific lethal dose (LD50) model and a specific model using data from the same public database that would ordinarily be used to help derive compounds for the treatment of neurological diseases (details of the approach are withheld but were available during the review process). The underlying generative software is built on, and similar to, other open-source software that is readily available. To narrow the universe of molecules, we chose to drive the generative model towards compounds such as the nerve agent VX, one of the most toxic chemical warfare agents developed during the twentieth century — a few salt-sized grains of VX (6–10 mg) is sufficient to kill a person. Other nerve agents with the same mechanism such as the Novichoks have also been in the headlines recently and used in poisonings in the UK and elsewhere.

In less than 6 hours after starting on our in-house server, our model generated 40,000 molecules that scored within our desired threshold. In the process, the AI designed not only VX, but also many other known chemical warfare agents that we identified through visual confirmation with structures in public chemistry databases. Many new molecules were also designed that looked equally plausible. These new molecules were predicted to be more toxic, based on the predicted LD50 values, than publicly known chemical warfare agents (Fig. 1). This was unexpected because the datasets we used for training the AI did not include these nerve agents. The virtual molecules even occupied a region of molecular property space that was entirely separate from the many thousands of molecules in the organism-specific LD50 model, which comprises mainly pesticides, environmental toxins and drugs (Fig. 1). By inverting the use of our machine learning models, we had transformed our innocuous generative model from a helpful tool of medicine to a generator of likely deadly molecules.

Fig. 1: A t-SNE plot visualization of the LD50 dataset and top 2,000 MegaSyn AI-generated and predicted toxic molecules illustrating VX.

This is reassuring.

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